Heart Attack (Myocardial Infarction - MI) Overview

Introduction

• Myocardial Infarction (MI), commonly known as a heart attack, occurs when the heart muscle cells die due to lack of oxygen.
• Blockages in coronary arteries cause a reduction in oxygen supply, leading to cell death (necrosis).
• Key phrase: "Minutes equals muscle" - timely intervention is critical.

Causes of Artery Narrowing

• Plaque buildup: Fatty deposits in coronary arteries.
• Factors contributing to plaque development:
  • Stress: Causes temporary narrowing.
  • Smoking: Scars arteries.
  • Obesity: BMI over 25.
  • Diabetes & Hypertension: Damage arterial walls.
  • Diet: High cholesterol from animal fats.
  • Atherosclerosis: Hardening/narrowing of arteries due to plaque.

Risk Factors

• More common in African-American males, those over 50, and men.

Symptoms

• Common symptoms:
  • Chest pain (substernal, jaw, left arm, mid-back, shoulder)
  • Shortness of breath, nausea, vomiting, sweating (diaphoresis), anxiety.
• Diabetic patients: May experience "silent MI" without classic symptoms.

Diagnostics

• EKG: First step in diagnosing chest pain.
  • ST elevation: Indicates lack of oxygen or hyperemia.
  • ST depression: Suggests low oxygen (ischemia).
• Troponin Levels: Gold standard test, >0.5 indicates heart muscle damage.
• Additional tests: CK, CK-MB, CRP, stress tests.

Treatment

• Immediate treatment philosophy: "MONA" - Morphine, Oxygen, Nitrates, Aspirin.
• Reperfusion therapy:
  • PCI (Percutaneous Coronary Intervention) and angioplasty to clear blockages.
  • CABG (Coronary Artery Bypass Graft) for severe cases.
  • Thrombolytics (TPA, streptokinase) if surgery unavailable.
• Medication Management:
  • Nitro precautions: No Viagra, max 3 doses 5 minutes apart.
  • Morphine for unrelieved pain.

Post-Operative Care

• Cath Lab Recovery Tips:
  • Monitor kidney function (creatinine levels) to avoid nephropathy.
  • Prevent infection: No soaking wounds, only showers.

Complications

• Cardiogenic Shock: Low BP, confusion, cool skin, requires urgent treatment.
• Arrhythmias: V-fib, V-tach, risk of defibrillation.
• Heart Failure: Rapid weight gain, edema.

Lifestyle Changes Post-MI

• Diet: Low sodium, low fluid intake, avoid high cholesterol foods.
• Exercise: 30 minutes, 5 days a week.
• No Smoking: To prevent artery scarring.
• Medication Compliance: Anti-platelets (e.g., aspirin), statins.

Prevention and Education

• Therapeutic Communication: Address patient fears post-MI.
• Patient Education: Avoid NSAIDs for pain relief due to clot risks.
• Long-term Medications: ACE inhibitors, statins for cholesterol control.

Key Takeaways

• Timely recognition and treatment can prevent heart muscle loss.
• Comprehensive care involves lifestyle changes and medication adherence post-MI.

For further study, consider engaging in practice quizzes and additional resources as provided. Always consult healthcare providers for personalized medical advice.