The heart is the body's hardest-working muscle. Whether you're awake or asleep, or exercising or resting, your heart is always at work. It pumps blood through arteries to deliver oxygen to organs and ...

A new study shows that the sinoatrial node (SAN) -- a small but powerful structure in the human heart that serves as its natural pacemaker and initiates every normal heartbeat -- runs on different ...

That gap may finally be closing. Researchers at Michigan State University have built tiny, beating human heart organoids that can be pushed into an atrial fibrillation state and then brought back ...