Interactive Guide to Physical Examination
So far, we have discussed examining the patient in the supine, left lateral decubitus, and upright position. Three other maneuvers valuable in identifying intracardiac sounds and the origin of murmurs involve auscultating while the patient stands, squats, or performs a valsalva maneuver.
With standing, venous return to the heart and peripheral vascular resistance both decrease. Blood pressure, stroke volume and left ventricular blood volume also decline. In contrast, with squatting, there is an increase in venous return to the heart and an increase in peripheral vascular resistance. As a result, arterial blood pressure, stroke volume, and volume of blood in the left ventricle all increase. Taking advantage of these hemodynamic changes may help you identify a click associated with a prolapsing mitral or tricuspid valve or determine the origin of a murmur.
The mechanics of actually auscultating while the patient stands and squats can be a little awkward at first. Have the patient stand next to the examining table and steady himself with one hand. Ask the patient to squat and then stand. You need to be ready to auscultate with the diaphragm of your stethoscope promptly after each position change.
Straining against a closed glottis, or "bearing down", causes a decrease in venous return to the right heart and a subsequent decrease in left ventricular volume and arterial blood pressure. With the patient in the supine position, ask him to take a breath and "bear down", then auscultate with the diaphragm of your stethoscope over all areas on the precordium.
Taking advantage of these hemodynamic changes with patient positioning may help you identify mitral valve prolapse, or sort out hypertrophic cardiomyopathy from aortic stenosis.
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Click on the interactive icon to practice hearing the changes brought out by these maneuvers. |
The cardiac exam requires careful integration of findings for accurate interpretation. You need to integrate all of your findings during inspection, auscultation, palpation of the precordium with evaluation of the arterial pulses, venous pressure, vital signs as well as general observations about the patient and his history. Lastly, cardiac maneuvers may be needed to further help sort out findings.
