Accuracy of smartphone-based ECG for the diagnosis of various cardiac arrhythmias

Abstract

Diagnosis of cardiac arrhythmias can be challenging due to their frequent transient nature. Smartphone-based ECG has previously been studied for atrial fibrillation (AF) diagnosis. However, data is lacking regarding diagnostic accuracy of smartphone-based ECGs for other frequent arrhythmias. To assess the accuracy of Alivecor smartphone-based ECG (AECG) device for the diagnosis of various bradyarrhythmias or tachyarrhythmias. Hospitalized patients were eligible for inclusion if they had any of the following arrhythmias: AF, atrial tachycardia/flutter (AT), sinus rhythm with frequent atrial premature depolarizations (APD), sinus rhythm with frequent ventricular premature depolarizations (VPD), sinus tachycardia > 120 beats/min, sinus bradycardia < 40 beats/min, high-degree atrioventricular (AV) block, atrioventricular node reentrant tachycardia (AVNRT) and ventricular tachycardia (VT). Reference twelve-lead ECG were recorded, and the corresponding one-lead AECG was independently interpreted by four blinded electrophysiologists. Seventy-three patients (57 men; aged 72 ± 14 years) were included. For the diagnosis of bradyarrhythmias, AECG had a sensitivity and specificity of 75%–95% for sinus bradycardia, and 52%–98% for AV block. For atrial tachyarrhythmias, sensitivites and specificites were good for APD (83%–97%), AF (82%–87%), and sinus tachycardia (86%–98%), whereas sensitivity was poor for AT (49%–93%) and AVNRT (10%–99%), with very frequent confusion between them. For ventricular tachyarrhythmias, sensitivities and specificities were 70%–95% for VPD, and 89%–100% for VT ( Table 1 , Fig. 1 ). AECG is accurate for the diagnosis of sinus bradycardia, sinus tachycardia, APD, VPD, AF and VT. However, AV block, AT and AVNRT were poorly diagnosed by AECG, with a low sensitivity and very frequent confusion between AT and AVRNT.