- Section 1 ICU organization and management
- Section 2 Pharmacotherapeutics
- Section 3 Resuscitation
- Section 4 The respiratory system
- Section 5 The cardiovascular system
- Part 5.1 Physiology
- Part 5.2 Cardiovascular monitoring
- Part 5.3 Acute chest pain and coronary syndromes
- Part 5.4 Aortic dissection
- Part 5.5 The hypotensive patient
- Part 5.6 Cardiac failure
- Part 5.7 Tachyarrhythmias
- Part 5.8 Bradyarrhythmias
- Part 5.9 Valvular problems
- Part 5.10 Endocarditis
- Part 5.11 Severe hypertension
- Part 5.12 Severe capillary leak
- Part 5.13 Pericardial tamponade
- Part 5.14 Pulmonary hypertension
- Part 5.15 Pulmonary embolus
- Section 6 The gastrointestinal system
- Section 7 Nutrition
- Section 8 The renal system
- Section 9 The neurological system
- Section 10 The metabolic and endocrine systems
- Section 11 The haematological system
- Section 12 The skin and connective tissue
- Section 13 Infection
- Section 14 Inflammation
- Section 15 Poisoning
- Section 16 Trauma
- Section 17 Physical disorders
- Section 18 Pain and sedation
- Section 19 General surgical and obstetric intensive care
- Section 20 Specialized intensive care
- Section 21 Recovery from critical illness
- Section 22 End-of-life care
(p. 593) The cardiovascular system
Preload modulates contractile performance, and is determined by end-diastolic volume (EDV) and ventricular compliance. Compliance falls with increasing preload, muscle stiffness or ventricular hypertrophy, making central venous pressure (CVP) a poor surrogate for EDV. Responsiveness to fluid loading can be identified by seeking a change in stroke volume (SV) with changes in cardiac loading. Afterload, the force to be overcome before cardiac muscle can shorten to eject blood, rises with transmural pressure and end-diastolic radius, and inversely with wall thickness. Afterload, being the tension across the ventricular wall, is influenced by pleural pressure. Reductions in afterload increase SV for any cardiac work, as do reductions in vascular resistance. Resistance is modified by changes in arteriolar cross-sectional area. A rise in resistance increases blood pressure and microvascular flow velocity. Increased resistance may reduce CO if cardiac work cannot be augmented sufficiently. Flow autoregulationis the ability of vascular beds to maintain constant flow across varied pressures by adjusting local resistance.
Access to the complete content on Oxford Medicine Online requires a subscription or purchase. Public users are able to search the site and view the abstracts for each book and chapter without a subscription.
Please subscribe or login to access full text content.
If you have purchased a print title that contains an access token, please see the token for information about how to register your code.
For questions on access or troubleshooting, please check our FAQs, and if you can't find the answer there, please contact us.
- Section 1 ICU organization and management
- Section 2 Pharmacotherapeutics
- Section 3 Resuscitation
- Section 4 The respiratory system
- Section 5 The cardiovascular system
- Part 5.1 Physiology
- Part 5.2 Cardiovascular monitoring
- Part 5.3 Acute chest pain and coronary syndromes
- Part 5.4 Aortic dissection
- Part 5.5 The hypotensive patient
- Part 5.6 Cardiac failure
- Part 5.7 Tachyarrhythmias
- Part 5.8 Bradyarrhythmias
- Part 5.9 Valvular problems
- Part 5.10 Endocarditis
- Part 5.11 Severe hypertension
- Part 5.12 Severe capillary leak
- Part 5.13 Pericardial tamponade
- Part 5.14 Pulmonary hypertension
- Part 5.15 Pulmonary embolus
- Section 6 The gastrointestinal system
- Section 7 Nutrition
- Section 8 The renal system
- Section 9 The neurological system
- Section 10 The metabolic and endocrine systems
- Section 11 The haematological system
- Section 12 The skin and connective tissue
- Section 13 Infection
- Section 14 Inflammation
- Section 15 Poisoning
- Section 16 Trauma
- Section 17 Physical disorders
- Section 18 Pain and sedation
- Section 19 General surgical and obstetric intensive care
- Section 20 Specialized intensive care
- Section 21 Recovery from critical illness
- Section 22 End-of-life care