Abstract
BACKGROUND: Sustained His-Purkinje system-related ventricular tachycardia (HPS-VT) after left bundle branch area pacing (LBBAP) has not to our knowledge been previously reported. CASE SUMMARY: A 65-year-old woman presented 1 month after dual-chamber LBBAP with hypotension and recurrent palpitations. Electrocardiogram showed 2 bundle branch block-like VT morphologies; device interrogation demonstrated ventriculoatrial dissociation, consistent with HPS-VT. Intracardiac echocardiography localized the left bundle branch pacing lead to the anterior left ventricular septum. Targeted septal ablation terminated VT, but early recurrence required a second ablation, resulting in complete atrioventricular block; pacing was revised to the right ventricular septum. VT had not recurred at the 1-month follow-up. DISCUSSION: This case illustrates that HPS-VT can complicate LBBAP. Lead-related conduction system stimulation or injury may provide the arrhythmic substrate. Diagnosis and management are challenging, requiring mechanistic understanding to guide therapy. TAKE-HOME MESSAGE: Sustained HPS-VT may occur after LBBAP; careful electrophysiologic assessment and accurate diagnosis are essential to minimize conduction system injury.