What is a myocardial infarction?

Myocardial infarction (MI) means that part of the heart muscle suddenly loses its blood supply. Without prompt treatment, this can lead to damage to the affected part of the heart. An MI is usually caused by a blood clot in a heart (coronary) artery that forms over a patch of atheroma (fatty deposit). See separate leaflet called 'Myocardial Infarction' which discusses MI in more detail.

What can I do to help after having a myocardial infarction?

Following an MI, there are things that you can do to reduce the risk of further heart problems. Everyone is different and individual circumstances will vary. You should discuss with a doctor or nurse what is best for you. This leaflet aims to complement any advice that you may receive.

Smoking

If you smoke, giving up smoking is the single most effective way to reduce your risk of having a further MI. The chemicals in cigarette smoke affect the arteries. If you stop smoking, your risk of a further MI is roughly halved compared to the risk if you continue to smoke. Angina is also more likely to develop in smokers.

If you find it hard to give up smoking then seek help from your doctor, practice nurse or pharmacist. They can give help and can advise on the use of nicotine replacement therapy (nicotine gum, etc) or other treatments that can help you to stop smoking. Separate leaflets give more details about smoking and ways that help you to stop smoking.

Diet

Changes in diet can make a big difference. Studies suggest that people who eat a healthy diet may halve their chance of a further MI compared to those who do not eat healthily. See separate leaflet called 'Healthy Eating' for more details.

Briefly:

• Eat at least five portions of a variety of fruit and vegetables each day. They are rich in vitamins and minerals. These can be fresh, frozen or dried.
• Do not eat much saturated fat. It is not just about the total fat content of the diet, but also the type of fat in the diet. Try to avoid eating foods that are high in saturated fat. Foods that are high in saturated fat include meat pies, sausages, butter, cream, hard cheese, cakes, biscuits and foods that contain coconut or palm oil. Eating foods that are high in unsaturated fat can help to reduce your cholesterol level. Foods high in unsaturated fat include oily fish (such as herring, mackerel, sardine, salmon), avocados, nuts and seeds, sunflower, rapeseed and olive oil.
• Reduce you salt intake. Many foods contain hidden salt. Lowering your salt intake can reduce your risk of another MI and also other cardiovascular diseases.

Alcohol

A little alcohol may be beneficial. People who drink one glass of wine per day, or about half a pint of beer per day, may have less risk of heart disease compared to those who do not drink at all. It is probably the alcohol rather than anything else in the drink that is the active ingredient. The exact way this works is not clear. Alcohol may affect the way atheroma is formed.

However, drinking too much alcohol can be harmful. Men should drink no more than 21 units per week (and no more than four units in any one day). Women should drink no more than 14 units per week (and no more than three units in any one day). One unit is about half a pint of normal strength beer, or two thirds of a small glass of wine, or one small pub measure of spirits. See separate leaflet called 'Alcohol and Sensible Drinking' for more details.

A Mediterranean diet

Eating a Mediterranean style diet is thought to be one of the best ways to reduce the risk of having an MI. This type of diet is, in effect, a summary of the advice above. That is - meals with poultry rather than red meat, lots of wholegrain pasta and breads and plenty of fruit, vegetables, olive oil, oil-rich fish, accompanied by a small glass of wine or beer.

Cholesterol

Cholesterol is involved in the formation of atheroma. Eating a healthy diet (described above) will help to lower cholesterol. In addition, most people who have an MI are advised to take a statin drug to lower the cholesterol level. Statins work by reducing the amount of cholesterol that is made in your liver.

In general, the lower the cholesterol level, the better. See separate leaflet called 'Cholesterol' for more details.

Physical activity and exercise

Normal physical activity and regular exercise is advised for most people who have had an MI. You should try and be physically active, for example take the stairs whenever possible, walk to the shops and wash your car. In the past, some people thought that exercise 'put a strain on the heart' and was bad. However, quite the opposite is true for most people who recover from an MI. Physical activity and regular exercise is good for the heart. Indeed, regular exercise is one of the main parts of cardiac (heart) rehabilitation programmes that are popular after having an MI (as discussed later). Regular exercise is a major way to reduce the risk of having a further MI.

However, before starting regular exercise, get the go-ahead from your doctor. This is because strenuous exercise in certain situations may not be advised. For example, some people with heart valve problems may not be advised to exercise. However, these people are the exception, and for most people who have had an MI, exercise is beneficial.

Following an MI, once you get the go-ahead, it is best to gradually build up the level of activity and exercise that you do. For the first week or so, try simply to go for a short walk each day. Everyone is different and the length of the walk depends on how fit you were to start with. For some people, at first it may simply be a walk to the end of the garden and back, for others a walk to the end of the road and for others a bit further.

You can then gradually build up the distance of your walking over time. A reasonable goal by about six weeks after having an MI is to aim to walk for 20-30 minutes each day. However, the amount of exercise that some people can do will be limited because of other medical problems. For example, some people develop angina which may limit the intensity of exercise that can be done. Others have other unrelated medical problems that limit exercise ability, or are too frail to exercise.

Regarding lifting and sudden bursts of strenuous effort. As a rule, normal manual work is fine, however, you should not do anything that makes you need to hold your breath. For example, lifting very heavy objects when you would need to 'grit your teeth' and hold your breath.

In most cases, after about 6-8 weeks following an MI the advice about exercise is the same as applies to anyone else to gain health benefits. That is, aim to build up to do at least 20-30 minutes of moderate exercise on most days (at least five days per week) to the extent of getting slightly short of breath with your exercise. See separate leaflet called 'Physical Activity for Health' for more details.

Weight

If you are obese or overweight then reducing your weight gradually will reduce your risk of a future MI. If you find it difficult to lose weight then see your practice nurse for encouragement and advice. See separate leaflets called 'Obesity and Overweight' and 'Weight Reduction - How to Lose Weight' for more details.

Blood Pressure

It is important to have your blood pressure checked regularly. High blood pressure is a major risk factor for heart disease. Normal blood pressure is less than 140/90 mmHg. If you are being treated for high blood pressure, the usual target is to reduce blood pressure in someone who has had an MI to below 130/80. In some cases this figure may vary depending on whether or not you have other conditions, for example kidney disease.

Lifestyle factors can help to lower blood pressure such as eating a healthy diet, exercise, losing weight if you are overweight and not eating much salt.

Medication is advised if your blood pressure remains persistently high. See separate leaflet called 'High Blood Pressure (Hypertension)' for more details.

Diabetes

If you have diabetes then good control of your blood sugar level and also your blood pressure will help to reduce the risk of a further MI. See separate leaflets called 'Diabetes - Type 1' and 'Diabetes - Type 2' for more details.

What medication is usual following a myocardial infarction?

Medication after an MI is discussed more fully in another leaflet called 'Myocardial Infarction - Medication'. Briefly, the following four drugs are commonly prescribed:

• Aspirin reduces the 'stickiness' of blood, which reduces the risk of blood clots forming. Clopidogrel is an alternative to aspirin which helps to prevent blood clots. It is usually used in people who are not able to take aspirin. It may be given with aspirin in some cases.
• A beta-blocker slows the heart rate and reduces the risk of abnormal heart rhythms.
• An ACE (angiotensin converting enzyme inhibitor) reduces the risk of developing heart failure and further MI.
• A statin reduces the cholesterol level (as discussed above).

Although the four drugs above are commonly advised, treatments may vary depending on other factors such as whether you have complications or other diseases.

Getting back to normal

After having an MI, it is natural to wonder if there are any 'dos and don'ts'. In the past, well-meaning but bad advice to 'rest and take it easy from now on' caused some people to become over-anxious about their hearts. Some people gave up their jobs, hobbies, and any activity that caused exertion for fear of 'straining the heart'. However, quite the opposite is true for most people who recover from an MI. Regular exercise and getting back to normal is usually advised.

Work issues

Following an MI, most people can go back to work within 2-3 months. However, each person is different. For example, some people who have a small MI and feel well go back sooner. On the other hand, some people with ongoing symptoms or complications such as angina or heart failure may take longer to go back or may not be able to go back to work.

Some people have wrong beliefs about work after an MI. For example, some people wrongly believe that work-related stress was the cause of their MI and they need to 'take things easy' from now on. However, as explained, an increase in activity is often preferable after an MI rather than 'taking it easy'. Some people believe that a physical job will be ruled out. Again, this is usually not the case provided that you feel well in yourself. Indeed, physical jobs are often better for the heart than office jobs. For many people, returning to work is an important part of regaining quality of life.

A possible sensible approach is:

• Get the go-ahead from your doctor about when you should return to work.
• Then, a phased return to work may be best if your employer is agreeable. For example:
  • Start with alternate half days, and build up to your normal routine over 2-3 weeks.
  • Start with light or less challenging duties at first.
  • Include additional rest periods if tiredness is a problem.

Understandably, some people consider early retirement following an MI, as the future may be uncertain. However, it is very important that you make such a decision for the right reasons and not based on fear or wrong beliefs about your heart.

Driving and flying issues

You should not drive for at least four weeks after an MI, provided you have made a satisfactory recovery (and your insurance company is notified). However, if driving causes angina, you should not drive until the angina is well controlled. PCV and HGV rules are stricter and further assessment is required.

You can usually fly as a passenger within two to three weeks of a MI, as long as you have no complications. This means that, for example:

• You have returned to your usual daily activities.
• Your condition is stable.
• You don't have any symptoms, or your symptoms are controlled.

It is usually sensible to check with your travel operator, airline and travel insurance company before you fly.

Stress, anxiety and relaxation

It is commonly believed that 'stress' can cause an MI. However, medical research has failed to show this and the conclusion is that stress does not cause an MI. However, being stressed and anxious can make you feel generally unwell in yourself.

Some people have unfounded concerns and wrong beliefs about MI which can cause symptoms of anxiety. Don't be afraid of talking to your doctor if you have concerns about your health. Alternatively, ring the helpline of the British Heart Foundation for advice (see below). They will give correct up-to-date advice (which may be very different to the 'old wives tales' that sometimes get passed around).

Many people who become anxious benefit from learning to positively relax. See separate leaflet called 'Relaxation Exercises' which may help as it goes through the two main ways to positively relax. That is, muscular exercises and deep breathing exercises. There is also another leaflet called 'Stress - Tips on How to Avoid It'. You can also buy relaxation tapes and CDs to help you learn to relax. Also, you should tell your doctor if you feel that you have become over anxious as there are other treatments for anxiety that may help.

Sex issues

Some people worry about resuming sex. For a few weeks it is probably best avoided. If you are able to walk without discomfort, then a return to sexual relationships should not cause any problems. If sex causes angina (chest pains) then tell your doctor.

Some men find that they have problems getting or maintaining an erection (erectile dysfunction) after having a MI. These problems can be caused by emotional stress or by medication such as beta-blockers. However, impotence can also have other causes. Speak to your GP who can check what is causing your problems and advise you on treatment. Various treatments (including medication) are now very effective for the treatment of erectile dysfunction.

Cardiac rehabilitation

You may be advised to attend a cardiac rehabilitation programme. Not every area has this facility, but these courses are becoming more widely available on the NHS. They are staffed by nurses, physiotherapists, and other health professionals. They aim to provide advice and help on exercise, diet, stress, and getting back to work and normal life following an MI. It is also useful to mix with others who are going through the same experience. Studies have shown that cardiac rehabilitation helps to reduce the risk of having another MI and improves general wellbeing.

Immunisation.

You should have the annual influenza jab and be immunised against the pneumococcal bacterium.

Some other general points

• Tell your doctor if you get angina following an MI. (Angina is a pain in the chest that comes on when you exercise such as when walking briskly. It is due to narrowing of the coronary arteries. See separate leaflet called 'Angina' for more details.) Further treatment may be needed.
• Tell your doctor if you get breathless, become more tired than usual, or notice your feet swelling. These symptoms may indicate a degree of heart failure (the heart muscle not pumping as well as normal). This can often be helped with medication. See separate leaflet called 'Heart Failure' for more details.
• Depression is common after an MI, often made worse by unfounded concerns. Again, tell your doctor if you think you are depressed. Treatment for depression often works well and can improve your quality of life.

Some thoughts to remember:

• Most people who have an MI make a full recovery.
• In many cases, only a small part of the heart muscle is damaged. The rest of the heart muscle remains undamaged and in many cases easily manages to do the work needed.
• Most people who have a job should be able to get back to work and do their normal job after having an MI.
• An MI often causes people to review and change their diet and lifestyle. Some people actually become fitter and healthier after they have an MI.
• A gradual increase in physical activity is good for the heart after an MI. (As one example, the famous explorer Sir Ranulph Fiennes had an MI in 2003 and even had a cardiac arrest. Just a few months later he was training for seven marathons in seven continents in seven days. Perhaps this is a bit excessive - but it shows it can be done.)
• For some people, the biggest cause of disability following an MI is not their heart, but unfounded worries and anxiety about their heart. Try to learn to positively relax, and talk to your doctor if you have any concerns.

Further sources of information and help

British Heart Foundation

Greater London House, 180 Hampstead Road, London, NW1 7AW
Tel (Heart Help Line): 0300 330 3311 Web: www.bhf.org.uk

HEART UK (the Hyperlipidaemia Education and Atherosclerosis Research Trust UK)

7 North Road, Maidenhead, Berkshire SL6 1PE
Tel (Helpline): 0845 450 5988 Web: www.heartuk.org.uk

British Cardiac Patients Association

15 Abbey Road, Bingham, Notts, NG13 8EE
Tel (Helpline): 01223 846845 Web: www.bcpa.co.uk

References

• Secondary prevention in primary and secondary care for patients following a myocardial infarction, NICE Clinical Guideline (2007)
• Acute coronary syndromes, SIGN (2007)
• Myocardial infarction - secondary prevention, Clinical Knowledge Summaries (January 2008)
• Giannuzzi P, Temporelli PL, Marchioli R, et al; Global secondary prevention strategies to limit event recurrence after myocardial Arch Intern Med. 2008 Nov 10;168(20):2194-204. [abstract]