Ischaemic cardiomyopathy: weakened heart muscle after coronary heart disease

The heart is a muscle that pumps blood around the body. It receives its own blood supply through the coronary arteries on its surface. The NHS explains that coronary heart disease is what happens when this supply is blocked or interrupted by a build-up of fatty substances, called atheroma, in the artery walls, a process known as atherosclerosis.

Cardiomyopathy is the general term for diseases of the heart muscle in which the chambers have become stretched, thickened or stiff, so that pumping is affected. Ischaemic cardiomyopathy is the label used where the muscle is weak because it has been starved of blood, either gradually through narrowed arteries or through damage after one or more heart attacks. The NHS and BHF pages used for this guide do not use the term itself; they describe the two ends of the pathway, coronary heart disease on the one hand and heart failure on the other.

The British Heart Foundation explains that if a piece of atheroma breaks off, a blood clot can form and block a coronary artery, cutting off blood and oxygen to part of the heart muscle. This is a heart attack, and it can cause lasting damage to the muscle. It says that a heart attack is among the most common causes of heart failure, alongside cardiomyopathy and high blood pressure.

The NHS says heart failure does not mean the heart has stopped working or is about to stop. It means the heart cannot pump blood properly. Heart failure can happen suddenly or come on slowly over months and years. When it follows coronary disease, narrowed arteries and damaged muscle can both play a part, so treatment looks at both the arteries and the pumping.

Risk factors for coronary heart disease are the same ones that lead to this type of muscle damage. The NHS says atherosclerosis can be caused by lifestyle factors such as smoking and regularly drinking excessive amounts of alcohol, and that you are more at risk with high cholesterol, high blood pressure or diabetes. The British Heart Foundation adds living with excess weight, not doing enough physical activity, family history of coronary heart disease and getting older, and notes that men develop it from a younger age while women's risk rises during and after the menopause.

For heart failure itself the NHS says anyone can get it but you may be more at risk if you are 65 or older, living with overweight or obesity, smoke, drink a lot of alcohol or use cocaine.

Symptoms come from the heart not pumping enough blood to meet the body's needs and from fluid backing up. The NHS lists the following for heart failure.

• Breathlessness when doing everyday activities or lying down, or being more breathless than expected with exercise.

• Feeling weak, light-headed, dizzy or very tired, particularly after moving.

• Swelling in the feet, ankles, legs or tummy, or feeling bloated.

• Sudden weight gain, coughing at night and coughing up frothy pink phlegm.

The NHS says to see a GP if you think you have symptoms of heart failure. It advises asking for an urgent GP appointment or getting help from NHS 111 if you feel breathless when lying down or from everyday activity, you are coughing up frothy pink phlegm, or you have suddenly gained weight. It says to call 999 for severe difficulty breathing (gasping, choking or not able to get words out), pale, blue or grey lips or skin, or if someone has passed out and is not responding normally, and not to drive yourself to A&E.

Because the cause is often coronary disease, chest pain or heart attack symptoms are also an emergency. The British Heart Foundation says to dial 999 for possible heart attack symptoms or severe difficulty breathing.

A doctor will ask about your medical history and symptoms and examine you. The British Heart Foundation lists the tests that may follow: a 24-hour ECG, a chest X-ray to look for fluid in the lungs, an echocardiogram (an ultrasound of the heart), blood tests that may include BNP, and breathing tests. The NHS also lists an MRI scan and says you will be referred to a heart specialist (cardiologist).

The echocardiogram measures the ejection fraction, the amount of blood squeezed out of the main chamber with every beat. The British Heart Foundation says more than 50% is considered normal, and that heart failure may be classed as preserved (50% or more), mildly reduced (40% to 49%) or reduced (40% or less). Where coronary disease is suspected, the NHS says further tests may include a coronary angiogram, and the British Heart Foundation lists exercise stress tests, radionuclide tests and CT or MRI scans.

Treatment aims to ease symptoms, prevent the condition getting worse and reduce the chance of further heart attacks. The NHS says it depends on the type and stage of heart failure and your overall health.

The NHS says heart failure affects everyone differently and that symptoms can vary from day to day and week to week. It suggests taking medicines as prescribed, weighing yourself regularly because sudden weight gain can mean fluid building up, having vaccinations such as the flu vaccine, staying active through cardiac rehabilitation, eating a balanced diet, keeping to a healthy weight, quitting smoking and cutting down on alcohol. The British Heart Foundation adds watching your fluid intake if your team advises it.

If you drive, the NHS says you will need to tell the DVLA, and you should check with your insurance company. Some people need to adjust work duties or stop working. The NHS also notes that heart failure can be difficult to live with emotionally and that you can refer yourself to NHS talking therapies. Palliative care teams focus on improving quality of life as the condition progresses, and the British Heart Foundation encourages talking about concerns with the heart failure team.

Most people with a weak heart from coronary disease are looked after in NHS cardiology and heart failure services, with GP follow-up and cardiac rehabilitation. Some choose a private cardiologist for faster scans or a second opinion. The tests and medicines are the same; the larger interventions, such as angioplasty, devices and surgery, are performed in both sectors. Keep a single record of your scans, ejection fraction results and medicines so that all clinicians see the same information, and ask who to contact if breathlessness or swelling increases.