Ultra–High Density Mapping of Ventricular Tachycardia in a Patient With Arrhythmogenic Right Ventricular Cardiomyopathy

Figures

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  Figure 1. ECG During VT and Sinus Rhythm (A) ECG during VT demonstrated a left bundle branch block pattern, consistent with an origin in the upper right ventricle. (B) ECG during sinus rhythm showed epsilon waves (low-amplitude distinct signals between the QRS complex and T-wave in precordial leads V1-V3) and negative T waves in precordial leads V1 to V4, which were major diagnostic criteria for ARVC. ARVC = arrhythmogenic right ventricular cardiomyopathy; ECG = electrocardiogram; VT = ventricular tachycardia.

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  Figure 2. Ultra–High Density Activation Mapping and Potentials Along the Re-Entrant Circuit (Left) ECG obtained upon laboratory entry. (Right) An ultra–high density activation map was acquired during VT. A counterclockwise re-entrant circuit was clearly identified at the upper aspect of the right ventricular free wall. Electrical potentials along the re-entrant circuit spanned the entire cycle length. ECG = electrocardiogram; PA = pulmonary artery; VT = ventricular tachycardia.

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  Figure 3. Results of Isochronal Late Activation Mapping and Bipolar Voltage Mapping (Upper Panels) ILAM demonstrated significantly slow conduction at the upper anterior aspect of the right ventricular free wall. (Lower Panels) Bipolar mapping showed extensive distribution of low-voltage regions and severely lesioned myocardium. AP = anteroposterior; ILAM = isochronal late activation mapping; LL = left lateral; RAO = right anterior oblique.

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  Figure 4. Results of Entrainment Mapping Concealed entrainment was observed at sites A and B, with characteristics consistent with the “exit” and “mid-isthmus” of the re-entrant circuit identified at these 2 sites, respectively. (A) PPI = 447 ms, S-QRS = 114 ms, EGM-QRS = 116 ms. (B) PPI = 474 ms, S-QRS = 162 ms, EGM-QRS = 162 ms. PPI = postpacing interval; S-QRS = stimulus-to-QRS interval; EGM-QRS = electrogram-to-QRS interval.

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  Figure 5. Postablation Activation Remapping During Sinus Rhythm Postablation activation mapping during sinus rhythm demonstrated the conduction sequence and distribution of scar regions. The right ventricular free wall was divided into 3 distinct regions that were disconnected from each other, indicating a low likelihood of subsequent macro-re-entrant arrhythmias. Nevertheless, the last map illustrated a potential peritricuspid conduction (red arrows), which necessitated additional lesions connecting the tricuspid annulus to the inferior aspect of the scar (yellow dotted line). AP = anteroposterior; LAO = left anterior oblique; RAO = right anterior oblique; RL = right lateral.