If you use a smartwatch or activity tracker to keep an eye on your heart health, you may wonder how accurate the numbers on the screen are and what they could mean. Wearables may collect useful information between appointments, but understanding their role and limits can help you bring the right questions to your healthcare team.

If you believe you are experiencing a life-threatening emergency, do not wait for your wearable to tell you so. Head to the nearest emergency room or call 911.

What Is Wearable Technology for Heart Health?

Wearable technology refers to digital health devices worn on the body. This may include activity trackers and smartwatches, as well as sensor patches placed on the chest or stomach. Small built-in sensors collect health information and may send it to a smartphone or other connected device.

For heart health, these devices may be used to track information over time. In some cases, they may support screening for possible irregular heart rhythms in people at higher risk. They may also be part of remote care for people managing chronic conditions such as heart failure or peripheral artery disease. A wearable may support your care, but it does not replace medical testing, follow-up visits or a clinician’s interpretation.

What Do Wearables Measure?

What wearables measure depends on the devices’ features. Wearables may track:

• Activity: Step count, movement and activity intensity. This information may be useful when working toward an activity goal as part of a heart-healthy routine.
• Heart rate: How fast your heart is beating. Some devices can collect these readings throughout the day.
• Heart rhythm: The pattern of your heartbeat. Some devices may flag a possible irregular rhythm or allow you to record an ECG, also called an electrocardiogram. An ECG is a tracing of the heart’s electrical activity.
• Sleep and breathing: Sleep duration, breathing patterns or respiratory rate, which is the number of breaths you take in a minute.
• Other health measures: Depending on the device, this may include blood pressure, oxygen saturation or blood sugar levels.

How Wearables May Support Your Health

Wearables may support heart care by helping you:

• Screen for a possible irregular rhythm: For people at higher risk of arrhythmia, or irregular heartbeat, a wearable may identify a reading that needs further evaluation by a doctor.
• Share information between visits: For some people with heart failure or peripheral artery disease, wearable data may be reviewed remotely as part of ongoing care. Peripheral artery disease is a condition in which narrowed arteries reduce blood flow, often to the legs.
• Follow a care routine at home: A device or connected health app may help you track activity, monitor certain health measures or send a reminder to take medicine.

The information from a wearable can add to the conversation, but your healthcare team decides how it fits into your care plan.

What Your Wearable Readings Can and Cannot Tell You

A wearable technology reading is not a diagnosis. For example, an alert for a possible irregular heart rhythm does not diagnose atrial fibrillation, a common type of irregular heartbeat. A wearable ECG may provide useful information, but a clinician still needs to review it alongside your symptoms, health history and any other testing.

Accuracy may vary by device and by type of measurement. Movement, device fit and where the device is worn may affect a reading. Some devices may also be less accurate for people with certain skin tones. A device may flag a possible concern that is not confirmed through medical evaluation. It may also miss an episode, especially if it records information only when you activate it.

Using Wearable Technology With Your Care Team

Wearables can be a useful part of heart care when they are used with guidance from a healthcare provider. Your doctor may recommend a device for a specific purpose, such as checking for possible rhythm concerns or following a chronic condition between visits.

Talk with your doctor about symptoms or health changes, even when your wearable does not show an alert. Your care team can determine whether the information is relevant, whether more testing is needed and what the next step may be.

Sources:
American College of Cardiology
American Heart Association
European Journal of Cardiovascular Medicine