Advanced interatrial block independently predicts appropriate and inappropriate ICD therapies in hypertrophic cardiomyopathy
摘要
Implantable cardioverter-defibrillators (ICDs) reduce the risk of sudden cardiac death in hypertrophic cardiomyopathy (HCM); however, both appropriate and inappropriate shocks carry important clinical implications. Advanced interatrial block (IAB) is an electrocardiographic marker of atrial conduction disease, but its prognostic impact on ICD shocks in HCM remains unclear.
MethodsWe retrospectively analyzed consecutive patients with HCM who underwent ICD implantation between 2014 and 2024. Advanced IAB was defined as a P-wave duration of ≥ 120 ms with biphasic morphology in the inferior leads. Appropriate ICD shocks were delivered for sustained ventricular tachycardia or ventricular fibrillation, whereas inappropriate shocks resulted from supraventricular arrhythmias or device-related causes. Time to first ICD shock was assessed using Kaplan–Meier analysis and multivariable Cox proportional hazards regression.
ResultsA total of 184 patients were included (median follow-up: 68.5 months). Patients with advanced IAB exhibited significantly lower shock-free survival for both appropriate and inappropriate ICD shocks. Advanced IAB independently predicted appropriate ICD shocks (hazard ratio [HR]: 6.03, 95% confidence interval [CI]: 2.68–13.57; p < 0.001), together with non-sustained ventricular tachycardia (HR: 7.98; p < 0.001). Advanced IAB was also an independent predictor of inappropriate ICD shocks (HR: 3.50, 95% CI: 1.78–6.86; p < 0.001), along with left atrial diameter, atrial fibrillation, and age.
ConclusionAdvanced interatrial block is independently associated with an increased risk of both appropriate and inappropriate ICD shocks in patients with HCM. This simple ECG marker may enhance risk stratification and help optimize ICD follow-up and programming strategies.