Atrial Fibrillation and Wearables
Atrial fibrillation (AFib) is a common heart rhythm condition that poses serious health risks. Some patients have it for months or years before they are diagnosed.
Smartwatches with EKG monitoring offer the potential to screen people for AFib. A new generation of these devices, such as the Apple Watch Series 4, and Australia’s TGA-approved Kardia Mobile 6L, can produce medical-grade EKG readings with a single tap.
How reliable are the AFib data these devices produce?
Smartwatches use photoplethysmography (PPG) to detect and record the signal that starts each heartbeat. Many also have reflexive single-lead electrocardiogram (ECG) capabilities that can be triggered when there’s a suspected abnormal PPG pattern. The ECG records a strip of 10 electrodes on your chest, with the lead on the bottom right side, and is often used for screening to determine if you’re at risk for stroke.
In this study, researchers evaluated five different devices — the Apple Watch 6, Samsung Galaxy Watch 3, Fitbit Sense, Withings Scanwatch and AliveCor KardiaMobile — to see how accurate they were at detecting AF during both rest and physical activity. They compared these results to a physician-interpreted 12-lead ECG Holter test as the reference standard.
They found that the sensitivity and specificity of the devices in their analysis were comparable. In other words, all of the devices correctly identified AF at rest and during moderate physical activity. However, they did not have the same level of accuracy during vigorous activity. And that could be a problem for people who live alone and need a quick way to alert someone in case of a medical emergency. These are just the first results of what are likely to be numerous studies testing the ability of these consumer-grade wearables to detect AFib and help prevent a stroke.
Are there certain types of people who could most benefit from wearing these biomedical bands?
Many people live with AFib without knowing it, putting them at risk for stroke or other serious complications. Wearables that detect, monitor and record heart rhythm data can help doctors determine whether AFib is present.
Currently, multiple smart devices are capable of detecting atrial fibrillation (AF) by utilizing photoplethysmography or electrocardiography. A small number of them also come with a feature that can record a 30-second EKG strip.
In order to get the reading, patients must press or hold the crown of the Apple Watch 6 or Samsung Galaxy Watch 3 and touch the center and 2 diagonal corners of their wrist with both hands for 30 seconds. To obtain the reading from the AliveCor KardiaMobile device, patients must place both index and middle fingers on the sensor pads. The device then records the SL-ECG, and the result is sent to a patient’s smartphone app.
The accuracy of these devices compared to the reference standard of a physician-interpreted 12-lead EKG was evaluated in a real-world cohort of patients. The study found that sensitivity and specificity of automated detection of AF was high for all five devices. However, the quality of signals needs to be improved in order for these devices to have medical value as remote patient monitoring devices.
Are doctors prescribing them to their patients?
Many smartwatches and fitness trackers can detect a person’s pulse rate using light sensors. A software algorithm can analyze overlapping pulse signals from these devices and identify the presence of atrial fibrillation. The device then alerts the wearer to a potential problem, and the user can then verify the information with an ECG patch.
A large modeling study found that using wrist-worn wearables equipped with photoplethysmography and single-lead ECG to screen for AF was more cost-effective than the use of traditional pulse palpation or 12-lead ECGs. The results showed that the devices could be particularly beneficial for high-risk people ages 65 and older, who are at a greater risk of stroke due to undiagnosed AF.
The technology may be exciting, but it’s important to keep in mind that these devices can only do so much. Even the most sophisticated models are not reliable enough to replace a visit to your cardiac physician. Ultimately, this type of technology will provide valuable data that can help cardiologists understand more about how to manage your heart health. The future is bright for these types of devices, but they will always be a complement to regular visits with your heart doctor. —Dr Robert Perel, Cardiac Electrophysiologist, Queensland Cardiovascular Group. 2019 TCP Media Pty Ltd.
OnePhenix is the only IPAAS software that connects your wearable data to your healthcare professionals. www.Onephenix.com.au
References
https://www.cedars-sinai.org/blog/are-wearables-heart-smart.html
Early Warning Signs of Cancer
Researchers are working to develop smartwatch technologies that can detect early warning signs of cancer. The technology is based on optical biosensing, which converts a wearable device into a round-the-clock diagnostic tool for monitoring the molecular signatures of cancer cells circulating in the bloodstream.
The sensors fit into a watchband and work by through-the-skin detection to measure the levels of specific biomarkers circulating in the body. The system is designed to detect and record multiple biomarkers at the same time, reducing the number of trips to the doctor for testing and providing early warning signs that can be acted on.
Studies of general population samples have identified low symptom awareness, and a link between symptom recognition and delayed help-seeking, particularly in groups with lower socioeconomic status and ethnic minority background who are more likely to suffer from late diagnosis (Stubbings et al, 2009; CR-UK, 2012a, 2012b). Increasing the use of early detection tools could improve health outcomes and save lives by improving the speed of diagnosis.
OnePhenix is the only IPAAS software that connects your wearable data to your healthcare professionals. www.Onephenix.com.au
References