Internal Medicine · Year 3 · from Internal Medicine

Case 1: Acute Coronary Syndrome

Patient Presentation

A 58-year-old man with a history of hypertension, type 2 diabetes mellitus, and hyperlipidemia presents to the emergency department with severe substernal chest pain that started 2 hours ago while he was mowing his lawn. He describes the pain as a "crushing" sensation radiating to his left arm and jaw, rated 9/10 in intensity. He also reports associated diaphoresis, nausea, and shortness of breath. He took two aspirin at home before calling EMS.

Vital Signs

  • Blood Pressure: 155/95 mmHg
  • Heart Rate: 102 bpm
  • Respiratory Rate: 22/min
  • Oxygen Saturation: 94% on room air
  • Temperature: 37.1°C

Physical Examination

  • General: Anxious, diaphoretic, clutching chest
  • Cardiovascular: Tachycardic, regular rhythm, S4 gallop, no murmurs
  • Pulmonary: Bibasilar crackles
  • Extremities: No edema, peripheral pulses intact

Initial Workup

  • ECG: ST-segment elevation in leads V1-V4 with reciprocal ST depression in inferior leads
  • Troponin I: 0.8 ng/mL (normal <0.04 ng/mL)
  • BNP: 450 pg/mL (normal <100 pg/mL)

Clinical Image

Figure 1: 12-lead ECG demonstrating ST-segment elevation in anterior leads (V1-V4) consistent with acute anterior wall ST-elevation myocardial infarction (STEMI).

Image Source: Educational illustration for teaching purposes.

Questions

  1. What is the most likely diagnosis?
  • A) Unstable angina
  • B) NSTEMI
  • C) Anterior STEMI
  • D) Pericarditis
  1. What is the most appropriate immediate management?
  • A) Medical management with anticoagulation and stress testing
  • B) Emergent percutaneous coronary intervention (PCI)
  • C) Thrombolytic therapy
  • D) Coronary artery bypass grafting
  1. Which artery is most likely occluded?
  • A) Right coronary artery
  • B) Left circumflex artery
  • C) Left anterior descending artery
  • D) Posterior descending artery
  1. What is this patient's HEART score, and what does it indicate?
  1. What adjunctive medications should be administered in the emergency department?

Answers

  1. C) Anterior STEMI - The patient has classic symptoms of ACS with ST-elevation in leads V1-V4 indicating anterior wall involvement, elevated troponin, and reciprocal changes inferiorly.
  1. B) Emergent percutaneous coronary intervention (PCI) - Primary PCI is the preferred reperfusion strategy for STEMI when door-to-balloon time can be achieved within 90 minutes. This patient is within the optimal window for intervention.
  1. C) Left anterior descending artery - ST-elevation in V1-V4 indicates anterior wall involvement, which is supplied by the LAD artery. The LAD supplies the anterior wall of the left ventricle and the anterior two-thirds of the interventricular septum.
  1. HEART Score Calculation:
  • History: Highly suspicious (2 points)
  • ECG: Significant ST-elevation (2 points)
  • Age: 58 years (1 point)
  • Risk factors: HTN, DM, hyperlipidemia (2 points)
  • Troponin: >3x normal (2 points)
  • Total: 9 points - High risk, indicating need for emergent intervention
  1. Adjunctive medications:
  • Aspirin 325 mg (already taken)
  • P2Y12 inhibitor (clopidogrel, ticagrelor, or prasugrel)
  • Anticoagulation (unfractionated heparin or bivalirudin)
  • High-intensity statin
  • Beta-blocker (if no contraindications)
  • Supplemental oxygen if SpO2 <90%
  • Morphine for pain control (with caution)
  • Nitroglycerin for ongoing ischemic symptoms (if BP allows)

All cases for this lecture as Markdown