American Heart Association
American Heart Association
November 21, 2019
2 min read

ECG patch monitoring identifies arrhythmias beyond AF: Apple Heart Study

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Marco Valentin Perez

PHILADELPHIA — ECG patch monitoring after receiving an irregular pulse notification on the Apple Watch identified several arrhythmias beyond atrial fibrillation, according to a secondary analysis of the Apple Heart Study presented at the American Heart Association Scientific Sessions.

“Atrial fibrillation was the most common rhythm abnormality ... and frequent premature atrial contraction and atrial tachycardias were commonly associated with irregular tachograms and notifications,” Marco Valentin Perez, MD, associate professor of medicine (cardiovascular medicine) at Stanford University Medical Center, said during a presentation.

As Healio previously reported, of the 419,297 healthy participants who self-enrolled in the Apple Heart Study, 0.52% received an irregular pulse notification. Forty-four percent of those who received a notification went on to attend the first telehealth study visit. The ECG patch was mailed to 70% of participants (n = 658) and 68% returned their patch for analysis. Of 450 participants who received an ECG patch to wear at home, 34.8% had observed AF (97.5% CI, 27-43).

“The overall goal of the Apple Heart Study was to measure the ability of a smartwatch to use an application that identified atrial fibrillation,” Perez said during the presentation.

In this secondary analysis of 450 participants with completed ECG patches (23% women; 40% older than 65 years), 20 patients were contacted for AF findings at rates greater than 200 bpm (n = 18), pause for longer than 6 seconds (n = 1) and nonsustained ventricular tachycardia for longer than 6 seconds (n = 1), according to the new results.

Overall, 153 (34%) participants had AF for longer than 30 seconds. Among 297 participants who did not have AF, 74 (25%) had premature atrial contraction burden between 1% and 15%, and four (1.3%) participants had a burden greater than 15%, according to results presented here.

Three participants had high-grade atrioventricular block episodes that were linked to transient sinus slowing that lasted less than 4 seconds.

Two participants had premature ventricular contractions of at least 15%, and 11 participants (3.7%) had a nonsustained ventricular tachycardia episode for at least eight beats.

No complete heart block or second-degree heart block type 2 were recorded.

“What we do need is a better understanding of long-term implications and outcomes in these participants who don’t have atrial fibrillation, but might have another rhythm that might need attention,” Perez said during the presentation. – by Darlene Dobkowski


Perez MV, et al. Late Breaking Trials in EP and LV Function. Presented at: American Heart Association Scientific Sessions; Nov. 16-18, 2019; Philadelphia.

Disclosures: The Apple Heart Study was sponsored by Apple. Perez reports he is an expert witness for Boehringer Ingelheim and received a research grant from Apple and NIH/NHLBI. Please see the abstract for all other authors’ relevant financial disclosures.