C7. Coronary heart disease

Coronary heart disease

About coronary heart disease

Coronary heart disease (CHD) is a largely preventable disease. There are approximately 8,000 deaths in Scotland each year (7,541 people in 2012) where CHD is the underlying cause.

The heart

The heart is a muscle that is about the size of your fist. It pumps blood around your body and beats approximately 70 times a minute. After the blood leaves the heart, it goes to your lungs where it picks up oxygen.

The oxygen-rich blood returns to your heart and is then pumped to the organs of your body through a network of arteries. The blood returns to your heart through veins before being pumped back to your lungs again. This process is called circulation.

The heart gets its own supply of blood from a network of blood vessels on the surface of your heart, called coronary arteries.

Coronary heart disease

Coronary heart disease, or CHD, is the term that describes what happens when your heart’s blood supply is blocked or interrupted by a build up of fatty substances in the coronary arteries.

Over time, the walls of your arteries can become furred up with fatty deposits. This process is known as atherosclerosis, and the fatty deposits are called atheroma. If your coronary arteries become narrow due to a build up of atheroma, the blood supply to your heart will block your arteries.

If a coronary artery becomes partially blocked, it can cause chest pains (angina). If it becomes completely blocked, it can cause a heart attack (myocardial infarction).

Symptoms of coronary heart disease

Heart attacks can cause permanent damage to the heart muscle and, if not treated straightaway, can be fatal. If you think that you are having a heart attack, you should dial 999 for immediate medical assistance.

The symptoms of a heart attack

The discomfort or pain of a heart attack is similar to that of angina, but it is often more severe. During a heart attack, you may also experience the following symptoms:

  • sweating
  • light-headedness
  • nausea
  • breathlessness

The symptoms of a heart attack can be similar to indigestion. For example, they may include a feeling of heaviness in your chest, a stomach ache or heartburn. A heart attack can happen at any time, including while you are resting.

Heart palpitations

If you have CHD, you may experience heart palpitations. Heart palpitations occur when your heart beats irregularly. Heart palpitations are not necessarily caused by coronary heart disease nor does everyone with CHD experience heart palpitations. However, it is always best to have it checked out by your GP.

Heart failure

Heart failure can occur in people with CHD. The heart becomes too weak to pump blood around the body, which can cause fluid to build up in the lungs, making it increasingly difficult to breath. Heart failure can happen suddenly (acute heart failure) or gradually, over a period of time (chronic heart failure).

By making some simple lifestyle changes, you can reduce your risk of getting coronary heart disease (CHD). And if you already have heart disease, you can

Causes of coronary heart disease

Coronary heart disease (CHD) is usually caused by a build up of fatty deposits on the walls of the coronary arteries. The fatty deposits, called atheroma, are made up of cholesterol and other waste substances.

The build up of atheroma on the walls of the coronary arteries makes the arteries narrower and restricts the flow of blood to the heart. This process is called atherosclerosis. Your risk of developing atherosclerosis is significantly increased if you:

  • smoke
  • have high blood pressure
  • have a high blood cholesterol level
  • do not take regular exercise
  • have a thrombosis (blood clot in an artery or vein)
  • have diabetes

Other risk factors for developing atherosclerosis include:

  • being obese or overweight, and
  • having a family history of heart attack or angina.

For men, the likelihood of developing atherosclerosis is increased if you have a close family member (father or brother) who has had a heart attack or angina before the age of 55. For women, the risk is increased if you have a close family member (mother or sister) who has had a heart attack or angina before the age of 65.

Risk factors you can do something about are known as modifiable risk factors. It is important that you understand and know how to manage your modifiable risk factors to either reduce your risk of developing CHD or, if you have been diagnosed, to help prevent your condition worsening.


Cholesterol is a fat that is made by the liver from the saturated fat that we eat. Cholesterol is essential for healthy cells, but if there is too much in the blood, it can lead to coronary heart disease.

Cholesterol is carried in the blood stream by molecules called lipoproteins. There are several different types of lipoproteins, but two of the main ones are low-density lipoproteins (LDL) and high-density lipoproteins (HDL).

LDL, often referred to as ‘bad cholesterol’, takes cholesterol from the liver to the cells. LDL cholesterol tends to build up on the walls of the coronary arteries, increasing your risk of heart disease. HDL, often referred to ‘good cholesterol’, carries cholesterol away from the cells and back to the liver, where it is broken down or passed from the body as a waste product. If your LDL cholesterol level is too high, the HDL will not be able to remove it sufficiently.

Blood cholesterol is measured in units called millimoles per litre of blood (mmol/litre). In the UK, the current government recommendation is that you should have a total blood cholesterol level of less than 5 mmol/litre, LDL cholesterol level of under 3 mmol/litre and HDL cholesterol 1 mmol/litre or over. A level of total cholesterol above 6mmol/litre is considered to be high and a risk factor for arterial disease.

High blood pressure

Hypertension (high blood pressure) puts a strain on your heart and can lead to coronary heart disease.

Blood pressure is measured at two points during the blood circulation cycle. The systolic pressure is a measure of your blood pressure as the heart contracts and pumps blood out. The diastolic pressure is a measure of your blood pressure when your heart is relaxed and filling up with blood.

Blood pressure is measured in terms of millimetres of mercury (mmHg). When you have your blood pressure measured, the systolic pressure is the first, higher number to be recorded. The diastolic pressure is the second, lower number to be recorded. High blood pressure is defined as a systolic


Smoking is a major risk factor. Carbon monoxide (from the smoke) and nicotine both put a strain on the heart by making it work faster. They also make it more likely that your blood will clot. Other chemicals in cigarette smoke damage the lining of your coronary arteries, leading to furring of the arteries. Around 20% of CHD-related deaths in men and 17% in women are attributable to smoking.


A thrombosis is a blood clot within an artery (or a vein). A coronary thrombosis is a blood clot within the artery of your heart muscle.

Diagnosing coronary heart disease

A number of different tests are used to diagnose heart-related problems including:

  • coronary angiogram
  • electrocardiogram (ECG)
  • magnetic resonance imaging (MRI)
  • cardiac computerised tomography (CT) scan
  • thallium scan (myocardial perfusion scintigraphy)
  • electrophysiological testing (eg myocardiac perfusion scan, stress echocardiogram)

Coronary angiogram

A coronary angiogram, also known as a catheter test, is usually performed under local anaesthetic. As well as providing information about your heart’s blood pressure and how well your heart is functioning, an angiogram can also identify whether the coronary arteries are narrowed and how severe any blockages are.

In an angiogram, a catheter (flexible tube) is passed into a vein or artery in your groin or arm, and, using X-rays, it is guided into the coronary arteries. A dye is injected into the catheter to show up the arteries supplying your heart with blood. A number of X-ray pictures are taken, which will highlight any blockages.

A coronary angiogram is a relatively safe procedure, and serious complications are very rare. The risk of having a heart attack, stroke or dying during the procedure is estimated at about one or two in every 1,000. However, after having a coronary angiogram, you may experience some minor side effects including:

  • a slightly strange sensation when the dye is put down the catheter
  • a small amount of bleeding when the catheter is removed, or
  • a bruise in your groin or arm

Depending on the result of the coronary angiogram, medication or further procedures may be recommended.

Electrocardiogram (ECG)

An electrocardiogram, or ECG, records the rhythms and electrical activity of your heart. A number of electrodes (small, sticky patches) are put on your arms, legs and chest. The electrodes are connected to a machine that records the electrical signals of each heartbeat.

Although an ECG can detect problems with your heart rhythms, an abnormal reading does not always mean that there is anything wrong. Therefore, as well as an ECG, you may need to have some other tests, such as:

  • an exercise ECG – an electrocardiogram recording is taken while you are exercising and while your BP is being recorded (usually on a treadmill or exercise bike). Changes identified both on your recordings and how you feel while exercising will help make a diagnosis possible. The test can help to identify if your symptoms are caused by angina, which is usually due to coronary heart disease.
  • 24-hour ECG recording – an electrocardiogram recording is taken continuously over 24 hours. It can be used to diagnose symptoms that do not occur regularly, such as palpitations. This test can be done wearing the monitor at home. The results will then be discussed at an outpatient appointment.

Cardiac Computerised Tomography (CT) scan

CT scan is a special type of x-ray machine which takes images round your body, in this case of your heart.

Magnetic resonance testing (MRI)

MRI can be used to produce very detailed pictures of your heart. During an MRI scan, you lie inside a ‘tunnel-like’ scanner that has a magnet around the outside. The scanner uses a magnetic field and radio waves to produce detailed images. This is can be used if you are unable to undertake an exercise ECG.

Thallium scan (myocardial perfusion scintigraphy)

This scan shows how well blood is reaching the heart muscle through your coronary arteries. A small amount of thallium (radioactive substance) is injected into a vein and a special camera moves around your body. The camera picks up traces of thallium and produces pictures. As thallium will not travel well to areas where there is a poor blood supply the pictures can be used to see how well blood is reaching your heart.

The scan can compare how well the thallium is taken up by your heart muscle when it is made to work harder, that is in the form of an exercise test or by an injection of a stimulant drug. This again is a useful test when exercise tests cannot be done or when an exercise test cannot provide the necessary information. The levels of radiation used are not harmful.

Electrophysiological testing

Electrophysiological testing is a relatively new method of understanding and treating fast, abnormal heart rhythms. A catheter (flexible tube) is inserted into a vein in your arm or groin. The catheter is gently passed into your heart, where it stimulates the heart and measures its electrical activity.

As well as identifying abnormal heart rhythms, electrophysiological testing can determine if they are being effectively controlled by medication. It can also confirm whether abnormal heart rhythms are causing palpitations. If they are, it may be possible to treat the problem at the same time using radio-frequency electrical energy to destroy the parts of the heart that are causing the abnormal heart rhythm. This procedure is known as radiofrequency ablation.

Blood test

A blood test is used to measure the amount of cholesterol in your blood. Before having the test, you may be asked not to eat for 12 hours to ensure that all food is completely digested and will not affect the results. Your GP, or practice nurse, can carry out the blood test, and they will take a sample either using a needle and a syringe, or by pricking your finger.

Anyone can have their blood cholesterol level tested, but it is particularly important to have it checked if:

  • you are over 40 years of age
  • you have a family history of cardiovascular disease – for example, if your father or brother developed heart disease, or had a heart attack or a stroke before the age of 55, or if your mother or sister had these conditions before the age of 65
  • a close family member has a cholesterol related condition, such as familial hyperchloresterolaemia or combined hyperlipidaemia
  • you are overweight or obese
  • you have high blood pressure (hypertension), or
  • you have another medical condition, such as a kidney condition, an under-active thyroid gland or acute inflammation of the pancreas (acute pancreatitis). These conditions can cause an increased level of cholesterol.

Other factors

In assessing your risk of cardiovascular disease, heart attack or stroke, your cholesterol ratio should not be taken on its own. A number of other factors should also be taken into consideration, including:

  • smoking
  • diet
  • body mass index (BMI), which is a measure of your weight in relation to your height
  • physical inactivity
  • alcohol intake
  • treatable risk factors, such as high blood pressure (hypertension) and diabetes
  • fixed risk factors, such as your age, sex, family history and ethnicity

Treating coronary heart disease

Coronary heart disease cannot be cured, but recent progress in the research and development of new medicines and significant improvements in surgical procedures have meant that the condition can now be managed more effectively. With the right treatment, the symptoms of coronary heart disease can be reduced and the functioning of the heart improved.


Many different medicines are used to treat CHD. This gives doctors a wide choice and means that a medication can be prescribed to meet your particular circumstances and needs. Some heart medicines have side effects, so it may take a while to find one that works for you. Your GP or specialist will be able to discuss the various options with you.

Some of the medicines that are commonly used to treat heart conditions are outlined below.

Low-dose aspirin medication

Blood clots in the coronary arteries are a major cause of heart attacks. A low-dose aspirin and/or other anti platelet medicine may be prescribed for you by your doctor, unless there are reasons not to, for example if you have a bleeding disorder. This type of medicine will help prevent your blood clotting, reducing your risk of heart attack and angina.


Anticoagulants such as warfarin are sometimes used to stop the blood clotting. If you are prescribed warfarin, you will need regular blood tests to ensure your clotting rate is within an agreed limit. This is called the INR test. It is also a good idea to carry a card with you stating that you are taking an anticoagulant.


A high level of ‘bad cholesterol’ (LDL) in your blood can cause a build up of atheroma (fatty deposits) in your arteries, increasing your risk of heart attack or stroke. If you have a high blood cholesterol level, cholesterol-lowering medicine called statins may be prescribed.

Statins work by blocking the formation of cholesterol and increasing the number of LDL ‘receptors’ in the liver, which, in conjunction with any lifestyle modifications discussed with you, will help to remove the LDL cholesterol from your blood. This all helps to slow the progression of CHD, making having a heart attack less likely.


Beta-blockers are often used to prevent angina and treat high blood pressure. They work by blocking the effects of stress hormones, which make your heart beat faster and harder. This slows down your heartbeat, improves blood flow and helps your heart to pump more effectively. Beta blockers are usually taken alongside ACE inhibitors (see below). Your doctor may decide that beta blockers are not suitable for you especially if you have respiratory problems, such as asthma or diabetes. You may also be prescribed diuretics (medicine that helps your body get rid of extra fluid).

ACE (angiotensin-converting enzyme) inhibitors

ACE inhibitors are commonly used to treat heart failure and high blood pressure. If you have had a heart attack, they are also used to help reduce the risk of you having a further heart attack. They block the activity of a hormone (called angiotensin II), which narrows blood vessels. As well as stopping your heart working so hard, ACE inhibitors improve the flow of blood around the body.

Your blood pressure will be monitored while you are taking ACE inhibitors. ACE inhibitors can affect the function of your kidneys, so your GP will give you regular blood tests to check that your kidneys are working properly.

If ACE inhibitors have been prescribed for you, do not stop taking them without first consulting you doctor. If you do, it is very likely that your symptoms will get worse quickly. Common side effects of ACE inhibitors include a dry cough, dizziness and fainting. Please discuss potential side affects with your GP.

Angiotensin II receptor antagonists

Angiotensin II receptor antagonists work in a similar way to ACE inhibitors. They are used to lower your blood pressure by limiting angiotensin II. These are usually prescribed if you are experiencing side effects from ACE inhibitors as an alternative. Mild dizziness is usually the only side effect from angiotensin II antagonists.

Anti-arrhythmic medicine

Anti-arrhythmic medicine is sometimes used to control the rhythm of your heart. It is important to remember to take your prescribed dose daily, as this type of medicine is most effective when exactly the right level is in your bloodstream, so it is important that the correct dosage is taken.


Nitrates are used to widen your blood vessels. Doctors sometimes refer to nitrates as vasodilators. They are available in a variety of forms, including tablets, sprays and skin patches. They work by relaxing your blood vessels, letting more blood pass through them. This lowers your blood pressure and aims to relieve symptoms of angina that you have. Nitrates can have some mild side effects, including headaches, dizziness and flushed skin.

Cardiac glycosides

Cardiac glycosides, such as digoxin, strengthen and slow the heartbeat. By making the heart muscles contract (squeeze together) more strongly, blood is pushed around the body with more force. Cardiac glycosides are usually only taken in addition to other medicine, such as ACE inhibitors and diuretics.

Surgical procedures 

If your blood vessels are very narrow due to a build up of atheroma (fatty deposits), or if your symptoms cannot be controlled using medication, surgery may be needed to open up or replace the blocked arteries. Some of the main surgical procedures that can be used to treat blocked arteries are outlined below.

Coronary angioplasty

Coronary angioplasty is sometimes used to treat mild coronary heart disease. An angioplasty opens up a blocked or narrowed coronary artery, improving the blood flow to the heart.

Coronary artery bypass

A coronary artery bypass is a procedure that allows the blood flowing through the coronary artery to bypass (get round) the part of the artery that is blocked.

Heart transplant

In a small number of cases, when the heart is severely damaged and medicine is not effective, or when the heart becomes less efficient at pumping blood around the body (heart failure), a heart transplant may be needed. A heart transplant involves replacing a heart that is damaged or is not working properly with a healthy donor heart.

Not all people are suitable candidates for having a heart transplant, and finding a suitable donor may take many months. However, the success rate of heart transplant surgery has improved significantly over the past few decades, and many people who have had transplants more than ten years ago are still doing well.

Although heart transplant surgery is usually a successful procedure, afterwards you will need to take medicine to control your immune system’s reaction to having a ‘foreign heart’. The medicine can cause your immune system to become weaker, making you more vulnerable to illness and infection. Your doctor may also prescribe medicine to help reduce your risk of a having heart attack.

The future 

Research into heart-related problems continues. Much of this is funded by charities, and doctors are looking at new ways of preventing the body rejecting donor hearts, as well as developing new treatments so that people with heart conditions can live long, healthy lives. In the future, cardiologists (heart doctors) hope to be able to investigate, diagnose and treat heart conditions without the need for using surgical procedures.

Recovering from coronary heart surgery

The purpose of cardiac rehabilitation is to both help you to recover and resume a normal life as soon as possible after having a coronary angioplasty, coronary artery bypass surgery or heart transplant. It is also to reduce the risk of having further events. However, evidence shows that comprehensive cardiac rehabilitation is both safe and effective and should be offered to patients with angina, heart failure and following a heart attack too. Ask your GP or cardiologist about cardiac rehabilitation programmes in your area.

Cardiac rehabilitation programme

If you have not been referred to a cardiac rehabilitation programme, speak to your GP who will refer you if it is appropriate to do so. Programmes vary widely throughout the country. However, following an assessment, on most programmes you will cover the following basic areas:

  • exercise
  • education
  • relaxation and emotional support

The information and advice you receive will be tailored to suit your individual risk factor profile, with long-term management strategies being identified and agreed by you to meet your individual goals.

Once you have completed your rehabilitation programme, it is very important that you continue to take regular exercise and lead a healthy lifestyle, in order to protect your heart and reduce the risk of further heart-related problems.

Returning to work

After recovering from heart surgery, you should be able to return to work, but it may be necessary to change the type of work that you do. For example, it may be appropriate to change the type of tasks you undertake if your job involves periods heavy physical exertion. Your specialist will be able to advise you about when you can return to work and what type of activities you should avoid.

Preventing coronary heart disease

  • The best way to prevent coronary heart disease is to make sure that your ‘bad cholesterol’ (LDL) level is low and that your ‘good cholesterol’ (HDL) level is high. There a number of ways you can do this.

Eat a healthy, balanced diet

  • Your diet should be low in saturated fat, sugar and salt, and contain plenty of fruit and vegetables (at least five portions a day).
  • Fish, such as herrings, kippers, mackerel, pilchards, salmon, sardines and trout contain oils that can reduce the risk of thrombosis. Many vegetables, fruit and cereals contain antioxidant vitamins (beta-carotene and vitamins C and E) that prevent saturated fats from being changed into cholesterol. Other foods that may help to lower your cholesterol level are beans, peas, lentils and oats, because they contain soluble fibre, and Brazil nuts.

Be more physically active

Make sure that you take regular aerobic (cardiovascular) exercise, for a minimum of 30 minutes a day, on most days through the week. Exercise is known to increase ‘good cholesterol’ (HDL), which helps to keep your ‘bad cholesterol’ (LDL) levels down. As exercising burns calories, it can help you to control your weight and reduce stress.

If you have been diagnosed with heart disease individual advice around the level of exercise you take may be required, therefore it is important to check first by speaking to your GP.

Keep to a healthy weight

Your GP or practice nurse will be able to tell you what your ideal weight is in relation to your build and height.

Give up smoking

If you smoke, giving up will reduce your risk of developing coronary heart disease. Smoking is a major risk factor for developing atherosclerosis (hardening of the arteries). It also causes the majority of cases of coronary thrombosis in people under the age of 50.

Research shows that people who are referred to a Smoking Cessation Service have more success in quitting. To be referred to your local services, speak to your GP.

Reduce your alcohol consumption

If you drink, make sure that you stick to the recommended guidelines for alcohol consumption. The recommended daily amount of alcohol for men is three to four units a day, and it is two to three units for women. Try to have a few alcohol free days throughout the week and you should always avoid binge drinking.

Keep your blood pressure under control

You can keep your blood pressure under control by maintaining a healthy weight eating a healthy diet that is low in saturated fat, exercising regularly and, if required, taking appropriate blood-pressure-lowering medication. Your target blood pressure should be below 140/85mmHg. If you have high blood pressure, ask your GP to check your blood pressure regularly.

Keep your diabetes under control

If you are diabetic, you have a greater risk of developing coronary heart disease. You can reduce your chances of developing diabetes by being physically active, controlling your weight, and keeping your blood pressure under control. If you have diabetes, these three things will help you to keep control of your blood sugar level. If you are diabetic, your target blood pressure level is below 130/80mmHg.

Take any medication that is prescribed for you

If you have coronary heart disease, you may be prescribed medication to help relieve your symptoms and stop further problems developing. If you do not have coronary heart disease but you have high cholesterol, high blood pressure or a history of family heart disease, your doctor may prescribe medication to prevent you developing heart-related problems.

If you are prescribed medication, it is vital that you take it and follow the correct dosage. Do not stop taking your medication without consulting your doctor first, as doing so is likely to make your symptoms worse and put your health at risk.

Due to potential adverse effects, supplements or herbal remedies should not be taken with cardiac medications without a discussion with medical or nurse specialist consultation.