The physical examination findings during STEMI are similar to those of stable angina, unstable angina and NSTEMI, however frequently more severe due to the larger amount of myocardium experiencing ischemia.
Physical examination findings are relatively non-specific. The heart rate and blood pressure may be elevated due to increased sympathetic tone or the blood pressure can be low due to cardiogenic shock depending on the extent of the STEMI.
An S4 heart sound may be present during myocardial ischemia due to the lack of ATP production impairing left ventricular relaxation. Recall that myocardial relaxation is an active process requiring ATP which is reduced during ischemia and a S4 heart sound occurs when a non-compliant, stiffened left ventricle receives blood after atrial contraction.
During inferior ischemia, posteromedial papillary muscle dysfunction can cause mitral regurgitation resulting in a holosystolic murmur at the cardiac apex radiating to the axilla (see Heart Murmurs). This rarely occurs during anterior or lateral ischemia since the anterolateral papillary muscle has dual supply from the left anterior descending and circumflex coronary artery (see Coronary Artery Anatomy).
When the left ventricular end-diastolic pressure (LVEDP) increases during myocardial ischemia, that pressure can be transmitted backward to the pulmonary veins and into the pulmonary vasculature causing transient pulmonary edema resulting in dyspnea and rales on lung examination.
Treatment - Revascularization
Treatment - Medical
Review Questions - STEMI - Multiple Choice
Review Questions - STEMI - Case Based
Acute Coronary Syndromes Jeopardy