Adult Cardiac Surgery: Decision Logic and Perioperative Traps
Adult Cardiac Surgery - Core Concepts and Exam Traps
Focus on the decision logic that drives operative planning. For coronary disease, know the indications for CABG versus PCI (left main, three-vessel disease with diabetes or reduced ejection fraction, high SYNTAX score), conduit selection (left internal mammary artery to LAD is the benchmark; bilateral IMA increases sternal wound risk in obese diabetics), and antiplatelet timing around surgery. For valve disease, understand severity thresholds: severe aortic stenosis is typically aortic valve area ≤1.0 cm², mean gradient ≥40 mmHg, or peak velocity ≥4 m/s; symptoms or left ventricular dysfunction trigger intervention. Mitral regurgitation requires attention to mechanism (primary versus secondary) because repair is preferred for degenerative disease. Aortic dissection is a classic trap: type A is a surgical emergency, while uncomplicated type B is usually managed medically with impulse control. Postoperative complications to recognize include tamponade (hypotension, rising central venous pressure, oliguria, pulseless electrical activity), low cardiac output syndrome, bleeding with coagulopathy, and sternal dehiscence.
Worked example/rule of thumb: a 68-year-old diabetic with left main stenosis and an ejection fraction of 35% should be discussed by a heart team; CABG is generally favored over multivessel PCI. Rule of thumb: fix the valve when it is severe and symptomatic, or when ventricular function is threatened - not merely because a number is abnormal.