The sinoatrial (SA) node is the natural pacemaker of the heart. It generates electrical impulses that cause the heart’s chambers to contract, setting the heart rate. The SA node typically generates 60 ...

This screening test measures how well blood flows through your heart. It may be used to diagnose coronary artery disease or to assess damage caused by a heart attack. Share on Pinterest JazzIRT/Getty ...

The heart is a muscular organ composed of four chambers: two upper chambers called atria and two lower chambers called ventricles. These four chambers pump blood through the body in a rhythmic pattern ...

Your heart’s job is to keep your pulse steady to pump blood throughout your body. Sometimes your heart rate is slower when you’re relaxing, and sometimes it’s faster when you’re exercising or stressed ...

A heart perfusion imaging scan, or myocardial perfusion scan, is a test that tells doctors how well a person’s heart pumps blood. Doctors may use this test when diagnosing the cause of chest pain or ...