Coronary Artery Disease (CAD)

Supply-and-demand balance - The governing principle: avoid tachycardia and hypotension above all. One raises demand while cutting supply, the other cuts supply. Keep the heart rate controlled and coronary perfusion pressure up.

Continue cardiac meds - Keep beta-blockers and statins going through the perioperative period; whether to continue aspirin depends on the surgery and the stent history.

Stents and antiplatelets - Ask about stent type and timing. Premature interruption of dual antiplatelet therapy risks stent thrombosis — coordinate any interruption with cardiology.

Monitor for ischemia - Watch the ECG (ST segments, leads II and V5); an arterial line helps in higher-risk cases and major surgery.

Treat ischemia promptly - Correct the trigger — slow the rate, restore pressure, treat anemia and hypoxia — and give nitroglycerin for ongoing ischemia.

Smooth emergence - Blunt the sympathetic surge of laryngoscopy and extubation; postoperative pain, shivering, and tachycardia all provoke ischemia.

Coronary artery disease is atherosclerotic narrowing of the epicardial coronaries that limits myocardial blood flow. Ischemia occurs when oxygen demand outstrips a fixed, flow-limited supply — the central perioperative problem.

Demand rises with tachycardia, hypertension, and increased wall stress; supply falls with tachycardia (shortened diastole), hypotension (reduced coronary perfusion pressure), anemia, and hypoxemia. Perioperative stress, catecholamine surges, and plaque instability make myocardial infarction a real risk. The whole anesthetic goal is keeping the myocardial oxygen supply-and-demand balance in the patient's favor.