- 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. 154) Mapping the accessory pathway
- (p. 154) Mapping the accessory pathway
, Mattias Duytschaever
, and Haran Burri
Introduction to the case
The patient, a woman aged 59, was admitted for ablation of circus movement tachycardia over a left anterolateral accessory pathway. A mapping and ablation catheter (Figure 39.1) is introduced into the left atrium via a trans-septal sheath and positioned at two positions, 2mm apart, alongside the mitral annulus during ventricular pacing (Figure 39.2) from a para-Hisian position.
(p. 155) Question
A mapping and ablation catheter is introduced into the left atrium via a trans-septal sheath and positioned alongside the mitral annulus during ventricular pacing from a para-Hisian position. At which position would you ablate?
Electrograms during accessory pathway ablation
The timing of the earliest atrial activation on the ablation bipole (Map d) is similar in both panels. The atrial electrograms are smaller than the ventricular electrograms, as is desired for ablation. In the left panel, there is a clear polarity reversal of the atrial electrograms, being initially positive in the proximal mapping bipole and negative in the distal bipole. This indicates that the insertion of the accessory pathway is located in the middle between both bipoles. Delivering energy from the 4mm ablation tip would be too inferior in relation to the insertion and hence would fail to ablate the accessory pathway. At the right side, the catheter tip has been withdrawn a few millimetres more towards the anterior mitral annulus. The timing of the earliest atrial activation is the same, but there is now a small initial positive deflection on the distal ablation bipole. Therefore, the ablation tip now resides over the atrial insertion of the accessory pathway itself. Such finely titrated ablation position will usually lead to a block of the accessory pathway conduction within a few seconds after initiation of energy delivery.
Figure 39.4 helps to explain further.