What should you get for the heart patient who has everything this holiday season? Technology and digital health are all the rage. Since 2013, the number of people tracking their health data has doubled. Wearable electronic devices can capture a wide range of health data and can be very useful for the health of and the care of the heart patient. Wearable devices have sensors that are incorporated into a watch or clothing or can be worn like a vest. What kind of wearables are available for the heart patient in your life?
Fitbit, Apple Watch, Kersh activity monitor, Kionix Acclerometer, SenseWear Pro3 armband, Zephyr BioHarness:
These accelerometers can measure activity and mobility. The devices estimate step counts or the number of miles walked per day. This can be very helpful for the individual to track his or her own activity. They can differentiate between exercise and standing. Workouts (such as running or cycling) can also be tracked. In addition, the Apple watch has a heart rate monitor and there are available apps which are designed for sleep tracking (measuring sleep time, breathing and snoring). These features are useful not only for the individual, but they have medical applications. The accelerometers are being used to monitor cardiac rehab patients and patients with congestive heart failure, with real time interventions to keep the patient active and moving.
Apple Watch 4 and 5, AliveCor:
The Apple watch uses light sensor technology to see if there are irregular contractions of the heart. If so, an algorithm decides if there is atrial fibrillation (Afib, an irregular rhythm from the upper chambers of the heart). The AliveCor device has a small external monitor with two electrodes. The patient places two fingers on each electode and an electrocardiogram (EKG) is recorded. Again an algorithm can help decide if Afib is present. How accurate are these devices in detecting Afib? The Apple Heart Study was a huge study (more than 400,000 participants) recently published in the New England Journal of Medicine. The study claims that the watch was 84 percent accurate in diagnosing Afib. This sounds impressive, but the study has flaws. Only 6 percent of the participants were over age 65 (the age group most at risk for Afib) while 52 percent were under 40 years old (a very low risk population). The Apple watch found an irregular pulse in only 0.16% of those under 40, most of whom did not have Afib on further testing. In the over 65 age group, 3.2 percent had an irregular pulse, but again only a small number had Afib. In all, only a few hundred participants among the more than 400,000 actually were diagnosed with Afib. We don’t know whether these few hundred participants had clinically significant Afib (meaning that medications needed to be added or adjusted for the Afib). While the technology seems promising, it needs to be tested in a population that is prone to Afib.
Omron Heart Guide:
This device is a wrist-based wearable that takes blood pressure (BP). The smartwatch has a secondary, inflatable strap that works like a small BP cuff on the wrist. To take a BP reading, the arm is held at chest level and a button is pressed. The BP is displayed, along with a notification (green if the BP is good, red if the BP is high). It has been shown that BP taken at home is more accurate and more predictable of cardiac outcomes than BP taken in a doctor’s office. So this device may make a difference for the hypertensive patient. In addition, this device gives 24 hour BP trends, which have also shown to be important. On the plus side, this wearable was approved for use by the Food and Drug Administration (FDA). On the other hand, it is bigger and heavier than an average smartwatch and it is quite expensive ($500).
This wearable may be beneficial in the detection of and management of congestive heart failure (CHF). CHF occurs when the lungs fill up with fluid. In the United States, CHF is the most common reason for hospitalization. The ability to detect fluid build up in the lungs before full-blown CHF occurs would be a major advance for patients, avoiding many hospital stays. This device works on dielectric principles to estimate the fluid level in the lungs. The vest sensors do not require skin contact and can be worn over clothing. The vest calculates fluid volume in 90 seconds and relays the information to the patient’s doctor. If fluid is accumulating, medication can be adjusted before the patient runs into trouble. In a study of CHF patients, the ReDS vest reduced hospitalization by 87%. The vest is FDA approved and commercially available.
CHF patients with weakened heart muscles are especially prone to sudden cardiac arrest, an irregular rhythm from the lower chambers of the heart. Sudden cardiac arrest is deadly unless the heart is promptly (within 10 minutes) defibrillated (shocked back into normal rhythm). The automatic implantable cardiac defibrillator (AICD) is a device that is implanted in a patient and can detect these irregular rhythms and internally shock the heart back to normal. The AICD has been shown to save lives. However, there is often a period of several months between the diagnosis of a weakened heart muscle or a heart attack and AICD implantation. This is where the Life Vest steps in. The Life Vest is worn 24 hours per day and requires skin contact. It can detect and shock a patient who is in sudden cardiac arrest. The VEST trial showed a 35% reduction in death between those who wore a Life Vest and those who didn’t. The Life Vest is currently being used as a bridge. If a patient’s heart recovers after an acute event then an AICD my not be needed. If the heart doesn’t recover, the patient is protected and an AICD is placed.