Cardiology
Core concepts
Master the acute coronary syndrome pathway: ECG territory-to-artery mapping, troponin kinetics, and when reperfusion (PCI vs fibrinolysis) is indicated. Know heart failure by ejection fraction, the four pillars of HFrEF therapy (ARNI/ACEi, beta-blocker, MRA, SGLT2 inhibitor), and diuretic titration. Understand valvular disease murmurs and their dynamic maneuvers, pericarditis versus tamponade physiology, and the major tachyarrhythmias with their acute management (unstable = synchronized cardioversion; stable narrow-complex = vagal then adenosine).
Traps
Questions love the "distractor that is almost right": nitroglycerin is contraindicated in right ventricular infarction and severe aortic stenosis; beta-blockers are harmful in acute decompensated heart failure and cocaine-associated chest pain. Remember that a normal ECG does not exclude ACS, and that troponin elevation is not synonymous with MI (myocarditis, PE, renal failure). Watch for digoxin toxicity clues (yellow-green vision, bidirectional VT) and for hyperkalemia mimicking STEMI.
Worked rule of thumb
ST elevation in II, III, aVF = inferior MI; check for reciprocal depression in I/aVL and obtain right-sided leads (V4R) to detect RV involvement, which changes management (avoid nitrates, give fluids). For any wide-complex tachycardia, treat as VT until proven otherwise - especially with structural heart disease.
Key points
- Inferior MI + hypotension: think RV infarct; fluids, not nitrates.
- Unstable arrhythmia = electricity first.
- HFrEF: start all four pillars early; SGLT2 inhibitors benefit regardless of diabetes.
- Troponin rise ≠ automatically MI; correlate clinically.
- Aortic stenosis: avoid vasodilators and vigorous preload reduction.