Edinburgh Napier University

  Atrial fibrillation (AF) is the most common sustained arrhythmia, and its prevalence increases with age. In those aged 65 or older, screening studies reveal the prevalence (in AF at time of screening) to be 4.4%, with 1.4% of those having previously undiagnosed AF [1]. In our own study of ambulant patients, 6.7% of those ≥ 65 years were in AF and in 10% of these, AF was incidentally detected, most without symptoms of palpitations or the elevation of resting heart rate [2].

AF is associated with increased morbidity and mortality including a 5-fold increased risk of stroke. Since many with AF are asymptomatic, presentation with a complication such as stroke may be the first manifestation of this arrhythmia. In up to one quarter of cases of ischemic stroke, a cause is not found and subclinical AF is a likely aetiological factor. A recent pacemaker study revealed a significant association between device-detected silent AF and the risk of stroke or systemic embolization [3].

With temporal trends showing an increasing AF incidence, in part due to the aging population, a community screening program to detect silent AF could have a significant impact on stroke prevention. However, until now, community screening with ECGs has not been thought cost-effective for AF detection [4].

The development of new technology, such as an iPhone application which records a high quality single lead ECG (Fig. 1), makes mass ECG screening feasible. We assessed the accuracy of the iPhone ECG as a diagnostic screening tool for the detection of AF by comparing it with a contemporaneous 12-lead ECG interpreted by a cardiologist.