Desfibrilador automático implantado en pacientes con miocardiopatía hipertrófica: criterios de selección, evolución y predictores de terapia apropiada / Automatic defibrillator implanted in patients with hypertrophic myocardiopathy: selection criteria, evolution and appropriate therapy predictors

RESUMEN

Introducción y objetivos: la miocardiopatía hipertrófica es una enfermedad de origen genético con prevalencia de 1 porciento al 2 porciento. La mitad de los pacientes fallecen por muerte súbita cardiaca, la mayoría por arritmias ventriculares. Todavía no está claro a qué pacientes se les debe implantar un desfibrilador automático. El objetivo de este trabajo es describir una serie de pacientes con implante, los criterios empleados y los resultados obtenidos, así como analizar los predictores de terapia apropiada por el desfibrilador.Métodos: se incluyeron 20 pacientes que recibieron un desfibrilador de tercera generación. En todos se realizó estudio electrofisiológico y seguimiento prospectivo con registro de eventos. En 18 (90 porciento) se hizo estudio genético.

ABSTRACT

Introduction and objectives: hypertrophic myocardiopathy is a genetic entity with 1% to 2% prevalence. Half patients die of sudden cardiac death, most due to ventricular arrhythmias. There is still no clarity with regard to the patients to whom an automatic defibrillator has to be implanted. The objective of this work is to describe a series of patients with implant, the criteria used and the results obtained, as well as to analyze the predictors of appropriate therapy with the defibrillator. Methods: 20 patients that received a third generation defibrillator were included. Electrophysiological study and prospective follow-up with register of events was performed in all. Genetic study was done in 18 (90%). Results: 55% were men with mean age 40 (11-78) years. Six (30%) received implant for secondary prevention and 14 (70%) for primary prevention; the last ones because of several risk factors. A sustained arrhythmia was induced in 15 (75%) and in 3 (15%) monomorphic sustained ventricular tachycardia. At 22 months of follow-up, 4 (20%) underwent appropriate therapy and 2 (10%) died. Clinical monomorphic ventricular tachycardia (p=0.03) and the induced one (p<0.01) were significant therapy predictors. In 10 (56%) a mutation was identified; in 8 (44%) in the b-myosin gene. Conclusions: monomorphic sustained clinical ventricular tachycardia and the induced one were predictors of the appropriate defibrillator therapy in this series. The stratification based on the risk factors addition is actually a good option for primary prevention. Mutations in the heavy b-myosin chain are also the most frequent in our population.