Cardiac Resynchronization Therapy in Patients With End-Stage Inotrope-Dependent Class IV Heart Failure

Although cardiac resynchronization therapy (CRT) is beneficial in patients with drug-refractory New York Heart Association (NYHA) class III/IV heart failure (HF) and left ventricular (LV) dyssynchrony, CRT efficacy is not well established in patients with more advanced HF on inotropic support. Ten patients (age 55 ± 13 years) with inotrope-dependent class IV HF (nonischemic [n = 6] and ischemic [n = 4]) received a CRT implantable cardioverter-defibrillator device. QRS duration was 153 ± 25 ms (left branch bundle block [n = 7], intraventricular conduction delay [n = 2], and QRS