How can people with normal cholesterol get a heart attack?

Cholesterol and heart attack

High blood cholesterol is one of the important risk factors for a heart attack. High blood cholesterol leads to formation of plaques in the blood vessel carrying oxygenated blood to the heart (coronary arteries). When a coronary artery gets blocked, a region of the heart muscle becomes damaged, producing a heart attack.

Other risk factors for heart attack

Several factors other than high cholesterol also can increase the chance of blockade of a coronary artery and lead to heart attack. These risk factors can be classified into modifiable and nonmodifiable ones.

Modifiable coronary risk factors

  1. High blood pressure
  2. Diabetes mellitus (high blood sugar)
  3. High cholesterol
  4. Smoking
  5. Physical inactivity

Non-modifiable coronary risk factors

  1. Gender (higher chance in males)
  2. Age (risk increases as age advances)
  3. Genetic factors (family history of premature heart attack)

Since there are so many other risk factors which a person can have, a heart attack is possible even with normal cholesterol levels. But cholesterol is one of the potentially easily modifiable risk factors, hence the importance of cholesterol as risk factor. Levels can also be brought down by modification of diet, exercise and medications.

Birth defects of the coronary arteries can also be a rare cause of heart attack in children. In one of such defects, the left coronary artery instead of arising from the aorta (the largest blood vessel carrying oxygenated blood, arising from the heart), arises from the pulmonary artery (large blood vessel carrying ‘impure’ blood to the lungs for oxygenation). This anomalous origin of left coronary artery from pulmonary artery (ALCAPA) is a cause for heart attack in infants.