What is a Heart Attack?

A heart attack, also known as myocardial infarction or coronary thrombosis, happens when the blood supply to the heart muscle is reduced or completely blocked off due to an obstruction in one or more the coronary arteries which encircle the heart. When this happens, the heart muscle is deprived of essential oxygen and eventually stops working.

Heart attacks are very common – statistics show that over 50,000 people in Australia die from heart attacks every year. In fact, about one third of all deaths of people under the age of 75 years old are the result of a heart attack, which makes it one of the leading causes of death in Australia.

If only a small area of the heart is involved, there may be no loss of pumping efficiency. Sometimes there are not even any symptoms – this is referred to as a ‘silent’ heart attack. However, if there is extensive damage to the heart, varying degrees of disability, and at worst, death, will result.

What causes a heart attack?

In most cases a heart attack is caused by the formation of a blood clot in a narrowed coronary artery. Narrowing of the coronary arteries is caused by atherosclerosis, a condition in which deposits of fat collect on the inside of the artery walls.

Less commonly, a temporary spasm (contraction) of the muscle in the wall of a coronary artery may cause a heart attack. This may occur in normal arteries, but it is more common in those narrowed by arteriosclerotic deposits.

During the course of a heart attack, the blood supply to the heart muscle is decreased and cells in the muscle die. A mild heart attack may last less than an hour and cause little damage to the muscle. Severe attacks can destroy large areas of the heart muscle and cause permanent disability or death.

A common complication of a heart attack is the development of an abnormal, rapid heart rhythm which impairs its ability to pump blood. However, 80% of those who survive a heart attack can return to a normal life within a few months of the attack.

How is a heart attack diagnosed and treated?

Diagnosis of a heart attack is based on the description of the pain and the symptoms listed overleaf. The diagnosis will be confirmed by an electrocardiogram (ECG), which indicates the electrical activity going on inside the heart muscle. A heart attack usually causes a typical pattern of abnormalities on the ECG trace. Blood tests may also be taken to detect enzymes released from the damaged heart muscle.

What will the doctor do?

Until recently, the primary treatment for a heart attack involved easing the patient’s pain, providing medication to regulate the heart rhythm and then restarting the heart with electrical simulation or medication if it had stopped beating (cardiac arrest). However, new medications, known as streptokinase and tissue plasminogen activator (TPA), are now available. These dissolve the blood clots that cause most heart attacks. To halt a heart attack and cut the risk of muscle damage, these drugs must be injected within hours of an attack.

What can I do to avoid a heart attack?

There are various ways to avoid a heart attack. The most important steps you can take are to stop smoking and follow a low-fat, high-fibre diet. You should keep to your ideal weight and take regular exercise.

What factors contribute to a heart attack?

Various factors contribute towards the risk of a heart attack, including:

-          Smoking
-          Age
-          Family history of early heart attacks.
-          High blood cholesterol which encourages clogging of the arteries with fatty deposits (atherosclerosis)
-          Being male (oestrogen hormones protect women from atherosclerosis until they reach the menopause).
-          High blood pressure
-          Diabetes
-          Obesity

What to do when someone is having a heart attack?

A heart attack needs urgent medical attention, so call for a doctor or ambulance immediately. There is a danger that the heart may stop beating properly. If the affected person stops breathing, give artificial ventilation. If the heart stops beating, cardiac massage should be given, but only by someone who knows the proper technique, since if it is carried out on a casualty whose heart is still beating, it could actually cause a cardiac arrest. Stay with the victim until help arrives.

Heart Attack Symptoms

The main symptom of a heart attack is pain, which may manifest itself in many ways:

-          A mild ache or pressure, a severe squeezing or crushing sensation or a burning or bloated feeling.
-          Pain located in the centre of the chest, or spreading into the neck, jaw or shoulder, or down the arms.
-          Cold sweats, nausea, vomiting, weakness, anxiety, palpitations or shortness of breath may accompany the pain.

Warning / Precaution

Many of the symptoms of a heart attack can be mistaken for heartburn. However, if you do experience these symptoms and do not regularly suffer from heartburn, you should go to the casualty department at the nearest hospital, or your doctor’s surgery, as soon as possible. You may be suffering a heart attack and if so, delay in treatment could be fatal.

A Healthy Diet

A healthy diet is particularly important in controlling or lowering high blood pressure and reducing your risk of heart disease. There are no strict rules or magical potions. Healthy eating starts and finishes with “balance” and “variety”. This includes eating foods low in salt and drinking alcohol in moderation.

Control Your Weight

Controlling your weight is an important step to reducing risk of developing high blood pressure. Being overweight puts a strain on the heart. If you have high blood pressure, losing excess weight will help control it  – sometimes even drug treatment becomes unnecessary.

The best way to control your weight is to eat less fat and to exercise regularly. The Heart Foundation has a range of cookbooks with healthy recipes and helpful shopping hints. Ask also for a copy of their weight guide book.

Salt

Most people eat more salt than they need. This salt comes mainly from processed foods. A high salt diet is linked to blood pressure, salty foods can also interfere with your control of it.  Eating more fresh foods and choosing “no added salt”, “low”, or “reduced salt” processed food is best. The Heart Foundation’s “tick of approval” is a guide to foods that are relatively low in salt.

Alchohol

Excess alcohol can increase high blood pressure. If you drink three or more glasses of alchohol a day, you are more likely to develop high blood pressure. If you are taking tablets for high blood pressure, alcohol can reduce their effectiveness. Less than two drinks of alcohol a day is advised.

Physical Activity

Having high blood pressure does not mean you are an invalid in any way. On the contrary, exercise should definitely be part of your daily program. Try walking, swimming, cycling or games such as tennis and golf. Avoid more strenuous exercises such as body presses and lifting heavier weights, which can actually raise blood pressure too much while you are doing them. Ask your doctor about the best kind of exercise program for you.

Drug Treatment

There is a variety of drugs to control blood pressure. If you need them, your doctor will start you on a small dose of drug and note its effect. If necessary, the dosage will be gradually increased, or other drugs used, until your blood pressure is well controlled. Two different drugs are often used to keep any side effects to a minimum. Once you start drug treatment you will probably have to continue for the rest of your life. The drugs control high blood pressure, not cure it. These high blood pressure drugs will not “build up” inside your body and the longer you are on them the better they will work. You should always carry a list of your drugs and their doses with you.

Side Effects

Blood pressure tablets may cause side effects, but these can be kept to a minimum by adjusting the type of drug and dose. You must tell your doctor about any side effects and their severity. Drugs for blood pressure are effective and their benefits far outweigh the problems that can occur. Most people don’t have any side effects and can live a normal lifestyle by working in partnership with their doctor.

Be A Non-Smoker

Your doctor will strongly advise you to give up smoking. Smoking does not cause high blood pressure but it can make it more harmful, leading to heart attack, stroke and gangrene of the legs, and other damage. Once you stop smoking the extra risk is reduced quickly.

Help Yourself

Keep doctors appointments. Your doctor will probably advise you to have your blood pressure checked regularly, maybe weeks or a few months apart. It’s important to keep appointments as your blood pressure and drug dosage need constant monitoring. Your doctor may advise you to monitor your own blood pressure at home with a device you can buy from a chemist.

Take your blood pressure tablets as directed. If you think a drug is not agreeing with you, tell your doctor exactly how you feel. Your treatment will be adjusted and side effects can be minimised.

Follow medical advice about diet, exercise and smoking. Make a strong effort to lose excess weight, switch to a healthy eating pattern, and exercise regularly.

Eventhough it’s a team effort, you can do more than anyone else to bring your blood pressure under control – and keeping it there.