What You Need to Know About the ECG Feature in the New Apple Watch
The new Apple Watch, priced at $ 399 and up, will be able to measure the electrical activity of your heart, its revolutionary EKG or EKG function. (Both abbreviations stand for “electrocardiogram.”) But there are some important caveats.
What is a portable ECG for?
The EKG function should detect when your heart begins to atrial fibrillation, which means that it vibrates rather than swinging at its normal rhythm. If you have atrial fibrillation or afibrillation, clots may form in your blood. And these clots can eventually end up in your brain and cause a stroke.
For this reason, if you have afib and your doctor thinks you are at risk of stroke, they may prescribe you anticoagulants, drugs that reduce the chances of blood clotting. There may be other treatments. too .
You don’t need an Apple Watch to monitor your heart
Apple Watch’s ECG feature is new- isha, but it is not the first product of its kind. For example, you can buy a stand-alone ECG device for less than $ 100. And since last year, AliveCor sold an ECG reading bracelet for Apple Watch ($ 199 plus subscription). What’s new is that this feature is now available as a built-in part of the Apple Watch, no special wristband is required.
You can also do an EKG analysis at the clinic, where you will wear 10 electrodes instead of just one in the watch. This is a more thorough test and is interpreted by the doctor. Home ECG readings are not a substitute for it, although they may collect data on whether you are in Afib all the time compared to the short time you are with the doctor.
Experts are divided over whether this is a good idea
If you have atrial fibrillation and are at risk of a stroke, then, of course, it would be good to catch it early and undergo additional examination and treatment. This is a plus. But does this mean that every Apple Watch owner should be monitored for heart problems?
Any screening program in which you screen healthy people for signs of a problem has both disadvantages and potential benefits. We have seen this in cancer screening, such as mammography. If the test shows that you may have a serious health condition, you will have to take additional testing and worry about your health, even if it turns out to be empty. In some cases, the test can induce people to take drugs or undergo procedures that carry their own risks.
Are we better off with or without screening? This is a tricky question and it all depends on what you are checking for. The US Preventive Services Task Force does not recommend ECG screening in healthy adults with a low risk of heart disease . For high-risk adults, they say, there isn’t enough evidence to recommend or against it. (They were evaluating EKG screening in general, not specifically Apple Watch.)
How accurate is this?
STAT reports that the ECG app for Apple Watch has received FDA clearance based on two studies. It was found that the watch could not read the heart rate in 10 percent of the subjects, but among the remaining 90 percent, it performed quite well. He informed 98 percent of people with atrial fibrillation that they have it; In addition, 99.6% of people were identified who did not. In a second study, the app found 79 percent of people who had atrial fibrillation, according to a traditional monitor.
But the more important question is this: If the app tells you about AF, what are the chances that it is correct? Even if this is only wrong a small percentage of the time, multiply that by all people wearing an Apple watch and you end up with a huge number of false positives.
When you do the math, the app is likely to be wrong 45% of the time, medical scientist Sekar Katiresan told STAT.
And what is the use of this warning if you cannot access a specialist or afford follow-up? Even if you rush to see a doctor, an unexpected warning is not safe. “I fear that this technology will lead mainly to hype, anxiety, overdiagnosis, medicalization of normal life and harm from over-treatment,” wrote cardiologist-electrophysiologist John Mandrola in Medscape .
Is uncertainty worth it?
“We need prospective research to find out if there really is a benefit?” Cardiologist and researcher Eric Topol told me. I asked if the EKG feature in Apple Watch is a good or bad idea, and Poplar says it partly depends on how many healthy people have a suspicious heart rate when they don’t actually have a problem. We do not know this yet. The device can record many false positives, but when it detects real heart disease, it can actually save lives .
Updated 09/17/2018 to note that the 12-lead ECG uses 10 electrodes instead of 12.