Most of us have become inseparable from our smartphones, and a growing segment of the population wears smartwatches that connect with their phones. They’re not just a neat way to send and receive calls and texts, as smartwatches and smartphones are increasingly equipped with health-tracking apps. In addition to simply counting daily steps and calories burned, these devices can also monitor heart rate and other functions, including irregular heartbeats and arrhythmias. The question is, how accurate are they?
“Wearable technology in heart rhythm monitoring currently lives in two worlds,” explains Dr. AmitThosani, cardiac electrophysiologist and director of cardiac electrophysiology at Allegheny Health Network (AHN). “One world is the home prescribing system and the second, which is more visible and accessible to the consumer public, is like the Apple Watch and KardiaMobile.”
Thasani says the Apple Watch and KardiaMobile are both highly accurate and FDA-approved for detecting irregular heart rhythms like atrial fibrillation. “We see a significant number of our heart patients using these wearable technology devices, and frankly, the pace of usage has somewhat outpaced our understanding of its application,” Thasani says. “The results up to this point have been accurate, but the question of whether they compare to clinical implant technology, I think it’s safe to say is yet to be determined.”
The data so far shows that most heart rate-monitoring apps are pretty accurate at measuring your heart at rest, losing just a beat or two per minute. The problem arises when measuring heart rate during exercise, with some studies showing up to 20 lost beats per minute. A study published in the National Library of Medicine shows substantial differences in accuracy between four different smartphone heart rate monitoring apps. Heart rates measured by an EKG monitor showed a difference of more than 20 beats per minute in 20% of the results.
Heart rate is one thing, but what about the ads you see for those little fingers that connect to a smartphone to take an ECG on your heart? Thasani believes they can be very useful for doctors.
“The KardiaMobile device, for example, will display a personal single-lead EKG, which is sufficient for a cardiologist to confirm a normal heart rhythm or, alternatively, detect an irregular heart rhythm, extra beats, and/or associated factors that could lead to a diagnosis of atrial fibrillation,” she says. of the electrical activity of the heart”.
In other words, they work well for basic readings but shouldn’t replace those with more serious heart problems. In these cases, however, technology has advanced so that patients can monitor at home using higher quality equipment. “For more advanced home systems that require a prescription, they are highly accurate at detecting abnormal heart rhythms,” says Thasani. “However, in these cases, the patient can only have the device at home for the prescribed allotted time. If the symptom or incidence in question does not occur within that specific time window, we have no idea what may be at play. In these cases, she says consumer-based wearable technology like smartwatches can actually help your doctor monitor you for a longer period of time. “Wearable devices, like a smartwatch, don’t have a limited time for patient use and therefore can provide insight into what’s causing a patient’s heart symptoms in real time.”
As for the accuracy of the readings from the Apple Watch and other apps, Thasani believes they are generally accurate. However, he cautions that sometimes they won’t produce a clear reading of the trace or a definitive diagnosis. “Importantly, if an individual is experiencing concerning cardiac symptoms or if there is ever a question or any ambiguity regarding notifications on a wearable device, it is always advisable to consult a primary care physician or cardiologist,” adds Thasani. “Even with all this information at hand, it’s no substitute for seeing a doctor.”
In terms of what he recommends and uses with patients, the Apple Watch and KardiaMobile are his favorite products. “In my office, we very often deal with patients using Apple Watch or KardiaMobile,” he says. “If those aren’t available or accessible to the patient, we will diagnose based on symptoms, prescribe a home monitoring system to detect irregularities, or schedule more advanced tests.”
Overall, Thasani thinks the new trend of wearable healthcare tech can go hand in hand with doctor checkups.
“What’s great about wearables is that patients can store strips for a certain amount of time and upload them to their electronic health record or take them to office appointments,” he says. “So if there’s something going on — a specific complaint or concern — we may have the ability to correlate a rhythm to it based on readings from their device.”
He says that in today’s world of virtual health options, wearable technology has played a huge role in increasing cardiologists’ access and ability to better understand heart patients, their vital signs and symptoms of concern.
“The boom in wearable technology has come at a time when patients are expecting more virtual on-demand services, and the ability to have this kind of intelligent vision is an accelerator,” Thosani says. “There is a convergence of what patients expect from their care team and how innovative technology is further advancing it, all at an exciting pace.”