Heart Attack 2

What is angina pectoris?

Angina pectoris is chest pain or pressure that occurs when the oxygen supply to the heart muscle cannot keep up with oxygen consumption by the heart muscle. (Oxygen consumption by the heart muscle increases with physical exertion or excitement and decreases with rest and relaxation.) Most commonly, the inadequate supply of oxygen is due to narrowing of the coronary arteries by atherosclerosis. When coronary arteries are narrowed by more than 50% to 70%, the arteries cannot increase the supply of blood to the heart muscle during exertion or other periods of high oxygen demand. An insufficient supply of oxygen to the heart muscle causes chest pain (angina). Chest pain that occurs with exercise or exertion is called exertional angina. Please read the MedicineNet Angina article for more information on the different types of angina.

What is a heart attack?

A heart attack (myocardial infarction) is the death of heart muscle due to the sudden and complete blockage of a coronary artery by a blood clot. A coronary artery blockage usually occurs in arteries that contain cholesterol plaques. A plaque can rupture and initiate the formation of a blood clot next to it. A blood clot can completely block blood flow through a coronary artery and deprive the heart muscle of needed nutrients and oxygen. The heart muscle then dies, which produces a heart attack. For additional information, please read the Heart Attack article, and the Heart Attack Photo Essay, with real pictures of coronary artery blockage.

Ventricular fibrillation

A heart attack can trigger the sudden onset of ventricular fibrillation. Ventricular fibrillation is a chaotic electrical rhythm of the heart that causes cardiac arrest (the heart stands still and ceases to pump blood). Ventricular fibrillation causes permanent brain damage and death unless a normal heartbeat can be restored within five minutes of its onset. Of the 1 million Americans who suffer heart attacks annually, approximately 400,000 of them die suddenly and unexpectedly from ventricular fibrillation before the victims can reach any medical assistance. For these people, the first sign of coronary heart disease is sudden, unexpected death. Read More......

Heart Attack

Coronary atherosclerosis is the hardening and narrowing of the arteries that supply blood to the heart muscle. Coronary atherosclerosis is the major cause of heart attacks. Heart attacks are the major cause of sudden unexpected death among otherwise healthy adults in the prime of their lives. Heart attacks are also a significant cause of heart failure (due to weakened heart muscle) in this country.

Heart failure considerably decreases a person's longevity and quality of life. In dollar terms, coronary heart disease is costly. The total cost of coronary artery bypass surgery, coronary angioplasty and stenting, medications, and hospitalizations exceeds 50 billion dollars annually. Coronary atherosclerosis, and hence heart attacks, are preventable. A person can significantly lower his or her risk of heart attack by lowering high blood pressure, controlling diabetes, stopping cigarette smoking, losing excess weight, exercising regularly, and lowering the levels of bad “LDL” cholesterol and increasing the level of the good “HDL” cholesterol in the blood. In recent years, other risk factors for coronary atherosclerosis have been identified. These include a high serum homocysteine level and certain subtypes of LDL cholesterol. The following is a comprehensive review of the causes of atherosclerosis and heart attacks, and the means for their treatment and prevention. What is atherosclerosis?

Atherosclerosis is a gradual process whereby hard cholesterol substances (plaques) are deposited in the walls of the arteries. Cholesterol plaques cause hardening of the artery walls and narrowing of the inner channel (lumen) of the artery. Arteries carry blood that is enriched with oxygen and nutrients to the vital organs such as the brain, heart, kidneys, and liver. Arteries also transport blood to other tissues such as the fingers, toes, nerves, bones, skin, and muscles. Healthy arteries can deliver an ample supply of blood to the organs and tissues. In contrast, arteries that are narrowed by atherosclerosis have difficulty delivering blood to the parts of the body they supply. For example, atherosclerosis of the arteries in the legs causes poor circulation in the lower extremities. Poor circulation in the lower extremities can lead to pain while walking or exercising, deficient wound healing, and/or leg ulcers. Atherosclerosis can also cause the complete blockage of an artery from a blood clot. This complete blockage interrupts oxygen supply and results in tissue injury or death. Thus, the blockage of an artery that furnishes blood to the brain can lead to a stroke (death of brain tissue). Likewise, the blockage of the arteries to the heart can result in a heart attack (death of heart muscle), also called myocardial infarction (MI). What are coronary heart diseases (CHD)?

Coronary atherosclerosis refers to the hardening and narrowing of the coronary arteries. The coronary arteries supply the blood that carries oxygen and nutrients to the heart muscle. When coronary arteries are narrowed or blocked by atherosclerosis, they cannot deliver an adequate amount of blood to the heart muscle. Disease caused by the lack of blood supply to heart muscle is called coronary heart disease (CHD). Coronary heart diseases include heart attacks, sudden unexpected death, chest pain (angina), abnormal heart rhythms, and heart failure due to weakening of the heart muscle. Read More......