Theurapeutic education

Coronary artery disease

What is coronary atherosclerosis?

Atherosclerosis is a chronic disease that results from cholesterol / fat deposits in the coronary arteries.

These changes lead to internal diameter narrowing of the coronary artery, called stenosis, limiting the blood supply to the heart muscle and thus leading to the appearance of angina pectoris. A prolonged occlusion of the artery leads to the occurrence of a myocardial infarction / heart attack.

Coronary stenosis
Coronary stenosis — Image of a normal coronary artery, by comparison to a pathologic coronary artery with an atheroma narrowing limiting normal blood flow

What is angina pectoris?

A sensation of pain, tightness or heaviness in the chest which may radiate to the jaw, shoulders, back or arms.

  • Duration: between 2 to 10 minutes.
  • Precipitating factors: symptoms usually occur during exertion, emotional stress, in the cold or after a meal.
  • Relieving factors: symptoms disappear on their own with rest after 5 minutes or after taking trinitrine spray.

Other symptoms may suggest problems with the coronary arteries: shortness of breath, marked tiredness or weakness / dizziness.

Gravity factors

Myocardial Infarction

What happens when a coronary artery is completely blocked?

Myocardial infarction is characterized by the rupture of an atherosclerotic coronary plaque, which causes an abrupt interruption of blood flow to a specific area of the heart muscle.   When a plaque rupture occurs within a coronary artery, blood components such as platelets and red blood cells will clump together to form a blood clot within the coronary artery, thus blocking normal blood circulation to the heart muscle.  The lack of blood and oxygen supply to the heart generate symptoms such as angina pectoris (Figure B). Myocardial infarction or a “heart attack” occurs when the artery is occluded for a prolonged period of time (Figure C), leading to permanent damages to the heart muscle.  Myocardial infarction may lead to subsequent complications, such as heart failure, ventricular arrhythmias and sudden death, a substantial burden for coronary patients. It is therefore imperative to act quickly to restore the normal blood flow in the artery in order to avoid any irreversible damage and long-term complications.

Athérosclérose coronaire, sténose et occlusion coronarienne
Coronary atherosclerosis, coronary stenosis and occlusion — (A) Grossly normal coronary artery without severe stenosis; (B) significant coronary stenosis of the middle right coronary artery (white arrow); (C) Occlusion of the mid-right coronary artery, without blood circulation beyond the occlusion (white arrow).
Next ressource : Cardiovascular prevention after a heart attack