How can little green lights help detect a deadly heart condition? And what data should you be looking at to understand your heart health? We chat with Tony Faranesh, lead research scientist at Fitbit, on a new study that’s using data from real Fitbit users to help detect a person’s risk for atrial fibrillation—a condition that affects 8 million Americans and is a leading cause of stroke. Discover how wearing a Fitbit on your wrist could enable more cases of AFib to be diagnosed than ever before.