The new watch, which will go on sale later this month, is equipped with an electrocardiogram (ECG) monitor, and can send alerts to the wearer if it detects a heart rate that seems too low. It can also detect irregular heart rhythms and alert the user if they may have atrial fibrillation, or afib. Ivor Benjamin, MD, president of the American Heart Association, who was present at the unveiling of the watch on September 12, 2018, commented, “I’m inspired by the lifesaving potential of technology and applaud Apple’s innovation and commitment to health. Capturing meaningful data about a person’s heart, in real time, is changing the way we practice medicine.” The ability to access health data from an on-demand ECG that the new Apple Watch offers is game changing, said Dr. Benjamin, especially when it comes to evaluating atrial fibrillation. The 2.7 million Americans who have afib are at increased risk for blood clots and congestive heart failure. According to the National Stroke Association, these people are 5 times more likely to have a stroke, which can happen when a blood clot leaves the heart and gets lodged in an artery in the brain. People with afib can experience symptoms such as heart palpitations and dizziness, but some have what is known as “silent afib,” and are asymptomatic. Often people with this type of atrial fibrillation have no idea they are at risk until they discover their condition at a routine checkup or an in-office EKG. “The Apple Watch would make diagnostics of asymptomatic arrhythmia more readily available for patients,” says Benjamin A. Steinberg, MD, a professor of medicine in the cardiovascular division of the University of Utah in Salt Lake City.The information from the watch could also help provide reassurance in the case of symptoms that are not arrhythmia, and help correlate (heart) rate symptoms with arrhythmia for others, he adds. It’s important to note that in the clearance letter for both associated apps, the FDA specifies that the watch and the apps are “not intended to replace traditional methods of diagnosis or treatment.”
How to Use the New Features
The new Apple Watch Series 4 features a digital crown on the side of the watch. Intended primarily for user navigation, it has a titanium electrode built into the top for the ECG app. The user puts their finger on the digital crown and the watch passes a current across the chest to track electrical signals in the heart. An ECG waveform is generated in just 30 seconds. “Historically, the watch-based heart rate monitors that rely on light transmission have not been terribly helpful clinically,” says Dr. Steinberg. “The availability of an actual electrocardiogram tracing, similar to Kardia’s AliveCor, could certainly change that.” The resulting waveform, its classification, and any notes entered about the circumstances or other symptoms are automatically stored in the Health app on your iPhone. The user can choose to send a PDF to their doctor with the waveform and supplementary information. The technology found in the Apple Watch and the ability to share the information could be significant in new clinical care models and shared decision-making between people and their healthcare providers, according to Nancy Brown, CEO of the American Heart Association. “In my experience, people often report symptoms that are absent during their medical visits,” Benjamin says. “That’s why information is vital — information about a person’s daily lifestyle choices and their specific health data.”
