In most cases, deposits in the coronary arteries (plaques) are responsible for a heart attack. These are made up of fat and calcium. The deposits narrow the coronary arteries, compromising the heart‘s supply of oxygen-rich blood. If the vessels close completely, a myocardial infarction occurs. In this, parts of the heart muscle no longer get enough oxygen, so they die.
Most common cause of heart attack: coronary artery disease
By far the most common cause of heart attack is atherosclerosis (hardening of the blood vessels), which – when it affects the coronary arteries – is called coronary artery disease (CAD). Vascular calcification or arteriosclerosis is particularly widespread in industrialized countries.
Coronary heart disease often exists unnoticed for years before the heart attack. The disease becomes noticeable through shortness of breath and chest pain, which mainly occur during physical or mental exertion. After exertion, the pain subsides quickly (stable angina). Coronary artery disease is dangerous because it sets the stage for a heart attack.
Risk factors of a heart attack
Quite a few causes and risk factors for myocardial infarction are known:
- Smoking
- Excessive alcohol consumption
- Improper diet
- Overweight
- Lack of exercise
- Diabetes
- Increasing age
- Continuous stress
- High blood pressure
- An increased blood concentration of fibrinogen (which contributes to clotting).
Genetic predisposition as a cause?
A genetic predisposition to heart or myocardial infarction is also believed to be one of the causes. Hypertension, dyslipidemia, and diabetes interact with coronary artery disease (CAD) to increase the risk of myocardial infarction (heart attack).
When these four diseases occur together, it is known as metabolic syndrome. An increased concentration of the substance fetuin-A seems to indicate an increased risk of myocardial infarction (although the exact relationships are not yet known).
Rare Causes in Myocardial Infarction.
Rather rare causes of myocardial infarction include vascular occlusion from an entrained blood clot (embolism) or inflammation of the coronary vessels.
In younger patients who have suffered a myocardial infarction, spasm of a coronary vessel (vasospasm) may also underlie the condition.
Myocardial infarction in men and women
Compared with women, men suffer heart attacks earlier (sometimes before the age of 40) and more frequently. However, the diagnosis of myocardial infarction is more often misdiagnosed in women. In addition, more women than men die from myocardial infarction.