- 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. 302) Slow-fast AVNRT
- (p. 302) Slow-fast AVNRT
, Mattias Duytschaever
, and Haran Burri
Introduction to the case
Case 76 shows a 20-year-old woman with palpitations. Transition from a 2:1 narrow complex tachycardia to a 1:1 wide complex tachycardia is shown in Figure 76.1.
(p. 303) Question
Slow/fast atrioventricular nodal re-entrant tachycardia and infra-Hisian block
Figure 76.1 (left): 2:1 tachycardia compatible with AVNRT or AT (cycle length of 286ms). Orthodromic AVRT and VT are excluded. There is 2:1 infra-Hisian AV block. A His bundle potential is recorded in the blocked complexes.
Figure 76.1 (middle): a spontaneous premature ventricular beat from the RV with early precocity advances His and atrial activation. Advancement of atrial activation by a PVC occurs in AVRT, but also in cases of early precocity in AVNRT and AT. The PVC unmasks the atrium at the His bundle electrogram (after the retrograde H deflection). The earliest A at the His bundle electrogram (anterior septum) suggests slow/fast AVNRT. In slow/fast AVNRT, 2:1 AV block is due to infra-Hisian block (absence of LCP) and maintained by long refractoriness at the proximal His–Purkinje system (prolonged refractoriness is explained by the 2-fold longer cycle length just distal from the site block).
Figure 76.1 (right): the PVC results in early retrograde activation of the His bundle. Together with delayed conduction over the slow pathway, this lengthens the H–H interval, enabling resumption of 1:1 AV conduction. Because of a prolonged A–H interval over the slow pathway, the cycle length is prolonged during the next AVNRT beats (cycle length of 298ms). This facilitates 1:1 infra-Hisian AV conduction (longer H–H interval), now with block in the right bundle (whereas before there was block in both bundles).
After ablation of the slow pathway, the tachycardia was rendered non-inducible. (p. 305)