Heart Attack vs. Cardiac Arrest

Overview: Heart Attack (MI) vs. Cardiac Arrest

Feature Heart Attack (MI) Cardiac Arrest
Definition Heart muscle death due to lack of blood supply. Abrupt loss of heart function, breathing, consciousness.
Primary Problem Circulatory (Plumbing): Blockage in coronary artery. Electrical (Wiring): Malfunction in heart's electrical system.
Cause Blood clot in coronary artery (atherosclerosis). Life-threatening arrhythmia (e.g., VF), or other severe issues.
Consciousness Conscious (may feel faint). Unconscious immediately.
Breathing Still breathing (may be labored). Not breathing (or gasping).
Pulse Present (may be weak/irregular). Absent.

Heart Attack (Myocardial Infarction)

  • Mechanism: Blockage of blood flow to heart muscle, causing tissue death.
  • Causes: Coronary Artery Disease (CAD), blood clot, spasm.
  • Symptoms: Chest pain (radiating), shortness of breath, cold sweat, nausea, lightheadedness.
  • ECG Findings: ST-segment elevation (STEMI) or depression (NSTEMI), pathological Q waves.
  • Treatment: Restore blood flow (angioplasty, thrombolytics), oxygen, pain relief.

Cardiac Arrest

  • Mechanism: Abrupt cessation of heart's pumping function due to electrical problem.
  • Causes: Ventricular Fibrillation (VF), Pulseless Ventricular Tachycardia (pVT), Asystole, PEA. Can be caused by MI, electrocution, etc.
  • Symptoms: Sudden collapse, loss of consciousness, no breathing, no pulse.
  • ECG Findings: VF, pVT, Asystole, PEA.
  • Treatment: Immediate CPR and Defibrillation (if shockable rhythm).

The Critical Relationship

  • A heart attack can lead to cardiac arrest if the damage causes a severe electrical disturbance (arrhythmia).
  • However, not all heart attacks lead to cardiac arrest, and not all cardiac arrests are caused by heart attacks.
  • Understanding the distinction is vital for proper emergency response.