Stanford Medicine Apple Watch Study Shows Heart Warnings Work

Standford Medicine has conducted a study that looked at the Apple Watch and the wearable's ability to detect atrial fibrillation. The study found the Apple Watch app can identify heart rhythm irregularities, which can help catch atrial fibrillation. The study authors say that atrial fibrillation is a type of irregular heart rhythm and is a leading cause of stroke and hospitalization in the US.

The challenge is that the symptoms are had to detect, so the condition often goes undiagnosed. The Apple Heart Study had over 400,000 participants enrolled over its eight-month duration, making it the most extensive virtual study to date. The study was launched via a research partnership with Apple in November 2017. The goal was to determine if the Apple Watch could use data from the heart-rate pulse sensor to identify atrial fibrillation.

The researchers found that only 0.52% of participants in the study received an irregular pulse notification. That statistic helped to squash fears that the wearable would over-notify healthy participants. Participants who were flagged with atrial fibrillation received follow-up care via a health-monitoring technique called patch ECG for one week.

Of those who received a notification via the Apple Watch, 34% were found to have atrial fibrillation. The researchers note that since atrial fibrillation is an intermittent condition, it's not surprising for it to go undetected in ECG patch monitoring. The team says that during ECG patch monitoring, the Apple Watches of the participants continued to monitor pulse irregularities.

The team found that if a participant on ECG patch monitoring had an irregular pulse detected, 84% of the time, it was confirmed to be atrial fibrillation on the ECG patch. The team says that this proves that the Apple Watch can successfully identify atrial fibrillation. The team also notes that 75% of participants who received an irregular pulse notification sought out medical treatment.