Single-lead electrocardiogram built into latest version cleared by FDA
This story was originally published Sept. 12, 2018. As part of MedPage Today's year-end review of 2018's top stories, we are republishing it along with an update on what has happened since with wearable health technology.
The latest iteration of the Apple Watch, dubbed Series 4, was released Wednesday and with it came FDA clearance for use in detection and notification of atrial fibrillation and other arrhythmias.
The device generates a single-lead electrocardiogram (ECG) without any special band or third-party add-on, as has been the case with the single-lead ECG offered for arrhythmia detection by AliveCor devices for the Apple Watch previously. Instead, a user touches a finger to electrodes built into the crown and a new electrical heart rate sensor in the back crystal provides the other contact.
Alerts are sent when abnormal rhythms are detected or when heart rates go above or below preset thresholds. Recordings, classifications, and any noted symptoms also go into a PDF file that can be sent to physicians.
In clearing the Apple Watch device and its software application for over-the-counter heart rhythm detection, the FDA noted that these functions are "intended for informational use only." It shouldn't be interpreted or acted upon without consulting with a qualified healthcare professional, nor can it replace traditional methods of diagnosis or treatment.
The agency also cautioned that the ECG app is not intended for use by people under age 22 or for those already diagnosed with atrial fibrillation.
"Apple's advances in cardiac monitoring validate the need for this technology for which AliveCor has paved the way," AliveCor CEO Vic Gundotra said in a statement.
But he questioned the broad utility in part because of the price point, starting at $399 for the Series 4 device.
"Apple Watch is great for affluent people who are comfortable with the technology, but medical technology can't succeed unless you can get it in the hands of the people who need it and can use it -- and millions of older people may struggle with the Apple Watch's technology or its expense."
His company's competing products include the $199 AliveCor ECG watch band accessory for Apple Watch (which costs $279 and up for the older Series 3 models) and the $99 KardiaMobile device for smartphones.
For older adults, the U.S. Preventive Services Task Force has cautioned that ECG can't be recommended for screening for cardiovascular disease risk in asymptomatic people, citing insufficient evidence of benefit for hard outcomes beyond simply detecting more arrhythmia.
With newer devices like smart watches, "we need evidence," USPSTF member Seth Landefeld, MD, of the University of Alabama at Birmingham, previously told MedPage Today. "The whole wearable device issue is an area where we're operating in a data-free environment."
Another new health feature in the Series 4 watch is detection of hard falls, using the accelerometer and gyroscope built into the device, which can be used to initiate a call to emergency services.