Angina pectoris is a clinical manifestation of inadequate coronary blood supply which in the past was given many names, e.g. angina of effort, decubitus angina, nocturnal angina, intractable angina, Prinzmetal angina etc. but it is now proposed that if the angina is due to coronary vasospasm it should be called primary but if it is due to an established lesion it should be called secondary. But in actual fact both factors may operate specially in elderly people.
When it occurs suddenly at rest or by disturbing the sleep, it is called angina of decubitus or “nocturnal angina”. When it is brought about by effort it is named ‘angina of effort’. Sometimes it occurs without exercise, but associated with ST elevation in ECG as in Prinzmetal’s angina. These attacks are attributed to coronary spasm and may even end in myocardial infarction.
Older people may get attacks in toilet or during shaving. Raising the arms during shaving often precipitates the attack while more strenuous efforts may not do it. Emotional outburst is a notorious precipitating agent.
Clinical Types of Angina Pectoris:
Angina pectoris may be clinically classified into two groups:
(i) Stable angina
(ii) Unstable angina.
(i) Stable Angina:
This is commonest form of angina pectoris. The pain usually occurs during physical exertion or severe emotional stress, often during bathing or defecation. It is usually relieved by chewing or sucking a tablet of glyceryl trinitrate. The pain may recur again and similar episodes may continue for months or years unless properly treated. This recurrent episodic angina is termed chronic intractable angina.
(ii) Unstable Angina:
This is a new name of the well-known syndrome of “acute coronary insufficiency” also known as intermediate coronary syndrome, pre-infarction syndrome, acute coronary failure, threatened myocardial infarction and status angiosus etc.
To avoid further confusion W.H.O. has included all these into a group called “unstable angina”, which may be of two types e.g. Type-I and Type-II.
Type-I is recent onset of angina which has increased in severity.
Type-II attacks occur at rest due to various triggering factors e.g. emotional upsets exertion heavy meals, exposure to cold or sexual activity.
(1) Sometimes anginal pain may have no radiation from precordium to periphery or it may have radiation in the reverse direction.
(2) The precordial pain may be very mild or even non-existent but pain may be felt in inner forearm and arm and mistaken for neuritis or fibrositis.
(3) Precordial pain may only be felt at rest or only a choking sensation associated with pain in throat or jaw.
(4) Sometimes it is associated with tachycardia with or without lone auricular fibrillation pain being mild or minimal.
(5) Prinzmetal described a type, in which attacks occur in similar time and situation each day In E.C.G. there is elevation of S.T. segment instead of depression but there is no evidence of myocardial infarction. This type is also known as ‘angina pectoris inversa’. In this Prinzmetal-variant-angina, E.C.G. changes disappear as pain subsides. Prinzmetal’s angina may sometimes precipitate ventricular fibrillation.
Clinical Findings of Angina Pectoris:
In angina pectoris, physical signs are usually lacking. In coronary insufficiency, clinical features vary considerably; sometimes it is only local pain with tachycardia or bradycardia. B.P. may rise or fall.
In MI the signs may be plentiful. Usually there is tachycardia, pulse rate reaching over 120 p.m. or even bradycardia, various types of heart block, severe hypotension, signs of shock, collapse even unconsciousness. Gallop rhythm may be heard proclaiming left ventricular dysfunction.
In many instances of anginal attacks patients initially may not have severe symptoms. They may attribute the discomfort to gas due to indigestion or rheumatism. The pain is often felt as pressure or load on the chest or some kind of compression in the anterior chest wall.
The clinical picture of a classical myocardial infarction may be as follows:
(a) Sudden onset of acute anterior wall chest pain with or without radiation to the periphery.
(b) Sweating and cold extremities and cardiogenic shock
(c) Rapid pulse rate
(d) Ectopic beats, tachy, or brady-arrhythmias
(e) Signs of L.V.F. and pulmonary oedema
Sudden death may occur in severe AMI within a few minutes, usually due to ventricular fibrillation.
Diagnosis of Angina Pectoris:
If ECG is taken during pain of angina pectoris, ST-T changes or depression of S.T. segment may be noted, ECG taken soon after an attack or angina may or may not show any abnormality.
However, various new methods have been developed for diagnosis of early I.H.D. and angina pectoris which may have to be done in doubtful cases discussed in subsequent pages.
Exercise stress test:
This test can be carried out in the doctor’s clinic, where the patient is asked to do Master’s step- test. The patient with normal ECG, who is a Sufferer of anginal pain, may show a typical horizontal ST depression during exercise. Sometime it is difficult to interpret borderline ST-T changes.
More sophisticated tests consist of E.C.G. monitoring during exercise on a tread-mill. During the tread-mill exercise ECG monitoring can be carried out along with automatic recordings of pulse and B.P.
(1) Ischaemic heart disease
(3) Aneurysm of Aorta
(4) Dissecting Aneurysm
(3) Pulmonary embolism
(5) Spontaneous pneumothorax
(C) Chest Wall and Spine:
(1) Fibrositis/Neuritis/Tietze’s syndrome
(2) Bornholm’s Syndrome
(3) Disc Syndrome
(4) Caries Spine
(5) Trauma to ribs, sternum and spine
(6) Impending herpes zoster
(1) Hiatus hernia
(2) Mediastinal tumour or carcinoma
(4) Oesophageal spasm or oesophagitis
(1) Peptic Ulcer
(2) Gall bladder and hepatic pain
(3) Splenic flexure syndrome
(4) Acute or subacute pancreatitis
(1) Anxiety state
(2) Ischaemic abdominal vessels
(3) Herpes Zoster
(4) Tabes dorsalis-gastric crisis
(5) Epigastric fatty herniation
But sometimes even after routine ECG, X-ray studies, enzymes estimations, etc., it may not be possible to pinpoint the cause of anterior chest wall pain. In such cases coronary angiography may be very useful. It will also show the vessels affected and the degree of narrowing due to the obstructive lesions.
Depending on the findings one can decide if coronary by-pass surgery may be necessary, provided the patient can afford. Facilities of coronary angiography are becoming gradually available in big cities and teaching hospitals in India and hence it may not be necessary to refer these cases to UK or USA.
Treatment of Angina Pectoris:
Many drugs are now available for treatment of acute angina pectoris, but nitroglycerin (glyceryl trinitrate) is still the drug of first choice. It acts within a minute or so and relieves anginal pain by decreasing arteriolar and venous tone as well as relieves preload and after load. One tablet (5 mg) should be placed under the tongue and is allowed to be dissolved. In urgency it can be chewed for almost immediate action. The side-effects are headache and hypotension.
Headache rarely may be so disturbing that patient wants alternative drugs. Hypotensive patients may even faint after taking a tablet of trinitrate under the tongue, which passes off in a short time. Patient should be warned about these possibilities or the first dose may be given under supervision. As an alternative nifedipine can be used.
Usually isosorbide dinitrate or tetranitrate are used. Initially five and ten mg is given orally. These may be given every four or six-hourly.
Nitroglycerin ointments are now available which provide continuous cover for some hours. Transdermal nitroglycerin can give continuous release of the drug up to 24 hours.
The patient should also be taught to ward off the attack by rest, when attacks come after walking some distances. Window shopping or bird watching is a good method to avoid embarrassment in public. Trinitrate tablets should be in hand. Crush the tablet in mouth.
Smaller meals five or six times in a day are better than large conventional breakfast, lunch and dinner. Mental relaxation, prayers, musical evenings, religious meetings, good friendly atmosphere and card playing may be quite helpful. However, modern civilised life and high-tempo-action- packed occupational hazards may cause real problems. A good family doctor may be of great assistance to tide over problems than Cath-lab specialists.
Hence judicious use of tranquilizers and practice of detached attitude are useful. The family doctor should be the guide to decide when specialist consultation is necessary.
(1) Beta-Adrenergic-Blocking Agents:
Quite a few new anti-anginal drugs are now available. These drugs reduce heart rate and relieve angina by reducing oxygen consumption of myocardium. But their effect on coronary vasculature is controversial.
However, all these drugs should be used with caution. Contraindications are CHF, AV-block, resting bradycardia, hypotension, arrhythmias and W-P-W syndrome. It should not be used in cases of bronchial asthma and Raynaud’s disease. Side-effects vary on the type of β blocker used. Beta-I blockers are less harmful in precipitating asthma or in masking hypoglycaemia symptoms in diabetics. Hence use of β-blockers-like propranolol in diabetics may be risky. Usual side-effects must also be carefully watched.
Calcium — Entry Blockers:
These drugs control calcium-influx into the myocardial cells and vascular smooth muscles. These drugs chiefly act by reducing tone of vascular smooth muscle and reduce oxygen demand. Myocardial oxygenation is also improved and coronary vasospasm is also reduced. However, atherosclerotic vessels may have little scope for the action.
The two drugs commonly used are Nifedipine and verapamil. The third drug Diltiazem is also available in India now.
In spite of some risks in using these drugs they are very useful in treating cases of unstable or variant angina and even stable angina, who do not tolerate nitrates or fi-blockers. Both these drugs are also useful in controlling hypertension.
Platelet Inhibitor Drugs:
Anti-platelet aggregating agents have come into vogue since recent researches stressed the importance of prostaglandin-synthesis and role of thromboxane (the platelet aggregating agent). Prostacyclin diminishes platelet aggregation and helps vasodilatation. Drugs generally used are aspirin, sulphin-pyrazone and dipyridamole.
However, its possible role in preventing heart attacks and its long-term value has not been fully evaluated.
In all cases of I.H.D., it is important that life style of the patient may have to be readjusted as follows:
(1) Smoking must stop permanently.
(2) Reduce weight in obese patients.
(3) Diet has to be adjusted depending on body weight and lipid profile.
(4) If lipid profile is still normal, one egg for breakfast may be allowed if patient likes it. Animal fat, red meat and butter should be avoided.
(5) Alcohol: if patient is in the habit of taking alcohol regularly and is not prepared to give up, he may be allowed 30 to 60 ml of whisky or brandy to drink slowly in the evenings.
(6) Sedatives and tranquilizers are to be used as and when required.
(7) Diabetic patients with angina must be more careful regarding follow-up. Even minor chest pain if continued should be evaluated. Diabetes may cause cardiomyopathy and silent myocardial infarcts may occur. β-blockers be better avoided.
(8) Anaemia, if present, should be treated as well as its cause should be determined.
(9) Associated endocrine disorders if any need thorough investigation. Thyroid disorders whether thyrotoxicosis or myxoedema, both may cause and aggravate angina pectoris.
(10) Graduated exercise programme should be organised. In the author’s experience, place of yoga is supreme in achieving mental tranquillity and relaxation.
(11) Proper sex-life depending as cardio-vascular status is also very important. Role of wife is supreme in this direction.
Anticoagulants in unstable angina are still a controversial subject. As treatment of unstable angina is unsatisfactory and drugs therapy with newer drugs also are not always rewarding, it is worthwhile giving a trial of anticoagulant therapy provided facilities are available, especially when patients cannot afford coronary by-pass surgery.
Heparin is best drug to use as it is short acting and rapid in action. Oral anticoagulants can be convenient for the patient. In author’s personal experience in the Armed Forces Hospitals both methods, produced satisfactory results, while in many large civil hospitals where facilities do not exist, there are many problems in prescribing anticoagulants, hence it is better to avoid.
Role of Surgery (Coronary Artery Bypass):
Recent reports of the results of coronary artery bypass surgery are certainly encouraging. Selection of cases is most important. Good coronary angiography and left ventricular function assessment are the most essential steps. Anginal pain is usually relieved and many home-ridden patients are going to lead active life after bypass.
Those with good left ventricular function are better candidates even when three vessels are affected. Patients with unstable angina are the most difficult cases and require very expert handling. These patients are at the risk of developing sudden acute myocardial infarction, unless treated continuously. Aspirin therapy in addition to antianginal drugs is helpful.
Aspirin however will not relieve anginal pain, so long acting nitrates, β-blockers and calcium channel blockers should be judiciously used. When these measures fail, complete bed rest may relieve angina to recur again on resuming activity. These patients need careful handling to decide whether they should go for bypass surgery. Some patients are also becoming better with anticoagulants and antiplatelet therapy.
Percutaneous transluminal coronary angioplasty is also being done in recent times with good results and it is probable, that angioplasty will become more popular than by-pass surgery.