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Cardiology 

Cardiology
Chapter:
Cardiology
Author(s):

Charlotte Frise

and Sally Collins

DOI:
10.1093/med/9780198821540.003.0002
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date: 11 April 2021

Physiological changes

  • Pregnancy is associated with global haemodynamic changes

  • These occur early and gradually return to normal after delivery

  • Peripheral vasodilatation → ↓ systemic vascular resistance

  • Cardiac output ↑ by:

    • 40% during pregnancy (↑ heart rate and ↑ stroke volume)

    • 15% in the 1st stage of labour

    • 50% in the 2nd stage of labour

  • After the 3rd stage there is further ↑ cardiac output due to ↑ venous return from:

    • Relief of vena caval obstruction

    • Tonic uterine contraction (expels blood into systemic circulation)

  • ↓ BP in pregnancy, lowest towards the middle of the 2nd trimester

  • Colloid osmotic pressure ↓ causing ↑ susceptibility to pulmonary oedema

  • ↑ LV wall thickness and mass

  • Plasma volume expansion

  • ↑ cholesterol (50%)

  • ↑ triglycerides (300%)

Changes on clinical examination

  • Hyperdynamic circulation

  • Ejection systolic (flow) murmur

  • Elevated JVP

  • A 3rd heart sound (S3; occurs after the 2nd heart sound, S2)

  • Apex beat is forceful, displaced

  • Premature atrial and ventricular ectopics

  • Resting heart rate may ↑ by 10–20 beats per minute

Investigations

  • CXR:

    • ↑ cardiothoracic ratio and vascular markings (hila can look bigger)

  • ECG (Cardiology see Fig. 2.1):

    • Tachycardia, small Q waves, and TWI in lead 3 and aVR

    • Can see left axis deviation and ST sagging

  • Echocardiogram:

    • Mild mitral, tricuspid, and pulmonary regurgitation can be a normal finding but aortic regurgitation is usually abnormal

    • LV is hyperdynamic

Fig. 2.1 Normal pregnancy changes. Reproduced from Adamson D. et al. (2011) Heart Disease in Pregnancy Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.1 Normal pregnancy changes. Reproduced from Adamson D. et al. (2011) Heart Disease in Pregnancy Oxford University Press: Oxford with permission from Oxford University Press.

General management principles

Preconception

  • Imaging

  • Assessment of functional status (NYHA functional classification)

  • Consider surgical intervention

  • Adjust medications if needed

  • Assess level of maternal risk for each specific condition (WHO classification, see Table 2.1)

  • Contraceptive discussion where avoidance of pregnancy is advisable

NYHA functional classification for cardiac disease

  1. I No symptoms and no limitation in ordinary physical activity

  2. II Mild symptoms (mild breathlessness and/or angina) and slight limitation during ordinary activity

  3. III Marked limitation in activity due to symptoms even during less than ordinary activity. Comfortable at rest

  4. IV Severe limitations. Symptoms even at rest. Mostly bedbound

Criteria Committee, New York Heart Association Inc. (1964) Diseases of the Heart and Blood Vessels: Nomenclature and Criteria for Diagnosis, 6th edition. Little, Brown and Co.

Table 2.1 Modified WHO classification of maternal risk (examples included here, please see ESC guidelines for full list)

WHO I: noin maternal mortality, no/mildin morbidity

  • Uncomplicated, small, or mild pulmonary stenosis, PDA, or mitral valve prolapse

  • Atrial or ventricular ectopics

  • Successfully repaired ASD, VSD, PDA, anomalous pulmonary venous drainage

WHO II: smallrisk of maternal mortality or moderatein morbidity

  • Unoperated ASD or VSD

  • Repaired ToF

  • Most arrhythmias

  • Turner’s syndrome without aortic dilatation

WHO II or III (depending on individual)

  • Mild LV impairment (EF >45%)

  • Hypertrophic cardiomyopathy

  • Native or tissue valvular heart disease that is not class I or IV

  • Marfan or other aortic syndrome without aortic dilatation

  • Aorta <45 mm associated with bicuspid aortic valve

  • AVSD

WHO III: significantlyrisk of maternal mortality or severe morbidity

  • Moderate LV impairment (EF 30–45%)

  • Previous peripartum cardiomyopathy with no residual LV dysfunction

  • Mechanical valve

  • Systemic RV

  • Fontan circulation

  • Cyanotic heart disease (uncorrected)

  • Moderate mitral stenosis

  • Severe asymptomatic AS

  • Moderate aortic dilatation

  • VT

WHO IV: extremely high risk of maternal mortality or severe morbidity, pregnancy contraindicated

  • Pulmonary arterial hypertension

  • Severe systemic ventricular dysfunction (LVEF <30%)

  • Previous peripartum cardiomyopathy with residual impairment of LV function

  • Severe mitral stenosis

  • Severe symptomatic AS

  • Marfan syndrome with aorta >45 mm

  • Native severe coarctation

Source: ESC 2018 pregnancy guidelines https://academic.oup.com/eurheartj/article/39/34/3165/5078465

Antenatal

  • Management as part of a MDT

  • Echocardiography regularly if at risk of deterioration

  • Fetal echocardiography if congenital heart disease present

  • Monitoring for factors that may worsen maternal condition (e.g. anaemia, arrhythmias)

  • Fetal growth scans

At delivery

  • Aim for a vaginal delivery unless clear indications for caesarean section are present, e.g.:

    • Aortic size (thresholds are condition dependent)

    • Aortic dissection

    • Very poor LV function

  • Careful positioning to avoid aortocaval compression

  • Consider limiting the 2nd stage

  • Consider invasive monitoring

  • Active management of 3rd stage of labour

  • Strict fluid balance

  • Medication plan:

    • Avoid ergometrine if BP changes or coronary spasm could worsen the maternal condition

    • Avoid PGF2α‎

  • Cautious use of oxytocin which can cause ↓ BP:

    • ► One alternative to the normal bolus is a bolus of 2–5 units followed by an infusion of 40 IU/hr

Ischaemic heart disease

Background

  • Ischaemic heart disease is a broad term encompassing both chronic angina and acute ischaemic events (‘acute coronary syndrome’)

  • Traditional risk factors include:

    • ↑ BP

    • Family history of vascular disease

    • DM

    • Smoking

    • Hypercholesterolaemia

  • Cardiology Absence of risk factors does not exclude ischaemic heart disease

  • Ischaemic heart disease in pregnancy is associated with:

    • ↑ age

    • ↑ parity

    • Obesity

    • Ethnicity

    • Physical inactivity

  • Both atherosclerotic lesions and vessel dissection can cause myocardial ischaemia in pregnancy:

    • Atherosclerotic lesions are a more common cause of myocardial ischaemia than vessel dissection during pregnancy

    • Incidence of dissection ↑ in the 3rd trimester (left anterior descending > right coronary artery > circumflex)

    • Dissection more common than atherosclerotic lesions postpartum

  • Ischaemic events, irrespective of aetiology, are associated with significant maternal mortality, particularly postpartum

Differential diagnosis for an ↑ troponin level in pregnancy

Associated with chest pain

  • Myocardial infarction:

    • Atherosclerosis

    • Coronary artery dissection

    • Coronary artery embolism (e.g. from a PFO)

  • Vasoconstriction from drugs (e.g. ergometrine, cocaine)

  • Hypercoagulation

  • Coronary artery spasm

  • Myopericarditis

  • Pulmonary embolism

  • Takotsubo cardiomyopathy

  • SVT with very fast rate

Not associated with chest pain

  • Any condition causing myocardial dysfunction (e.g. severe sepsis)

  • Pregnancy-related conditions such as pre-eclampsia

Cardiology Troponin is NOTin normal pregnancy, at vaginal delivery, or caesarean section.

Management of an acute coronary syndrome

Background

  • Combination of acute chest pain, with ECG changes and cardiac enzyme elevation consistent with acute damage to the myocardium

  • The term ‘acute coronary syndrome’ (ACS) includes:

    • ST elevation myocardial infarction (STEMI)

    • Non-ST elevation myocardial infarction (NSTEMI)

    • Unstable angina

Clinical assessment

  • Careful history and examination with consideration of other causes

Investigations

  • ECG: repeat if any suspected abnormalities

  • Bloods: FBC, troponin, renal function, LFTs

Treatment

  • Oxygen

  • Analgesia: morphine if necessary

  • GTN: sublingual spray or tablet

  • Aspirin: 75 mg daily can be used at any time in pregnancy, one-off dose of 300 mg is not contraindicated (Cardiology see ‘Ischaemic stroke’, p. [link])

Intervention

  • ST elevation on ECG:

    • Immediate (‘primary’) percutaneous coronary intervention (PCI), i.e. angiography ± stent insertion

    • Thrombolysis can be performed if PCI not available

  • Dynamic ischaemic changes on ECG, e.g. ST ↓ or TWI:

    • Discuss with cardiology about PCI and timing

  • Dual antiplatelet therapy indicated for atherosclerotic events:

    • 75 mg clopidogrel preferred to ticagrelor (Cardiology see p. [link])

  • Consider β‎ blocker (e.g. bisoprolol)

  • Avoid ACE-I until after delivery

  • Do not check lipids during pregnancy

  • Avoid statins:

    • Generally contraindicated in pregnancy

    • If deemed advisable, then pravastatin may be used

  • The type of stent should be discussed with Cardiology:

    • In contrast to drug-eluting stents, a bare metal stent does not require dual antiplatelet therapy for a year (2nd agent can be stopped near delivery, with ↓ risk of haemorrhage)

    • New guidelines for ACS outside pregnancy advocate new-generation drug-eluting stents (which require a shorter duration of dual antiplatelet therapy); this may be useful in pregnancy

Myocardial infarction

Management of a patient with previous MI

  • Pre-pregnancy assessment including:

    • Cardiology review

    • Echocardiography

    • Exercise testing

  • Review medications:

    • Ensure cessation of agents including ACE-I, statin, and spironolactone (and start alternatives if indicated)

    • Modification of agents such as clopidogrel instead of ticagrelor

  • Aspirin 75 mg OD throughout pregnancy

  • 2nd antiplatelet agent (i.e. clopidogrel) to continue in pregnancy if indicated by previous event or intervention

Ticagrelor in pregnancy

  • Ticagrelor is an antiplatelet agent similar to clopidogrel

  • Recent guidelines recommend ticagrelor in preference to clopidogrel for high-risk lesions in non-pregnant individuals

  • Animal models show no adverse fetal effects with equivalent doses

  • At doses 2–3× higher, fetal growth and development was affected

  • There has been one case report of ticagrelor use throughout pregnancy with a good pregnancy outcome.

Delivery in a ♀ with recent myocardial infarction

  • Review medication before delivery, i.e. antiplatelet agents

  • Consider limiting length of 2nd stage

  • Avoid ergometrine

Troponin rise and normal coronary arteries on angiography

  • Pre-eclampsia

  • Pulmonary embolism

  • Severe decompensated AS

  • Coronary arteritis esp. polyarteritis nodosa

  • Coronary embolus 2° to paradoxical embolus, intramural thrombus or vegetation

  • Severe anaemia

  • Thyrotoxicosis

  • Phaeochromocytoma

  • Cocaine

  • Amphetamines

ECG changes in pregnancy and STEMI

See Figs. 2.1–2.3.

Normal pregnancy changes

Example of an inferolateral STEMI

Fig. 2.2 Example of an inferolateral STEMI. Reproduced from Olson K. (2014) Oxford Handbook of Cardiac Nursing Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.2 Example of an inferolateral STEMI. Reproduced from Olson K. (2014) Oxford Handbook of Cardiac Nursing Oxford University Press: Oxford with permission from Oxford University Press.

Example of an anterior STEMI

Fig. 2.3 Example of an anterior STEMI. Reproduced from Olson K. (2014) Oxford Handbook of Cardiac Nursing Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.3 Example of an anterior STEMI. Reproduced from Olson K. (2014) Oxford Handbook of Cardiac Nursing Oxford University Press: Oxford with permission from Oxford University Press.

Persistent ductus arteriosus

The ductus arteriosus connects the descending aorta to the pulmonary artery and normally closes at birth. Failure to close results in a left-to-right shunt which can cause heart failure in childhood and pulmonary hypertension. Small ducts can be incidental findings. See Fig. 2.4.

  • Usually the diagnosis is made and treated in childhood (most common in preterm infants)

  • Most multifactorial and probably a combination of a genetic tendency and environmental factors, e.g. in utero (maternal rubella infection) or at time of delivery (preterm delivery)

  • Can be associated with:

    • VSD

    • Pulmonary stenosis

    • Coarctation of the aorta

  • Examination may reveal:

    • Machinery murmur at the 2nd left intercostal space (or outer border of clavicle)

    • Heaving apex beat

    • A systolic or diastolic thrill at the 2nd intercostal space

    • Collapsing pulse

Fig. 2.4 Persistent ductus arteriosus. Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology 2nd Ed. Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.4 Persistent ductus arteriosus. Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology 2nd Ed. Oxford University Press: Oxford with permission from Oxford University Press.

Management of PDA in pregnancy

  • Haemodynamically insignificant with no pulmonary hypertension:

    • No impact on pregnancy

  • Haemodynamically significant, i.e. associated with LV dilation and/or dysfunction:

    • Can develop heart failure in pregnancy

  • PDA and presence of pulmonary hypertension:

    • Should be viewed as very high risk and counselled against pregnancy

Patent foramen ovale

See Fig. 2.5.

  • Very common septal lesion

  • Results from failure of embryonic closure of the foramen ovale

  • Found in 20% of the healthy population

  • Associated with:

    • Migraine

    • Stroke

    • Paradoxical embolism

  • May be associated with an atrial septal aneurysm

Fig. 2.5 Patent foramen ovale. Reproduced from Archer and Manning (2018) Fetal Cardiology 2nd Ed. Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.5 Patent foramen ovale. Reproduced from Archer and Manning (2018) Fetal Cardiology 2nd Ed. Oxford University Press: Oxford with permission from Oxford University Press.

Management of PFO in pregnancy

  • Closure is rarely indicated

  • Thromboprophylaxis is required if history of paradoxical embolus and the lesion has not been closed

Atrial septal defect

  • Types of ASD are classified by septal location (Table 2.2 and Fig. 2.6)

Table 2.2 Types of ASD

Ostium primum

  • Defect in the atrial primum septum, with formation at the level of the mitral and tricuspid valves

  • Cleft in mitral valve, which often → mitral regurgitation

  • Usually requires surgical closure

Ostium secundum

  • Most common type

  • Hole in the secundum septum

  • Transcatheter closure possible

Sinus venosus

  • Inferior (IVC) or superior (SVC) defect

  • Superior defect associated with anomalous pulmonary venous drainage

Fig. 2.6 Atrial septal defects. Reproduced from Khavandi A. (2014) Essential Revision Notes for the Cardiology KBA Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.6 Atrial septal defects. Reproduced from Khavandi A. (2014) Essential Revision Notes for the Cardiology KBA Oxford University Press: Oxford with permission from Oxford University Press.

  • All involve blood flow from left to right resulting in ↑ size of the right atrium and ventricle

  • Signs on examination may include:

    • A fixed split 2nd heart sound with pulmonary flow murmur

    • Atrial flutter/fibrillation and a left parasternal heave

  • ASD closure recommended if a significant shunt is present, or right heart dilatation

  • An uncorrected ASD can be associated with:

    • Right heart failure

    • Paradoxical embolism

    • Arrhythmias such as AF

    • Pulmonary hypertension

At delivery

  • Shunt may reverse and therefore saturations drop

  • Risk of air embolism, preventative filters should be used on IV lines

  • If complications are present:

    • Consider limiting 2nd stage of labour

    • Lower threshold for instrumental assistance

Management of ASD in pregnancy

  • If small and uncomplicated:

    • No excess maternal risk

    • Paradoxical embolism and arrhythmias very uncommon

  • If closed with no complications (including pulmonary hypertension), can be treated as normal

  • Consider aspirin 75 mg OD if recently closed

  • Thromboprophylaxis if:

    • ♀ at high risk of VTE

    • If the ASD has resulted in enlarged atria

    • Atrial arrhythmias

Cardiology If pulmonary hypertension present, ♀ should be counselled against pregnancy.

Atrial septal defects

Ventricular septal defect

  • Can be part of complex congenital heart disease including:

    • ToF

    • Truncus arteriosus

    • Double-outlet RV

  • Can also be associated with:

    • PDA

    • Pulmonary stenosis

    • ASD

    • Coarctation of the aorta

    • Tricuspid atresia

    • Transposition of the great arteries

    • Pulmonary atresia

Types of VSD

  • Type 1 (infundibular)

    • Septal defect above and anterior to the crista supraventricularis

  • Type 2 (membranous)

    • Septal defect of the membranous septum; the commonest defect

  • Type 3 (inlet)

    • Septal defect beneath the mitral and tricuspid valve

  • Type 4 (muscular)

    • Septal defects away from the valves, which can be small or large

  • Atrioventricular VSD (Gerbode defect)

    • Caused by a membranous septal defect between the LV and right atrium

VSDs can also be classified by size, i.e. restrictive/small, or non-restrictive/ large defects. The latter are closed in childhood to prevent the development of pulmonary hypertension.

Complications

  • Aortic regurgitation

  • Endocarditis

  • Pulmonary hypertension

  • Thromboembolism

  • Arrhythmia

  • LV or RV dysfunction

Management of VSD in pregnancy

  • Fetal echocardiography

  • If surgically closed with no residual complications, or restrictive and no sequelae, ♀ can be treated as normal in pregnancy

  • Otherwise can be monitored in each trimester, with echocardiography for assessment of pulmonary pressures

Cardiology If pulmonary hypertension is present, ♀ should be counselled against pregnancy.

Ventricular septal defect

See Fig. 2.7.

Fig. 2.7 Diagram of a ventricular septal defect. Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology 2nd Ed. Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.7 Diagram of a ventricular septal defect. Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology 2nd Ed. Oxford University Press: Oxford with permission from Oxford University Press.

Atrioventricular septal defect

Background

  • Most commonly found in association with trisomy 21

  • Term encompasses a variety of atrial septal lesions, that can be associated with VSDs, and/or lesions of the mitral/tricuspid valves

  • They are often identified and corrected surgically in childhood

Management of AVSD in pregnancy

  • Arrhythmias and atrioventricular valve regurgitation have been described

  • Follow-up every trimester is advised in ESC guidelines unless significant valve issues are present, which require more frequent review (e.g. every 2–4 wks)

Cardiology ESC 2018 pregnancy guidelines: Cardiology https://academic.oup.com/eurheartj/article/39/34/3165/5078465

Eisenmenger’s syndrome

See Fig. 2.8.

  • When shunt reversal occurs, e.g. in uncorrected VSD

  • Associated with significant maternal mortality:

    • Inability to ↑ cardiac output

    • Prone to sudden death from ischaemia

    • Paradoxical embolism

  • ↓ BP can result in shunt reversal:

    • ↓ in cardiac output and therefore ↑ cyanosis

    • Close attention should be paid to bleeding and cardiovascular stability at delivery

  • IV prostacyclins, sildenafil, or inhaled NO can be of benefit (but watch for the development of methaemoglobinaemia)

Fig. 2.8 Diagram illustrating the progressive reversal of a left-to-right shunt and Eisenmenger syndrome. Reproduced from Hezelgrave N. et al. (2015) Challenging Concepts in Obstetrics and Gynaecology: Cases with Expert Commentary Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.8 Diagram illustrating the progressive reversal of a left-to-right shunt and Eisenmenger syndrome. Reproduced from Hezelgrave N. et al. (2015) Challenging Concepts in Obstetrics and Gynaecology: Cases with Expert Commentary Oxford University Press: Oxford with permission from Oxford University Press.

Effects in pregnancy

  • Miscarriage is common, which correlates with the degree of maternal hypoxia

  • Higher risk of bleeding

  • Fetal outcomes are poor when maternal saturation <85%

Cardiology Caution is required when administering IV medications due to the risk of a paradoxical air embolism, preventative filters should be used.

Transposition of the great arteries

The RV pumps blood into the aorta and the LV connects to the pulmonary trunk (Fig. 2.9).

Fig. 2.9 Diagram illustrating transposition of the great arteries. Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology 2nd Ed. Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.9 Diagram illustrating transposition of the great arteries. Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology 2nd Ed. Oxford University Press: Oxford with permission from Oxford University Press.

Atrial switch

  • Creates baffles (artificially created vascular tunnels)

  • Mustard procedure uses either synthetic or pericardial tissue baffles, to allow systemic venous return into the LV (Fig. 2.10)

  • Senning procedure baffle is endogenous tissue which connects the systemic venous return into the LV

  • The result is a systemic RV and tricuspid valve

  • Complications include baffle stenosis, tricuspid regurgitation, heart failure, and arrhythmias

Fig. 2.10 Surgical approaches to complete transposition of the great arteries. Ao, aorta; LV, left ventricle; PA, pulmonary artery; RV, right ventricle; PVA, pulmonary venous atrium; SVA, systemic venous atrium. Reproduced from Adamson D. et al. (2011) Heart Disease in Pregnancy Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.10 Surgical approaches to complete transposition of the great arteries. Ao, aorta; LV, left ventricle; PA, pulmonary artery; RV, right ventricle; PVA, pulmonary venous atrium; SVA, systemic venous atrium. Reproduced from Adamson D. et al. (2011) Heart Disease in Pregnancy Oxford University Press: Oxford with permission from Oxford University Press.

Arterial switch

  • Replaced Mustard and Senning procedures in the late 1980s

  • Usually performed in early infancy

  • Involves surgically resecting the aorta and pulmonary artery and anastomosing to the anatomically correct ventricle (Table 2.3)

  • The coronary arteries are reattached to the newly formed aorta

  • Can be complicated by stenoses at any of the anastomosis sites, but low rate of arrhythmias and ventricular dysfunction

Table 2.3 Surgically corrected TGA in pregnancy

Assessment

Risks

Atrial switch

Pre-pregnancy

  • Ensure up-to-date assessment of baffle patency

  • Check ventricular function and tricuspid regurgitation

  • Cardiac MRI

  • Cardiopulmonary exercise test

During pregnancy

  • Check for arrhythmias

  • Check ventricular function

  • Arrhythmias

  • Heart failure

  • ↓ in functional status

Fetus

  • Premature delivery

  • Growth restriction

  • ↑ mortality rate

Arterial switch

During pregnancy

  • Check for regurgitant neoadjuvant valve

  • Check abnormalities of coronary artery reimplantation

  • ↑ risk of stenosis

  • ↑ risk of occlusion

  • Ventricular outflow tract obstruction

  • Pulmonary artery stenosis

Transposition of the great arteries

Mustard/Senning (interatrial repair)

Congenitally corrected transposition of the great arteries

  • The left and right ventricles are reversed:

    • Left ventricle receives blood from the right atrium and connects to the pulmonary trunk

    • Right ventricle receives blood from the left atrium and connects to the aorta

  • Patients have a systemic RV

  • Can occasionally present in pregnancy

Complications of congenitally corrected TGA in pregnancy

  • Generally fewer than those in ♀ with TGA:

    • RV failure and tricuspid regurgitation

    • Pulmonary oedema from RV volume overload

    • Arrhythmias especially heart block

    • Impaired functional status

  • Fetal effects:

    • Association with small-for-gestational-age babies

    • Congenital heart disease

Congenitally corrected TGA

See Fig. 2.11.

Fig. 2.11 Features of congenitally corrected transposition of the great arteries. Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology 2nd Ed. Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.11 Features of congenitally corrected transposition of the great arteries. Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology 2nd Ed. Oxford University Press: Oxford with permission from Oxford University Press.

Cyanotic heart disease

Cardiology ♀ with high pulmonary pressures should be counselled against pregnancy.

Pregnancy in ♀ with cyanotic heart disease without pulmonary vascular disease

  • Systemic vascular resistance ↓ in pregnancy can cause an ↑ right-to-left shunt with resulting ↑ cyanosis

  • ↓ oxygen saturation and ↑ haemoglobin concentration (as a result of hypoxia) is associated with a ↓ chance of a live birth

Risks of cyanotic heart disease in pregnancy

Fetal risks

  • Intrauterine death

  • Prematurity

  • Low birthweight (correlates to oxygen saturation)

Maternal risks

  • Haemorrhage

  • Paradoxical embolism

  • Impaired renal function

  • Heart failure

  • Arrhythmias

  • Endocarditis

Tetralogy of Fallot

  • Four main features (Fig. 2.12):

    • VSD with a right-to-left shunt

    • RV outflow tract obstruction

    • Over-riding of aorta

    • 2° RV hypertrophy

  • It may also be associated with:

    • An ASD

    • A right-sided aortic arch

    • Left-sided SVC

    • Hypoplastic pulmonary arteries

Surgical correction

  • Usually involves:

    • Temporary measure in infancy: shunt to increase pulmonary blood flow e.g. Blalock–Taussig shunt

    • Later complete repair with closure of the VSD and relief of the outflow tract obstruction with a transannular patch

Cardiology A transannular patch can cause significant pulmonary regurgitation and RV failure ∴ pulmonary valve replacement before pregnancy may be indicated.

Fig. 2.12 Tetralogy of Fallot. Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology 2nd Ed. Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.12 Tetralogy of Fallot. Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology 2nd Ed. Oxford University Press: Oxford with permission from Oxford University Press.

Pregnancy

Uncorrected

  • A few are identified in adulthood and present in pregnancy with:

    • ↑ cyanosis

    • Arrhythmias

    • Heart failure

  • Associated with significant maternal and fetal mortality

Surgically corrected

  • Pregnancy usually occurs without complication

Management of ToF in pregnancy

  • Pre-pregnancy counselling

  • Genetic assessment (15% have DiGeorge syndrome)

  • Regular echocardiography

  • Fetal echocardiography

  • Regular assessment of fetal growth

  • Monitor for arrhythmias (risk of atrial and ventricular tachyarrhythmias and bradycardia, particularly complete heart block with surgically corrected ToF)

  • Anticoagulation with prophylactic LMWH if residual shunt (risk of paradoxical embolus)

  • Oxygen if cyanosis present

Tetralogy of Fallot

See Fig. 2.12.

Univentricular heart

See Fig. 2.13.

  • A variety of conditions in which one ventricle supports both the systemic and pulmonary circulation

  • Lesions usually present when very young and require surgery (Fontan procedure)

  • Causes include:

    • Hypoplastic left heart syndrome

    • Double-inlet LV

    • Tricuspid atresia

    • Unbalanced AVSD

Fig. 2.13 Univentricular heart. Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.13 Univentricular heart. Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology Oxford University Press: Oxford with permission from Oxford University Press.

Fontan procedure

There are several procedures included in this label, where venous blood is diverted directly to the pulmonary artery (Fig. 2.14):

Atriopulmonary

  • Connects the right atrium to pulmonary artery

Cavopulmonary circulation

  • Extracardiac:

    • Connects IVC to the pulmonary artery with a synthetic conduit

  • Intracardiac:

    • Uses an intra-atrial conduit to divert blood from the IVC to the pulmonary artery

Complications of a Fontan procedure

  • Ventricular dysfunction and AV valve regurgitation

  • Atrial arrhythmias

  • Thrombosis

  • Cyanosis from right-to-left shunting

  • Infection

  • Systemic complications, e.g. cirrhosis and protein-losing enteropathy

Management of pregnancy post Fontan procedure

  • Pre-pregnancy assessment involves:

    • Ensuring up-to-date assessment of ventricular function

    • Cardiac MRI

    • Cardiopulmonary exercise testing

  • Anticoagulation:

    • Therapeutic or prophylactic LMWH

  • 4-weekly assessment of maternal condition and fetal growth

  • ↑ risk of miscarriage and preterm delivery

  • No contraindication to vaginal delivery, early epidural advisable

  • Lateral position in labour recommended

  • Cardiology There is a risk of impairment of functional capacity that may not recover entirely after pregnancy.

Univentricular heart

Fontan procedure

Fig. 2.14 Diagrams illustrating various types of Fontan operation. (A) Atriopulmonary Fontan. (B) Total cavopulmonary connection (TCPC, lateral tunnel). (C) TCPC (extracardiac conduit). Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.14 Diagrams illustrating various types of Fontan operation. (A) Atriopulmonary Fontan. (B) Total cavopulmonary connection (TCPC, lateral tunnel). (C) TCPC (extracardiac conduit). Reproduced from Myerson S. G. et al. (2009) Emergencies in Cardiology Oxford University Press: Oxford with permission from Oxford University Press.

Pulmonary stenosis

  • Common cause of congenital heart disease

  • Can be seen in Noonan’s syndrome

Management of pulmonary stenosis in pregnancy

  • If RV function normal, pregnancy is usually well tolerated

  • If a significant gradient across the valve is present (>50 mmHg):

    • Ideally surgery should be performed before conception

    • If surgery has not been performed, clinic review every 4 wks is advised

  • Balloon valvuloplasty has been performed in pregnancy in ♀ with severely symptomatic pulmonary stenosis which is unresponsive to medical therapy

Noonan’s syndrome

  • Autosomal dominant condition

  • Features include:

    • Short stature

    • Pectus excavatum

    • Developmental delay

    • Bleeding disorders

    • Characteristic facial appearance

  • Congenital heart defects in 50–80%, including:

    • Pulmonary stenosis

    • Hypertrophic cardiomyopathy

    • AVSD

Ebstein’s anomaly

The tricuspid valve is displaced towards the apex of the RV, → right atrial enlargement and tricuspid regurgitation.

Causes

  • Can be associated with:

    • Maternal lithium use in pregnancy

    • Other abnormalities such as an ASD or WPW syndrome

Surgical correction

  • Surgical prior to correction should be considered if:

    • Cyanosis is present

    • Exercise capacity is ↓

    • Severe tricuspid regurgitation

Risks of pregnancy with Ebstein’s anomaly

Maternal risks

  • Cardiology Symptomatic ♀ should be advised against pregnancy

  • In the absence of cyanosis or right heart failure, ♀ do well

  • Potential complications:

    • Heart failure

    • ↑ cyanosis

    • Arrhythmias

    • Paradoxical embolus

    • Infective endocarditis

Fetal risks

  • If maternal cyanosis is present, ↑ risk of

    • Low birthweight babies

    • Preterm birth

    • Fetal loss

Investigations

  • CXR can show cardiomegaly

  • ECG changes may include tall and broad P waves, ↑ PR interval, right bundle branch pattern, and ‘fragmented’ QRS complex

Management of Ebstein’s anomaly in pregnancy

  • Review at least every 4 weeks and monitor for complications

  • Thromboprophylaxis should be considered if ASD also present

  • Regular fetal growth scans

Mitral stenosis

  • Commonly caused by rheumatic fever

  • Less commonly mitral annular calcification or congenital stenosis

  • Normal valve area is 4–6 cm2:

    • Pregnancy usually tolerated well if the valve area >1.5 cm2

    • ESC guidelines advise valve replacement prior to pregnancy in ♀ with severe mitral stenosis, i.e. <1.0 cm2

  • Diastolic filling time is prolonged in mitral stenosis:

    • ↑ reliance on left ‘atrial kick’ for adequate LV filling

    • If tachycardia develops, the diastolic filling time is ↓, or if the atrial kick is lost, e.g. if AF develops, rapid decompensation can occur

  • Signs of severity include:

    • Signs of pulmonary hypertension (loud P2, RV heave)

    • Signs of right heart failure with no other cause (hepatomegaly, ↑ JVP/features of tricuspid regurgitation, oedema, ascites)

    • Longer duration of murmur

    • Reduced time between S2 and opening snap

  • CXR shows upper lobe congestion and LA enlargement causing a double silhouette; 2° pulmonary haemosiderosis

Management of mitral stenosis in pregnancy

  • Echocardiography and clinical assessment every 2–4 wks (Tables 2.4 and 2.5)

  • Medical therapy for symptoms or clinically significant pulmonary hypertension (systolic pulmonary artery pressure ≥50 mmHg):

    • Diuretics

    • β‎ blockade to control heart rate and ↑ diastolic filling time

  • Anticoagulation:

    • Therapeutic LMWH if history of embolic events, a left atrial appendage thrombus is present, or AF present

    • Consider in ♀ in sinus rhythm with significant MS and spontaneous echocardiographic contrast in left atrium, left atrium ≥60 mL/m2, or heart failure

  • Treatment of AF with β‎ blockade and/or digoxin:

    • Consider cardioversion

  • If symptomatic despite maximal medical treatment, percutaneous mitral commissurotomy can be performed in pregnancy

Table 2.4 Echocardiographic assessment of mitral stenosis

Valve area (cm2)

Gradient (mmHg)

Mild

1.6–2.0

<5

Moderate

1.0–1.5

5–10

Severe

<1.0

>10

Table 2.5 Clinical assessment of mitral stenosis

Symptoms

• Breathlessness

• Orthopnoea

• Paroxysmal nocturnal dyspnoea

• Palpitations

• Systemic embolism

• Hoarse voice (recurrent laryngeal nerve compression)

• Dysphagia (left atrial compression of oesophagus)

• Cough (can be haemoptysis; white/pink frothy sputum suggests pulmonary oedema)

Signs

• Malar flush

• AF

• Mid to late rumbling diastolic murmur at apex (can be exaggerated by exercise)

• Palpable S1 (tapping apex beat)

• Pulmonary oedema

• Loud S1

• Opening snap (opening of stenosed valve; heard after a loud S2 at apex in lateral decubitus position)

↑ severity suggested by:

  • Signs of pulmonary hypertension (loud P2, RV heave)

  • Right heart failure (tricuspid regurgitation, peripheral oedema, hepatomegaly)

Management at time of delivery

  • Risk of pulmonary oedema is greatest at the time of labour

  • Positioning in labour to avoid being supine or in the lithotomy position

  • Vaginal delivery with epidural analgesia is advised, with a limited 2nd stage

  • Careful fluid balance and cautious fluid supplementation

Complications of mitral stenosis in pregnancy

Maternal

  • Left atrial enlargement

  • AF

  • Systemic embolization

  • Pulmonary hypertension

  • Right heart failure

Fetal

  • Preterm delivery

  • IUGR

  • Stillbirth

Aortic stenosis

  • Common causes include:

    • Accelerated calcification of a bicuspid aortic valve

    • Rheumatic heart disease

    • Degeneration of calcified valve

  • Symptoms develop when gradient is severe and include exertional:

    • Chest pain

    • Breathlessness

    • Syncope

  • The chest pain may sound ischaemic in nature:

    • Can be associated with ischaemic ECG changes resulting from ↑ myocardial oxygen demand

  • LV failure can occur in decompensated severe AS

  • Signs of severe AS include:

    • A slow rising pulse

    • Narrow pulse pressure

    • Quiet S2

    • A ‘heaving’ apex beat

Supravalvular AS

  • Much less common

  • More likely to be above the coronary arteries and not have the same ischaemic sequelae to the myocardium

  • May → ischaemic symptoms in limbs

Echocardiographic changes

  • Severe stenosis is a valve area of <1 cm2, or if the mean gradient is >50 mmHg (measured when not pregnant)

  • Gradient across the aortic valve is affected by ↑ cardiac output as pregnancy progresses, so an ↑ in the gradient is to be expected, and the absence of an ↑ is concerning

  • Aortic valve gradient is an unreliable marker of the severity of AS in the context of impaired LV function and the valve area should be assessed

Pre-conceptual considerations in AS

  • Pregnancy is not contraindicated even in severe AS if:

    • Asymptomatic

    • No LV impairment

    • Normal exercise test

  • Aortic valve replacement should be considered with:

    • Critical AS (valve area of <0.7 cm2, or if the mean gradient is >50 mmHg) even in the absence of symptoms

    • Symptomatic severe AS

    • LV dysfunction

    • Onset of features of LV failure

Management of AS in pregnancy

  • In severe AS, monthly or bimonthly clinical evaluation with echocardiography is indicated (Table 2.6)

  • In individuals with severe symptoms despite medical therapy, percutaneous valvuloplasty can be considered

  • Potential fetal complications include IUGR and preterm birth, more commonly in ♀ with severe AS

  • Fetal echocardiography advised due to potential inheritance, e.g. bicuspid aortic valve

  • Anaesthetic considerations: aim to avoid BP fluctuations (epidural preferred to spinal)

  • Vaginal delivery not contraindicated, but adequate analgesia and maintenance of normal BP is important

  • In symptomatic severe AS, caesarean delivery is preferred

Table 2.6 Echocardiographic assessment of severity in AS

Valve area (cm2)

Gradient (mmHg)

Mild

>1.5

<25

Moderate

1.0–1.5

25–50

Severe

<1.0

>50

Critical

<0.7

>80

Differential diagnosis of ejection systolic murmur

Physiological

  • Flow murmur

Subvalvular outflow obstruction

  • Hypertrophic cardiomyopathy

Valvular

  • AS

  • Pulmonary stenosis

Supravalvular

  • Williams syndrome (in >95% of affected individuals, mutation in ELN gene which codes for the protein elastin):

    • Typical facies

    • Loud A2

    • Thrill

Mitral regurgitation

  • Asymptomatic, mild mitral regurgitation is not an uncommon finding on echocardiography

  • Mild/moderate regurgitation is usually well tolerated in pregnancy because of the ↓ in systemic vascular resistance

  • Moderate/severe MR can result in heart failure

Overview

  • Most common cause in pregnancy is mitral valve prolapse

  • Other causes include:

    • Ischaemic heart disease

    • Infective endocarditis

    • 2° to LV dilatation

    • Associated with Ehlers–Danlos syndrome, Marfan syndrome, and pectus excavatum

  • Prolapse of the mitral valve is a common finding (about 2% of normal population) and results from displacement of an abnormal mitral valve leaflet into the left atrium during systole

  • If severe, LV enlargement and systolic dysfunction can occur and may therefore warrant valve replacement

Examination

  • Pansystolic murmur at the apex

  • In mitral valve prolapse the murmur may be late systolic and associated with a mid-systolic click; in such cases the mitral regurgitation is not usually haemodynamically severe

Management of mitral regurgitation in pregnancy

  • In ♀ with acute severe regurgitation refractory to medical therapy for heart failure, surgery may be unavoidable

  • Monitor with echocardiography every trimester in mild/moderate regurgitation, more often if severe

  • Concerning features include:

    • Any decline in LV function from normal

    • ↑ systolic LV dimensions

  • Vaginal delivery with early epidural with low threshold for assisted 2nd stage is usually appropriate

Tricuspid regurgitation

  • An element of mild tricuspid regurgitation is present in many normal people on echocardiography

  • 1° tricuspid regurgitation may be due to Ebstein’s anomaly or endocarditis

  • 2° tricuspid regurgitation due to left-sided valve disease or pulmonary hypertension is more common and is managed according to the 1° condition

Aortic regurgitation

  • Mild or moderate regurgitation is well tolerated in pregnancy as a result of the ↓ systemic vascular resistance

  • Severe regurgitation can result in heart failure

Causes of aortic regurgitation

Abnormal valve

  • Infective endocarditis

  • Congenital bicuspid valve

  • Rheumatic fever

Normal valve, but abnormal aorta

  • Aortic root dilatation

  • Acute aortic dissection

  • Aortitis, e.g. in giant cell arteritis, Takayasu arteritis, syphilis

  • Ankylosing spondylitis

Symptoms

  • May be asymptomatic

  • Symptoms of consequences such as heart failure

Signs

  • Collapsing pulse

  • Wide pulse pressure

  • Hyperdynamic ± displaced apex

  • Early diastolic murmur most easily heard in expiration at when sitting forward, at lower left sternal edge

  • An additional diastolic murmur can sometimes be heard at the apex, and results from the blood hitting the mitral valve from the aorta and the left atrium simultaneously (‘Austin Flint’ murmur)

  • Sometimes an ejection systolic murmur can also be heart at the base (which can be loud)

Investigations

  • Echocardiography

  • CXR:

    • May show a large heart (‘cor bovinum’)

Management of aortic regurgitation in pregnancy

  • Mild/moderate: likely to tolerate pregnancy well

  • Severe (symptoms or LV dysfunction): diuretics, treatment of arrhythmias, vasodilators (hydralazine and nitrates)

  • Surgery is only needed in the acute setting, e.g. acute valve dysfunction in endocarditis or dissection

Prosthetic heart valves

Cardiology ♀ with prosthetic heart valves usually have normal cardiac function, so can adapt well to the physiological demands of pregnancy.

Cardiology The problems that these ♀ encounter in pregnancy are from the thrombotic risks of pregnancy and the use of anticoagulation.

Decisions about which valve to use in ♀ of childbearing age should include alternatives such as the Ross procedure for aortic disease (pulmonary autograft to replace the aortic valve, and a pulmonary graft inserted) or transcatheter valve implantation (pulmonary valves).

Bioprosthetic valves

  • Do not require therapeutic anticoagulation unless there is a history of associated arrhythmias

  • Aspirin 75 mg OD recommended for all ♀

  • ↑ chance of valve degeneration in pregnancy

Metal valves

  • Need therapeutic anticoagulation throughout pregnancy, in addition to aspirin 75 mg OD

Warfarin

  • Warfarin is preferable to LMWH to prevent thrombosis of a metal heart valve and is the main treatment in the non-pregnant population

  • Cardiology Warfarin crosses the placenta and is known to be teratogenic

  • Associated with miscarriage

  • Fetal exposure in 1st trimester can result in:

    • Nasal bone hypoplasia

    • Shortened fingers

    • Microcephaly

    • Ventriculomegaly

    • Congenital cardiac abnormalities

  • Thought to be dose dependent, with ↓ rates of embryopathy occurring with a daily dose of <5 mg of warfarin

  • Cardiology Later in pregnancy, warfarin use can also cause complications:

    • Fetal haemorrhage (including intracranial haemorrhage)

    • Occurs due to the relative deficiency of vitamin K in the fetus the fetal INR is greater than maternal INR

Low-molecular-weight heparin

  • Does not cross the placenta

  • Is appropriate for many conditions in pregnancy (treatment of VTE)

  • Is not associated with fetal complications

  • Cardiology In ♀ with metal heart valves, LMWH is inferior to warfarin for prevention of thrombosis thus ↑ maternal morbidity and mortality

  • See Table 2.7

Table 2.7 Suggested target anti-Xa levels if on LMWH

Peak (4–6 hrs post dose)

Trough

Aortic valve replacement

0.8–1.2 IU/mL

≥0.6 IU/mL

Mitral valve or right-sided valve replacement

1.0–1.2 IU/mL

≥0.6 IU/mL

Source: data from ESC 2018 pregnancy guidelines https://academic.oup.com/eurheartj/article/39/34/3165/5078465

Antenatal anticoagulation for metal heart valves

Options include:

  • LMWH throughout pregnancy (deemed highest risk to the mother)

  • If a ♀ is particularly high risk, or is on a low daily dose, i.e. <5 mg warfarin per day:

    • Warfarin throughout pregnancy

  • If a ♀ is on high daily dose, i.e. >5 mg warfarin per day, changing between the two drugs can be considered:

    • LMWH from positive pregnancy test to 12 wks

    • Warfarin in wks 12–36

    • LMWH 36 wks until delivery

Cardiology ESC 2018 pregnancy guidelines: Cardiology https://academic.oup.com/eurheartj/article/39/34/3165/5078465

Management of peripartum anticoagulation

Delivery

  • Induction of labour at 37–38 wks suggested:

    • Enables planning of timing of LMWH doses

    • ↓ the risk of delivery occurring when fully anticoagulated

  • Regional anaesthesia contraindicated <24 hrs after therapeutic dose of LMWH

Cardiology No pregnancy-specific guidelines are available regarding intrapartum LMWH if labour is long.

Cardiology If ♀ spontaneously labour within 2 wks of warfarin cessation, a caesarean delivery is advisable to ↓ risk of fetal intracranial haemorrhage due to the likelihood of the fetus still having a high INR.

Anticoagulation after delivery

► In a non-pregnant setting, treatment-dose LMWH is withheld for 48 hrs after surgery, with prophylactic LMWH doses being given instead but there is no evidence that this is appropriate in pregnancy especially as the prothrombotic changes are maximal around the time of delivery.

Possible options for anticoagulation after delivery

These include:

Day of delivery

  • No LMWH, or prophylactic dose 4–8 hrs after delivery for most ♀

  • Therapeutic-dose LMWH in highest risk ♀ (ESC 2018 guidelines)

Day 1 post delivery

  • Higher doses (i.e. therapeutic doses) can be considered provided there are no concerns regarding ongoing bleeding

  • Dose may be divided depending on individual circumstances

Day 2 post delivery

  • Usually appropriate to restart therapeutic dose

    Cardiology There is a significant risk of bleeding, irrespective of anticoagulant regimen so care should be in an appropriately monitored setting

  • Both LMWH and warfarin can be used in breastfeeding

  • It is advisable to wait for 7–10 days post-delivery before restarting warfarin because of the risk of late PPH

If bleeding, or delivery imminent, and fully anticoagulated

Warfarin

  • Prothrombin complex concentrate:

    • Dose determined by weight

    • Do not need to wait for INR result before administering, it will return to normal within 15–20 mins

  • Vitamin K 5–10 mg IV

  • Cross-match blood

LMWH

  • Discuss with haematologist about giving protamine sulfate

  • Cross-match blood

Pulmonary hypertension

Symptoms

  • Breathlessness without other cause of cardiac or respiratory disease

  • Symptoms of right heart failure including:

    • Abdominal distension (↑ girth > than gestational age)

    • Oedema

  • Syncope, pre-syncope, or chest pain can also occur

Signs

  • Mild PH will not cause any abnormalities on clinical examination

  • Advanced PH can be associated with:

    • RV heave

    • Loud 2nd (pulmonary) heart sound

    • ↑ JVP

    • Signs of right heart failure including hepatomegaly, which may be pulsatile, peripheral oedema, and ascites

Diagnosis

  • ECG is often abnormal showing features including:

    • P pulmonale

    • Right axis deviation

    • RV hypertrophy

    • RV strain

    • Right bundle branch block

    • QTc prolongation (indicator of severe disease)

  • Cardiology A normal ECG does not exclude the diagnosis

  • Right heart catheterization:

    • Mean pulmonary artery pressure >25 mmHg at rest, or >30 mmHg on exercise

    • With pulmonary wedge pressure <15 mmHg

  • Echocardiography:

    • Systolic pulmonary artery pressure can be estimated from tricuspid regurgitant velocity if tricuspid regurgitation is present

    • Enlarged RA and RV (suggestive not diagnostic features)

  • CXR:

    • Features of PH can be present in up to 90%

    • Other respiratory conditions that contribute to development of PH may also be identified on a plain CXR

  • Lung function tests can be performed to look for underlying causes

  • Imaging (V/Q scan or CTPA) to assess for underlying thromboembolism

Classification

See Box 2.1.

Source: data from Galiè N et al. (2015) 2015 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension. Eur Resp J 46:903–975.

Pulmonary hypertension in pregnancy

  • Physiological changes in the cardiovascular system (↑ blood volume and ↑ cardiac output) require a well-functioning RV

  • Cardiology Irrespective of aetiology, PH is very high risk in pregnancy and associated with significant maternal mortality

  • Highest risk time is 1st few days postpartum

  • Mortality rate was thought to be up to 50% but recent data appears to show it is more like 20–30%

  • Contraception and pregnancy should be discussed with any ♀ of childbearing age with PH

  • In all pregnancies, termination must be discussed and offered

  • PH should be looked for in any ♀ of childbearing age with a condition that can cause it

  • Hormonal changes also influence the pulmonary vasculature

  • In PH, there is a fixed pulmonary vascular resistance and an inability to ↑ pulmonary blood flow

Management of pulmonary hypertension in pregnancy

  • Care should be coordinated in a centre with expertise in PH

  • Consider prophylactic LMWH if poor RV function or factors that ↑ their thrombotic risk such as AF

  • Oxygen

  • Regular fetal growth scans

  • Regular echocardiography

  • Diuretics may be required (some use the IVC dimensions to guide this treatment)

  • Routine use of a Swan–Ganz catheter for monitoring is not required and may ↑ the risk of arrhythmias

At delivery

  • Spinal or epidural is viewed in many centres as mandatory

  • Avoid suddenly ↑ vagal tone and venous return, e.g. ergometrine

  • Avoid PGF2α‎ which can cause pulmonary vasoconstriction

  • Delivery and postnatal care needs to be in a location where tight BP control and careful fluid balance can occur

  • Cardiology Mode of delivery is controversial:

    • Many undergo caesarean with epidural anaesthesia as a result of preterm delivery and the ability to maintain careful control of the anaesthesia

    • Vaginal delivery is possible and can be supported in many ♀ with PH

  • Timing of delivery—many advocate delivery by 36 wks’ gestation

  • Very careful fluid balance should be maintained

  • Cardiology Some advocate significant diuresis post delivery (up to 5 L in the 1st 3 days postpartum)

  • Careful haemostasis as any bleeding risks decompensation

  • Continue anticoagulation postnatally

Medications used in pulmonary hypertension

Prostanoids

  • Iloprost (can be nebulized)

Phosphodiesterase inhibitor

  • Sildenafil

Calcium channel antagonists

  • Amlodipine

  • Nifedipine

Endothelin antagonists

  • Bosentan

  • Macitentan

Cardiology NB There are some fetal concerns with agents such as bosentan from animal models, so this agent is often discontinued after conception. However, if this agent has helped this could be used, particularly after the 3rd trimester, as the likely benefit is > the theoretical risks based on animal studies.

Aortopathies

Cardiology Pregnancy ↑ the likelihood of aortic dissection.

Marfan syndrome

  • Autosomal dominant resulting from a defect in the FBN1 gene

  • Diagnosis made by the Ghent criteria, which gives weight to a variety of clinical findings alongside the family history

(Cardiology Ghent criteria can be found at: Cardiology https://www.marfan.org/dx/rules)

Classical features

  • ↑ arm span

  • Pectus carinatum or pectus excavatum

  • Ectopia lentis

  • Dilation or dissection of the ascending aorta

  • Mitral valve prolapse

  • Spontaneous pneumothorax

  • Dural ectasia

Cardiac complications

  • Vessel dissection, particularly aortic

  • Mitral valve prolapse/regurgitation

  • Arrhythmias

Obstetric complications

  • Premature rupture of membranes

Loeys–Dietz syndrome

  • Relatively recently described syndrome associated with mutations in components of the TGFβ‎ pathway

  • Originally described phenotype included:

    • Generalized arterial tortuosity

    • Hypertelorism

    • Bifid or broad uvula

    • Cleft palate

  • Cases are ↑ being identified which lack these features

  • Syndrome is associated with vessel dissection which can occur at an earlier age (including in childhood) compared to Marfan syndrome

Management of aortopathies in pregnancy

► Aortic root replacement may be appropriate preconception to ↓ the risk of dissection (Table 2.8).

  • Assessment of vascular tree (ideally pre-pregnancy)

  • Counselling about inheritance

  • MDT including cardiology, obstetrics, and neonatology

  • Optimize medication, e.g. change from losartan to a β‎ blocker (if regular periods and pregnancy testing, then continue losartan until test is positive, otherwise change in advance of conception)

  • Excellent BP control

  • Counselling about ↑ risk of aortic dissection (further ↑ if aortic dilatation present or if family history of dissection)

  • Regular assessment of aortic diameters with echocardiography or cardiac MRI

  • Delivery in a centre with access to cardiothoracic surgery and neonatal intensive care

  • Individualized delivery plan:

    • Timing and mode of delivery depends on obstetric history and degree of aortic abnormality (Table 2.9); caesarean delivery is not mandatory

Table 2.8 European guidelines for consideration of aortic root replacement in Marfan and Loeys–Dietz syndromes

Non-pregnant population

Consider surgery

  • Maximum aortic diameter >50 mm

  • Maximum aortic diameter >45 mm with other risk factors

    • Family history of dissection

    • Yearly growth >2–3 mm

    • Severe aortic regurgitation

If contemplating pregnancy

Marfan syndrome

  • Consider surgery if maximum aortic diameter >45 mm

Loeys–Dietz syndrome

  • No cut-off for aortic root diameter

The North American guidelines differ from the European guidelines and advocate a lower threshold for intervention in Loeys–Dietz syndrome:

Table 2.9 Mode of delivery by aortic root diameter

Aortic diameter

Recommendation

<40 mm

• Vaginal delivery

40–45 mm

• Consider either vaginal delivery with epidural and expedited 2nd stage, or caesarean section

>45 mm

• Caesarean section advised

Coarctation of the aorta

  • A narrowing of the aorta

  • Usually identified (and corrected) in childhood:

    • These are usually associated with aortic arch abnormalities

  • Can present in adulthood, often with hypertension:

    • These tend to have stenosis in the descending aorta, distal to the left subclavian artery

  • Associated with a bicuspid aortic valve in up to 85% of cases

  • Also associated with:

    • Turner’s syndrome

    • VSD

    • PDA

    • Mitral valve dysfunction (stenosis or regurgitation)

  • ↑ risk of congenital heart disease in the offspring of mothers with coarctation

Symptoms

  • Headache

  • Intermittent claudication

Signs

  • LV hypertrophy

  • Palpable collaterals

  • Systolic murmur (mid systolic) anteriorly or posteriorly in the chest

  • Systolic thrill in suprasternal notch

  • Bruits over scapulae, anterior axillary areas, and left sternal edge

Investigations

  • CXR can show rib notching

  • ECG may show LV hypertrophy

Preconception

  • If corrected, cardiac MRI to establish the success of correction and presence of any complications

  • If uncorrected, there is a risk of ↑ BP and heart failure (risk is related to the gradient)

  • Risk of aortic dissection so careful BP control is required

  • Intracranial aneurysms are 5× more common with aortic coarctation

Complications following surgical correction of aortic coarctation

  • Re-coarctation

  • ↑ BP even in the absence of re-coarctation

  • Aneurysm formation at site of previous repair

  • Risk ↑ if a patch repair was performed

Other aortic pathologies

See Table 2.10.

Table 2.10 Summary of aortic conditions affecting pregnancy

Location of aneurysms

Comorbidities

Advise against pregnancy if

Low risk of aortic dissection (<1%)

Bicuspid AV

• Ascending aorta

• AS or regurgitation

• Ascending aorta >50 mm

High risk of aortic dissection (1–10%)

Marfan syndrome

• Everywhere

  • Dural abnormalities

  • Mitral regurgitation

  • Heart failure

  • Arrhythmias

  • Ascending aorta >45 mm

  • Ascending aorta >40 mm and family history of dissection or sudden death

Loeys–Dietz syndrome

• Everywhere

  • Dural abnormalities

  • Mitral regurgitation

  • Ascending aorta >45 mm

  • Ascending aorta >40 mm and family history of dissection or sudden death

Turner’s syndrome

  • Ascending aorta

  • Aortic arch

  • Descending aorta

  • Low height

  • Infertility

  • Hypertension

  • Diabetes

  • Bicuspid

  • aortic valve

  • ASI >25 mm2

Vascular EDS

  • Everywhere

  • Dural abnormalities

  • Uterine rupture

  • All ♀

Source: data from European Society of Cardiology guidelines https://academic.oup.com/eurheartj/article/39/34/3165/5078465

Bicuspid aortic valve

  • Associated with an ↑ risk of aortic regurgitation, aneurysm formation, and aortic dissection

  • Echocardiography may miss distal ascending aortic dilatation so MRI may be required

  • Aortic diameter >50 mm is a contraindication to pregnancy

Turner’s syndrome

  • Spontaneous pregnancy is unlikely (<2%) given the associated ovarian abnormalities and premature ovarian failure

  • However, pregnancies are becoming more common due to ART using egg donation

  • Cardiology There is a significant risk of aortic root dilatation and dissection in pregnancy

  • Cardiology Concern regarding maternal deaths following aortic root dilatation in Turner’s ♀ led the French Agence de la biomédecine to issue guidelines regarding pregnancy and Turner’s syndrome

  • (Cardiology http://www.cngof.asso.fr/D_TELE/RPC_Turner_et_gro_090723_en.pdf)

  • Cardiology Pregnancy is not advisable if:

    • Aortic size index (ASI) >2.5 cm/m2

    • ASI 2–2.5 cm/m2 with risk factors such as coarctation or hypertension, or history of a previous dissection

Cardiology There is not a consensus as to whether actual aortic size should be used, or ASI, i.e. corrected for weight and height.

Ehlers–Danlos syndrome type 4 (vascular EDS)

  • ↑ risk of large artery rupture and dissection including aorta

  • ↑ risk of uterine rupture in labour

  • Cardiology Pregnancy usually advised against.

Familial thoracic aortic aneurysm and/or dissection (FTAAD)

  • A number of mutations have been identified in this condition including ACTA2, SMAD3, and MYH11

  • Presentation is heterogeneous and not all affected individuals have a mutation identified

  • Pregnancy is high risk and associated with ↑ risk of dissection

Pre-pregnancy considerations after aortic surgery

  • Consider the underlying disorder:

    • Assess the maternal risk of pregnancy

    • Plan appropriate management

  • Assessment of aortic valve function and appearance of aorta adjacent to the graft using echocardiography and/or cardiac MRI

  • If reimplantation of coronary arteries was performed, need to be aware of risk of anastomosis stenoses

Heart failure

The clinical syndrome of signs of fluid overload in the context of an abnormally functioning heart.

  • Presence of normal LV systolic function on echocardiography does not exclude diagnosis as diastolic dysfunction can also occur

  • It is important to distinguish ‘heart failure’ from pulmonary oedema

  • Echocardiographic appearances of the LV change in normal pregnancy so it is important that echocardiography is performed by someone experienced and familiar with pregnancy-related changes

  • Symptoms can ↑ in pregnancy as a result of the ↑ demand on the heart, this classically occurs in the 1st trimester or at 27–30 wks

Left ventricular systolic dysfunction

Causes in pregnancy

  • Underlying cardiomyopathy:

    • Dilated cardiomyopathy

    • Previous ischaemia

  • Rate related, i.e. poorly controlled tachyarrhythmias

  • New cardiomyopathy:

    • Peripartum cardiomyopathy

    • New presentation of ischaemic or dilated cardiomyopathy

Management

  • Maintenance of normovolaemia

  • Diuresis with furosemide

  • Consideration of use of a mineralocorticoid receptor antagonist, e.g. eplerenone rather than spironolactone (former theoretically preferable as it lacks the anti-androgen effects of the latter)

  • β‎ blocker

  • LMWH prophylaxis if EF greatly ↓ (thresholds vary)

Pulmonary oedema

  • Pregnant ♀ are more inclined to pulmonary oedema (↓ oncotic pressure)

  • Should be considered even in the absence of known cardiac disease

  • Pulmonary oedema can occur with a structurally normal heart, so the absence of abnormalities on echocardiography does not exclude the diagnosis

Cardiology Excessive IV fluid administration in pre-eclampsia is an important iatrogenic cause of pulmonary oedema so careful fluid monitoring ± restriction is advised until diuresis occurs.

Investigations

  • CXR

  • Echocardiogram

Management

  • Identify and treat the underlying cause

  • Diuresis with furosemide

  • Fluid restriction

  • Supportive care

Causes of pulmonary oedema

Non-cardiogenic causes

  • Excessive fluid administration

  • Pre-eclampsia

  • Drugs:

    • Steroids

    • NSAIDs (diclofenac)

  • Tocolytics

  • Infection:

    • Pyelonephritis

    • Chorioamnionitis

    • Appendicitis

Cardiogenic causes

  • Cardiac ischaemia

  • Peripartum cardiomyopathy

  • Undiagnosed congenital heart disease

  • Other causes of cardiomyopathy (e.g. rate related)

Peripartum cardiomyopathy

An idiopathic cardiomyopathy presenting with heart failure 2° to LV systolic dysfunction towards the end of pregnancy or in the months following delivery.

  • No other cause of heart failure is identified

  • Remains a common misdiagnosis, on review other causes of heart failure are often identified, such as:

    • A missed ischaemic event

    • Undiagnosed dilated cardiomyopathy

    • LV dysfunction from sepsis or pre-eclampsia

  • Cardiology It is a diagnosis of exclusion

  • Incidence 1 in 3000–15,000 pregnancies, and varies geographically (is as high as 1 in 300 in Haiti)

  • The aetiology is unknown; autoimmunity, viral infection, high prolactin, and fetal microchimerism have all been suggested

Clinical features

  • Presenting symptoms can include breathlessness, pleural effusions, peripheral oedema, and embolic phenomena

  • LV may not be dilated but EF nearly always <45%

Risk factors for peripartum cardiomyopathy

  • Tocolytics

  • Multiple pregnancy

  • Gestational hypertension or pre-eclampsia

  • African origin

  • Gravida

  • Parity

  • Extremes of age

Management of peripartum cardiomyopathy

  • Optimize medical treatment including β‎ blockade and diuresis

  • If postpartum, also consider ACE-I

  • If occurs antenatally, delivery is indicated

  • Prophylactic LMWH

  • Close monitoring postpartum

  • Cardiology Prolactin has been implicated in the aetiology:

    • In some series, breastfeeding appears to be associated with ↑ LV EF recovery, so cessation is not advocated at present

    • Bromocriptine shows some promise and consideration of its use is suggested in the ESC 2018 guidelines

Subsequent pregnancies

  • Good outcomes are seen when cardiac dysfunction has resolved by 6 months postpartum

  • Morbidity and mortality are associated with a persistently impaired EF or a LV end-diastolic diameter of >60 mm (which also correlates with BMI)

Hypertrophic cardiomyopathy

Definition: an asymmetrical ↑ in myocardial thickness in the absence of another cause such as ↑ BP.

  • Inheritance is autosomal dominant in about 60% of cases, but penetrance is variable

  • Many ♀ are asymptomatic

Clinical features

Symptoms of LV outflow tract obstruction

  • Breathlessness

  • Chest pain

  • Syncope

  • Palpitations

Signs

  • Double apical impulse

  • Systolic thrill over the left sternal edge

  • 4th heart sound

  • Ejection systolic murmur at left 3rd interspace (inspiration can → a pronounced ↓ in volume of the murmur)

ECG changes

  • LV hypertrophy

  • Q waves

  • Conduction defects

Echocardiography

  • Asymmetric septal hypertrophy (apical is more common in Japan)

  • Systolic anterior motion of anterior leaflet of mitral valve

Complications

  • Arrhythmias

  • Endocarditis

  • Sudden death

Cardiology An implantable defibrillator may be indicated if sustained ventricular arrhythmias or a strong family history of sudden cardiac death.

Management of hypertrophic cardiomyopathy in pregnancy

Antenatal management

  • Pregnancy usually well tolerated if asymptomatic before conception

  • Maternal death is rare

  • Risk of sudden death is not ↑ by pregnancy

  • Asymptomatic ♀ do not require any treatment

  • Careful screening for arrhythmias should be undertaken

  • β‎ blockade should be continued if taking prior to conception

  • β‎ blockade should be initiated if there is a significant LV outflow tract gradient, or if symptoms develop (diuretics may also be required in the latter setting)

  • If AF develops, prompt pharmacological treatment or electrical cardioversion is advised

Intrapartum management

  • Careful fluid balance:

    • Keep normovolaemic

  • Regional anaesthesia/analgesia may result in vasodilation which may be poorly tolerated

  • Valsalva manoeuvres may ↓ preload and worsen symptoms

  • Vaginal delivery is often preferred

  • β‎ blockers can be continued

Dilated cardiomyopathy

Where there is systolic dysfunction of the LV ± RV, or unexplained ventricular dilatation in the absence of other causes (e.g. ↑ BP, coronary artery disease).

  • A significant proportion are inherited

  • Can be idiopathic, but can also occur in other medical conditions

Causes of dilated cardiomyopathy

  • Idiopathic

  • Familial

  • Genetic

  • Infective:

    • Viral (e.g. Coxsackie B)

    • TB

  • Toxins:

    • Alcohol

    • Drugs (e.g. anthracyclines)

  • Cardiac:

    • Tachyarrhythmias

    • Myocardial ischaemia

  • Nutrition:

    • Niacin deficiency

    • Thiamine deficiency

Pre-pregnancy advice

  • Risk of irreversible deterioration in LV function

  • Most are advised against pregnancy

  • Potentially better outcomes if condition is stable and asymptomatic over many years

  • Poor prognostic indicators include:

    • Very poor EF, i.e. <20%

    • Poor performance status pre-pregnancy (NYHA class III or IV)

    • ↓ BP

Management in pregnancy

  • Diuretics:

    • Furosemide

    • Eplerenone could be considered if a mineralocorticoid receptor antagonist is warranted (spironolactone has anti-androgen activity so may affect masculinization of a ♂ fetus)

  • Vasodilators

  • Cautious β‎ blockade

  • Anticoagulation

Restrictive cardiomyopathy

Dysfunction caused by a rigid, stiff myocardium, resulting from infiltration of abnormal material or fibrosis.

  • Can present with heart failure

  • Atrial arrhythmias are common

Causes of restrictive cardiomyopathy

  • Idiopathic

  • Familial

  • Infiltrative:

    • Amyloid

    • Sarcoid

    • Gaucher’s disease

  • Endomyocardial conditions:

    • Hypereosinophilic syndrome

    • Endomyocardial fibrosis

  • Storage disorders:

    • Haemochromatosis

    • Fabry’s disease

    • Glycogen storage disorders

  • Other conditions:

    • Carcinoid

    • Systemic sclerosis

Clinical features

  • ECG:

    • No specific changes

  • Echocardiography:

    • Typical pattern involves a LV that looks normal

    • Biatrial enlargement

  • Cardiac MRI shows a similar pattern, but can give more detail about the myocardial appearance and therefore help identify a specific cause

Management of restrictive cardiomyopathy in pregnancy

  • Very few reported cases of restrictive cardiomyopathy in pregnancy

  • Supportive treatment including diuretics

Cardiology Pregnancy is likely to be high risk (as it is unlikely a stiff ventricle can cope well with the ↑ cardiac output of pregnancy).

Takotsubo cardiomyopathy

The rapid development of systolic dysfunction in the absence of coronary artery disease.

  • Has been reported in a wide range of individuals, some with an identifiable stressful precipitant, some without

  • Thought to account for up to 10% of young ♀ with suspected ACS

  • Imaging findings are characteristic with abnormal contraction of the mid and upper parts of the ventricle with apical sparing (likened to a Japanese fishing pot used to trap octopus, hence the name; see Fig. 2.15)

  • Most likely explanation is that this is catecholamine mediated, hence the alternative name of ‘stress cardiomyopathy’

Fig. 2.15 Left ventriculography from a 65-year-old ♀ who presented as a primary angioplasty call showing a typical apical ballooning with dynamic proximal ventricular contraction. This patient had unobstructed coronaries. On the right, a picture of a Japanese fishing pot with a narrow neck and wide base that is used to trap octopus. Reproduced from Zamorano J. L. et al. (2015) The ESC Textbook of Cardiovascular Imaging 2nd Ed. Oxford University Press: Oxford with permission from the European Society of Cardiology.

Fig. 2.15 Left ventriculography from a 65-year-old ♀ who presented as a primary angioplasty call showing a typical apical ballooning with dynamic proximal ventricular contraction. This patient had unobstructed coronaries. On the right, a picture of a Japanese fishing pot with a narrow neck and wide base that is used to trap octopus. Reproduced from Zamorano J. L. et al. (2015) The ESC Textbook of Cardiovascular Imaging 2nd Ed. Oxford University Press: Oxford with permission from the European Society of Cardiology.

Management of Takotsubo cardiomyopathy in pregnancy

  • There have been a small number of cases of this reported in pregnancy and 1 probable case developing at the time of caesarean section

  • An ↑ troponin level can occur

  • Arrhythmias can also occur

  • Recurrence can be seen in 5–10% of individuals and is not entirely prevented by β‎ blockade

Other cardiomyopathies

Arrhythmogenic right ventricular cardiomyopathy

A condition where the RV myocardium is progressively replaced by fibrofatty tissue.

  • Leading cause of sudden cardiac death in young people and athletes

  • Most common presentation is palpitations or syncope on exertion

  • Often autosomal dominant

  • Ventricular arrhythmias and ventricular dysfunction can occur and may require pathway ablation and/or an implantable defibrillator

  • ECG changes include TWI in leads V1–V3

Management of arrhythmogenic right ventricular cardiomyopathy in pregnancy

  • Anti-arrhythmic treatment may need to be ↑ during pregnancy

  • Implantable defibrillators can be placed in pregnancy if required

  • Emergency pathway ablation can also be performed if medical treatment is not sufficient to control arrhythmias

Left ventricular non-compaction

  • A rare cardiomyopathy seen both in children and adults

  • Myocardium is abnormal, with a thin epicardial layer and a non-compacted endocardial layer, with prominent trabeculations

  • Thought to result from abnormal development in the fetus

  • This is ↑ recognized as a result of improved imaging techniques, i.e. echocardiography and cardiac MRI

  • Heart failure, thromboembolism and arrhythmias can occur

Management of left ventricular non-compaction in pregnancy

  • A small number of cases in pregnancy have been reported

  • Outcome is dependent on pre-pregnancy status; if asymptomatic before with minimal complications, pregnancy is usually relatively well tolerated

  • Thromboprophylaxis should be considered but full anticoagulation is not advised for all cases

Assessment of palpitations

Most important diagnostic feature is the history.

Features that ↑ likelihood of a pathological tachyarrhythmia

  • Sudden rather than gradual onset/offset

  • Occurrence at rest rather than on exertion

  • Nature of heart rate (ask to tap out), e.g.:

    • Fast and regular

    • Fast and irregular

    • Big beat and then a pause (often reflects ectopy)

  • Associated breathlessness, syncope, or chest pain

  • No features that are more suggestive of other diagnoses, e.g.

  • nausea/vomiting and prolonged recovery are more common in vasovagal syncope than syncope due to an arrhythmia

Other important aspects of the assessment

  • Symptoms or signs of an underlying cause such as:

    • Hyperthyroidism

    • Pulmonary embolism

  • Risk factors for tachyarrhythmias:

    • Caffeine

    • Alcohol

    • Drugs

  • Family history of cardiac disease or sudden cardiac death

  • Any abnormality on cardiac examination

Investigations

  • Bloods:

    • FBC

    • TFTs

  • ECG

  • Ambulatory ECG monitoring:

    • Duration depends on the frequency of the episodes

  • Echocardiogram:

    • If underlying structural heart disease or ventricular dysfunction is suspected

Sinus tachycardia

  • Commonest cause of tachycardia in pregnancy

  • Relevant investigations include Hb and TFTs to exclude anaemia and hyperthyroidism as contributory factors

  • Sinus tachycardia in the setting of other symptoms should not be ignored and may represent other underlying pathology such as pulmonary embolism

  • An isolated, asymptomatic sinus tachycardia does not cause harm to mother or fetus so pharmacological therapy is not indicated

  • Sometimes the sinus tachycardia may be ‘inappropriate’ but even in this setting, the benefits of β‎ blockade are not clear and so conservative management and reassurance can appropriately be the mainstay of treatment

Ventricular ectopy

  • Normal frequency of ectopy is 200–500 beats/day

  • ↑ risk of LV dysfunction if:

    • Ectopy >15% or 10,000 beats/day

    • Non-outflow tract origin

    • QRS is broad on a baseline ECG

► Echocardiogram is only required if ectopy burden is significant or other suspicions of underlying structural heart disease.

► Cardiac MRI is particularly poor in the presence of a high ectopy burden so this should be treated before an MRI is undertaken.

Atrial arrhythmias

See Table 2.11.

Table 2.11 Management of atrial arrhythmias in pregnancy

Rhythm control

  • DC cardioversion if haemodynamically unstable

    • Signs of heart failure or ↓ BP

  • Pharmacological cardioversion

    • Flecainide

    • Amiodarone (used in acute setting if other agents fail, not for regular use in pregnancy as can be fetotoxic)

Rate control

  • Digoxina

  • β‎ blockadea

    (not in ♀ with history of asthma)

  • Verapamil

Anticoagulation

  • Therapeutic LMWH if high risk

  • Prophylactic LMWH if low risk

Radiofrequency catheter ablation

  • Can be a successful curative measure for atrial flutter or those arrhythmias associated with an accessory pathway

  • Usually delayed until after delivery

a Larger doses may be required in pregnancy because of ↑ metabolism and clearance.

Atrial tachycardia

  • Uncommon but occur more frequently with structural heart disease

  • Difficult to diagnose, may be wrongly labelled sinus tachycardia

  • Risk of a tachycardia-related cardiomyopathy:

    • Echocardiographic monitoring is recommended

  • Ambulatory ECG monitoring may aid diagnosis as atrial tachycardia has a different pattern throughout the day to sinus tachycardia

  • Aggressive rate control required if LV EF compromised

Atrial fibrillation/flutter

  • Uncommon in pregnancy

  • Previously thought to mostly occur in structural heart disease, but more cases now reported in absence of structural heart disease (so may reflect the changing health status of pregnant ♀ and ↑ maternal age)

  • Needs urgent treatment in conditions such as mitral stenosis, where arrhythmia development can cause a rapid deterioration in cardiac function

Diagnosis of AF or atrial flutter

  • ECG:

    • Irregular QRS complexes without a P wave before each complex (AF)

    • Organized atrial activity, reflected by regular P waves, but these are not followed each time by a QRS complex (atrial flutter)

Pre-excitation syndromes

Wolff–Parkinson–White syndrome

WPW syndrome: an accessory pathway and a resulting AV re-entrant tachycardia.

WPW abnormality: a delta wave alone, without a history of tachyarrhythmia.

  • Can cause pre-excited AF

  • If AV nodal blocking medications are given, can degenerate into ventricular fibrillation (↑ conduction through accessory pathway)

  • ECG shows a short PR interval and

    • A left-sided accessory pathway (type A WPW) with a delta wave positive in V1

    • Or

    • A right-sided accessory pathway (type B WPW) with negative delta waves in V1 and V2 and positive in V4–V6

Management of WPW syndrome in pregnancy

  • Regular review

  • If symptoms ↑, ambulatory monitoring may be beneficial to establish whether symptoms represent pathological arrhythmia prior to ↑ or altering therapy

Treatment options for WPW syndrome in pregnancy

  • DC cardioversion

  • Pharmacological including:

    • Flecainide

    • Sotalol

    • Disopyramide

    • (Amiodarone in an emergency setting only)

Lown–Ganong–Lavine syndrome

  • Another cause of pre-excitation

  • ECG shows a short PR interval and normal QRS complexes

  • Principles of management are the same as in WPW

Supraventricular tachycardia

  • Most common tachyarrhythmia in pregnancy

  • Less common than ectopy and sinus tachycardia, so empirical treatment before diagnosis confirmed is not usually advised

  • The description encompasses a variety of abnormal rhythms including:

    • Atrial tachycardia which involves the AV node (AV nodal re-entrant tachycardia; P wave is present)

    • Atrial tachycardia that does not require the AV node as are transmitted by an accessory pathway (AV re-entrant tachycardia; P wave is absent)

Treatment of an acute SVT in pregnancy

  • Vagal manoeuvres

  • Adenosine may stop the episode (normal doses can be used)

  • β‎ blockade, e.g. with oral bisoprolol or IV metoprolol

  • Verapamil can be used (oral or IV)

Prophylaxis for SVT

  • Advisable if recurrent episodes, or severe episode

  • β‎ blocker

  • Verapamil (up to 240 mg in 3–4 divided doses)

  • If difficult to treat, consideration of catheter ablation

Ventricular tachycardia

Causes

See Table 2.12.

Table 2.12 Causes of ventricular tachycardia

Structurally normal heart

Structurally abnormal heart

  • Idiopathic

  • Long QT syndrome

  • Brugada syndrome

  • Hypertrophic cardiomyopathy

  • Congenital heart disease

  • Arrhythmogenic RV cardiomyopathy

Idiopathic VT

  • Normal ECG between episodes

  • Normal echocardiogram, cardiac MRI, and stress test

Repetitive monomorphic VT

  • Can be treated with:

    • Adenosine

    • β‎ blocker

    • Verapamil

  • Ablation can be considered if medical treatment fails or the EF is ↓

High-risk features

  • Family history of sudden death

  • Syncope or haemodynamic compromise

  • Sustained or polymorphic VT

  • Heavy ectopy burden

Treatment

  • DC cardioversion

  • Pharmacological:

    • Lidocaine 1st choice agent in pregnancy

    • Amiodarone in emergency

  • If this fails, overdrive pace:

    • Temporary pacing wire at rate 10/20/30 beats > rate

    • Check for capture, then ↓ rate to normal after a few beats

  • β‎ blockade:

    • Essential if underlying structural heart disease

  • Consider an ICD:

    • Indications same as in non-pregnant population but there is a high recovery rate after delivery for those arrhythmias that develop during pregnancy

Brugada syndrome

  • Rare channelopathy, resulting from mutations in the cardiac voltage-gated Na+ channel

  • Associated with sudden cardiac death from tachyarrhythmias

  • Two typical patterns of ECG changes, mainly seen in V1/2 in association with a pseudo right bundle pattern:

    • Type 1: ST elevation (with upward convexity) and TWI

    • Type 2: ST elevation with saddle ST-T wave changes, which → a positive or biphasic T wave

  • Ajmaline challenge used to unmask Brugada syndrome

Management of Brugada syndrome in pregnancy

  • High-risk cases may require an ICD

  • Avoid medications that could be arrhythmogenic

Cardiology Advice on these medications can be found at: Cardiology https://www.brugadadrugs.org

Long QT syndrome

  • Abnormal repolarization of the myocardium manifests as an abnormally long QT interval on ECG:

    • Normal QT interval corrected for rate is <0.45–0.46 s in ♀

  • Associated with sudden death from ventricular arrhythmias

  • In ♀ with high-risk features (family history, or symptoms such as syncope) then there is no specific QT cut-off and dynamic testing should be considered

  • Causes include:

    • Congenital

    • Drugs, e.g. anti-arrhythmics, some antihistamines, and some antibiotics including macrolides

    • Cardiology For a full list see Cardiology https://www.crediblemeds.org

  • Risks from ventricular arrhythmias, in particular torsades de pointes, may be ↓ in pregnancy as a result of the ↑ heart rate (which ↓ the QT interval) but the reverse is true in the postpartum period where risk of VT is ↑

Management of long QT syndrome in pregnancy

  • β‎ blockers are advised but do not entirely protect against arrhythmia development

  • Guidelines recommend consideration of an ICD in addition to a β‎ blocker, if an individual has a pathogenic mutation and the QT is >500 ms, even if asymptomatic

  • A low-grade exercise test can be used to look at the QT dynamics if there is doubt about the phenotype

  • If either parent is positive for a long QT-associated mutation then a neonatal ECG should be performed

  • Anaesthetic considerations:

    • Avoid any medications that can prolong the QT interval

    • Avoid hypothermia

    • Do not stop β‎ blocker

  • Consider genetic testing and cord blood testing

Bradyarrhythmias

These are unusual in pregnancy, but a pacemaker can be inserted in pregnancy if required for a pathological bradycardia.

Permanent pacemakers

  • Majority of ♀ with pacemakers have them implanted before conception

  • Small number of ♀ may need pacemakers in pregnancy for pathological bradyarrhythmias (ideally inserted after 1st trimester due to radiation exposure of the procedure)

  • Pacemaker checks should occur at normal frequency

  • Adjustment of rate is not routinely required in pregnancy, however pacemaker-dependent ♀ with symptoms such as syncope or pre-syncope may benefit from an ↑ in the rate

Implantable defibrillators

  • Similar advice applies for ♀ with ICDs as in ♀ with permanent pacemakers

  • Pregnancy does not ↑ the risk of complications

Cardiology ♀ with one of these devices should be referred to an obstetric

anaesthetist and obstetrician prior to delivery to ensure magnet availability (to disable tachyarrhythmia detection if needed during a procedure where electromagnetic interference is likely, i.e. with diathermy at time of surgery).

► If a magnet is to be used, the response of the ICD/permanent pacemaker to the magnet should be tested before the procedure is started.

Cardiac transplantation

  • May be performed for peripartum cardiomyopathy, but the majority of cases are performed for other reasons unrelated to pregnancy

  • The heart is denervated, which has some important consequences:

    • ↑ resting heart rate which does not respond to exercise or hypovolaemia

    • May not experience ischaemic pain in the event of MI

    • Can contribute to ↑ BP (can be worse with calcineurin inhibitors)

  • Transplant recipients have accelerated coronary artery disease (up to 40% 3 years after transplantation) so recipients have regular angiography

  • In some transplant recipients, persistent sinoatrial node dysfunction can occur, requiring a permanent pacemaker

  • In some countries the unintended pregnancy rate is up to 50% in ♀ with cardiac transplants, emphasizing the need for early discussion about contraception and pre-pregnancy counselling

Pre-pregnancy recommendations

  • Consider the underlying reason for the transplant

  • As with other solid organ transplants it is advisable to delay conception until ♀ has been in good health for a year (i.e. not necessarily 1 year post procedure)

  • ↑ BP should be well controlled

  • No episodes of rejection in the preceding year

  • The immunosuppressive regimens for cardiac transplants use the same agents as for other solid organ transplants in pregnancy

  • ► Avoid MMF and sirolimus

Management of a ♀ with cardiac transplant in pregnancy

  • A high level of suspicion for ischaemia is required, in the absence of typical symptoms

  • Pacemaker checked regularly

  • Risks to the mother include:

    • Gestational hypertension or pre-eclampsia

    • Toxicity from immunosuppressive agents

    • Infection

  • Risks to the fetus include:

    • IUGR

    • Preterm delivery

  • It is not a contraindication to vaginal delivery

  • There are no reports of recurrence of peripartum cardiomyopathy in a transplant patient, but the numbers of subsequent pregnancies are small

Acute pericarditis

Background

  • Most common cause of pericardial disease in ♀ of childbearing age

  • Inflammation of the pericardial sac around the heart

  • Most commonly virally mediated (e.g. Coxsackie virus, echovirus, or adenovirus) or no cause is identified

  • Poor prognostic factors include:

    • Associated fever

    • Subacute onset

    • Large effusion

    • Tamponade

    • Lack of response to therapy after 1 week

Clinical features

  • Chest pain:

    • Typically central

    • May be pleuritic

    • ↑ on lying down

    • ↓ by sitting and leaning forward

  • Examination may be normal

  • Pericardial friction rub may be present but its absence does not exclude the diagnosis

Investigations

  • ECG:

    • Concave ST elevation and PR depression are the classic changes

    • Later TWI can occur, which then normalizes after several weeks

Management of acute pericarditis in pregnancy

  • NSAIDs up until 24–28 wks

  • Colchicine:

    • Commonly viewed as contraindicated in pregnancy (although no adverse pregnancy outcomes have been shown in ♀ on colchicine for familial Mediterranean fever)

  • Aspirin:

    • High doses advocated in non-pregnant individuals are higher than most feel appropriate to use in pregnancy

  • Paracetamol

  • Prednisolone:

    • Preferred treatment later in pregnancy

Diagnostic criteria for acute pericarditis

Inflammatory pericardial syndrome with at least 2 of:

  • Pericardial chest pain

  • Pericardial rub

  • New widespread ST elevation or PR depression on ECG

  • Pericardial effusion

Additional supporting findings

  • Elevation of inflammatory markers (CRP, ESR, WBC count)

  • Evidence of pericardial inflammation on imaging

Cardiology ESC 2015 pericardial diseases guidelines: Cardiology https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Pericardial-Diseases-Guidelines-on-the-Diagnosis-and-Management-of

Constrictive pericarditis

  • Results from pericardial scarring and restricts cardiac filling

  • Typical echocardiographic features include:

    • Pericardial thickening

    • Moderate biatrial enlargement

    • Abnormal ventricular septal motion in diastole with inspiration

Causes

  • Idiopathic

  • Post-cardiac surgery

  • TB

  • Connective tissue disease:

    • Rheumatoid arthritis

    • Scleroderma

  • Mediastinal irradiation

  • Other causes:

    • Neoplasia

    • Drugs, e.g. amiodarone

Management of constrictive pericarditis in pregnancy

  • Medical therapy including diuretics

  • Consideration of pericardiectomy or pericardial window depending on severity and gestation

Pericardial effusion

Hydropericardium

  • The most common pericardial abnormality in pregnancy, found in up to 40% of pregnant ♀ in the 3rd trimester

  • Usually asymptomatic and occasionally is associated with non-specific ECG changes

Haemopericardium

  • Following trauma or aortic dissection

Exudative

  • Metastatic disease

  • Acute pericarditis

Transudative

  • Heart failure

  • Nephrotic syndrome

Cardiology Cardiac tamponade may be indicated by:

  • ↑ JVP

  • Pulsus paradoxus (drop in systolic BP >10 mmHg on inspiration)

  • Kussmaul’s sign (↑ JVP with inspiration)

Infective endocarditis

An infection of the cardiac endocardium, which commonly affects the native valves but can also affect mechanical valves and other intracardiac devices.

Causative organisms

  • Staphylococcus aureus

  • Viridans streptococci

  • Streptococcus bovis

  • Community-acquired enterococcus without a 1° focus

  • HACEK organisms:

    • Haemophilus aphrophilus

    • Aggregatibacter actinomycetemcomitans

    • Cardiobacterium hominis

    • Eikenella corrodens

    • Kingella kingae

Treatment

  • Medical

  • Antibiotic treatment depending on the microorganism

  • Long duration of parenteral antibiotic therapy

  • Surgical management is undertaken for:

    • Infection not controlled with medical treatment

    • Valvular dysfunction causing cardiac failure

    • Prevention of embolic events if the vegetation is of large size

Complications

  • Uncontrolled infection

  • Heart failure from valvular dysfunction

  • Embolic events such as ischaemic stroke or transient ischaemic attack, intracranial haemorrhage, and abscess formation

  • Splenic complications such as infarcts or abscesses

  • Myocarditis

  • Conduction abnormalities

  • Acute kidney injury

  • Musculoskeletal symptoms such as arthralgia and myalgia

Management of infective endocarditis in pregnancy

  • No role for antibiotic prophylaxis at delivery

  • Rare but associated with maternal and fetal morbidity and mortality

  • Pregnancy does not alter the diagnosis or management

  • Imaging can be performed as required, with the exception of PET/CT which would usually be avoided

  • Any delivery decision is individualized, depending on the gestation, severity of infection, and the timing of any potential surgical intervention

Diagnosis of infective endocarditis

See Table 2.13 and Box 2.2.

Table 2.13 Diagnosis of infective endocarditis

Definite IE

Clinical criteria

  • 2 major criteria

    OR

  • 1 major and 3 minor criteria

    OR

  • 5 minor criteria

Pathological criteria

  • Microorganisms on culture or histological examination of vegetation, embolized vegetation, or intracardiac abscess specimen

  • Pathological lesions; vegetation or intracardiac abscess confirmed on histology to show active endocarditis

Possible IE

Clinical criteria

  • 1 major and 1 minor criterion

    OR

  • 3 minor criteria

Not IE

Clinical criteria

  • Firm alternate diagnosis

    OR

  • Resolution of symptoms suggesting IE with antibiotic therapy for ≤4 days

Pathological criteria

  • No pathological evidence of IE at surgery or postmortem, with antibiotic therapy for ≤4 days

Cardiology See ESC 2015 guidelines on infective endocarditis: Cardiology https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Infective-Endocarditis-Guidelines-on-Prevention-Diagnosis-and-Treatment-of

Cardiac arrest in pregnancy

Cardiology Immediate maternal resuscitation is vital

Airway

Open airway with head tilt and chin lift; jaw thrust may be required.

Breathing and signs of life

Look listen and feel (with or without a pulse check) for 10 secs.

Cardiology If no signs of life, not breathing or very abnormal breathing (agonal breaths), or no pulse—call for help/put out cardiac arrest call and start CPR.

Resuscitation of the pregnant ♀

Cardiology If >20 wks the uterus must be manually displaced or it will cause aortocaval compression:

  • This can be performed by cupping the abdomen in 1 or 2 hands and drawing the uterus towards the left of the mother (Fig. 2.16)

Cardiology If CPR is required at >20 wks, resuscitative caesarean must be performed if there has been >4 mins of continuous CPR (i.e. 5 mins after the arrest):

  • This is for maternal resuscitation purposes, not for fetal reasons

  • It does not require transfer to theatre or GA

  • In a cardiac arrest the blood loss is minimal

  • If resuscitation is successful, the ♀ can be transferred to theatre for anaesthesia and closure afterwards

Cardiology Additional causes to consider in pregnancy:

  • Underlying/undiagnosed cardiac disease

  • Amniotic fluid embolism

  • Toxins including high spinal block, local anaesthetic toxicity (consider treatment with Intralipid®)

►► CPR and resuscitation is otherwise as per the Resuscitation Council (UK) adult life support guidelines (Fig. 2.17).

Fig. 2.16 Diagrams demonstrating how uterine displacement relieves aortocaval compression. Reproduced from Clyburn P. et al. (2008) Obstetric Anaesthesia Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.16 Diagrams demonstrating how uterine displacement relieves aortocaval compression. Reproduced from Clyburn P. et al. (2008) Obstetric Anaesthesia Oxford University Press: Oxford with permission from Oxford University Press.

Fig. 2.17 Adult Advanced Life Support algorithm. Reproduced with the kind permission of the Resuscitation Council (UK).

Fig. 2.17 Adult Advanced Life Support algorithm. Reproduced with the kind permission of the Resuscitation Council (UK).

Amniotic fluid embolism

A rare and often fatal maternal complication. It is not predictable or preventable, and is usually rapidly progressive.

Diagnosis

  • A clinical diagnosis based on the features in Box 2.3.

  • Essentially a diagnosis of exclusion

  • ► Differential diagnosis should include:

    • Pulmonary embolism

    • Anaphylaxis

    • Sepsis

    • Eclampsia

    • MI

Cardiology Clinical diagnosis is supported by retrieval of fetal elements in pulmonary artery aspirate and maternal sputum. The diagnosis is only definitively confirmed by the presence of fetal squamous cells and debris in the pulmonary vasculature at a postmortem examination.

Cardiology Fetal squames have been found in ♀ without clinical features of amniotic fluid embolism so their presence alone is not diagnostic.

Investigations

  • Arterial blood gas

  • Electrolytes including calcium and magnesium levels

  • FBC (↑ WBC count)

  • Coagulation profile

  • CXR (pulmonary oedema)

  • ECG (ischaemia and infarction)

Management of amniotic fluid embolus

  • Rapid maternal resuscitation/CPR

  • Admission to intensive care unit with senior input from obstetrics, anaesthetics, and haematology

  • Treatment of complications:

Respiratory compromise

  • O2 to maintain saturation close to 100% (helps to prevent neurological impairment from hypoxia)

  • Pulmonary artery wedge pressure monitoring may assist in the haemodynamic management (now infrequently required):

    • Blood aspirated via the catheter can be examined to aid with the diagnosis

Circulatory compromise

  • Fluid resuscitation is imperative to counteract hypotension and haemodynamic instability

  • For refractory hypotension, direct-acting vasopressors, such as phenylephrine, are required to optimize perfusion pressure

  • Inotropic support may be needed

Coagulopathy

  • DIC should be managed with the help of a haematologist

  • Plasma exchange techniques may be helpful in clearing fibrin degradation products from the circulation.

Fetal distress

  • If not yet delivered, continuous fetal monitoring is indicated