Volume 2: Cardiac Pathophysiology

The Ischemic Cascade: When Anatomy Fails

The Mechanical Failure (3D Logic): When a coronary artery (like the LAD) is blocked, the “plumbing” stops. In a 3D sense, the heart muscle doesn’t just stop squeezing all at once. It happens in layers:

  • Endocardium (The Inside): This layer dies first because it is furthest from the blood supply and under the highest pressure.
  • Epicardium (The Outside): This layer survives the longest. The Result: This “Transmural” gradient creates electrical chaos. The dead tissue cannot conduct electricity, forcing the electrical wave to “detour” around the scar. This is the 3D basis for Re-entry Arrhythmias.