A heart attack, also known as myocardial infarction or coronary thrombosis, happens when one of your coronary arteries becomes blocked. A coronary artery is a blood vessel that supplies your heart with oxygen-rich blood. The blockage is usually caused by a build-up of fatty deposits (plaques). Part of this blockage can break off and cause a blood clot to form and block your artery. This stops blood and oxygen from getting to your heart leading to damage to your heart muscle. This is a heart attack.
About 200,000 people in the UK have a heart attack each year. The risk of having a heart attack increases as you get older. They are more common in men than women up to the age of 70, after which there is no difference in risk.
You’re more likely to have a heart attack if you:
If you have a heart attack, you will most likely feel pain or discomfort in the middle of your chest. This pain is often described as a sensation of heaviness, tightness or squeezing, or it may feel like bad indigestion. The pain may come on suddenly causing you to collapse.
Other symptoms may include:
The symptoms of a heart attack can vary from person to person. Sometimes you may not have any obvious symptoms, especially if you’re elderly or have diabetes.
During a heart attack, you may develop life-threatening heart rhythms – this is why it’s a medical emergency.
If you suspect that you or someone you’re with is having a heart attack, call for emergency help immediately.
Complications will be different for everyone who has a heart attack. You may have very few or you may develop many.
In the first few days after a heart attack you may have an irregular heartbeat, known as arrhythmia. You may also get angina after having a heart attack. Angina is when you get pain or discomfort in your chest.
A heart attack can damage your heart muscle and cause it to become weaker, making it more difficult to pump enough blood and oxygen around your body. This is known as heart failure. The larger the area of your heart muscle that is damaged by a heart attack, the more likely you are to have heart failure. Getting treatment as soon as possible after a heart attack is important for limiting the damage to your heart muscle.
It’s also common to feel low or depressed after having a heart attack. You may be worried about having another one or concerned about your recovery. If you’re feeling anxious, speak to your doctor for advice.
Other, very rare complications include:
The underlying cause of most heart attacks is atherosclerosis. This is a condition in which your coronary arteries become narrowed over many years as fatty deposits (plaques) build up on the walls. These plaques can split, which leads to the release of substances that cause the blood in your coronary artery to clot to try to mend the damaged artery wall. Together the plaque and blood clot can completely block your coronary artery, stopping blood flow to your heart and causing a heart attack.
Either in the ambulance or when you get to hospital, a doctor, nurse or paramedic will ask you about your symptoms and examine you. You will have an ECG (electrocardiogram) as soon as possible to check the electrical activity of your heart. This can often show whether or not you’re having a heart attack.
Other tests that you may have, either immediately or over the next few days in hospital, are described here.
Emergency medical treatment is vital. Getting to hospital quickly and receiving specialist care greatly improve your chance of survival. If aspirin is available, chew a single tablet, unless you know you’re allergic to it. Aspirin reduces blood clots and can help to prevent the clot that is blocking your artery from spreading.
In response to an emergency call for a suspected heart attack, paramedics will be sent to you as soon as possible. Sit and rest in a position that is most comfortable until the paramedics arrive. They will give you initial treatment, such as medicines to relieve any pain, oxygen and aspirin if you haven’t had any yet. They may also do an ECG.
You will then be taken to a hospital for further tests and treatment. You may be taken to a specialist heart attack centre rather than your local hospital, even if this is further away. This is because you can only have important emergency treatment that can reduce damage to your heart muscle at these centres.
During or after a heart attack, you may have an irregular heartbeat, known as arrhythmia. The most serious form of this is called ventricular fibrillation. This is when the electrical activity of your heart becomes chaotic and your heart stops pumping and quivers or ‘fibrillates’ instead. This is known as a cardiac arrest and the paramedic may need to use a defibrillator. A defibrillator gives a large electric shock through the wall of your chest and can restore a regular heartbeat.
Your treatment will depend on how severe your heart attack is. Once you arrive at hospital, your doctor will decide on the best treatment for you.
There are two commonly used ways to restore blood flow in a blocked artery.
Sometimes a coronary angioplasty isn’t possible, for example if the blockages in your arteries are too severe, and you may be offered a coronary artery bypass graft (CABG) instead. CABG is an operation to bypass a narrowed section of your coronary artery using a blood vessel from your chest, leg or arm. This diverts the flow of blood around your narrowed or blocked coronary artery.
After a heart attack, you may need to take medicines regularly for a long time. Medicines you may be prescribed include antiplatelets, such as aspirin, along with other, stronger antiplatelet medicines (eg clopidogrel, prasugrel or ticagrelor), statins (eg atorvastatin or simvastatin), angiotensin-converting enzyme (ACE) inhibitors (eg ramipril) and beta-blockers (eg bisoprolol). You may also be prescribed fish oil capsules (eg Omacor).
You can reduce your risk of further heart attacks by taking these medicines. Always read the patient information leaflet that comes with your medicine and ask your doctor if you have any questions.
For the best possible recovery after a heart attack, you will be advised to follow a cardiac rehabilitation programme – you should receive information about this while you’re in hospital. These programmes vary but they will usually include an exercise regime devised by a specialist nurse or physiotherapist (a health professional who specialises in maintaining and improving movement and mobility), along with advice on relaxation, lifestyle and treatment choices.
You will have regular sessions with other people on the programme during which you can get advice and information from healthcare professionals. You will probably have these a couple of times a week for about two months. Ideally the programme will begin when you’re in hospital and continue after you leave.
You can reduce your risk of having a heart attack by adopting a healthy lifestyle. This includes:
Even if you have previously had a heart attack, these measures can still reduce your risk of having another one.
Produced by Polly Kerr, Bupa Health Information Team, April 2013.
For answers to frequently asked questions on this topic, see FAQs.
For sources and links to further information, see Resources.
This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional. For more details on how we produce our content and its sources, visit the about our health information page.