Expanding indications for resynchronization therapy.

Cardiac resynchronization therapy (CRT) is one of the major advances in the treatment of patients with chronic heart failure due to impaired left ventricular ejection fraction. Current guidelines recommend with the highest levels of recommendation and evidence CRT in patients with low ejection fraction wide QRS, LBBB, and mild to severe heart failure (New York Heart Association class II to IV). However, other patients might benefit from CRT. This is the case for patients with permanent atrial fibrillation, patients conventional pacemaker indication, patients with mildly impaired left ventricular function (>35 %), or asymptomatic patients (NYHA I). We will discuss in this manuscript each new potential indication for CRT.