Enumerate the line of treatment in case ECG indicates acute inferior wall myocardial infarction.

I. Pre-Hospital Phase

The initial management begins even before the patient reaches the hospital:

• Immediate Actions: Call for emergency medical services (EMS). The patient should be placed in a comfortable position, ideally semi-recumbent.
• Oxygen Administration: Administer high-flow oxygen (typically 4-6 L/min) to maintain oxygen saturation >90%.
• Nitroglycerin: Sublingual nitroglycerin (0.4mg) can be administered every 5 minutes for up to three doses, provided the patient is hemodynamically stable (systolic BP >90 mmHg). Contraindications include hypotension, right ventricular infarction, and recent phosphodiesterase-5 inhibitor use.
• Aspirin: Administer 300mg of aspirin (chewed and swallowed) unless contraindicated (e.g., active bleeding, allergy).
• ECG Acquisition & Transmission: EMS personnel should obtain a 12-lead ECG and transmit it to the receiving hospital for early activation of the cardiac catheterization lab.

II. Emergency Department Phase

Upon arrival at the hospital, the following steps are taken:

• Rapid Assessment & Triage: Quick assessment of vital signs, level of consciousness, and immediate life threats.
• Confirmation of Diagnosis: Review the pre-hospital ECG. Serial ECGs and cardiac biomarkers (Troponin I or T, CK-MB) are obtained to confirm the diagnosis of MI.
• Reperfusion Therapy: This is the cornerstone of treatment. Two main strategies exist:
• Primary Percutaneous Coronary Intervention (PCI): Preferred strategy if available within 90-120 minutes of first medical contact. This involves mechanical opening of the blocked RCA using a balloon and stent.
• Fibrinolytic Therapy: Considered if PCI is not readily available within the recommended timeframe. Commonly used agents include alteplase, tenecteplase, or reteplase. Contraindications must be carefully assessed (e.g., recent surgery, stroke, bleeding disorders).
• Adjunctive Therapies:
  • Anticoagulation: Heparin (unfractionated or low-molecular-weight heparin) is administered alongside fibrinolytic therapy. For PCI, bivalirudin or heparin is used.
  • P2Y12 Inhibitors: Clopidogrel, prasugrel, or ticagrelor are administered to prevent platelet aggregation. Choice depends on PCI strategy and patient characteristics.
  • Beta-Blockers: Administered orally or intravenously (with caution) to reduce heart rate, blood pressure, and myocardial oxygen demand. Contraindicated in hypotension, bradycardia, and severe heart failure.
  • ACE Inhibitors/ARBs: Initiated early to prevent ventricular remodeling and improve long-term outcomes.
  • Statins: High-intensity statin therapy is initiated regardless of cholesterol levels.

III. Post-Acute Phase & Ongoing Management

Following reperfusion, ongoing monitoring and management are essential:

• Continuous ECG Monitoring: To detect arrhythmias (e.g., ventricular tachycardia, ventricular fibrillation).
• Hemodynamic Monitoring: Assessment of blood pressure, heart rate, and cardiac output.
• Management of Complications: Address potential complications such as heart failure, cardiogenic shock, arrhythmias, and mechanical complications (e.g., ventricular septal rupture).
• Cardiac Rehabilitation: Enrollment in a comprehensive cardiac rehabilitation program to improve functional capacity and reduce future cardiovascular events.
• Long-Term Medications: Continued use of beta-blockers, ACE inhibitors/ARBs, statins, and P2Y12 inhibitors (duration varies based on stent type and clinical factors).

IV. Special Considerations in Inferior MI

Inferior MI often presents with specific challenges:

• Right Ventricular Involvement: RCA occlusion can also affect the right ventricle. Hypotension is common. Fluid resuscitation is crucial, and nitrates and diuretics should be used cautiously.
• Atrioventricular (AV) Block: Inferior MI can cause AV block due to edema and ischemia affecting the AV node. Temporary pacing may be required.
• Vagal Response: Patients may experience bradycardia and hypotension due to increased vagal tone.