Researchers at Northwestern University just found a way to make a temporary pacemaker that’s controlled by light—and it’s smaller than a grain of rice. A study on the new device, published last week ...

The heart may be small, but its rhythm powers life. When something throws that rhythm off—especially after surgery—it can become a race against time to restore balance. For decades, doctors have ...

As the search for Savannah Guthrie's mother, Nancy, continues, a cardiologist explains how pacemakers work and if they can be used to track a missing person's location.