Successful termination of ventricular tachycardia by an extravascular implantable cardioverter-defibrillator in a young patient with arrhythmogenic right ventricular cardiomyopathy

Figures

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  Figure 1. 12-lead electrocardiogram of the patient at rest. T-wave inversions in V1–V3 and epsilon wave in V1 are evident.

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  Figure 2. Chest radiograph after extravascular implantable cardioverter-defibrillator implantation. A: Anterior-posterior view. B: Lateral view. The subcutaneous battery is positioned at the left midaxillary line, and the substernal lead with defibrillation coils (arrows) and ring electrodes (arrowheads) is clearly visible.

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  Figure 3. EGM demonstrating T-wave oversensing after the ninth ventricular sensed (VS) signal (∗), annotated as TF (interval in the ventricular fibrillation zone). The PQ interval is marked throughout the channel “coil2 to can” by horizontal blue lines, showing a regular PQ interval preceding each QRS and ruling out P-wave oversensing as the cause for tachycardia detection. Perpendicular lines in green color delineate QRS complexes of the regular heart rhythm, whereas perpendicular dashed lines in red color identify oversensed T waves. Calculating the time between green lines gives cycle lengths of 540–560 ms (111–107 beats/min), being congruent to the cycle length of the preceding correctly identified VS tracings. Interposing oversensing of T waves “increases” the heart rate to 214–230 beats/min (cycle lengths 260–280 ms), thus triggering detection in the ventricular fibrillation zone (“TF”). EGM = electrogram.

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  Figure 4. A: Repeated nonsustained ventricular tachycardia (VT) episodes (arrows) after alcohol intake, indicating heightened sympathetic tone. B: Successful termination of VT by antitachycardia pacing (box). C: Successful termination of ventricular fibrillation by a 41.9 J shock (arrow).