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Your Apple Watch can help improve how you monitor your heart health. STUDIO TAURUS/Stocksy
  • Apple has offered a breakdown of five of the Apple Watch’s heart health features.
  • The device includes functions said to monitor cardio fitness, high and low heart rate, Atrial fibrillation, and more.
  • Experts say these functions can help you convey useful cardiovascular data to your heart doctor
  • However, they express concern about the accuracy of devices like the Apple Watch

Eating well, moving more, and reducing stress. When it comes to managing your health, some advice has been around for decades. But as technology develops, so too does the way we monitor our health.

In recent years, a slew of tech devices have helped clue us in on the metrics, allowing you to measure everything from your step count to the quality of your sleep. Now, global tech company Apple has shared how the Apple Watch may enable you to keep your heart health in check.

The company has listed five heart health features of the device on its website, claiming that it can improve your peak oxygen rate, monitor irregular heartbeats, identify an abnormally low resting heart rate, and more.

So, how do these features work, how important are they for a healthy heart, and crucially, what do experts make of them?

Apple says the Cardio Fitness feature gives you a “scientifically validated” estimate of VO2 Max, your body’s ability to intake oxygen during exercise. Users can choose to receive notifications when their classification drops to “low.”

Low V02 Max is associated with long-term health concerns such as cardiovascular disease and high blood pressure. Apple says you can combat low V02 Max by exercising more rigorously and more frequently; a habit you can easily track using the cardio fitness feature.

Public health-trained personal trainer and head coach at Wildstrong, Andrew Telfer, says VO2 Max has long been used as a proxy for overall health, noting that high VO2 max is associated with longer life spans.

“Measuring V02 Max is probably most useful in competitive athletic training as there are many training methodologies that use percentages of estimated VO2 to adjust intensity,” he explains. “Measuring your heart rate against estimated maximum heart rate can be useful for people who want to train for marathons or triathlons etc.”

However, Telfer says there’s a risk of focusing on this singular metric while ignoring equally important proxies for health and longevity.

He says, as well as V02 Max, you should pay attention to other health indicators, like strength and mobility as well.

Most of us have experienced the feeling of a racing heart after we’ve physically exerted ourselves, but do you really know how fast your heart beats when you’re at rest, and what that number means for your health?

The Apple Watch checks for heart rates that are unusually high or low when you are inactive, which the company says can help you identify “situations that may warrant further evaluation.”

If your heart is above 120 bpm or below 40 bpm for more than 10 minutes while you’re at rest, you’ll receive a notification.

Mario Ignacio Pascual, a cardiologist at Baptist Health, says tracking your heart rate can be a beneficial measure of overall heart health. However, he says it’s important to remember that an abnormally high or low heart rate isn’t always a cause for concern.

“There are many situations where having an abnormal pulse detected by an Apple watch either above or below this range is not accurate and not a serious health concern,” he explains.

“Apple watches are also known to have false positive alerts due to artifact or other benign arrhythmias,” he adds.

Still, the high and low heart rate function can give you a better idea of a healthy heart rate range, making you more aware of any abnormalities.

Similar to the high and low heart rate function, you can also receive a notification if you’re experiencing irregular heart rhythms, a symptom of atrial fibrillation (Afib), a condition where the upper chambers of the heart beat out of sync with the lower chambers.

Not everyone with Afib will experience symptoms, and when left untreated, it can result in heart failure or blood clots that can lead to stroke. For those without symptoms, a monitoring device like the Apple Watch may be a vital first step in identifying it.

“Irregular heart notifications on the Apple Watch can be used as a screening tool for serious arrhythmias such as atrial fibrillation,” says Pascual. “However, when it comes to diagnosing heart arrhythmias, a rhythm strip or ECG (an electrical map of the heart) remains the gold standard.”

Pascual says if you receive an irregular heart rhythm notification, further testing will be required to confirm or refute the alert. Again, he says that irregular rhythm notifications have been associated with false positives and can lead to significant patient anxiety.

An ECG is a device that measures the electrical activity of the heart to detect cardiac problems. You’ll usually come across them in medical settings.

However, Apple has included an ECG app with its watch that claims to capture and record irregular heart symptoms such as rapid or skipped heartbeat using an electrical heart sensor. Users then have the option to present these findings to their clinician in PDF format.

In Pascual’s opinion, the ECG app is the most exciting feature of the Apple Watch.

“Many times, patient symptoms can be quite sporadic or rare. The diagnosis of these symptoms requires a correlation between a patient’s symptoms and a rhythm strip or ECG,” he explains.

“The Apple watch has provided the consumer with the ability to quickly obtain a rhythm strip to provide their healthcare provider with this correlation.”

Afib History is a function of the Apple Watch that allows you to estimate the amount of time your heart shows signs of Atrial Fibrillation.

In addition, this feature lets you track lifestyle factors that can affect the amount of time spent in Afib such as sleep and exercise.

“Afib burden, or the amount of time being in and out of Afib, is becoming a very important clinical tool used to determine clinical outcomes,” says Pascual.

“Afib is not traditionally thought of as a curable issue but one which we can control very well, and so being able to measure AFIB burden will allow patients and their doctors the ability to quantify the overall success of different treatment strategies,” he explains.

Pascual believes managing Afib via the Apple Watch may encourage patients to address risk factors that can contribute to the condition too. “By tracking sleep, exercise pattern, and weight we hope to empower patients to take control of their Afib and truly diminish their burden,” he says.

That said, Pascual notes that these features are only available with continuous use of the Apple Watch.

While tech like the Apple Watch might make you more mindful of your heart health, Telfer says you should remember that they aren’t clinical devices.

“Many professional heart and health organizations have recommended against using Apple Watches and other similar devices due to the high incidence of false positives,” he points out.

“If you are experiencing any number of dangerous irregularities and the watch detects it, then it’s a net good. But we should be mindful that Apple may insinuate that the device is more accurate than it actually is.”

Bottom line, when it comes to heart health, the Apple Watch can’t replace the expertise of a physician, but it may make you more aware of your cardiovascular health and encourage you to adopt heart-healthy habits. It also provides data that you can present to a cardiologist.