Smart watches a potential ally in stroke prevention

Tuesday, July 31, 2018

The technology used in smart watches may provide a cue for people with abnormally fast heart rates to visit their doctor.

When people think of using a smart watch’s heart rate monitor, it is usually as a measure of how vigorously they have exercised.

Eastern Health and Monash University research led by cardiologists Dr. Anoop Koshy and Dr. Andrew Teh has found that smart watches may be helpful in detecting heart rhythm abnormalities- one of the leading causes of stroke.

Their research, published in the International Journal of Cardiology, found that the accuracy of these watches in most patients was comparable to an ECG machine - considered the gold standard for heart rate measurement.

“Our research indicates that patients who report persistently high heart rate values at rest on smart watches accurately reflect true elevations in heart rate. This could be an early warning sign of an abnormal heart rhythm that predisposes them to debilitating strokes.”

However, Dr. Koshy and Dr. Teh cautioned against people being solely reliant on smartwatches to measure their heart rates. While the research found that smart watches provided a reasonably accurate reading for those with abnormally fast heart rate at rate, it also found that in patients with certain abnormal heart rhythms, smart watches tended to underestimate heart rates.

“The take-home message from our research is that in patients with known abnormal heart rhythms, normal readings might be falsely reassuring. However, persistently high heart rates at rest may indicate an abnormal rhythm and should be further evaluated by their GP or cardiologist.“ Dr Teh said.

Smart watches calculate heart rate by using photoplethysmography (PPG), technology which is similar to that incorporated in hospital equipment for heart rate and blood oxygen saturation levels. With PPG, the heart rate is calculated by monitoring colour changes that occur with pulsatile blood perfusion at the skin surface.

“We have seen a range of medical devices being used in the domestic environment, from blood pressure monitors to blood glucose tests. A smart watch which assists in heart rate measurement might also be considered in similar terms.”