Angina is a heart condition that is typically manifested as chest pain and is more of a symptom of an underlying condition than a disease in itself.
The pain in the chest is caused when the blood supply to the heart muscles of cardiac muscles falls short of the required amount. This occurs when the arteries that supply the heart become hardened and narrowed - a condition called arteriosclerosis.
Arteriosclerosis of the arteries that supply heart muscles called the coronary arteries thus gives rise to symptoms of chest pain termed angina. 1-4
What happens in angina?
Angina is manifested as a dull, aching, tightness or heavy weight like feeling over the chest. The pain may sometimes spread beyond the chest to the left arm, neck, jaw or back.
The pain more often than not is triggered by some vigorous physical activity or extreme emotional distress where in both cases the heart beats faster and the muscles require more blood supply than usual.
The arteriosclerosis of the coronary arteries restricts blood flow and there is a shortage of blood to the heart muscles leading to a pain that usually only lasts for a few minutes. This is typically called an angina attack.
Who is at risk of angina?
Angina is caused by arteriosclerosis or atherosclerosis that causes hardening and narrowing of the coronary arteries. This is seen commonly in smokers, obese and overweight individuals, those with diabetes, high blood cholesterol, advanced age etc.
In the United Kingdom, 8% men and 3% women between 55 and 64 years of age have or have had an attack of angina. Between 65 and 74 years the figures are 14% men and 8% women.
People of South Asian origin in the UK have an increased risk of this type of heart disease termed ischaemic heart disease. Black Caribbean people have a reduced risk compared with the overall UK population.
In both men and women the rate is significantly higher in lower socio-economic groups. Angina appears to be more common in men than women. Smoking in the past was significantly higher in men and this could be the reason for this gender difference in incidence.
What are different types of angina?
Angina may be of two types - stable angina and unstable angina.
Stable angina
Those with stable angina develop the symptoms gradually over time. The symptoms initially may begin after strenuous exercise or climbing stairs or running hard or even when in extreme mental stress.
Symptoms usually only last for a few minutes and can be improved by taking medication called glyceryl trinitrate. This type of angina usually does not prove to be fatal but may be a prelude to a heart attack or a stroke and mandates medical attention.
Unstable angina
This type of angina usually develops rapidly and the course is often unpredictable. Those with stable angina may go on to develop unstable angina. The symptoms of chest pain may last for around 30 minutes and may persist even when the patient is at rest. Glyceryl trinitrate may not help relieve the symptoms.
This type of angina is an emergency situation since the course of the angina is unpredictable and the heart function may rapidly deteriorate and this can increase the risk of stroke or a heart attack. This type of angina is treated with medications and surgical techniques.
How is angina treated?
Angina management aims to relieve the symptoms of an angina attack, reduce the number of angina attacks for the patient and also to prevent worsening of the condition by prevention of restricted blood supply to the heart as this could lead to a heart attack or a stroke.
Medication therapy is the first line of treatment. This includes arterial dilators that allow more blood flow like Nitrates and Calcium Channel blockers.
Surgical techniques are suggested for patients who do not respond to medications. Coronary angioplasty is one form of treatment that allows widening of a particularly narrowed section with a small tube or mesh like structure called a stent. The stent also holds the lumen of the artery open and prevents its collapse.
Another method is coronary artery bypass graft where a section of blood vessel is taken from another part of the body and this acts a as bypass to the narrowed artery to supply the heart muscles.
What could happen in angina patients?
Angina may lead to complications like stroke or heart attack. In fact, 1 in every 100 people with stable angina may go on to develop a fatal heart attack or stroke. A non-fatal heart attack or stroke may occur in 1 in 40 people with stable angina.
Further Reading
Body mass index found to mediate causal associations between Helicobacter pylori infections and coronary artery disease risk