HEART ATTACK
Heart attacks result from blood vessel disease in the heart. Coronary heart disease (CHD), sometimes referred to as coronary artery disease (CAD), is a more general name for heart attack (and angina).
A heart attack (or myocardial infarction) occurs when the blood supply to part of the heart muscle itself (the myocardium) is severely reduced or stopped. This occurs when one of the coronary arteries (the arteries that supply blood to the heart muscle) is blocked by an obstruction, often plaque due to atherosclerosis. A heart attack also can be caused by a blood clot lodged in a coronary artery. Such an event is sometimes called a coronary thrombosis or coronary occlusion.
If the blood supply is cut off drastically or for a long time, muscle cells suffer irreversible injury and die. Disability or death can result, depending on how much heart muscle is damaged.
Sometimes a coronary artery temporarily contracts or goes into spasm. When this happens the artery narrows and blood flow to part of the heart muscle decreases or even stops. What causes a spasm is unclear, but it can occur in normal blood vessels as well as vessels partially blocked by atherosclerosis. If a spasm is severe, a heart attack may result.
Heart failure affects nearly 5 million Americans, including approximately 550,000 newly diagnosed heart failure patients each year. It is the leading cause of hospitalization in people older than 65.
Heart failure does not mean the heart has stopped working; rather, it means that the heart's pumping power is weaker than normal. With heart failure, blood moves through the heart and body at a slower rate, and pressure in the heart increases. As a result, the heart cannot pump enough oxygen and nutrients to meet the body's needs.
The chambers of the heart respond by stretching to hold more blood to pump through the body or by becoming more stiff and thickened. This helps to keep the blood moving for a short while, but in time, the heart muscle walls weaken and are unable to pump as strongly. As a result, the kidneys often respond by causing the body to retain water and sodium. If fluid builds up in the arms, legs, ankles, feet, lungs or other organs, the body becomes congested, a condition called congestive heart failure.
Heart failure is caused by many conditions that damage the heart muscle, including coronary artery disease, heart attack, cardiomyopathy and conditions that overwork the heart, such as valve disease, kidney disease and congenital heart defects.
Coronary Artery Disease: CAD is a disease of the arteries that supply blood and oxygen to the heart, causes decreased blood flow to the heart muscle. If the arteries become blocked or severely narrowed, the heart becomes starved for oxygen and nutrients.
Cardiomyopathy: Damage to the heart muscle from causes other than artery or blood flow problems, such as from infections or alcohol or drug abuse.
Conditions that overwork the heart. Conditions including high blood pressure (hypertension), valve disease, thyroid disease, kidney disease, diabetes or heart defects present at birth can all cause heart failure. In addition, heart failure can occur when several diseases or conditions are present at once.
Symptoms of heart failure can be mild to severe, be constant or come and go. They may include congested lungs, fluid and water retention, dizziness, fatigue and weakness, and rapid or irregular heartbeats.
If you have heart failure, you may have one, all or none of these symptoms. In addition, your symptoms may not be related to how weak your heart is; you may have many symptoms but your heart function may be only mildly weakened. Or you may have a more severely damaged heart but have no symptoms.
