The human heart is an organ that pumps blood throughout the body via the circulatory system, supplying oxygen and nutrients to the tissues and removing carbon dioxide and other wastes.
The heart has four chambers: two upper chambers (the atria) and two lower ones (the ventricles).
An adult heart pumps about 6 quarts (5.7 liters) of blood throughout the body and beats about
60 to 80 times per minute.
Coronary heart disease is the most common type of heart disease, killing more than 370,000 people annually. Plaque buildup in the arteries of a person with heart disease lessens or blocks the flow of blood. High blood pressure, high LDL cholesterol and smoking are key risk factors for heart disease. About half of Americans (49%) have at least one of these three risk factors.