Pharmacology Notes

Angina Pectoris
Angina pectoris is an episodic, reversible oxygen insufficiency. This condition is the most common form of IHD. Angina pectoris is applied to varying forms of transient chest pain that are attributable to insuffi cient myocardial oxygen. Atherosclerotic lesions that produce a narrowing of the coronary arteries are the major cause of angina. However, tachycardia (increased heart rate), anemia, hyperthyroidism, and hypotension can cause an oxygen imbalance. According to the American Heart Association, angina occurs more commonly in women than men. There are several types of angina: stable (classic), unstable, decubitus (nocturnal), and silent angina. The most common form is classic angina that may occur, with predictable frequency, from exertion (often from exercising), emotional stress, or a heavy meal. Classic angina is relieved by rest, nitroglycerin, or both.

Unstable angina is a medical emergency, and the patient must be treated in a hospital. It typically has a sudden onset, sudden worsening, and stuttering reoccurrence over days and weeks, and carries a more severe short-term prognosis than stable chronic angina. Unstable angina occurs during periods of rest. Signs of unstable angina include changes in blood pressure, transient heart murmur, and arrhythmias.

Decubitus angina is a condition characterized by periodic attacks of cardiac pain that occur when a person is lying down. It is also known as vasospastic angina. Decubitus angina occurs when the decreased myocardial blood fl ow is caused by spasms of the coronary arteries.

Silent angina is a condition that occurs in the absence of angina pain. One or more coronary arteries are occluded, but the individual remains asymptomatic.

Nocturnal angina is caused by coronary artery spasms and can be treated by calcium channel blockers and nitrates. It occurs during the REM
period of sleep.

• Treatment goals for angina include:

• Reducing the risk of sudden death

• Preventing myocardial infarction (MI)

• Increasing myocardial oxygen supply

• Reducing pain and anxiety associated with an angina attack

 Treatment for angina includes surgery and drug therapy. If the coronary arteries are signifi cantly occluded or blocked, coronary arterial bypass graft (CABG) or percutaneous transluminal coronary angioplasty (PTCA) are performed. CABG is a procedure wherein a vein graft is surgically implanted to bypass the part of the occlusion in the coronary artery. PTCA reduces obstruction by means of invasive procedures requiring cardiac catheterization. Th e catheter contains an infl atable balloon that flattens the obstruction. Newer techniques use laser angioplasty.