angina pectoris(redirected from unstable angina)
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angina pectoris(ănjī`nə pĕk`tərĭs), condition characterized by chest pain that occurs when the muscles of the heart receive an insufficient supply of oxygen. This results when the arteries that supply the heart muscle with oxygenated blood are narrowed by arteriosclerosisarteriosclerosis
, general term for a condition characterized by thickening, hardening, and loss of elasticity of the walls of the blood vessels. These changes are frequently accompanied by accumulations inside the vessel walls of lipids, e.g.
..... Click the link for more information. . In rare cases angina results from spasms of the coronary arteries. Angina is a primary symptom of coronary artery diseasecoronary artery disease,
condition that results when the coronary arteries are narrowed or occluded, most commonly by atherosclerotic deposits of fibrous and fatty tissue. Coronary artery disease is the most common underlying cause of cardiovascular disability and death.
..... Click the link for more information. .
The pain is usually experienced under or to the left of the sternum (breastbone) and radiates to the left shoulder and down the upper arm; less frequently, it spreads to the right shoulder. The attack usually subsides without residual discomfort and, when precipitated by physical exertion, is quickly halted when the subject rests. Often the attacks are separated by weeks, months, even years in which symptoms subside. Symptoms usually begin after the age of 50, more often in men than women, and frequently follow physical exertion, excitement, eating, smoking, or exposure to cold. Associated symptoms are faintness and difficulty in breathing.
Nitrates (e.g., amyl nitrite or nitroglycerin), drugs that dilate the blood vessels of the heart, are traditionally used in treatment. Newer drug treatments include beta-blockersbeta-blocker
or beta-adrenergic blocking agent
, drug that reduces the symptoms connected with hypertension, cardiac arrhythmias, angina pectoris, migraine headaches, and other disorders related to the sympathetic nervous system.
..... Click the link for more information. and calcium-channel blockerscalcium-channel blocker,
any of a class of drugs used in treating hypertension, angina pectoris, and certain arrhythmias. They prevent the calcium ions needed for muscle contraction from entering the cells of smooth and cardiac muscle.
..... Click the link for more information. . Significant narrowing of the coronary arteries may require surgical treatment, such as a coronary artery bypass, a procedure that splices healthy blood vessels taken from elsewhere in the body to the affected coronary arteries in such a way that the clogged areas are bypassed. In angioplastyangioplasty
, any surgical repair of a blood vessel, especially balloon angioplasty or percutaneous transluminal coronary angioplasty, a treatment of coronary artery disease.
..... Click the link for more information. , a balloon-tipped catheter is inserted through the skin into a blood vessel and maneuvered to the clogged artery. There it is threaded into the blockage and inflated, compressing the plaque against the arterial walls. New techniques use atherotomes to mechanically cut the plaque or cold lasers to remove plaque with bursts of ultraviolet light.
the most common clinical form of ischemic heart disease. Angina pectoris is caused by paroxysms of substernal or precordial constrictive pain, which often radiates to the left shouder, left arm, and neck. The disease was first described in 1768 by the English physician W. Heberden.
Angina pectoris may occur as a result of exertion or when resting. In the former case, pain is produced by walking or other physical effort, by entering the cold or wind from a warm place, or by nervous tension. The pain usually disappears after rest; if it appears while walking, the afflicted individual should stop and rest. In an attack that occurs when resting, the pain is not associated with physical exertion or nervous tension. These types of attacks frequently occur during sleep, waking the individual. In both types of angina pectoris an attack lasts several minutes and is quickly relieved by nitroglycerin and, in many cases, by Validol. It may be accompanied by temporary electrocardiographic changes and by reflex autonomic disorders, including pallor, cold sweat, and pulse inhibition. From the standpoint of prognosis, angina pectoris caused by exertion is less dangerous than that produced when resting and less frequently leads to the severe form of ischemic heart disease—myocardial infarction.
An attack of angina pectoris is a result of acute coronary insufficiency, which is a temporary disparity between the flow of blood to the heart along the coronary vessels and the requirements of cardiac muscle. In the great majority of cases, acute coronary insufficiency is caused by atherosclerosis of the coronary vessels, although it may also be caused by collagen diseases of the coronary vessels and syphilis of the aorta. These organic changes are accompanied by pain produced by functional disturbances (spasms) of the coronary vessels that occur, for example, with hypertension or an increase in the heart muscle’s demand for oxygen during physical exertion. An attack of angina pectoris may occur even in the absence of morphological changes in the blood vessels as a result of a spasm of the vessels, for example, in cases of cholecystitis and gastric and peptic ulcers.
Attacks of angina pectoris are distinguished from heartburn, or pain in the area of the heart. Many typical features of angina pectoris do not characterize heartburn. For example, unlike the pain produced by angina pectoris, heartburn pain is not paroxysmal in nature. Heartburn often accompanies various diseases of the heart and other organs and systems, including neuroses, climacteric cardiopathy, myocarditis, pericarditis, and osteochondrosis.
A regular balanced schedule of work, rest, and sleep is important in the treatment of angina pectoris. Dietetic treatment is directed against excessive weight, atherosclerosis, and hypertension. Habits that are detrimental to the health, above all smoking, should be abandoned. Sanatorium and health resort treatments are often helpful.
Drugs are used to halt and prevent attacks of angina pectoris. Validol and nitroglycerin are used for relief of attacks. In cases of severe, prolonged attacks these drugs may be ineffectual, and nonnarcotic analgesics, narcotics, and nitrous oxide may be prescribed. Attacks may be prevented and chronic ischemic heart disease treated by the use of vasodilators (papaverine, Nospa-num, Intensain, Depot-Nitroglycerine), beta adrenergic blocking agents (Propranolol hydrochloride and Proctalol), anabolic steroids (retabolil), and anginine.
REFERENCESPlots, M. Koronarnaia bolezn’. Moscow, 1961. (Translated from English.)
Miasnikov, A. L. Gipertonicheskaia bolezn’ i ateroskleroz. Moscow, 1965.
Vorob’ev, A. I., andT. V. Shishkova. Kardialgii. Moscow, 1973.
Miasnikov, L. A., and V. I. Metelitsa. Differentsirovannoe léchente khronicheskoi ishemicheskoi bolezniserdtsa. Moscow, 1974.
N. R. PALEEV