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 ...

A heart attack occurs after a sudden blockage of oxygen-rich blood coming into the heart, causing pain in the middle of the chest, the left side, or other parts of the upper body. According to the ...

Your aortic valve is part of your heart, a strong muscle that pumps blood through your body. The aortic valve controls the blood flowing out from the heart. It opens every time your heart contracts, ...

Your heart is a muscular organ that helps circulate your blood, which delivers oxygen and nutrients to your tissues. There are four chambers and four valves in your heart, and each ensures proper ...