The heart is simply a muscular pump with 4 chambers, connected to each other by valves. The heart’s job, in cooperation with the lungs, is to circulate oxygen-rich blood to all cells in the body.The heart beats about 100,000 times per day, so it needs a constant supply of energy. The heart strongly prefers to burn fat rather than glucose (sugar) or other fuels, which is why there is some fat wrapped around the heart.
The heart’s own cells also need oxygen, so there are 4 special vessels called coronary arteries which deliver blood to the heart itself. If any of these critical arteries becomes blocked, heart muscle cells will die from lack of oxygen. This is called a myocardial infarction, or heart attack. The most common cause of heart attacks is atherosclerosis (hardening of the arteries), which is strongly associated with high glycemic index carbohydrates, and not with saturated fat or cholesterol.
Other diseases affecting the heart include: hypertension (high blood pressure) atrial fibrillation, cardiomyopathy, angina, and valve disorders.