From smartphone apps that measure your pulse and heart rhythm to watches or patches that can perform electrocardiograms, the technology in consumer-grade wearable cardiac devices is becoming increasingly sophisticated and changing the way cardiac care is delivered.

“This type of technology can be very helpful,” said James Oujiri, MD, electrophysiologist with the Froedtert & the Medical College of Wisconsin health network. “It allows a patient to gather different data points over time and can give insight into their symptoms and overall health. I have patients with abnormal heart rhythms, such as atrial fibrillation, who will bring in data from their wearable, and we use it to inform treatment.”

Atrial fibrillation is on the rise

Atrial fibrillation (AFib) is a common irregular heart rhythm abnormality. It is an electrical disorder that occurs in the upper chambers of the heart. People with AFib are at an increased risk for stroke. According to the American Heart Association, 15 to 20 percent of individuals who experience a stroke have atrial fibrillation. The risk of stroke is high because an irregular heart rhythm allows blood to pool in the heart, which can lead to the formation of clots that travel to the brain. This is why people with AFib are often prescribed blood thinner medications.

The Centers for Disease Control and Prevention estimates 12.1 million Americans will have AFib by 2030.1 According to the CDC, many people have AFib and just don’t know it. They may not have been diagnosed because they don’t feel or notice the symptoms, which include shortness of breath, fatigue and palpitations.

“In some cases, a person’s first presentation of atrial fibrillation will be after a stroke,” Dr. Oujiri said.

Wearables enhance patient care

To detect AFib, hospitals use 12-lead ECGs, but wearable devices with more limited ECG functionality are available to consumers. The latest wearable on the market that measures heart rhythm is the Apple® Watch Series 4, which is designed with built-in electrodes to do ECGs on demand.

“I am inspired by innovation, and this is game changing,” said Ivor Benjamin, MD, cardiologist with the Froedtert & MCW health network and 2018-2019 president of the American Heart Association.

Dr. Benjamin represented the AHA onstage at Apple’s product launch in September 2018. While neither the AHA nor Dr. Benjamin were involved with the product and do not endorse the Apple Watch or any other device, he believes the technology could be impactful for enhancing patient care.

“This feature has the potential to be transformative, especially when evaluating atrial fibrillation,” Dr. Benjamin said. “Giving consumers deeper health insights by capturing meaningful data about their heart rate, right when it is happening, is of key importance. This functionality has the potential to be significant in new clinical care models and shared decision-making between people and their health care providers.”

Early treatment of atrial fibrillation improves outcomes

People can live with AFib for many years if they receive proper treatment. Treating underlying health conditions, such as diabetes, high blood pressure and sleep apnea, as well as identifying what triggers AFib in an individual, is the first step. Common triggers include nicotine, caffeine, alcohol and some over-the-counter medications containing pseudoephedrine. Medications are used to treat AFib to alleviate symptoms, keep the heart from racing and reduce risks. Blood thinner medications are an effective way to reduce the risk of stroke in people with AF.

Minimally invasive catheter-based procedures are also highly efficient treatments for AF. Catheter ablation uses either heat (radiofrequency) energy or freezing (cryo) energy to eliminate the source of an irregular heart rhythm. In the procedure, an electrophysiologist guides a catheter with an electrode at its tip to the area of heart muscle determined to be the source of the abnormal rhythm. With radiofrequency energy, the electrode supplies a burst of radiofrequency energy to the source to destroy it. With cryo energy, either a catheter or an inflatable balloon delivers freezing energy to destroy the abnormal heart tissue.

“Ablation reduces symptoms and improves quality of life,” Dr. Oujiri said. “It allows certain patients to discontinue some of the higher risk medications we sometimes need to use. Also, in some randomized trials, it has been shown to reduce mortality and stroke in certain patient populations.”

For individuals with AFib and who have a high risk of stroke, an implantable device can seal off a part of the upper chamber of the heart where the majority of blood clots occur. WATCHMAN FLX™ device is a left atrial appendage closure device that reduces the risk of stroke by preventing the formation of clots. Froedtert & MCW Froedtert Hospital is the leading implanter of the WATCHMAN devices in Wisconsin. The heart and vascular team is also highly experienced in other devices, such as the latest pacemakers and defibrillators, which can offer long-term management for the condition.

While research is underway to develop new techniques and tools to treat AF, wearable devices may play a bigger role in detecting it and preventing strokes.

“Capturing meaningful data about a person’s heart, in real time, is changing the way we practice medicine,” Dr. Benjamin said. “People often report symptoms that are absent during their medical visits. That’s why information is vital – information about a person’s daily lifestyle choices and their specific health data.”

1 https://www.cdc.gov/heartdisease/atrial_fibrillation.htm