Angina is the most common manifestation of ischaemic heart disease. It is a syndrome characterized by chest discomfort associated with myocardial ischaemia without necrosis. It is defined as stable if it has not changed in frequency, duration or precipitating cause in the past 60 days.
Who suffers from Angina?
The prevalence of angina increases with age and occurs in up to 5% of the 45-54-year age group and up to 20% in the 65-74-year age group. It is twice as common in men as in women, and occurs more commonly in developed countries.
How the chest pain occurs in Angina?
Angina results from an imbalance between the oxygen supply and demand of the myocardium, hence the relationship of chest pain with exercise. By far the most common cause is ischaemia resulting from atherosclerotic narrowing of the coronary arteries. Haemodynamic compromise usually occurs after a 70% reduction in the luminal diameter of a coronary artery. Reduction of flow may also occur from coronary artery vasospasm.
Angina can also result from reduced oxygen carrying capacity of blood (anaemia) and increased oxygen demand can be due to myocardial hypertrophy (e.g. valvular heart disease).
What can be the complications of Angina?
The acute complications of angina tend to result from atherosclerotic plaque instability. Ulceration and fissuring of the plaque may lead to acute coronary syndromes presenting as unstable angina or non ST elevation myocardial infarction (NSTEMI). Embolus or thrombosis may result in coronary artery occlusion and ST segment elevation myocardial infarction (STEMI). Myocardial ischaemia also predisposes to arrhythmia and sudden death.
Symptoms and diagnosis of Angina
The history is crucial to the diagnosis of angina. It is exemplified by the character, location and duration of chest pain. The most consistent feature in the history is the relationship of chest pain with exercise.
Classic angina is characterized by tight chest discomfort that originates in the centre of the chest and radiates into the jaw, shoulder or left arm. Occasionally it may be described as pressure, an ache, weight or constriction, but rarely as a sharp or stabbing pain. Typically, angina is precipitated by exertion and relieved with rest. Each episode usually lasts from 1 to 3 minutes if the initiating event is discontinued. Other precipitating factors may include emotion, meals, cold weather and lying supine (decubitus angina).
Different varieties of Angina:
Variants of angina include vasospastic (or Prinzmetal's) angina that occurs without provocation, due to coronary artery vasospasm. It is diagnosed by characteristic ECG changes of ischaemia associated with the attacks of chest pain .
Classical angina with objective evidence of myocardial ischaemia can manifest with apparently normal coronary arteries on angiography due to microvascular disease (syndrome X).
Occasionally, the only manifestation of cardiac ischaemia may be dyspnoea (angina equivalents).
A detailed history should identify risk factors associated with ischaemic heart disease and underlying factors predisposing to angina (anaemia, thyrotoxicosis, infections, drugs) and discriminate between other causes of chest pain.
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Canadian Cardiovascular Society's classification of angina pectoris
Class I. Ordinary physical activity does not cause angina
For example walking or climbing stairs, angina occurs with strenuous or rapid or prolonged exertion at work or recreation
Class II. Slight limitation of ordinary activity
For example, angina occurs walking or stair climbing after meals, in cold, in wind, under emotional stress or only during the few hours after awakening, walking more than two blocks on the level or climbing more than one flight of ordinary stairs at a normal pace and in normal conditions
Class III. Marked limitation of ordinary activity
For example, angina occurs walking one or two blocks on the level or climbing one flight of stairs in normal conditions and at a normal pace
Class IV. Inability to carry on any physical activity without discomfort
Angina syndrome may be present at rest
What is angina?
Diagnosis of Angina.
Medical and Surgical Treatment of Angina.
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