- Case 1 A special case of orthodromic AVRT
- Case 2 AV conduction during pacing
- Case 3 Narrow versus wide QRS
- Case 4 Infra-Hissian complete AV block
- Case 5 Para-Hisian pacing/1
- Case 6 Para-Hisian pacing/2
- Case 7 Para-Hisian pacing/3
- Case 8 Overdrive pacing during SVT/1
- Case 9 Unipolar electrogram morphology
- Case 10 RV pacing during orthodromic AVRT
- Case 11 VBP during orthodromic AVRT
- Case 12 A single VPB during SVT/1
- Case 13 Which wide complex tachycardia?
- Case 14 The wonderful effects of adenosine
- Case 15 Lower common pathway/1
- Case 16 Lower common pathway/2
- Case 17 Atrial tachycardia
- Case 18 Bipolar electrogram morphology
- Case 19 Cavo-tricuspied isthmus block?
- Case 20 Entry block during atrial fibrillation
- Case 21 A Mahaim case
- Case 22 Pacing during IART/1
- Case 23 Pacing the PV after isolation/1
- Case 24 Activation recovery interval
- Case 25 Double fire tachycardia
- Case 26 A single VPB during SVT/2
- Case 27 Sinus rhythm and something
- Case 28 Overdrive pacing during SVT/2
- Case 29 Slow pathway ablation
- Case 30 Is the slow pathway ablated?
- Case 31 Which narrow QRS tachycardia?
- Case 32 Block over a linear ablation line?
- Case 33 Pacing the PV after isolation/2
- Case 34 LAA or LSPV?
- Case 35 A right-sided bypass tract
- Case 36 Orthodromic AVRT
- Case 37 Peri-mitral flutter, or is it?
- Case 38 A single VPB during SVT/3
- Case 39 Mapping the accessory pathway
- Case 40 A ventricular bump during SVT
- Case 41 Atrial tachycardia
- Case 42 PV isolation
- Case 43 RSPV potentials
- Case 44 An interrupted inferior vena cava
- Case 45 Ventricular pacing during SVT
- Case 46 From narrow to wide QRS tachycardia
- Case 47 Where are we within the VT circuit?
- Case 48 Pacing manoeuvre during VT
- Case 49 Mapping the infarct scar
- Case 50 Fractionated electrograms
- Case 51 On the origin of VT
- Case 52 Fascicular VT
- Case 53 An APC during wide-QRS tachycardia
- Case 54 Entraining VT
- Case 55 VT mapping from the coronary sinus
- Case 56 Looking at preexcitation
- Case 57 Where do these VPBs come from?
- Case 58 Looking closely at VPB
- Case 59 Enterpreting entrainment during VT
- Case 60 VT with alternating cycle length
- Case 61 Dormant conduction
- Case 62 2:1 block during SVT
- Case 63 Slow pathway ablation
- Case 64 Entrainment pacing during SVT
- Case 65 Pacing during IART/2
- Case 66 Ablation-resistant PVCs
- Case 67 SVT induction
- Case 68 Residual conduction
- Case 69 Dissociated atrial fibrillation
- Case 70 Catheter bumps can teach
- Case 71 AVNRT subforms
- Case 72 Late far-field in the LAA
- Case 73 Post-MI VT
- Case 74 PV exit block testing
- Case 75 Bundle branch reentrant VT
- Case 76 Slow-fast AVNRT
(p. 94) Activation recovery interval
- (p. 94) Activation recovery interval
, Mattias Duytschaever
, and Haran Burri
Introduction to the case
Dispersion of the action potential duration (APD) is considered to be a parameter for arrhythmogenicity. Detection of the action potential requires intracellular recordings, which are not feasible in the clinical setting. As a substitute for the APD, the activation recovery interval (ARI) is used (Figure 24.1), which can be derived from unipolar recordings as the interval from the depolarization to the repolarization. Although the depolarization can be determined easily in a unipolar recording, the point of repolarization is less clear.
(p. 95) Question
Which interval in the electrograms marks the ARI?
A The interval from the white to the green dot
B The interval from the white to the red dot
C The interval from the white to the blue dot
D The interval from the white to the red dot for the left tracing and the interval from the white to the green dot for the right tracing.
Activation recovery interval
In a unipolar electrogram, the activation time is the point of the steepest negative deflection in the depolarizing phase of the signal (the white dot in the signals). Simultaneous intra- and extracellular recordings have shown that the repolarization corresponds to the point of the steepest positive deflection in the repolarizing phase of the unipolar electrogram.1 It does not matter whether the configuration of the repolarization wave is only positive (right tracing), negative (left tracing), or biphasic; the time of repolarization always corresponds with the point of the steepest upstroke.2,3 In this case, the repolarization (T-wave) is flat, and the point of repolarization cannot be determined.
1. Coronel R, de Bakker JM, Wilms-Schopman FJ, et al. Monophasic action potentials and activation recovery intervals as measures of ventricular action potential duration: experimental evidence to resolve some controversies. Heart Rhythm 2006; 3: 1043–50.Find this resource:
2. Gepstein L, Hayam G, Ben Haim SA. Activation-repolarization coupling in the normal swine myocardium. Circulation 1997; 96: 4036–43.Find this resource:
3. Haws CW, Lux RL. Correlation between in vivo transmembrane action potential duration and activation-recovery intervals from electrograms. Effects of interventions that alter repolarization time. Circulation 1990; 81: 281–8. (p. 97) Find this resource: