Ischaemic heart disease
Ischaemic heart disease is a disease characterized by reduced blood supply to the heart. It is the most common cause of death in most western countries.
Ischaemia means a "reduced blood supply". The coronary arteries supply blood to the heart muscle and no alternative blood supply exists, so a blockage in the coronary arteries reduces the supply of blood to heart muscle.
Most ischaemic heart disease is caused by atherosclerosis.
What is it?
- Initially there is narrowing of coronary arteries causing angina.
- The narrowing is mostly caused by fatty plaques lining the wall of the artery.
- Sometimes a fatty plaque will rupture leading to a heart attack. (Heart attacks caused by simple narrowing are relatively uncommon).
- A heart attack causes damage to heart muscle by cutting off its blood supply.
This can cause:
- Temporary damage and pain (ischaemia)
- Loss of muscle activity (acute heart failure)
- Permanent heart muscle damage (acute myocardial infarction /infarct)
- Long term loss of heart muscle activity (chronic heart failure)
- Cardiac arrhythmias: irregular heartbeat which can be fatal.
- Other structural damage to the heart including damaged heart valves, actual perforation of the heart and a thin walled fibrous floppy heart.
Prevent or delay atherosclerosis.
Treatment of a heart attack.
- Do not smoke.
- Treat hypertension (high blood pressure)
- Exercise regularly (Exercising the heart muscle strengthens it, like any other)
- Avoid obesity: a large body puts unnecessary strain on the heart and increases serum cholesterol and triglycerides.
- Avoid excess saturated fat in the diet. Some unsaturated fats may be beneficial in reducing the risk of heart disease when consumed in moderation. Dietary cholesterol is shown to have a modest effect on serum cholesterol.
- Take cholesterol reducing drugs.
Which of these options are required depends on the situation.
After a heart attack
- Specialised coronary care (the sooner the better).
- Cardiopulmonary resuscitation (heart massage).
- A defibrillator can revert cardiac arrhythmias.
- An artificial pacemaker can prevent cardiac arrhythmias.
- Drugs such as adrenaline can increase heart rate.
- Thrombolytic agents can clear away the causative blood clot.
- Anticoagulation can prevent additional blood clots.
- Inotropic drugs will raise blood pressure.
- Unblock arteries with surgery or angioplasty ("balloon angioplasty")
- Possible cardiac surgery.
- Possibly the regular administration of anti-coagulants to prevent further arrhythmias
- Possibly the regular administration of drugs to control heart rhythm.
- Increase exercise within limits of safety (see prevention) to train the heart.