Using limb-lead ECGs to investigate asymptomatic atrial fibrillation in primary care

Abstract

Atrial fibrillation (AF) is a dangerous, prevalent condition whose first presentation may be ischaemic stroke. Anticoagulation dramatically reduces stroke risk if patients are first identified. While screening enhances AF detection, it is unclear whether opportunistic pulse palpation or systematic electrocardiogram (ECG) screening is superior. Patients across 15 general practices in the Bradford and Airedale primary care trust aged over 65 years were invited for a limb-lead ECG. A total of 6,856 patients were subjected to an ECG. This study aimed to determine if screening improved AF detection and the prevalence of cardiac rhythms that may cause an irregular radial pulse. There were 248 patients diagnosed with AF (3.6%): 153 out of 207 traceable patients were previously diagnosed, hence, screening increased AF detection by 26.1%. Further abnormalities capable of causing an irregular pulse (i.e. ectopy) were highly prevalent at 18.3%. Overall, 99.0% of recorded ECGs were interpretable. In conclusion, limb-lead ECG screening improved detection rates in a simple and feasible screening strategy, avoiding the need for more costly and cumbersome 12-lead ECG screening. Furthermore, the high prevalence of ectopy suggests systematic ECG screening is more specific than opportunistic screening. This study demonstrates simple ECG models may have a promising potential role in improving AF detection, particularly if asymptomatic.