Valvular Heart Disease
Dermot Phelan
Patrick Collier,
Brian P. Griffin
POINTS TO REMEMBER
The heart comprises four valves, two atrioventricular valves (mitral on the left and tricuspid on the right) and two semilunar valves (aortic on the left and pulmonary on the right). Valvular heart disease may cause problems when the valve becomes stenotic; when it is regurgitant; or, as frequently occurs, a combined stenotic and regurgitant lesion is present.
Stenotic lesions produce problems by reducing cardiac output, particularly during stress, and by increasing the pressure in the chambers proximal to the valve.
Regurgitant lesions cause problems by increasing the volume load on the ventricles.
While history and physical examination will often identify the lesion in question, an electrocardiogram and chest x-ray provide supportive information.
Physical exam: a few key points
Blood pressure: A narrow pulse pressure (i.e., difference between systolic and diastolic blood pressure) may be related to aortic stenosis while a wide pulse pressure with low diastolic pressure may be secondary to aortic regurgitation.
Venous pressure: Venous pressure height and wave pattern should be assessed. Valvular disease is characterized by large A waves in pulmonary hypertension and pulmonary stenosis and large V waves in tricuspid regurgitation.
An anacrotic pulse with diminished volume and delayed upstroke (pulsus parvus et tardus). This is the most reliable physical sign of significant aortic stenosis. The pulse is best examined at the carotid artery.
Respiration: Right-sided lesions increase in intensity with inspiration (due to increased flow through the right heart). Left-sided lesions are louder with expiration.
Valsalva: The Valsalva maneuver decreases intracardiac volume and reduces the intensity of most murmurs. Exceptions are the murmurs of hypertrophic cardiomyopathy, which become louder, and of mitral valve prolapse, which become longer and louder.
Position: With standing, intracardiac volume decreases; therefore, most murmurs decrease in intensity (except those of hypertrophic cardiomyopathy and mitral valve prolapse). Squatting accentuates intracardiac volume. Therefore, most murmurs become louder, but those of mitral valve prolapse and hypertrophic cardiomyopathy usually decrease.Related posts:
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