Definition of Heart Disease
Heart disease is a general term that refers to any disease or condition of the heart, including coronary heart disease, hypertension, heart failure, congenital heart disease, disorders of the heart valves, heart infections, cardiomyopathy, conduction disorders, and heart arrythmias. This information item will focus on atherosclerotic changes – the changes that occur because of the build up of plaques or fatty streaks on the interior walls of the blood vessels that supply oxygenated blood to the heart muscle. This condition is also known as coronary artery disease.

Description of Heart Disease
The heart is a muscular pump in the chest. Throughout life it beats continuously and rhythmically to send blood to the lungs and the rest of the body.

The normal heart weighs approximately 10 1/2 ounces and is about the size of your fist. It beats 60 to 120 times a minute, depending on whether you are excited or resting.

The average blood cell makes a round trip through the body's arteries and veins every 60 seconds, and can hit speeds of up to 10 mph. The heart pumps your five quarts of blood around your body 500 times a day.

When the arteries become clogged with deposits made up of "bad" cholesterol, plaque, scar tissue, or calcium, the heart has a harder time circulating blood. This clogging causes a myriad of heart problems from angina pectoris (chest pain) to heart failure to a heart attack

Causes and Risk Factors of Heart Disease
The primary risk factors for the development of atherosclerotic heart disease are smoking, sedentary lifestyle, hypertension, diabetes, hypercholesterolemia, and a genetic predisposition to the disease.

Symptoms of Heart Disease
In its early stages there are no symptoms. The first symptom is usually angina pectoris (chest pain) or heart attack.

Angina pectoris is discomfort or pain in the chest, typically, brought on by exertion and relieved by rest. The pain may be a dull ache in the middle of the chest or a feeling of pressure that may spread up to the neck or down the arms.

The major symptoms of a heart attack are intense chest pain, suddenly cold, sweating, weakness and nausea.

Diagnosis of Heart Disease
The diagnosis of this problem is based upon clinical history and physical exam. Confirmatory tests include electrocardiography (electrodes are connected to the chest and heart activity is monitored) and measurement of the level of serum creatine kinase enzymes released into the blood by the damaged muscle. Another method is the heart imaging technique called an angiography (injection of dye into the arteries followed by x-ray).

Treatment of Heart Disease
There are several treatment methods that will help improve blood flow through the arteries:

Medications
Beta-blockers, such as atenol (Tenormin), nadolol (Corgard), metoprolol (Lopressor, Toprol XL), and propranolol (Inderal), lower blood pressure by reducing the amount of blood pumped by the heart. These drugs may also reduce the risk of a subsequent heart attack in patients who have already had one. Possible side effects include fatigue, impotence, abnormalities in fatty substances in the blood and interference with blood-sugar regulation. (View list of beta-blockers)

Calcium channel blockers, such as amlodipine (Norvasc), diltiazem (Cardizen, Tiazac), nifedipine (Adalat, Procardia), nisoldipine (Sular), and verapamil (Calan, Isoptin, Verelan), relax blood vessel walls, thereby lowering pressure. They are also quite expensive and may cause side effects such as constipation and swollen legs. There are also Nitrate-based drugs and vasodilator drugs. (View list of calcium channel blockers)

Diuretics, such as chlorothiazide (Diuril) and hydrochlorothiazide (Esidrix), lower blood pressure by causing the body to expel excess fluids and sodium through urination. If the desired effects aren't realized with diuretics alone, in combination they may enhance the effect of other blood pressure medications. (View list of diuretics).

Angiotensin-Converting Enzyme (ACE) Inhibitors, such as captopril (Capoten), enalapril (Vasotec), and lisinopril (Prinivil, Zestril), expand blood vessels and decrease resistance. This allows blood to flow more easily and makes the heart's work easier. (View list of ACE inhibitors).

Angiotensin-2 (AT-2) receptor antagonists, such as candesartan (Atacand) and

irbesartan (Avapro), have been shown to achieve effects similar to those found in ACE inhibitors. Instead of lowering levels of angiotensin II (as ACE inhibitors do), angiotensin II receptor blockers prevent it from effecting the heart and blood vessels. This keeps blood pressure from rising.

Statins, such as atorvastatin (Lipitor), pravastatin (Pravachol), and rosuvastatin calcium (Crestor), are very effective in lowering LDL ("bad") cholesterol levels and have few short-term side effects. They work in the liver to interrupt the formation of cholesterol from the circulating blood. (View list of statins). Ezetimibe (Zetia) is a newer drug that lowers LDL (“bad”) cholesterol by working in the digestive tract to reduce the absorption of cholesterol. It is sometimes prescribed along with a statin.

Bypass Graft Surgery
Bypass graft surgery was introduced as a way of treating coronary artery disease. In this operation (abbreviated as CABG and sometimes pronounced "cabbage"), cardiac surgeons remove part of the blood vessel (graft) from somewhere else in the body and attach it to a narrowed or blocked coronary artery so the muscle ordinarily supplied by the vessel can be nourished again. For many people who suffer from unremitting angina, CABG can provide dramatic relief.

The principle of bypass graft surgery is to construct a new channel so blood can get around the atherosclerotic blockages in the coronary arteries. Therefore, instead of trying to scrape out the plaques, the surgeon uses a segment of a vessel from another part of the body to transport blood to the far side of the obstruction. Usually the grafts are fashioned from one of the large, accessible saphenous veins that run down the inside of the leg, although recently there has been a trend towards using the internal mammary arteries located under the chest wall.