Ischemic Heart Disease (IHD) is a condition in which fatty deposits (atheroma) accumulate in the cells lining the wall of the coronary arteries. These fatty deposits build up gradually and irregularly in the large branches of the two main coronary arteries which encircle the heart and are the main source of its blood supply. This process is called atherosclerosis which leads to narrowing or hardening of the blood vessels supplying blood to the heart muscle (the coronary arteries ). This results in ischemia ( inability to provide adequate oxygen) to heart muscle and this can cause damage to the heart muscle . Complete occlusion of the blood vessel leads to a heart attack (myocardial infarction).
In the United States , cardiovascular disease is the leading cause of death among both sexes, and coronary artery disease is the commonest cause of cardiovascular disease.
Myocardial infarction causes 35% of deaths in men between 35 and 50. The death rate is higher for men than for women between the ages of 35 and 55. However, after the age 55, the death rate for men declines but the rate for women continues to climb.
Exact cause is unknown. However there are a number of risk factors. Control of these risk factors has been shown to reduce the severity and complications of the disease.
It is now clear that reducing certain risk factors, we can both prevent coronary artery disease and delay its progression and complications after it it has become manifest. Treatment of lipid abnormalities has now been shown to delay the progression of atherosclerosis and in some cases has even produced regression of the atherosclerotic plaques.
Signs & Symptoms
Angina pectoris (burning, squeezing, heaviness, or tightness in the chest that may extend to the left arm, neck, jaw, or shoulder blade). See Angina Pectoris.
Typically, angina is precipitated by physical activity, lasting no more than a few minutes, and is relieved by rest. Usually angina is worse when exertion follows a meal. It is also worse in cold weather and can be triggered by walking from a warm room into the cold air. Emotional stress can also cause or worsen angina.
Not all people with ischemia will present with angina. Ischemia without angina is called silent ischemia. It is not yet understood why ischemia is sometimes silent.
- Family history of coronary artery disease, diabetes, high blood pressure or atherosclerosis.
- Poor nutrition, especially too much fat in the diet.
- Previous heart attack or stroke.
- Elevated cholesterol and/or low level of HDL (high-density lipoprotein).
- Type A personality.
- Herbicide exposure.
Diagnosis & Treatment
Diagnosis of angina is a clinical diagnosis based on a characteristic complaint of chest discomfort or chest pain brought on by exertion and relieved by rest. Confirmation may be obtained by observing reversible ischemic changes on ECG during an attack or by giving a test dose of sublingual nitroglycerin that characteristically relieves the pain in 1 to 3 minutes.
Certain tests may help determine the severity of ischemia and the presence and extent of the coronary artery disease. Diagnostic tests may include electrocardiogram (measures electrical activity of the heart), echocardiogram (measures sound waves), exercise-tolerance test, thallium stress test, blood studies to measure total fat, cholesterol and lipoproteins, X-rays of the chest and coronary angiogram (cardiac catheterization).