Catheter ablation of short-coupled variant of torsade de pointes

Figures

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  Fig. 1. 12-lead ECG PVC trigger morphology among five patients with sc-TdP demonstrating a left superior frontal axis (R in I and aVL with SIII > SII), late (> V4) precordial transition and a coupling interval < 300 ms. The QRS is relatively narrow (≤ 130 ms.) with fast intrinsicoid deflection (< 60 ms.) indicating an origin within or close to the Purkinje network (paper speed 25 mm/sec)

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  Fig. 2. a12-lead ECG of sc-TdP in patient #2 who initially experienced arrhythmic syncope. b Recurrent sc-TdP in patient #2 which eventually degenerated into VF. Ajmaline bolus (black arrow) was given which led to VF termination and suppression of short-coupled PVCs. Ajmaline infusion (0.8 mg/kg body weight/min) was continued until the next morning when frequent ectopy returned during EP study. Ajmaline can have pro-arrhythmic and fatal consequences when given to patients with Brugada syndrome (BrS) or malignant Purkinje ectopy [27] who may also present with an electrical storm. It is, therefore, essential to recognize the pathognomonic PVC trigger morphology of sc-TdP (late transition, left superior axis with coupling interval < 300 ms). In contrast, VF triggers in BrS show an inferior axis with a longer coupling interval (> 300 ms) [28]

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  Fig. 3. High-resolution 3D activation maps of the culprit PVC in three patients demonstrating earliest activation at the free wall insertion of the MB. a The electrode pair (17,18) records a Purkinje potential fused with local activation during sinus rhythm that is separated from local activation and precedes the QRS onset with a unipolar QS pattern by 20 ms. during short-coupled PVC. The course of the MB—spanning from septum to lateral free wall—can be appreciated by the impressions in the electroanatomic shell of the RV. b Induction of short-coupled PVCs by atrial overdrive pacing. To locate the MB without ICE the earliest activation of the right ventricular free wall in sinus rhythm (right, brown tag) was mapped matching the earliest activation during short-coupled PVC (brown tag in the left picture), confirming the PVC origin to be at the free wall insertion of the MB. After focal ablation at this site short-coupled PVCs were no longer inducible by atrial pacing. c Assuming a RV MB site of origin the MB geometry was created on the electroanatomic mapping system and confirmed by ICE. The earliest activation of the short-coupled PVC was mapped to the free wall insertion of the RV MB,…