Aims: Insufficient data exists regarding predictors of electrical storms(ES) and clinical outcome in patients treated with an implantable cardioverter defibrillator(ICD). The purpose of this study was to delineate a subgroup of patients likely to experience ES and to determine the impact of ES on mortality in ICD recipients. Methods and results: Baseline characteristics of 307 ICD-treated patients were retrospectively analysed. ES was defined as two or more ventricular tachyarrhythmias within 24 h leading to an immediate electrical therapy(antitachycardia pacing and/or shock), separated by a period of sinus rhythm. Clinical characteristics and survival of 123 patients experiencing a totalof 294 episodes of ES(median 2 ES/ patient, range 1-9), were compared with those of 184 ES-free patients during a median follow-up of 826 days(inter-quartile 1141 days). Median actuarial duration for the first ES occurrence after ICD implant was 1417 days [95% confidence interval(CI) 1061-2363] with a median follow-up of 816 days(7-4642 days) in ES-free patients. Univariate analysis identified older age, depressed left ventricular ejection fraction(LVEF), ventricular tachycardia(VT) as index arrhythmia, chronic renal failure and absence of lipid-lowering drugs as variables significantly associated with an increased risk of ES. Multivariable Cox analysis confirmed an independent predictive value for chronic renal failure [hazard ratio(HR) 1.54, 95% CI 0.95-2.51, P=0.052], VT(HR 2.20, 95% CI 1.44-3.37, P=0.0003), and LVEF(HR 0.98, 95% CI 0.97-0.99, P=0.027). In contrast, diabetics(HR 0.49, 95% CI 0.27-0.90, P=0.022) were less affected by ES. There was no difference in survival between both groups. Conclusion: ES is frequent but does not increase mortality in ICD s recipients. Patients with severe systolic dysfunction, chronic renal failure and VT as initial arrhythmia are likely to experience ES. Diabetics are less affected by ES.
展开▼
