Inappropriate defibrillator shock due to fragmented potentials derived from an extensively diseased right ventricle in a patient with arrhythmogenic right ventricular cardiomyopathy

Figures

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  Figure 1. A: Chest radiograph (posterior-anterior [PA] view) after the implantable cardioverter-defibrillator (ICD) implantation. The right ventricle (RV) lead was positioned on the high RV septum (red arrow) because of the extensive low-voltage area at the apex and inferior wall. B: Chest radiograph (left-right [LR] view) after the ICD implantation. C: A voltage map of the RV (inferior view). An extensive low-voltage area (<1.5 mV: gray zone) was observed on the RV inferior wall and apex. D: A voltage map of the RV (superior view). An extensive low-voltage area (<1.5 mV: gray zone) was observed on the RV apex and RV outflow tract (RVOT). Inf = inferior; RV sept = right ventricle septum.

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  Figure 2. In the wavelet analysis, the QRS morphology match rate between the tachycardia and sinus rhythm was 0/8 (0%), all “unmatched,” and the therapy was conducted. RV = right ventricle.

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  Figure 3. After the inappropriate shock episode, we updated the template of the wavelet analysis. However, the match rate between the updated sinus rhythm template and sinus rhythm at present were relatively low (58%–76%) even immediately after the sinus rhythm template update owing to the abnormal QRS waveform (red arrows). A ring = the ring of atrial lead; RV = right ventricle.