Angina
What is angina?
When due to artery narrowing sufficient oxygenated blood does not get through to the heart muscle to keep up with the body’s demands, the heart will not work so efficiently. The pain that results from heart muscle that is not given enough oxygen from it’s blood supply is generally felt as a central ‘cramping’ or ‘crushing’ chest pain which occurs with exertion, and is relieved by rest within a few minutes. Often the discomfort also spreads into the neck, jaw or even down the arm.
Diagnosis
The diagnosis of angina is based on the type and site of the pain, which is short- lived and relieved by GTN, rest and withdrawal of the trigger factors.
ECG changes, which usually occur only on exercise (and can be detected by performing a treadmill exercise ECG test ). Other tests can also confirm the clinical suspicion.
Features
- intermittent, retrosternal (i.e. central, behind the breastbone) crushing pain.
- commonly radiates to jaw, neck and inner part of one or both arms, occasionally to the back and abdomen, and can be mistaken for indigestion.
- short-lived (i.e. less than 5 minutes; if it lasts longer than 20 to 30 minutes and does not respond to Trinitrin therapy, it may be an actual myocardial infarction (MI) brought on by exercise, stress and cold and food (large meal) or a combination of these.
- relieved by rest or administration of glyceryl trinitrate (GTN),or the removal of the emotional stimulus.
Severity
In general, the severity of angina symptoms will depend on how severely narrowed the coronary arteries are, and how large the artery is that is involved. The more disease there is, the more severe the symptoms are likely to be – but some patients may have severe symptoms with only one artery affected. [Depends on the number of coronary arteries affected and the degree of narrowing, also which vessels are affected (i.e. Left main stem vessel or severe 3 – vessel disease is of greater severity than minor, single or two – vessel disease)]
Variability
(NB: The most common form of angina occurs with exercise. The following are rare, but may be mentioned in reports).
- Angina may be characterised by breathlessness without any pain or discomfort – i.e. “angina equivalent”.
- Decubitus angina – occurs on lying down.
- Variant (Prinzmetal’s angina) – caused by coronary artery spasm – usually occurs at rest and not on exertion.
- Cardiac syndrome x – typically provoked by emotion or anxiety, and associated with a positive exercise test – but with normal coronary arteries on coronary angiography– thought to be due to abnormalities of the coronary artery micro circulation.
- Angina with syncope – more common in the elderly and suggests severe coronary artery disease.
- Unstable angina – Angina which is of recent onset, which increases rapidly in severity and/or occurs at rest. It suggests an unstable atheromatous plaque with superimposed clot in one of the coronary arteries. This condition carries a significant risk of progression to acute MI (myocardial infarction) or sudden death. If, despite optimal medical therapy, it persists, treatment with angioplasty (and stenting) or bypass surgery may be required.
