Understanding Heart Anatomy and Diseases

Oct 14, 2024

Lecture Notes on Heart and Cardiovascular System

Introduction to Heart's Blood Supply

  • Heart's Blood Supply: Heart requires its own blood supply due to lack of access to oxygen and nutrients within the heart chambers.
  • Coronary Circulation: Utilizes its own system of arteries, veins, and capillaries for blood delivery.

Blood Flow Dynamics

  • Blood Flow: Generally smooth and consistent in smaller arteries away from the heart.
  • Heart's Function: Blood exits the heart in pulses, following the rhythm of heartbeats.
  • Windkessel Effect: A mechanism ensuring smooth blood flow despite pulsating output from the heart.
    • Involves elastic rebound of arteries that alternately expand and contract.
    • Elastic Rebound: Arteries like the aorta expand with blood pressure and contract during heart relaxation, aiding in constant blood flow.

Coronary Circulation and Windkessel Effect

  • Elastic rebound ensures blood flow to the heart itself.
  • Coronary Arteries: Blood is pushed through coronary arteries during heart relaxation due to the aorta's elastic rebound.

Coronary Artery Disease (CAD)

  • Definition: Blockage of coronary arteries reducing blood flow.
  • Causes: Plaque formation within artery walls, leading to ischemia.
  • Symptoms: Angina pectoris (chest pain), potential radiating pain to arm, neck, or jaw.
  • Infarction: Tissue death due to prolonged ischemia; myocardial infarction (heart attack) is specific to heart muscle.

Diagnosis of Myocardial Infarction

  • Methods:
    • ECG: Monitoring heart's electrical activity.
    • Blood Tests: Checking for heart-specific enzymes released during cell death.

Treatment of Coronary Artery Disease

  • Lifestyle Modifications: Reducing risk factors like smoking, high blood pressure, and high cholesterol.
  • Medications:
    • Anticoagulants to prevent clotting.
    • Drugs to manage heart activity and dilate blood vessels.
  • Surgical Options:
    • Atherectomy: Inserting a device to clear plaques.
    • Balloon Angioplasty: Expanding arteries with a balloon and placing a stent.
    • Coronary Artery Bypass Graft (CABG): Using a blood vessel from another body part to bypass blocked arteries (can be single, double, triple, etc., depending on blockages).

Risk Factors

  • Modifiable: Smoking, hypertension, high cholesterol, diabetes, sedentary lifestyle.
  • Non-Modifiable: Genetics and age.

Conclusion

  • Emphasis on addressing both lifestyle and genetic predispositions to manage coronary artery disease effectively.