Physical Examination - STEMI

Physical Examination – CAD - STEMI

The physical examination findings during STEMI are similar to those of stable angina, unstable angina and non-STEMI, although frequently more dramatic due to the larger proportion of ischemic myocardium.

Physical examination findings are non-specific. The heart rate and BP may be elevated due to increased sympathetic tone, or the BP can be low due to reduced cardiac output (cardiogenic shock), depending on the extent of the STEMI.

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An S4 heart sound may be present during myocardial ischemia due to impaired left ventricular relaxation resulting from a lack of adenosine triphosphate (ATP) production. Myocardial relaxation is an active process requiring energy (ATP), which is reduced during ischemia, and an S4 filling sound occurs when the noncompliant, stiffened left ventricle is not able to relax adequately as it receives blood during 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 Topic Review. This rarely occurs during anterior or lateral ischemia because the anterolateral papillary muscle has dual supply from the left anterior descending (LAD) and circumflex coronary artery.

When the left ventricular end-diastolic pressure (LVEDP) increases during myocardial ischemia, the right ventricle (RV) maintains cardiac output by increasing pulmonary arterial and venous pressure. This compensatory process may cause transient pulmonary edema with dyspnea and rales on lung examination.

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