Cardiovascular Disorders
Core approach
Time-critical cardiovascular diagnoses must be stabilized before diagnostic certainty. For chest pain, obtain an ECG within 10 minutes, assess hemodynamics, and risk-stratify ACS. Know STEMI criteria, posterior and right ventricular infarcts, LBBB/Sgarbossa, and mimics such as pericarditis, early repolarization, and aortic dissection. Troponin elevations are not automatically ACS; interpret with timing, symptoms, and ECG. Manage acute heart failure by identifying congestion and perfusion, and treat cardiogenic shock with careful volume assessment, vasopressors, and inotropes when needed. Recognize tachyarrhythmias and bradyarrhythmias that cause instability and require synchronized cardioversion or pacing.
Traps
Questions often hide aortic dissection behind tearing pain, pulse deficit, or blood pressure differential; do not anticoagulate before imaging when dissection is plausible. Inferior STEMI with hypotension and clear lungs suggests right ventricular involvement; nitrates can precipitate collapse, so volume loading is preferred. Beware a normal initial troponin, a normal ECG in posterior MI, and troponin elevation from renal disease or sepsis. Tamponade may present with hypotension, distended neck veins, and muffled heart sounds, but these are insensitive.
Worked example
A patient with inferior STEMI becomes hypotensive after sublingual nitroglycerin. Clear lungs and elevated jugular venous pressure suggest RV infarct. Stop nitrates, give a cautious fluid bolus, and arrange reperfusion. Rule of thumb: in undifferentiated shock with suspected cardiac ischemia, treat life-threatening rhythm and mechanical complications first, and avoid reflexive nitrates.