It is natural to wonder what caused a heart attack to occur when it did, for in the vast majority of cases it seems to come out of the blue. Heart attacks can start at any time of day or night and are a little more likely to develop when exercising than when resting and about as likely to come on when one is tranquil as when one is excited. Very occasionally, they seem to be brought on by intense physical or emotional stress.
Although we don’t know why heart attacks come on when they do, we know a lot about why people get coronary heart disease. We have learned that when certain “risk” factors are found in apparently healthy people, the risk of getting a coronary is greatly increased. The most important risk factors are cigarette smoking, high blood pressure, and high cholesterol in the blood (the British Heart Foundation has publications on each of these Heart Information Series numbers 10, 8, and 16). We also
that coronary disease sometimes runs in families (see HIS 16) and that in middle age it is much more common in men than in women. Heart attacks may often occur in people who seem to have been perfectly well. In others, it may follow weeks, months, or years of angina-heart pain usually occurring on exercise and going away with rest.
How is it treated?
When a heart attack first occurs, it is treated as an emergency because of the severity of the pain, the risk of a serious disturbance of the heart rhythm (including a cardiac arrest), and the need to give,
if possible, a clot-dissolving drug such as streptokinase. The priority in treatment for most patients is the relief of pain. If the patient has glyceryl trinitrate tablets, one or two of these should be sucked. If the pain remains severe, opiates (morphine or heroin) are given into a vein by a doctor or nurse. Ambulance personnel are not authorized to give these drugs but may use a mixture of nitrous oxide and oxygen (Entonox) through a face mask.
If a cardiac arrest should occur, the patient loses consciousness almost at once, no pulse can be felt and breathing may stop. This is the most extreme emergency and unless resuscitation is started within 3-4 minutes irreparable damage will be done to the brain and other organs. Everyone should know how to carry this out because a cardiac arrest can occur at any time and there may be no one else to help. If it is done properly, patients can be kept alive until an ambulance comes. Many ambulance personnel are now trained in advanced resuscitation and most emergency ambulances are equipped with an apparatus called a “defibrillator”. Cardiac arrest is usually due to a disorder of the heart rhythm known as “ventricular fibrillation” in which the electrical activity of the heart becomes chaotic and the heart ceases to pump. It can only be corrected by a large electric shock delivered across the chest wall by a defibrillator. This is usually successful in restoring a normal heartbeat and the patient thereafter often does just as well as if they had not had a cardiac arrest.
What happens to the heart after a heart attack?
After the heart attack, the area of muscle that was damaged is replaced by a scar. This process takes from days to weeks, and it is as well not to put too great a strain on the heart at this time. Within two or three months, at the most, the hearts of many patients are functioning just about as well as they were before the attack; on the other hand, a proportion of patients have sustained more severe damage so that the pumping action of the heart is permanently impaired. Furthermore, some patients continue to experience angina (pain in the chest on exercise) because a narrowing of the coronary arteries remains.
What about rest and exercise?
When the heart attack has not been severe, gentle exercise started a day or two after the attack does not do any harm, and has the advantage that the rest of the body does not get out of condition. If, on the other hand, there has been much breathlessness or other complications, a more prolonged period of rest may be advisable.
In most British hospitals, it is now normal practice to get patients out of bed on the second or third day after admission, if there have been no problems.
Mobilization consists of sitting out of bed at first, followed by walks around the bed or, perhaps, to the toilet. Within another day or two, walking about the ward is permitted and by the fifth to seventh day, some stairs may be climbed. There is, however, a considerable variation between one individual and another in the amount of exercise that is permitted, depending on the severity of the heart attack, the general level of fitness, and the practices of different hospitals and doctors. But the standard practice of
doctors of 30-40 years ago of keeping their patients in bed for 4-6 weeks was fortunately abandoned a long time ago!
Most patients when they go home have been walking short distances in the hospital, and many may have undergone a short exercise test on a stationary bicycle or a treadmill to see how much they can manage comfortably. If they have gone through such a test with flying colors, they are ready to step up their exercise program and can progressively increase the amount of exercise they take out of doors. They must use common sense, and avoid walking in cold winds or climbing up steep hills until they have had some weeks of successfully managing less stressful exercise. Some patients experience breathlessness on mild exercise.
This may simply be due to being out of training and will respond to a slow but steady increase in the amount of exercise from day to day; in other cases, however, it is due to the heart not pumping as well as it should (this is called “heart failure”). A doctor’s advice is necessary in deciding which it is; in the latter case drug treatment or even surgery may be necessary. Angina may also be a problem at this time; this may subside spontaneously or with treatment, but if it does not, consideration may be given to the need for angioplasty or surgery.
