[Cardiac resynchronization therapy in patients with permanent atrial fibrillation--with or without atrial lead?].

A 59-year-old patient received a biventricular defibrillator for cardiac resynchronization therapy (CRT) due to severe heart failure and a left bundle branch block. He had suffered from mitral stenosis and had received valve replacement 16 years earlier. Because he had permanent atrial fibrillation since that time, no atrial lead was implanted. His symptoms improved with CRT until he received adequate shock therapy for a rapid ventricular tachyarrhythmia. After that his symptoms deteriorated again severely. The ECG recorded during an unscheduled follow-up visit 1 week after the shock explains the reason.