Trigger and Substrate Mapping and Ablation for Ventricular Fibrillation in the Structurally Normal Heart

Figures

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  Figure 1. Short-coupled VF (Mellor 2016 [34], reproduced with permission). (A) Dual-chamber ICD electrogram demonstrating multiple short-coupled PVCs eventually triggering VF. (B) 12-lead surface ECG and intracardiac recordings from an ablation catheter positioned at the site of earliest activation. Following each sinus beat, there is a discrete local potential seen on the proximal pole of the ablation catheter representing localized depolarization in the distal Purkinje system which occasionally captures the surrounding tissue resulting in a PVC.

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  Figure 2. Biventricular VF Analysis with rotors (Krummen 2014 [47], reproduced with permission). (A) Isochronal analysis of the RV and LV during VF. LV isochrones show a rotor (cycle length 220 ms) in the septal LV. This rotor persisted for 15 continuous rotations (depicted ~5 s into VF); rotor activity was seen in 82% of all VF cycles in this patient. (B) Basket electrograms during VF, numbered (1 to 6) near the rotor core. Note that activation spans >80% of the VF cycle length. (C) Wave front vector analysis of the subsequent VF cycle, showing consistent rotation about the core with radial activation of distant tissue.

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  Figure 3. 3D anatomical mapping in BrS. (Nademanee 2017 [62], reproduced with permission). The CARTO-Merge map shows a left anterior oblique view of the cardiac CT scan that is merged with the electro-anatomic maps of the right ventricular outflow tract epicardium of a patient with BrS with frequent ICD discharges. The arrow shows abnormal prolonged low-voltage fractionated electrograms recorded from the site of the ventricular outflow tract epicardium. Abl-d, bipolar ablation distal; Abl-p, bipolar ablation proximal; Abl-d-Uni, unipolar ablation distal.

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  Figure 4. (a). Decapolar mapping catheter and ablation catheter via an endocardial approach. (b). Multipolar mapping catheter and ablation catheter via an epicardial approach. (c). Simplified step-wise approach to individuals with ventricular fibrillation and a structurally normal heart. (d). Success rates of VF ablation in different diagnostic categories. VF = ventricular fibrillation. ICD = implantable cardioverter defibrillator. EPS = electrophysiology study. BrS = Brugada Syndrome. ERS = early repolarization syndrome. IVF = idiopathic ventricular fibrillation. SCVF = short-coupled ventricular fibrillation. VA = ventricular arrhythmia.