Heart Anatomy and Coronary Artery Disease

Coronary Arteries

  • The coronary arteries (right and left coronary arteries) supply blood to the heart muscle.

  • They provide essential blood flow, particularly during periods of increased heart activity, ensuring the heart gets the oxygen it needs to continue pumping effectively.

Coronary Artery Disease (CAD)

  • CAD occurs when the coronary arteries become diseased, often characterized by the buildup of plaque (fatty substances).

  • This buildup can be compared to plumbing clogs, where the arteries become narrowed, leading to restricted blood flow.

  • Causes of plaque buildup include cholesterol deposits and inflammatory responses from white blood cells, leading to a condition known as Atherosclerosis (hardening of the blood vessel).

  • Over time, plaque makes arterial walls hard and stiff, restricting blood delivery to the heart muscle.

Angina

  • Stable Angina: Occurs when exertion causes chest pain due to temporary insufficient blood flow to the heart during higher activity levels.

    • Symptoms occur predictably (e.g., during exercise) and subside with rest.

    • While at rest, blood flow is usually sufficient; however, increased heart workload leads to oxygen deprivation in muscles, resulting in a strangling chest pain referred to as Angina Pectoris (from Greek meaning 'to strangle').

Acute Coronary Syndrome

  • This is a severe condition resulting from CAD, characterized by unstable angina or heart attacks.

  • Unstable Angina: Unlike stable angina, this can occur unpredictably, even at rest, and is due to potential plaque rupture, leading to temporary blood flow restriction.

    • The ruptured plaque is thrombogenic, meaning it can cause clot formation that risks blood vessel blockage.

Heart Attack

  • A heart attack occurs when blood flow to the heart muscle is critically blocked, usually by a thrombus (blood clot).

  • This blockage can be caused by thrombosis (complete blockage) or embolization (clot detaching and blocking a smaller downstream vessel).

  • Without timely medical treatment (ideally within 20 minutes), the affected heart muscle can die due to lack of oxygen.

Distinction Between Heart Attack and Heart Failure

  • A heart attack results in the death of part of the heart muscle due to oxygen deprivation, whereas heart failure occurs when the heart cannot pump enough blood to meet the body's needs.

  • They can cause each other but are distinct conditions with different underlying issues.