Stable coronary artery disease

Stable coronary artery disease

Stable coronary artery disease

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Pathophysiology - The Arterial Squeeze

  • Demand-Supply Mismatch: Myocardial oxygen demand exceeds supply from stenosed coronary arteries, triggered by exertion or stress.
  • Atherosclerotic plaque creates a fixed obstruction, preventing vessel dilation in response to ↑ demand.

Critical Stenosis: Significant ischemia and symptoms typically occur when the coronary artery lumen is narrowed by >70%. This is a key threshold for intervention.

Clinical Presentation & Diagnosis - Chest Pains & Clues

  • Typical Angina (Classic Presentation): Meets all 3 criteria:
    • Substernal chest pressure, squeezing, or heaviness.
    • Provoked by physical exertion or emotional stress.
    • Relieved within 5-10 min by rest or nitroglycerin.
  • Atypical Angina: Meets only 2 of the 3 criteria.
  • Anginal Equivalents: Dyspnea on exertion, fatigue, nausea, diaphoresis. Common in women, diabetics, and the elderly.

Levine's Sign: Patient clenches a fist over their sternum to describe the pain-a classic, though not specific, indicator of ischemic chest pain.

Classic vs. Atypical Angina Symptoms

Risk Stratification - Gauging the Danger

  • Goal: Identify high-risk patients who benefit from revascularization over optimal medical therapy (OMT) alone.
  • Primary Tool: Stress testing (exercise ECG, echo, or nuclear).
  • High-Risk Markers:
    • Large ischemic defect (>10% myocardium).
    • Hypotension or significant ST depression at low workload.
    • ↓ LVEF with exercise.

⭐ High-risk angiographic findings mandating revascularization include >50% left main stenosis, three-vessel disease (especially with LVEF <50%), or two-vessel disease involving the proximal LAD.

  • Decision Pathway:

Medical Management - The Pill Arsenal

  • Antiplatelet: Aspirin 81 mg daily. Clopidogrel if aspirin-allergic.
  • Beta-blockers: First-line for angina relief (e.g., Metoprolol).
  • Cholesterol: High-intensity statin (Atorvastatin 40-80 mg).
  • Diet/Diabetes & Exercise/Education.

⭐ Ranolazine is a key second-line agent that reduces angina frequency without affecting heart rate or blood pressure, making it ideal for patients with bradycardia or hypotension on other meds.

Revascularization - Plumbing the Pipes

Goal is symptom control; survival benefit only in high-risk subsets (e.g., left main disease).

  • PCI (Percutaneous Coronary Intervention): Best for 1 or 2-vessel disease, non-complex lesions.
  • CABG (Coronary Artery Bypass Grafting): Superior for left main, ≥3-vessel disease, or 2-vessel disease in diabetics.

PCI vs. CABG for Coronary Artery Disease

⭐ The COURAGE trial showed that for stable angina, PCI did not reduce death or MI compared to optimal medical therapy, but did lead to greater symptom relief.

  • Stable angina is exertional chest pain, relieved by rest or nitroglycerin.
  • Pathophysiology involves fixed atherosclerotic plaques causing >70% coronary stenosis.
  • Stress testing is the primary non-invasive diagnostic tool; ECG may show ST depression.
  • Coronary angiography is the definitive gold standard diagnostic test.
  • First-line medical therapy includes aspirin, beta-blockers, and high-intensity statins.
  • Sublingual nitroglycerin is used for acute symptom relief.
  • Aggressive risk factor modification is critical to slow disease progression.

Practice Questions: Stable coronary artery disease

Test your understanding with these related questions

A 64-year-old man presents to the emergency department with sudden onset of chest pain and an episode of vomiting. He also complains of ongoing nausea and heavy sweating (diaphoresis). He denies having experienced such symptoms before and is quite upset. Medical history is significant for hypertension and types 2 diabetes mellitus. He currently smokes and has smoked at least half a pack daily for the last 40 years. Vitals show a blood pressure of 80/50 mm Hg, pulse of 50/min, respirations of 20/min, temperature of 37.2°C (98.9°F), and oximetry is 99% before oxygen by facemask. Except for the patient being visibly distressed and diaphoretic, the examination is unremarkable. ECG findings are shown in the picture. Where is the most likely obstruction in this patient’s cardiac blood supply?

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Flashcards: Stable coronary artery disease

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What is the main treatment for cardiogenic shock? _____

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What is the main treatment for cardiogenic shock? _____

IV Inotropes

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