Problems and troubleshooting in regular follow-up of patients with cardiac resynchronization therapy.

Biventricular pacing is an efficient treatment to improve symptoms and clinical outcome in patients with drug-refractory heart failure, low left ventricular ejection fraction and wide QRS. The basis of the treatment is the permanent delivery of biventricular pacing. During the follow-up of biventricular devices the assessment of permanent biventricular capture is fundamental. This requires a tailored programming with respect to the patient's activity and age, and thus also careful evaluations during an exercise test as well as adequate programming in case of cardiac arrhythmias.