Atrial pacing successfully suppressed drug-resistant ventricular fibrillation in a patient with early repolarization syndrome

Figures

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  Figure 1. A: Electrocardiogram (ECG) at baseline (first hospitalization) without antiarrhythmic drug use. Distinct J waves were observed at inferior and lateral leads, with an average amplitude of 0.36 ± 0.09 mV. B: ECG at the time of hospital admission for transvenous implantable cardioverter-defibrillator battery exchange (second hospitalization) under quinidine 600 mg/day. The average amplitude of the J waves at inferior and lateral leads was 0.17 ± 0.05 mV, significantly lower than the baseline (P = .002). C: Intracardiac ECG of ventricular fibrillation (VF) preceded by sinus bradycardia on day 2 after battery exchange. The R-R interval just before the onset of VF was 1172 ms.

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  Figure 2. A: Treatment chart during the entire period, including first and second hospitalizations. B: Treatment chart during second hospitalization. Blue arrows indicate ventricular fibrillation attacks with spontaneous termination and red arrows indicate those with implantable cardioverter-defibrillator shocks. AF = atrial fibrillation; ICD = implantable cardioverter-defibrillator; VF = ventricular fibrillation.

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  Figure 3. A: Changes of electrocardiograms at inferior and lateral leads at various heart rates. The J-wave amplitudes were markedly decreased by high-rate atrial pacing. B: Plots of the J-wave amplitudes at the inferior and lateral leads at various heart rates. The amplitudes of the J waves decreased according to heart rates, almost reaching a plateau at 75 beats/min. Abbreviations as in Figure 1.