As noted by MyHealthyApple: new research published this week in the American Heart Association Journal shows that the Apple Watch can detect arrhythmias other than Atrial Fibrillation (AFib). And you can enable notifications from the Heart Rate app on your Apple Watch to alert you to high or low heart rates and irregular heart rhythms.
° You can turn on heart rate notifications when you first open the Heart Rate app on your Apple Watch, or at any time later from your iPhone:
° On your iPhone, open the Apple Watch app.
° Tap the My Watch tab, then tap Heart.
° Tap High Heart Rate, then choose a BPM.
° Tap Low Heart Rate, then choose a BPM.
If your heart rate remains above or below a chosen beats per minute (BPM) while you appear to have been inactive for a period of 10 minutes, your Apple Watch can notify you. These notifications are available only on Apple Watch Series 1 or later for ages 13 and up.
But back to the American Heart Association study. The Apple Watch irregular pulse detection algorithm was found to have a positive predictive value of 0.84 for the identification of atrial fibrillation (AFib). Among 419,297 participants enrolled in the Apple Heart Study, 450 participant ECG patches were analyzed, with no AF on 297 ECG patches (66%). Non-AF arrhythmias (excluding supraventricular tachycardias <30 beats and pauses <3 seconds) were detected in 119 participants (40.1%) with ECG patches without AFib. 76 participants (30.5%) reported subsequent AF diagnoses.