Management of Angina Pectoris

Management of Angina involves 3 phases.

1. Assessment of the severity of the problem.
2. Measures to control the symptoms.
3. Treatment to improve life expectancy.

Assessment of severity involves general checkup and routine investigations to find out any associated problem that might have precipitated or helped in the progression of Coronary heart disease. Diabetes mellitus or Hyperlipidaemia if present have to be managed.

Severity of the disease is assesed by Exercise Tolerance test Or Trendmill Test commonly known as TMT.

Measures to contol the symptoms:
Education of the patient regarding the cause of Angina - a mismatch between coronary blood supply and the cardiac need. Stress on the natural process of repair by the development of anastomosis of small vessels to overcome the reduced blood supply to a particular area. Patients have to learn to help themselves by avoiding stressful situations.

Advise to patients of Angina

Avoid walking after meals.
Avoid walking in cold particularly against wind.
Avoid unaccustomed exertion.
Stop Smoking
To maintain ideal weight.
To take regular exercise: exercise upto and not beyond the point of chest pain is benificial.

Drug Treatment

Nitrates
Beta Blockers
Calcium Antagonists

Nitrates
Glyceryl Trinitrate (GTN 500 micro gram) taken under the tongue relieves pain within 2-3 minutes. It should be spit out when the pain is relieved. It causes slight headache. It can be put to best use by taking it prophylactically before exercise or a particular type of activity known to produce Angina.

Not more than 2 tablets per hour to be used. GTN shelf life is short. Angina patients should be encouraged to get use to increased amount of exercise. This helps in the formation of collateral circulation in the cardiac tissue.
GTN can also be given subcutaneously in the form of paste or plaster which gives longer duration of action.
GTN is ineffective when swallowed.

Oral Nitrate are also available which have prolonged action.

Isosorbide dinitrate 10 mg 3-6 per day. Oral nitrate cause more headache which tend to reduce with continuous use. Tolerance to nitrates occur and dose needs to be increased. A nitrate free period of 1-2 hours every 24 hours helps.
Long acting Oral Nitrate are also available which needs to be given 12 hourly.

Beta blockers
It helps by reducing oxygen demand of the myocardial tissue by reducing the heart rate for a given level of exercise.
e.g. Propranolol, Atenolol, Metoprolol, Pindolol, Oxprenolol,
Propranolol is lipid soluble and thus crosses blood brain barrier and thus causes CNS side effects like drowsiness, nightmares, depression. Atenolol is water soluble and thus does not cause CNS side effects.

Beta blocker drugs should not be withdrawn abruptly because of risk of dangerous arrhythmias and myocardial infarction.

Calcium antagonists
They inhibit slow inward current caused by the entry of extracellular calcium through the cell membrane of the excited cells. Their action is mainly in the arteriolar smooth muscles and the atrial cells. The effect is vasodilatation, reduction in excitability and conductivity.
e.g. Nifedipine, Verapamil, Diltiazem, Nicardipine.

Surgical Treatment

Coronary Angioplasty
Bypass Grafting

Coronary Angioplasty
This is performed by passing a fine guidewire across the coronary stenosis under radiographic contoll. Using it a baloon is positioned which is then inflated to dilate the stenosis. It is mainly used in single or two vessel disease.

Coronary artery bypass grafting
This is done under cardiopulmonary bypass. Narrowed segments od coronary artery are bypassed using grafts of saphenous vein or the patients internal mammary arteries.

UNSTABLE ANGINA
Unstable angina is anginal pain coming on at rest or on mininmal exertion. It can be new phenomenon or be occur over the preexisting stable angina. There are ST segment elevation or depression at the time of pain but no parmanent ECG changes occur.