Can Smart Watches Be Used to Screen for Atrial Fibrillation?

Atrial Fibrillation
Image: wired.com

Sanjiv M. Narayan, MD, PhD, is a cardiologist who now serves as faculty at Stanford University, and was previously in San Diego where he was voted Best Doctor for his work on heart rhythm disorders. Throughout his career, Dr. Sanjiv Narayan has focused on developing novel therapies for atrial fibrillation, a life-threatening rhythm disorder. Modern technology, such as smart watches, has a lot of potential for screening for this condition, but consumers also need to recognize the limitations.

Smart watches have quickly become more advanced, and some even have a single-lead electrocardiogram (ECG) function that traces the heart’s electrical activity through the skin. Recently, Apple received FDA approval for its ECG sensor and app, which includes an algorithm to detect atrial fibrillation. These algorithms are a major step forward, but they have limitations, especially due to the inaccuracy of ECG readings.

Movement, environmental conditions, and even skin color can influence ECG readings so that up to a third of the data is incorrect or uninterpretable. This amount of unusable data can make it difficult to judge the severity of atrial fibrillation. While such tools can prove very beneficial for patients, the technology still has a long way to go.