Rhythmic Disturbances In Patients With Cardiac Amyloidosis: Analysis From Cedars-Sinai Amyloidosis Registry

Introduction: Cardiac arrhythmias are frequent complications of patients with cardiac amyloidosis. The burden and nature of cardiac arrhythmias in patients with cardiac amyloidosis have not been investigated in a large patient population. Hypothesis: Cardiac amyloidosis is a highly arrhythmogenic disorder requiring implantation of cardiac electronic devices. Methods: Cedars-Sinai amyloidosis registry was analyzed to investigate the prevalence and nature of cardiac arrhythmias in patients with cardiac amyloidosis. Ambulatory ECG monitoring data, implantable cardioverter-defibrillator or pacemaker implantation, and interrogation data were reviewed to study the burden of cardiac arrhythmias in patients with cardiac amyloidosis. Results: A total of 156 patients were analyzed in the registry: 51 patients (32.7%) with AL amyloidosis, 101 patients (64.7%) with ATTR amyloidosis, and 4 patients with AA amyloidosis (2.6%). Thirty-seven patients (23.7%) were implanted with cardioverter-defibrillator; 23 patients (14.7%) for primary prevention, 11 patients (7.1%) for secondary prevention of ventricular tachycardia, and 3 patients (1.9%) for secondary prevention of ventricular fibrillation. Twenty-two patients (12.1%) needed pacemaker implantation; 9 patients (5.8%) for high-grade or complete heart block, and 13 patients (8.3%) due to sick sinus syndrome. The most common arrhythmias were atrial fibrillation occurring in 80 patients (51.3%) followed by first-degree AV block in 31 patients (19.9%). Sustained ventricular tachycardia occurred in 14 patients (8.9%) during hospitalization, device interrogation or ambulatory monitoring. Conclusions: Both atrial and ventricular arrhythmias are common manifestations of cardiac amyloidosis, frequently necessitating implantation of cardiac electronic devices.