Cardiac arrhythmias in systemic amyloidosis: correlation with echocardiographic abnormalities.

To determine the prevalence of cardiac arrhythmias in patients with systemic amyloidosis 24 hour electrocardiographic monitoring was performed in 27 patients with primary amyloidosis and in 6 patients with familial amyloid polyneuropathy. All patients underwent echocardiographic studies. Despite a high prevalence of conduction disturbances on standard electrocardiogram, clinically significant bradyarrhythmias were rare (one patient). Complex ventricular arrhythmias (multiform, paired or repetitive beats) occurred in 14 patients (47%) with primary amyloid and 3 patients (50%) with familial amyloid polyneuropathy. The presence of cardiac arrhythmia correlated with heart failure and, more strongly, with an abnormal echocardiogram. There were four sudden deaths, all in patients with abnormal echocardiograms and complex ventricular arrhythmias. These findings suggest that complex ventricular arrhythmia on Holter monitoring is common in cardiac amyloidosis and may be a harbinger of subsequent sudden cardiac death.