Is the coexistence of sustained ST-segment elevation and abnormal Q waves a risk factor for electrical storm in implanted cardioverter defibrillator patients with structural heart diseases?

AIM: The aim of this study was to determine whether or not the coexistence of sustained ST-segment elevation and abnormal Q waves (STe-Q) could be a risk factor for electrical storm (ES) in implanted cardioverter defibrillator (ICD) patients with structural heart diseases.

METHODS AND RESULTS: In all, 156 consecutive patients received ICD therapy for secondary prevention of sudden cardiac death and/or sustained ventricular tachyarrhythmias were included. Electrical storm was defined as ≥3 separate episodes of ventricular tachycardia (VT) and/or ventricular fibrillation (VF) terminated by ICD therapies within 24 h. During a mean follow-up of 1825 ± 1188 days, 42 (26.9%) patients experienced ES, of whom 12 had coronary artery disease, 15 had idiopathic dilated cardiomyopathy, 6 had hypertrophic cardiomyopathy, 4 had arrhythmogenic right ventricular cardiomyopathy, 4 had cardiac sarcoidosis, and 1 had valvular heart disease. Sustained ST-segment elevation and abnormal Q waves in ≥2 leads on the 12-lead electrocardiography was observed in 33 (21%) patients. On the Kaplan-Meier analysis, patients with STe-Q had a markedly higher risk of ES than those without STe-Q (P< 0.0001). The multivariate Cox proportional hazards regression model indicated that STe-Q and left ventricular ejection fraction (LVEF) (<30%) were independent risk factors associated with the recurrence of VT/VF (STe-Q: HR 1.962, 95% CI 1.24-3.12, P= 0.004; LVEF: HR 1.860, 95% CI 1.20-2.89, P= 0.006), and STe-Q was an independent risk factor associated with ES (HR 4.955, 95% CI 2.69-9.13, P< 0.0001).

CONCLUSION: Sustained ST-segment elevation and abnormal Q waves could be a risk factor of not only recurrent VT/VF but also ES in patients with structural heart diseases.