The Influence of Atrial Fibrillation on Cardiac Resynchronization Therapy

More successful recognition and treatment of cardiovascular risk factors and diseases continues to decrease mortality and increase the proportion of elderly population. Therefore, there are more people with increased risk of developing heart failure and atrial fibrillation (AF) in the course of their lives. The prevalence of AF, in patients with heart failure, increases with the severity of the disease, reaching up to 40% in advanced cases. In these patients with heart failure, AF is an independent predictor of morbidity and mortality increasing the risk of death and hospitalization. Despite the excellent results obtained with different drugs, the optimal medical treatment can fail in the intention to improve symptoms and quality of life of patients with severe heart failure. Thus, the necessity to use cardiac devices emerges facing the failure of optimal medical treatment in order to achieve hemodynamic improvement. The simultaneous electric stimulation of both ventricles with Cardiac Resynchronization Therapy (CRT) results in a significant hemodynamic improvement restoring a more homogeneous contraction pattern. However, CRT is interrupted in over 30% of patients after successful implantation of a CRT device, and the most common reasons for interruption of CRT are the development of AF (18%) and loss of left ventricular capture (10%). Therefore, there should be a strong effort with different maneuvers to prevent AF, since it would significantly improve the ability to deliver CRT in patients with heart failure. The search for better pharmacological maneuvers should continue to provide the help needed to cardiac devices. The incorporation of the AF suppression algorhythm to CRT devices may be very useful in eliminating AF, allowing a better performance of the CRT device without interruption. Sinus rhythm is associated with a long-term improvement in left ventricular systolic function after AF ablation. Therefore, AF ablation may have a primary role as a rhythm control strategy in the definite treatment of AF in patients with HF.