Aids to Identify Systolic Murmurs. Elsewhere in this chapter you have learned how to improve your auscultation of heart sounds and murmurs by placing the patient in different positions. Two additional techniques will help you distinguish the murmurs of mitral valve prolapse and hyper-trophic cardiomyopathy from aortic stenosis.
^ (1) Standing and Squatting. When a person stands, venous return to the heart decreases as does peripheral vascular resistance. Arterial blood pressure, stroke volume, and the volume of blood in the left ventricle all decline. On squatting, changes occur in the opposite direction. These changes help (1) to identify a prolapsed mitral valve, and (2) to distinguish hyper-trophic cardiomyopathy from aortic stenosis.
Secure the patient's gown so that it will not interfere with your examination, and ready yourself for prompt auscultation. Instruct the patient to squat next to the examining table and hold on to it for balance. Listen to the heart with the patient in the squatting position and again in the standing position.
(2) Valsalva Maneuver. When a person strains down against a closed glottis, venous return to the right heart is decreased and after a few seconds left ventricular volume and arterial blood pressure both fall. Release of the effort has the opposite effects. These changes help to distinguish prolapse of the mitral valve and hypertrophic cardiomyopathy from aortic stenosis.
The patient should be lying down. Ask the patient to "bear down," or place one hand on the midabdomen and instruct the patient to strain against it. By adjusting the pressure of your hand you can alter the patient's effort to the desired level. Use your other hand to place your stethoscope on the patient's chest.
Maneuvers to Identify Systolic Murmurs
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Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...