Coronary disease, infarction and cardiovascular emergencies
Coronary Artery Disease
Core concepts
Coronary artery disease includes stable obstructive disease, plaque rupture or erosion causing acute coronary syndrome, and microvascular or vasospastic angina. Candidates must distinguish supply-demand ischemia from acute plaque rupture, interpret high-sensitivity troponin kinetics against the 99th percentile, and recognize that one normal ECG does not exclude ACS. Risk stratification combines symptoms, ECG, troponin, renal function, bleeding risk, and comorbidities. Revascularization decisions depend on anatomy, ischemic burden, symptoms despite medical therapy, and left ventricular function. Antiplatelet therapy and high-intensity statin therapy are foundational after ACS.
Question traps
A common trap is calling any troponin elevation a myocardial infarction when demand ischemia, myocarditis, pulmonary embolism, or CKD is present. Another is missing atypical presentations in women, older adults, and patients with diabetes. Do not overrely on exercise testing in patients with known CAD or an uninterpretable ECG. Post-PCI chest pain requires consideration of stent thrombosis. Do not delay reperfusion for STEMI to obtain nonessential tests.
Worked example / rule of thumb
A patient with chest pressure and negative serial troponins still requires assessment of the symptom trajectory and the validated assay pathway. Negative troponins do not by themselves establish stable angina or exclude unstable angina. If pretest probability is intermediate and there is no known CAD, coronary CT angiography is a reasonable first test; with known CAD or high risk, functional testing or invasive angiography may be preferred. Rule: treat the patient and the trajectory, not the single troponin.
Critical Care and Perioperative Cardiology
Core concepts
Critical care cardiology covers shock, respiratory failure, arrhythmia management, mechanical circulatory support, and perioperative risk. Cardiogenic shock requires rapid identification of congestion and hypoperfusion, early revascularization in ACS, and careful vasopressor or inotrope selection. Perioperative evaluation uses clinical risk indices, functional capacity, and surgery-specific risk. Postoperative troponin elevation must be interpreted with symptoms, ECG, and hemodynamics. Bedside echocardiography helps distinguish cardiogenic, septic, obstructive, and hypovolemic shock.
Question traps
Do not use pulmonary artery catheters routinely without a question they can answer. Avoid fluid boluses in cardiogenic shock with pulmonary edema. Perioperative beta blockade is not routine and can cause hypotension or bradycardia. Do not delay STEMI reperfusion for preoperative clearance. Distinguish septic from cardiogenic shock using bedside echo, lactate, and perfusion findings. Postoperative MI can be silent and atypical.
Worked example / rule of thumb
A patient with acute MI, hypotension, cool extremities and pulmonary edema requires rapid assessment and appropriate reperfusion and circulatory support. Congestion argues against indiscriminate fluid loading. Vasoactive and mechanical support choices depend on perfusion, rhythm, ventricular function and response; a fixed combination is not mandatory for every patient. Rule: shock is a perfusion diagnosis, not a blood pressure number.