Lecture on Heart Attacks (Myocardial Infarction)

Key Concepts

Cardiovascular Disease: Leading cause of death globally. Heart attacks are a common type.
Heart Attack (Myocardial Infarction): Occurs when heart tissue experiences necrosis due to lack of oxygen, commonly caused by blocked blood supply.

Heart Structure:
- Four chambers: Right atrium, Right ventricle, Left atrium, Left ventricle.
- Atrium: Upper chambers that gather blood.
  - Right atrium: Collects deoxygenated blood from the body.
  - Left atrium: Collects oxygenated blood from the lungs.
- Ventricles: Lower chambers that pump blood.
  - Right ventricle: Pumps deoxygenated blood to lungs via pulmonary valve and trunk.
  - Left ventricle: Pumps oxygenated blood to body through aorta.
Valves in the Heart:
- Tricuspid Valve: Between right atrium and right ventricle.
- Pulmonary Valve: Between right ventricle and pulmonary trunk.
- Mitral Valve: Between left atrium and left ventricle.
Coronary Arteries:
- Provide oxygenated blood to heart muscle.
- Blockages here lead to myocardial infarctions.

Cardiac Muscle:
- Specialized, involuntary, capable of self-excitation.
- Does not regenerate; damage is irreversible.
Smooth Muscle: Found in digestive and urinary tracts, involuntary.
Skeletal Muscle: Voluntary, used for movement.

Causes: Blockage in coronary arteries due to cholesterol, plaque, or blood clots.
Effects: Tissue necrosis affecting heart's ability to pump blood.
Location Matters:
- Lower heart blockages are more severe.
- Affects how blood is pumped throughout the body.

Common Symptoms:
- Pain in left arm, jaw, neck, and chest.
- Breathlessness, varying between genders.
- Women may experience right arm pain too.

Critical Time Frame: Heart muscle can survive without oxygen for ~30 minutes.
Immediate Treatment: Essential for reversing damage and addressing root causes.