Causes of myocardial ischaemia
Myocardial ischaemia occurs when blood flow to your heart is reduced, preventing it from receiving enough oxygen. The reduced blood flow is usually
the result of a partial or complete blockage of your heart's arteries (coronary arteries).
Myocardial ischaemia, also called cardiac ischaemia, can damage your heart muscle, reducing its ability to pump efficiently. A sudden, severe blockage of
a coronary artery can lead to a heart attack. Myocardial ischaemia might also cause serious abnormal heart rhythms.
Treatment for myocardial ischaemia involves improving blood flow to the heart muscle. Treatment may include medications, a procedure to open blocked
arteries or bypass surgery.
Making heart-healthy lifestyle choices is important in treating and preventing myocardial ischaemia.
Some people who have ischaemia don't experience any signs or symptoms (silent ischaemia).
When signs and symptoms occur, the most common is chest pressure or pain, typically on the left side of the body (angina pectoris).
Other signs and symptoms — which might be experienced more commonly by women, older people and people with diabetes
• Neck or jaw pain
• Shoulder or arm pain
• A fast heartbeat
• Shortness of breath when you are physically active
• Nausea and vomiting
When to see a doctor
Seek emergency care if you have prolonged or severe chest pain.
Myocardial ischaemia occurs when the blood flow through one or more of your coronary arteries is decreased. The low blood flow decreases the amount
of oxygen your heart muscle receives.
Myocardial ischaemia can develop slowly as arteries become blocked over time. Or it can occur quickly when an artery becomes blocked suddenly.
Conditions that can cause myocardial ischaemia include:
• Coronary artery disease (atherosclerosis). Plaques made up mostly of cholesterol build up on your artery walls and restrict blood flow.
Atherosclerosis is the most common cause of myocardial ischaemia.
• Blood clot. The plaques that develop in atherosclerosis can rupture, causing a blood clot. The clot might block an artery and lead to sudden, severe
myocardial ischaemia, resulting in a heart attack. Rarely, a blood clot might travel to the coronary artery from elsewhere in the body.
• Coronary artery spasm. This temporary tightening of the muscles in the artery wall can briefly decrease or even prevent blood flow to part of the
heart muscle. Coronary artery spasm is an uncommon cause of myocardial ischaemia.
Chest pain associated with myocardial ischaemia can be triggered by:
• Physical exertion
• Emotional stress
• Cold temperatures
• Cocaine use
Factors that can increase your risk of developing myocardial ischaemia include:
• Tobacco. Smoking and long-term exposure to second-hand smoke can damage the inside walls of arteries. The damage can allow
deposits of cholesterol and other substances to collect and slow blood flow in the coronary arteries. Smoking also increases the risk of
blood clots in your coronary arteries.
• Diabetes. Type 1 and type 2 diabetes are linked to an increased risk of myocardial ischaemia, heart attack and other heart problems.
• High blood pressure. Over time, high blood pressure can accelerate atherosclerosis, resulting in damage to the coronary arteries.
• High blood cholesterol level. Cholesterol is a major part of the deposits that can narrow your coronary arteries. A high level of "bad"
(low-density lipoprotein, or LDL) cholesterol in your blood may be due to an inherited condition or a diet high in saturated fats and cholesterol.
• High blood triglyceride level. Triglycerides, another type of blood fat, may also contribute to atherosclerosis.
• Obesity. Obesity is associated with diabetes, high blood pressure and high blood cholesterol levels.
• Waist circumference. A waist measurement of more than 89 centimetres (35 inches) for women and 102 cm (40 inches) in men increases
the risk of high blood pressure and heart disease.
• Lack of physical activity. An inactive lifestyle contributes to obesity and is associated with higher cholesterol and triglyceride levels.
People who get regular aerobic exercise have better cardiovascular fitness, which is associated with a decreased risk of myocardial ischaemia.
and heart attack. Exercise also lowers high blood pressure.
Myocardial ischaemia can lead to serious complications, including:
• Heart attack. If a coronary artery becomes completely blocked, the lack of blood and oxygen can lead to a heart attack that destroys part of the heart muscle.
The damage can be serious and sometimes fatal.
• Irregular heart rhythm (arrhythmia). An abnormal heart rhythm can weaken your heart and may be life-threatening.
• Heart failure. Myocardial ischaemia can damage the heart muscle, reducing its ability to effectively pump blood to the rest of your body. Over time, this
damage might lead to heart failure.
The same lifestyle habits that can help treat myocardial ischaemia can also help prevent it from developing in the first place. Leading a heart-healthy lifestyle
can help keep your arteries strong, elastic and smooth, and allow for maximum blood flow.