[Cardiac resynchronization therapy: who is a candidate and who is not?].

- Cardiac resynchronisation therapy (CRT) is a treatment for patients with impaired cardiac pump function (left ventricular ejection fraction ≤ 35%) and a wide QRS complex who, despite maximum tolerated medical therapy, remain symptomatic.- In addition to reducing symptoms, CRT can reduce hospital admissions and improve survival.- Selection of patients for CRT remains difficult. Despite the fact that predicting and influencing success of CRT has improved, ~30% of patients do not respond to the therapy.- Optimizing therapy and follow-up of patients after implantation requires a multidisciplinary approach tailored to the individual patient.- Cardiac rehabilitation with life style advices and structured exercise training maximizes patient benefit from CRT.