The role of cardiac resynchronization therapy in permanent atrial fibrillation patients: current indications to treat heart failure

The aim of this article is a comprehensive review of the publications during the last decade in order to evaluate current indications for cardiac resynchronization therapy (CRT) in patients with heart failure (HF) and atrial fibrillation (AF). Clinical studies show that CRT not only improves HF symptoms and quality of life but also reduces morbidity in New York Heart Association (NYHA) class III or IV patients with reduced left ventricular ejection fraction (LVEF) and wide QRS. The loss of atrioventricular synchrony and difficulty to ensure an adequate biventricular pacing worsens these patients response to CRT. According to the latest guidelines CRT should be considered for patients to reduce all-cause mortality in patients with chronic HF, QRS ≥ 120 ms and LVEF ≤ 35% who remain in NYHA functional class III/ambualtory class IV despite at least 3 months of optimal pharmacological theraphy who are expected to survive at least 1 year with good functional status, provided that biventricular pacing as close as possible to 100% can be achieved (class IIa, level B). Despite the fact that there is a general agreement on the indication for CRT in AF patients, their optimal management strategy still remains a matter of discussion.