RESUMEN
Cardiac resynchronization therapy [CRT] is an effective treatment for patients with moderate to severe heart failure. However, 20-30% of patients remain non-responders to CRT. We sought to identify which patients benefit the most from CRT in regard to the etiology of heart failure. Eighty-three consecutive patients [62 men] who had a biventricular pacemaker inserted at Tehran Heart Center between May 2004 and March 2007 were evaluated retrospectively. The inclusion criteria were comprised of New York Heart Association [NYHA] class III or IV, left ventricular ejection fraction<35%, and QRS>120ms. After 6 months, response was defined as being alive, no hospitalization for cardiac decompensation, and an improvement in NYHA class>1 grade. After 6 months, 60 patients out of the 83 patients were responders. Amongst the 83 patients, 48 had ischemic cardiomyopathy and 35 had non-ischemic cardiomyopathy. A cross-tabulation of response versus etiology showed no significant difference between ischemic versus non-ischemic cardiomyopathy with regard to response to CRT [P=0.322]. According to our study, there was no difference in response to CRT between ischemic versus non-ischemic cardiomyopathy at six months' follow-up