If you're suffering from pain in your chest, it could be angina pectoris. Often brought on by particular activities such as physical exertion, it's most common in men, diabetics, those with high blood pressure and smokers.
There's more than one type of angina, and many different treatment options. Dr Roger Henderson looks at the causes, diagnosis and treatment options for angina chest pain:
What is angina?
Derived from the Latin for ‘tight chest’, angina pectoris usually feels like a heavy or crushing pain in the centre of the chest behind the breast bone, although it can radiate out into the neck, throat and arms.
Angina is usually brought on by certain activities but the underlying cause is always the same – there is an increase in oxygen demand that cannot be met by the heart. In most cases this is due to thickening of the heart arteries, known as coronary atherosclerosis, as narrow coronary arteries reduce the blood flow to heart muscle. This is a common problem in developed countries and is often linked to obesity and a diet rich in fat.
The different types of angina
There are two main types of angina: stable and unstable.
• Stable angina
If you have stable angina, your symptoms will usually develop gradually over time and follow a set pattern. For example, you may only experience symptoms when climbing stairs or if you are under a lot of stress.
The symptoms of stable angina usually only last for a few minutes and can be improved by taking medication called glyceryl trinitrate. Stable angina is not life-threatening on its own but is a serious warning sign that you have an increased risk of a heart attack or stroke.
• Unstable angina
In cases of unstable angina, the symptoms develop rapidly, can persist even at rest and can last up to 30 minutes. The symptoms of unstable angina may also be resistant to treatment with glyceryl trinitrate.
You may experience symptoms of unstable angina after previously having symptoms of stable angina. However, unstable angina can also occur in people who do not have a previous history of stable angina.
Unstable angina should be regarded as a medical emergency because it is a sign that the function of your heart has suddenly and rapidly deteriorated, increasing your risk of having a heart attack or stroke. Unstable angina can be treated with medication and surgery.
• Variant angina
A much less common type of angina can also occur called variant angina, where: chest pain is caused by sudden artery spasm. This means pain can happen when the heart is at rest, more often in the early morning. This type of angina occurs more often among women but is quite rare.
Risk factors of angina
There are a number of common risk factors, including the following:
- A family history of heart disease or high cholesterol levels
- Lack of regular exercise
- High blood pressure
- Being male
Angina can also be aggravated by other illnesses, including a sustained fast heartbeat, anaemia, heart valve diseases and thickening of the heart muscle (hypertrophy), which can be a result of high blood pressure over several years.
What causes angina?
Factors that often cause an angina attack include the following:
🔹 Physical exertion, especially climbing stairs or an incline
🔹 Cold, windy weather
🔹 A heavy meal
🔹 Strong emotion – especially anger and anxiety
🔹 Exciting television programmes
All of these may be additive, such as shovelling snow or walking up a hill in bad weather after a heavy meal.
How is angina diagnosed?
Diagnosing angina is usually on the basis of the symptoms described, the medical history and whether nitrate sprays or tablets (which dilate heart arteries) have an immediate effect during symptoms.
More formal investigations usually include both a resting and an exercise ECG (electrocardiogram) - that record whether the heart is under undue strain during exercise or at rest – and an examination of the coronary arteries known as an angiogram. Here, a dye is injected into the circulation, which then shows up on X-ray pictures, and any narrowing of the heart blood vessels is highlighted.
If tests do not confirm the diagnosis and angina is still considered as a possibility then further diagnostic techniques may be needed, such as:
✔️ A nuclear myocardial perfusion scan (MPS): In this test, a small dose of a radioactive substance is injected into the patient, and taken up by areas of healthy heart tissue, but not by unhealthy heart tissue, or those areas supplied by a narrowed artery. This allows the doctor to distinguish between normal heart muscle, heart muscle that has died from a heart attack, and heart muscle at risk of damage from narrowed arteries. It is considered a reliable test.
✔️ Stress echo test: in this test an ultrasound scan of the heart is done while a medicine is administered that makes the heart think it is exercising. A healthy heart contracts more vigorously with this medicine, whereas a heart with narrowed arteries beats less vigorously.
✔️ Perfusion cardiac magnetic resonance imaging test (perfusion MR): during which a chemical (gadolinium) is given, is used to determine how much scar tissue there is in the heart, while the heart is being imaged with a magnetic resonance image scanner. Other techniques are also used to examine heart arteries during this procedure. This is also a very good test, although approximately 10 per cent of patients find the scanner claustrophobic.
✔️ A heart CT scan: this is used to determine the amount of calcium in the heart arteries –the more narrowed the artery the higher the level of calcium within it. It is also possible to carry out a CT angiogram on the heart arteries, where dye is injected into the patient's veins, and the CT used to see if any narrowing is present in the heart arteries.
How is angina treated?
Reducing the number of risk factors will also reduce the risk of angina developing, and this is the usual first-line treatment suggested by doctors. This includes stopping smoking, losing weight, exercising more and eating a low fat diet rich in fresh fruit and vegetables. Any pre-existing conditions such as high blood pressure or diabetes should always be as strictly controlled as possible, and once all the risk factors have been taken into account then medication may be considered.
Aspirin is commonly prescribed as a small daily dose reduces the ‘stickiness’ of the blood and so helps ease the flow of blood through the heart arteries. Your doctor or cardiologist (an expert in treating heart conditions) will usually try one medication first to see whether it helps prevent your symptoms - known as monotherapy – but if one medication is not effective, two medications may be recommended, called combination therapy.
The first medication often used to try to reduce the frequency of angina attacks is either a medication called a beta-blocker or alternatively a medication called a calcium channel blocker. Exactly which medication you will be prescribed may depend on your current level of health and, in some cases, your personal preference - there are a number of different medications available that can now be used in the treatment of angina and your doctor can determine which combination is the best for you.
Angina and surgery
If investigations show that the angina is being caused by severe coronary artery narrowing then surgical intervention is often required. This is often in the form of angioplasty or percutaneous coronary intervention (PCI) - where a narrowed section of artery is widened using a tiny tube called a stent, so allowing blood to flow more readily through the heart.
In certain cases a heart bypass operation is the only way to restore the normal blood supply to the heart but this is now performed so often as to be viewed as a routine operation. In this type of surgery, a section of blood vessel is taken from another part of the body and used to re-route the flow of blood past a blocked or narrowed section of artery in the heart.