Electrical Storm in Chagas Cardiomyopathy: Clinical Predictors, Outcome, and Arrhythmic Characteristics in a Prospective Registry.

Objectives: This study of patients with Chagas heart disease (CHD) with an implantable cardioverter-defibrillator (ICD) for secondary prevention of sudden cardiac death sought to compare the characteristics of those with or without electrical storm (ES) during long-term follow-up.

Background: ES is a common problem in patients with CHD harboring an ICD, but data on clinical predictors and outcomes are limited.

Methods: The authors retrospectively evaluated 110 patients with CHD with a mean follow-up of 1,949 ± 1,271 days. Demographic, clinical, arrhythmia characteristics, ICD treatment, and death data were collected. Descriptive statistics included mean ± SD and Fisher exact tests used for comparisons. A p value <0.05 was considered significant.

Results: The ES group (n = 57; 43 men; age 62 ± 10 years) and the non-ES group (n = 53; 43 men; age 57 ± 14 years) had similar baseline demographic and clinical parameters, but left ventricular ejection fraction was higher in the ES group (44 ± 14% vs. 37 ± 14%; p = 0.02) and QRS duration was shorter (109 ± 35 ms vs. 134 ± 36 ms; p = 0.0027). Mortality rates were comparable in the 2 groups (odds ratio: 1.2; 95% confidence interval: 0.79 to 1.85; p = 0.44). The ES group presented 116 ES (2.03 ±1.47, 1 to 6). A total of 2,953 (61%) arrhythmic events required ICD therapy. No deaths occurred directly caused by ES, but clinical triggers were reported in 20 patients.

Conclusions: ES is frequent in CHD but in itself does not carry a worse prognosis in this study population and was not associated with a more depressed left ventricular systolic function or a longer QRS.