Validation of a handheld single-lead ECG algorithm for atrial fibrillation detection after coronary revascularization

Atrial fibrillation (AF) is a rapidly increasing global public health concern entailing a high risk for ischemic stroke that can largely be avoided with anticoagulation therapy. AF is often underdiagnosed and there is a need for a reliable method of detection in individuals with additional risk factors for stroke such as coronary artery disease. We aimed to validate an automatic rhythm interpretation algorithm in thumb ECG in subjects with recent coronary revascularization.

Thumb ECG, a patient-operated handheld single-lead ECG recording device with an automatic interpretation algorithm, was performed three times daily for a month after coronary revascularization and 2-week periods 3, 12, and 24 months post-procedure. The detection of AF by the automatic algorithm on subject and single-strip ECG level was compared to manual interpretation.

48,308 of 30 s thumb ECG recordings from 255 subjects (mean 212 ± 3.5 recordings per subject) were retrieved from a database (AF 47 subjects/655 recordings; non-AF 208 subjects/47,653 recordings). The algorithm sensitivity at subject level was 100%, specificity 11.2%, positive predictive value (PPV) 20.2%, and negative predictive value (NPV) 100%. At the single-strip ECG level, sensitivity was 87.6%, specificity 94.0%, PPV 16.8%, and NPV 99.8%. The most common reasons for false positive results were technical disturbance and frequent ectopic beats.

The automatic interpretation algorithm in a handheld thumb ECG device can rule out AF in patients recently undergoing coronary revascularization with high accuracy, but manual confirmation is needed to confirm the diagnose of AF because of high false positive rates.