Electrical storms in patients with an implantable cardioverter defibrillator

• Published in: Yonsei medical journal Vol. 52; no. 1; pp. 26 - 32
• Main Authors: Song, Pil Sang, Kim, June Soo, Shin, Dae-Hee, Park, Jung Wae, Bae, Ki In, Lee, Chang Hee, Jung, Dong Chae, Ryu, Dong Ryeol, On, Young Keun
• Format: Journal Article
• Language: English
• Published: Korea (South) Yonsei University College of Medicine 01.01.2011; 연세대학교의과대학
• Subjects: Adult; Aged; Defibrillators, Implantable - adverse effects; Female; Humans; Male; Middle Aged; Original; Tachycardia, Ventricular - diagnosis; Tachycardia, Ventricular - etiology; Ventricular Fibrillation - diagnosis; Ventricular Fibrillation - etiology; 의학일반
• ISSN: 0513-5796; 1976-2437
• DOI: 10.3349/ymj.2011.52.1.26

In some patients with an implantable cardioverter defibrillator (ICD), multiple episodes of electrical storm (ES) can occur. We assessed the prevalence, features, and predictors of ES in patients with ICD. Eighty-five patients with an ICD were analyzed. ES was defined as the occurrence of two or more ventricular tachyarrhythmias within 24 hours. Twenty-six patients experienced at least one ES episode, and 16 patients experienced two or more ES episodes. The first ES occurred 209 ± 277 days after ICD implantation. In most ES cases, the index arrhythmia was ventricular tachycardia (65%). There were no obvious etiologic factors at the onset of most ES episodes (57%). More patients with a structurally normal heart (p = 0.043) or ventricular fibrillation (VF) as the index arrhythmia (p = 0.017) were in the ES-free group. Kaplan-Meier estimates and a log-rank test showed that patients with nonischemic dilated cardiomyopathy (DCMP) (log-rank test, p = 0.016) or with left ventricular ejection fraction < 35% (p = 0.032) were more likely to experience ES, and that patients with VF (p = 0.047) were less affected by ES. Cox proportional hazard regression analysis showed that nonischemic DCMP correlated with a greater probability of ES (hazard ratio, 3.71; 95% confidence interval, 1.16-11.85; p = 0.027). ES is a common and recurrent event in patients with an ICD. Nonischemic DCMP is an independent predictor of ES. Patients with VF or with a structurally normal heart are less likely to experience ES.