Bradyarrhythmias in Cardiac Amyloidosis and Role of Pacemaker.

Cardiac amyloidosis (CA) is an underdiagnosed disease that is caused by deposition of misfolded transthyretin (ATTR) or immunoglobulin light chain (AL) fibrils in the myocardium. Bradyarrhythmias are commonly seen in CA, due to disruption of conducting system by amyloid fibrils. Atrioventricular conduction defect is more common than sinus node dysfunction. Bradyarrhythmias are most prevalent in wtATTR, followed by hATTR and AL. Pacemaker implantation, when indicated, can help provide symptomatic relief but does not confer mortality benefit. Progression of conduction system disease is common and often leads to increased right ventricular pacing burden with time. Therefore, cardiac resynchronizing therapy (biventricular therapy) is often considered as a better and safer option in these patients. Finally, the role of prophylactic pacemaker implantation is controversial, and current guidelines do not recommend prophylactic pacemaker insertion in CA patients.