OBJECTIVE: It is controversial the correlation between complex ventricular arrhythmia of hypertrophic cardiomyopathy and cardiac sudden death (CSD). In patients with hypertrophic cardiomyopathy and at risk for CSD that have been undergone implantable cardioverter-defibrillator (ICD) implantation, we evaluated: a- occurrence of arrhythmic events; b- clinical event occurrence and its correlation with arrhythmic events; c- ICD shock therapy occurrence and clinical-functional correlation; d- prognosis clinical-functional predictors. METHODS: Twenty-six patients have been studied. They presented hypertrophic cardiomyopathy and risk factors for CSD. These patients underwent ICD implantation, period May, 2000 through January, 2004 (average follow-up - 19 months). Fourteen patients (53.8%) were female and the mean age was 42.7. Sixteen patients (61.5%) ICD was performed due to primary prevention for sudden death and ten (38.5%) secondary prevention. Twenty patients (76.9%) had had syncope, previus to ICD implantation, half of them associated with ventricular fibrillation or sustained ventricular tachycardia; 15 had had family sudden death; 12 patients (46.2%) presented non-sustained ventricular tachycardia at 24-hour Holter and 5 (19.2%) showed the ventricular septum thickness larger than 30 mm. RESULTS: During the follow-up, 4 shocks therapy were recorded by ICD in potentially lethal arrythmias (3 sustained ventricular tachycardia and 1 ventricular fibrillation). There was one death, due to likely stroke. Four patients had syncope recurrence, with no arrhythmic event recorded by ICD. The statistical analysis has showed precocity significance of ICD shock, in patients whose ventricular septum thickness was larger than 30 mm. CONCLUSION: 1- arrhythmic events have occurred in 50% of the patients. Most of those events (62%) were ventricular tachycardia, 31% sustained tachycardia and 31% non-sustained ventricular tachycardia. The remainders had supraventricular tachycardia. 2- recurrent syncope in only 16% of the patients. Nevertheless, they were not related to the presence of arrhythmic events. 3- the presence of ventricular septum larger than 30mm, at Echocardiogram, was associated with early shock therapy occurence (p = 0.003). 4- absence of clinical or functional predictors.
Hypertrophic cardiomyopathy; arrhythmia; implantable cardioverter-defibrillator; risk factors; sudden cardiac death
