crescendo angina
angina
[an-ji´nah, an´jĭ-nah]Angina pectoris occurs more frequently in men than in women, and in older persons than in younger persons. It is not a disease entity but a symptom of an underlying disease process involving the arteries that supply blood to the heart muscle. About 90 per cent of all cases can be attributed to coronary atherosclerosis. Studies have shown that at least one of the three major coronary arteries usually is stenosed before angina develops. In most cases, all of the major coronary arteries are involved.
Angina pectoris also can result from stenosis of the aorta, pulmonary stenosis and ventricular hypertrophy, or connective tissue disorders such as systemic lupus erythematosus and periarteritis nodosa that affect the smaller coronary arteries.
Coronary arteriography and ventriculography are valuable in determining the prognosis for angina pectoris. The mortality rate for patients having a narrowing of all three main coronary arteries is higher than for those who have only one vessel involved. Severity of pain is not a good prognostic indicator; some patients with severe discomfort live for many years, while others with mild symptoms die suddenly. An enlarged heart, a third heart sound, ECG abnormalities at rest, and hypertension are all indicative of a poor prognosis.
Organic nitrates may be administered orally or sublingually for relief from anginal pain. They act by dilating the arteries and may be used to treat acute attacks, for long-term prophylaxis and management, or for prophylaxis in situations likely to provoke an attack. Commonly used nitrates are erythrityl tetranitrate, isosorbide dinitrate, and nitroglycerin.
Beta-adrenergic blocking agents, such as propranolol, are used to treat patients who do not respond to weight control and treatment with vasodilators and whose angina significantly limits their activities. These agents decrease the heart rate, blood pressure, and myocardial oxygen consumption and increase the patient's exercise tolerance.
The calcium channel blocking agents (nifedipine, verapamil, diltiazem, and others) are drugs that are particularly beneficial in relieving pain in patients whose angina is the result of coronary artery spasm or constriction. They act by selectively inhibiting the transport of calcium across the cell membrane of myocardial cells and also by reducing myocardial oxygen utilization. Patients most likely to obtain dramatic relief from drugs of this kind are those who experience chest pain while resting or sleeping, upon exposure to cold, or during emotional stress.
Surgical procedures involving arterial bypass and angioplasty have become fairly common as a form of treatment of certain types of ischemic heart disease and resulting angina pectoris. The surgical procedures attempt to bypass the diseased portion of the coronary artery by suturing a vein graft or the internal mammary artery from the aorta to one or more coronary arteries beyond the area of obstruction. In most instances the graft is obtained from the patient's saphenous vein. Angioplasty reestablishes patency of the vessels; in most cases, it is now accompanied by insertion of a stent to help prevent restenosis.
An attitude of calmness and efficiency is most important when caring for a person suffering from an attack of angina pectoris. The pain produces emotional reactions and the strongest of these is fear. Most of these patients know that their pain is resulting from an insufficient supply of oxygen to the heart and they frequently have a feeling of impending death. It usually helps to raise the patient to a sitting position so that breathing is less difficult. The prompt administration of nitroglycerin or the specific drug ordered by the physician should shorten the attack and relieve pain. Above all, the calm presence of someone who knows how to care for them can do much to reassure patients and help them relax, thus lessening the severity of the attack.