Cardiac dyssynchrony in congestive heart failure and atrial fibrillation - Integrating regularization and resynchronization

Congestive heart failure (HF) is associated with electrical and conduction abnormalities. Aside from the higher risk for sudden cardiac death, patients often present with atrial fibrillation (AF) and left ventricular (LV) conduction abnormalities. The prevalence of atrial fibrillation increases with the severity of heart failure and worsens its course by loss of atrial contraction, poor rate control, and irregular rhythm. Cardiac resynchronization therapy (CRT) improves symptoms and exercise tolerance in patients with congestive heart failure and cardiac dyssynchrony. These effects are paralleled by reverse LV remodeling, improve LV function, and translate into an improved prognosis on top of the optimal medical treatment (1). Clinical benefits are consistent across the multiple studies, and the therapy has evolved into the class I indication for HF patients with a broad QRS complex, severely depressed LV function, and sinus rhythm (2).