Epidemiology, Mechanisms, and Management of Atrial Fibrillation in Cardiac Amyloidosis

Cardiac amyloidosis (CA) is a restrictive disease that results from intramyocardial amyloid deposition due to immunoglobulin light chain or transthyretin proteins. Up to two-third of CA patients have atrial fibrillation (AF) due to electromechanical, autonomic, and hemodynamic disturbances. AF in CA carries particularly increased risk of thromboembolism, prompting anticoagulation therapy irrespective of CHA₂DS₂VASc score. However, CA is also associated with enhanced bleeding risk that warrants thorough assessment of bleeding profile before initiation of anticoagulation. Management of AF in CA is challenging because these patients poorly tolerate rate control agents, while cardiomyopathy precludes most antiarrhythmic agents, leaving amiodarone as the preferred antiarrhythmic drug. The effectiveness of direct current cardioversion in restoring sinus rhythm in CA is comparable with that in the general population, although intraprocedural complication rates could be higher. Transesophageal echocardiogram should be performed prior to direct current cardioversion, given high incidence of intracardiac thrombus in these patients. Finally, the data on catheter ablation is limited.