Causes and Consequences of Occlusion of the Coronary Arteries

1. Function:
   1. Deliver Oxygen-Rich Blood: Supply the heart’s muscular walls (myocardium) with oxygen and nutrients.
   2. Maintain Continuous Contractions: Essential for the heart to pump blood effectively throughout the body.
2. Main Coronary Arteries:
   1. Right Coronary Artery:
      1. Supplies the right side of the heart.
   2. Left Coronary Artery:
      1. Divides into the left anterior and posterior descending arteries, supplying the left side of the heart.

Coronary Artery Occlusion

Coronary heart disease (CHD) occurs when the coronary arteries, which supply blood to the heart muscle, become occluded (blocked), usually by a buildup of plaque (atherosclerosis).

1. Lipid Deposition: Saturated fats and cholesterol accumulate in the arterial walls, forming fatty streaks that evolve into plaques.
2. Calcium Impregnation: Over time, plaques harden through calcification, reducing the arteries' flexibility and narrowing the blood flow.
3. Hypertension (High Blood Pressure): High pressure damages arterial walls, making them more prone to plaque formation.
4. Smoking: Nicotine triggers vasoconstriction (narrowing of blood vessels), increasing blood pressure and promoting plaque buildup.
5. Obesity and Poor Diet: Diets high in saturated fats, sugars, and salt contribute to both hypertension and high cholesterol levels.
6. Sedentary Lifestyle: Lack of physical activity exacerbates obesity and weakens cardiovascular health.
7. Genetic Factors: Some individuals inherit a predisposition to high cholesterol or hypertension, increasing their risk.
8. Diabetes: People with diabetes, particularly those with poorly controlled blood sugar levels, are at an increased risk of developing atherosclerosis.

Consequences of Coronary Artery Occlusion

The severity and duration of a coronary artery blockage determine its consequences. Below are the primary outcomes:

1. Angina (Chest Pain)

1. Reduced blood flow to the heart can cause chest pain, or angina, especially during physical exertion or stress.
2. Angina is a common symptom of CHD and is a warning sign of potential future heart attacks.

2. Heart Attack (Myocardial Infarction)

1. When a coronary artery becomes completely blocked by a blood clot or plaque rupture, it can cause a heart attack.
2. The heart muscle is deprived of oxygen and nutrients, leading to damage or death of heart tissue.
3. This can be fatal if the blockage is not cleared or treated promptly.

3. Heart Failure

If a heart attack damages a significant portion of the heart muscle, it can lead to heart failure, where the heart is unable to pump blood effectively to meet the body's needs.

4. Arrhythmias (Irregular Heart Rhythms)

Coronary artery occlusion can also disrupt the normal electrical impulses of the heart, leading to arrhythmias, which can range from mild palpitations to life-threatening irregular rhythms, such as ventricular fibrillation.

5. Stroke