Prevalence of unknown atrial fibrillation in patients with risk factors

Atrial fibrillation (AF) is the most common cardiac arrhythmia. 'Silent', undiagnosed AF is often only detected with the first complication, e.g. a stroke. Detection of 'silent' AF prior to the first cerebrovascular event would be valuable to institute adequate therapy and prevent complications related to AF. We performed a simple electrocardiography (ECG) screening for silent AF in patients at risk for AF.

One hundred and thirty-two adult patients (76 male; age: 64 ± 14, mean ± SD) without known AF presenting to the diabetes, hypertension, and dyslipidaemia clinics (76 outpatients in the different clinics), or to the stroke unit (56 stroke survivors) at the University Hospital Muenster were screened for unknown AF using a simple patient-operated, single-channel ECG recorder (Omron hcg-801-e, Germany). Silent AF was found in 7/132 patients (5.3%; four stroke survivors, two diabetics, one patient with hypertension, median CHADS2 score: 2 (25-75 quartiles 1-3). The prevalence of AF was higher in patients with multiple risk factors for stroke and AF: AF was found in 3% (1/32) patient with hypertension and no other risk factors for AF, but in 7% (5/71) patients with two risk factors including stroke patients (diabetes and hypertension, stroke, or stroke and hypertension), and in 11% (1/9) with stroke, hypertension, and diabetes. Standard ECG did not detect further patients with AF.

A simple ECG screening could help to detect 'silent' AF prior to the first cerebrovascular events, especially in patients with multiple cardiovascular conditions. Larger studies of such a screening are warranted.