Angina occurs due to a mismatch in the myocardial oxygen supply and demand. In normal physiology, if there is increased oxygen demand e.g. the heart is beating faster and therefore the tissues need more oxygen, the body is able to handle the increased need by increasing blood supply to the myocardium via the coronary arteries.
If, for example, there is stenosis (narrowing) of the coronary arteries from an atheromatous plaque, there may be sufficient blood flow to the heart tissue at rest. However, in this situation if the individual exerts themselves e.g. by going up the stairs, it is more difficult to get sufficient blood (and in turn oxygen) supply to the heart, manifesting in the symptoms of angina.
Angina can be provoked by various triggers including exertion, heavy meals, exposure to extreme temperatures and strong emotions. Underlying causes include coronary artery disease and anaemia. Coronary artery vasospasm can also cause pain at rest and is known as variant or Prinzmetal angina. It tends to affect women more than men.
There are 3 main symptoms to remember with angina:
These 3 symptoms are used to classify angina. 3/3 symptoms correlates to typical angina, 2/3 correlates to atypical angina and 1 of the symptoms should prompt consideration of an alternative diagnosis. Other symptoms include nausea, vomiting, dyspnoea and sweating. Continuous pain, pleuritic pain, palpitations, dizziness and tingling make a diagnosis of angina less likely.
Diagnosis of angina is largely clinical, but they should be referred to a specialist chest pain service to confirm the diagnosis. Important investigations to consider include:
Bedside
Bloods
Imaging
Cardiac Causes of Chest Pain
Respiratory Causes of Chest Pain
Gastrointestinal Causes of Chest Pain
Other Causes of Chest Pain
There are a few things that need to be controlled in angina. These include the acute episodes of angina, secondary prevention of cardiovascular disease and prevention of further episodes of angina. The following summarises the NICE guidance on managing stable angina. Let’s consider each of these:
Acute Episodes
Treatment of anginal episodes is mainly with a short-acting nitrate e.g. a glyceryl trinitrate (GTN) spray. This is usually a sublingual spray administered under the tongue by the patient themselves. Patients should repeat the spray if pain does not subside within 5 minutes. If the pain is still present following the second dose, patients should be advised to call for an emergency ambulance.
Anti-Angina Treatment
NICE guidelines state that patients should be offered either one or two anti-anginal drugs (and drugs for secondary prevention of cardiovascular disease) for optimum drug treatment. The following summarises the NICE guidance for anti-angina treatment.
One of these drugs can also be added to a beta-blocker or CCB monotherapy regimen if symptoms remain uncontrolled, provided the patient cannot tolerate or has a contraindication to being given the other (beta-blocker/CCB) drug.
Secondary Prevention of Cardiovascular Disease
NICE suggest considering 75mg aspirin OD, controlling hypertension and offering statin treatment in order to protect against further cardiovascular disease. Patients who are diabetic should be offered ACE inhibitors.
Revascularisation
Patients who still have ongoing symptoms despite optimal drug treatment can be considered for revascularisation therapy, either via a coronary artery bypass graft (CABG) or a percutaneous coronary intervention (PCI). A coronary angiogram is done prior to this in order to assess which treatment option would be most appropriate.
https://cks.nice.org.uk/angina#!diagnosisSub:1
https://www.ncbi.nlm.nih.gov/books/NBK559016/
https://cvpharmacology.com/vasodilator/CCB
https://www.ncbi.nlm.nih.gov/books/NBK559016/
https://bnf.nice.org.uk/treatment-summary/calcium-channel-blockers.html
