Wearable health-monitoring devices have come a long way from manual, waistband pedometers. Today’s modern offerings, such as smartwatches and smart rings, can monitor everything from your heart rate and blood pressure to sleep patterns.
Dr. David Weisman, a board-certified cardiac electrophysiologist at Jupiter Medical Center, says self-monitoring devices are revolutionary in empowering patients being treated for heart rhythm problems including atrial fibrillation, or AFib. He doesn’t promote a specific brand or style but notes that it’s important to use one of the several devices or apps approved by the Food and Drug Administration (FDA) that use electrocardiogram (EKG) and photoplethysmography (PPG) to detect irregular heart rhythms. He has patients who’ve come to his office because their device discovered AFib “and that was the first time anyone had ever told them that they had a very important medical diagnosis,” he says.
The devices that monitor EKG and PPG generate data that are easily relayed to your doctor for their assessment. Sometimes, the devices can show an irregular pattern due to an “artifact” created by movement, sweat, or the way the device touches the skin, resulting in incorrect, automated interpretations. “That's why you can't self-diagnose,” Weisman says. “You need to have someone who knows what they're looking at confirm it or deny it for you.”
Consumer devices can be helpful when symptoms are not picked up by a medical monitor that is attached to the chest or implanted for a limited duration. “Everything, of course, is good,” Weisman says. “And then the minute they take off the monitor, they have symptoms. And they're frustrated.’” When a patient has their own wearable device, they can wear it at home, when traveling, or playing a sport—there is no time limit. Weisman then examines the data to confirm a new diagnosis or monitor an existing condition. “It's been really game-changing in terms of patient care,” he says. “They're reasonably good alternatives that empower the patient.”
Some devices monitor a variety of heart-related vitals including cardio capacity, heart rate, heart rate variability, and cardiovascular age. But what’s really important? For general heart health, Weisman says it’s the long-term, global picture, not just what’s happening at a particular point in time.
The range of consumer wearables aimed at “digital patients” continues to grow. While the FDA has cleared only two devices to screen for sleep apnea—the Apple watch S E3 and the Samsung Health Monitor app that comes on the latest Samsung Galaxy Watch—these tools are gaining popularity. JMC pulmonologist Dr. Michael Marsh explains that these devices can detect signs such as oxygen desaturation, heart rate variability, and restlessness during sleep. However, they cannot differentiate between obstructive and central sleep apnea, which is a critical limitation. Nor can they measure carbon dioxide retention, which may play a role in more complex. sleep-disordered breathing. These devices may raise suspicion of a disorder, but they are not substitutes for formal diagnostic studies.
Sleep apnea is a potentially serious condition, often caused by airway obstruction from the tongue or soft palate during sleep. It may also be triggered by the use of sedating medications such as opioids or benzodiazepines, which suppress respiratory drive. Other risk factors include asthma, chronic obstructive pulmonary disease, lung scarring, and stroke. Marsh notes that untreated sleep apnea is associated with increased risk for stroke, heart attack, dementia, and accidents related to sleep deprivation. During deep sleep, the body enters a state of muscular relaxation, including reduced movement of the diaphragm. As oxygen levels fall and carbon dioxide rises, the brain signals the body to wake and resume breathing. These repeated interruptions can cause abnormal heart rhythms and significant fatigue. The severity of sleep apnea is determined by how often this cycle occurs each hour. Repeated arousals prevent the body from entering restorative REM sleep.
Marsh has seen several patients present specifically because their wearable devices detected abnormal sleep patterns, low oxygen levels, or frequent arousals. While these tools are not diagnostic, they are becoming more relevant to screening prompts. Although wearables can raise important concerns, Marsh emphasizes that they should not replace formal evaluation and clinical decision-making.
Both Marsh and Weisman advise patients to speak with their health care provider before interpreting data from wearable devices. Physiological changes can occur for harmless reasons. Patients should begin with their primary care doctor, who can determine whether a referral to a sleep or cardiology specialist is appropriate.
Weisman also cautions that the data can cause unnecessary anxiety. “Every time there’s a slight change in something, outside of what they determined to be their baseline, they’re concerned that there's something wrong,” Weisman says. “So, it has that opposite kind of effect” on that person’s health.