Cardiovascular Emergencies
What to know
Cardiovascular items cluster around acute coronary syndrome, dysrhythmias, heart failure, and the great-vessel catastrophes. For ACS, time is muscle: obtain a 12-lead within 10 minutes, give chewed aspirin 162–325 mg, and recognize that ST elevation in II, III, and aVF signals inferior injury with possible right ventricular involvement. Heart failure presents with pulmonary edema, crackles, an S3, and orthopnea; nitrates plus noninvasive positive-pressure ventilation are mainstays when blood pressure permits. Unstable dysrhythmias - hypotensive, ischemic, or altering mentation - get synchronized cardioversion, not another pill. Aortic dissection (tearing pain to the back, pulse or blood pressure differential) and cardiac tamponade (Beck triad, pulsus paradoxus, electrical alternans) are can't-miss diagnoses in which anticoagulation and thrombolytics cause harm.
Traps
Atypical presentations are common: women, older adults, and people with diabetes may report dyspnea, nausea, or fatigue instead of classic pain. Nitroglycerin is contraindicated in hypotension, recent PDE5 inhibitor use, and right ventricular infarction. The reflexive "MONA" bundle is outdated; morphine is used sparingly and oxygen is for hypoxemia, not routinely.
Worked example
A 63-year-old man has 45 minutes of chest pressure, ST elevation in II, III, and aVF, and a blood pressure of 84/52. Suspect right ventricular infarction: obtain right-sided leads, give a cautious fluid bolus, withhold nitroglycerin, and prepare for reperfusion. Rule of thumb: hypotension plus an inferior STEMI means no nitrates until the right side has been evaluated.