Predictores clínicos de tormenta arrítmica en pacientes con cardiomiopatía Chagásica con un desfibrilador automático implantable / Clinical predictors of ventricular arrhythmia storms in Chagas cardiomyopathy patients with implantable defibrillators

ABSTRACT

OBJECTIVES: To define the predictive factors of electrical storm (ES) in patients with Chronic Chagas Heart Disease (CCh) with an implantable cardioverter defibrillator (ICD). MATERIAL AND METHODS: We retrospectively studied 21 consecutive patients with CCh in whom an ICD was implanted between April 2005 and December 2008, with a mean follow up of 867 days. Patients were classified into two groups according to the presence of electrical storm episodes. We compared baseline characteristics, medical treatment and determinants of ventricular function. P values less than 0.05 were considered statistically significant. RESULTS: Of the 21 patients with CCh there were eight women (37%), mean age 61 years and an EF of 30%. It was noted at least one episode of arrhythmic storm in 9 cases (incidence of 43%). The total number of episodes of arrhythmic storm was 13 and the number of ventricular arrhythmias in each episode of arrhythmic storm was 15.6 (range 3-61). A trigger was identified in only two cases (pulmonary infectious process and decompensation of chronic heart failure). After analyzing the possible predictors of arrhythmic storm was found that a greater percentage of subjects with this complication had an EF <35% (89% vs. 50%, p = 0.01) and NYHA functional class III (66% vs. 8.3%, p = 0.001). In contrast, a lower percentage of subjects with arrhythmic storm were under beta-blocker treatment (55% vs. 100%, p = 0.01). CONCLUSIONS: In subjects with CCh with an ICD, the following variables are predictive of arrhythmic storm EF <35%, NYHA functional class III-IV and absence of beta-blocker treatment.