Frequency of cardiac arrhythmias in older adults: findings from the subclinical atrial fibrillation and risk of ischemic stroke (SAFARIS) study

Background Prolonged monitoring of cardiac rhythm has been used in patients with symptomatic arrhythmias and to assess for atrial fibrillation (AF) after cryptogenic stroke, but not in the general population and especially in older adults. Purpose To evaluate the frequency of arrhythmias in a community-based cohort of older adults through 14-days continuous cardiac monitoring using a patch-based device. Methods Cardiac rhythm was analyzed in 533 participants free of AF and congestive heart failure (CHF) from the tri-ethnic (white, black, Hispanic) Subclinical Atrial Fibrillation and Risk of Ischemic Stroke (SAFARIS) study. AF, supraventricular tachycardia (SVT, defined as 4 beats or more), premature atrial (PACs) and ventricular (PVCs) contractions, ventricular tachycardia (VT, defined as 4 beats or more), sinus pauses (SP) and atrio-ventricular blocks (AVB) were analyzed. Gender, age and race-ethnic differences were examined. Results Mean age was 77.2±6.8 years (198 men, 335 women). Recording duration was over 10 days in 91%, and over 13 days in 84%. AF was present in 10 participants (1.9%), atrial flutter in 1 (0.2%). Other arrhythmias are reported in the Table. SP (1.9%) and high-degree AVB (Mobitz II: 0.6%; 3rd degree: 0.9%) were rare. No significant race-ethnic differences were observed. Conclusion In older adults without history of stroke or CHF, prolonged rhythm monitoring revealed moderate frequency of AF, but higher than expected frequencies of AF-predisposing conditions such as SVT and frequent PACs. VT episodes were relatively frequent, whereas SP and AVB were less frequent than commonly believed. Most arrhythmias were more frequent in the oldest; ventricular arrhythmias were more common in men than in women. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): NINDS R01 NS083874