Coronary Artery Disease
This is a problem with the blood vessels that deliver blood to the heart muscle. If these blood vessels get very small, or if they become blocked, blood cannot flow through them normally. Since less blood is supplied to the heart muscle, the muscle cannot work at normal capacity. The heart muscle can become sick and weak. Heart muscle can even die if blood flow stops. Blocked arteries in the heart are often caused by smoking, high cholesterol, high blood pressure, diabetes, and inherited traits from parents. All of these problems damage the lining of the heart's blood vessels and make them become narrowed or blocked completely.
Congestive Heart Failure
This is a condition that means that the heart is not pumping at normal levels. Two common causes are a weak or sick heart muscle and abnormal heart valves. The valves may not let enough blood through because they are too narrowed. Or the valve may "leak" and let blood flow backwards (the wrong direction) inside the heart. When the heart valves do not work normally, the heart muscle has to do extra work and it can become tired.
Bad Heart Rhythms
This is a problem with electrical activity in the heart. This can make the heart beat too fast or too slow. Very bad heart rhythms may make the heart stop pumping blood. The heart needs a normal rhythm to pump the blood well. If the rhythm is too fast, the heart may not have time for blood to enter the chambers, so there is not enough blood moving through the heart with each beat. If the heart is too slow, there may not be enough contractions of the heart to supply the body with the blood that it needs.
