Rethinking ICD therapy. This article extends important understanding of the role of ICD (implantable cardic defibrillator) therapy. It has long been conventional wisdom that any form of chf related to reduced left ventricular function (severe enough by criteria) would experience a survival benefit with the implantation of an ICD. This paper states that ICD’s help save lives only if the LV dysfunction is due to ischemic heart disease (a heart attack). Thus in patients on optimal medical therapy for lv dysfunction including controlling for CRT (cardiac resnchronization therapy), only the patients with ischemic lv dysfunction derived a benefit from ICD (as opposed to non ischemic cardiomyopathy). This is important because the implantation of an ICD is invasive and can have side effects. The authors recommend the immediate cessation of ICD implantation in non ischemic cardiomyopathy. Click link below for abstract of the article in NEJM.