Echocardiographic Correlations And Mechanisms Of Sound Production

Figure 10-70 illustrates the relationship between the aortic and pulmonary valve echocardiogram and A2 and P2. The first high-frequency component of both A2 and P2 is coincident with completion of closure of the aortic and pulmonic valve leaflets. A2 and P2 are not due to the clapping together of the valve leaflets but are produced by the sudden deceleration of retrograde flow of the blood column in the aorta and pulmonary artery when the elastic limits of the tensed leaflets are met. This abrupt deceleration of flow sets the cardiohemic system into vibration; the lower-frequency vibrations are recorded as in the incisura of the great vessels, whereas the higher-frequency components result in A2 and P2. This pressure gradient across the valves is the result of both the level of the diastolic pressure in the great vessel and the rate of pressure decline in the ventricle and is consistent with the well-known clinical observation of increased intensity of A2 and P2 in systemic and pulmonary hypertension.

Figure 10-70: (Left) The base and apex phonocardiograms are recorded simultaneously with the aortic valve echocardiogram. The first high-frequency component of A2 is coincident with the completion of closure of the aortic valve. (Right) Base and apex phonocardiograms are recorded with the pulmonary valve echocardiogram. The first high-frequency component of P1 is coincident with the completion of closure of the pulmonic valve. (From Shaver JA, et al. Normal and abnormal heart sounds in cardiac diagnosis: I. Systolic sounds. CurrProbl Cardiol 1985: 10:43. Reproduced with permission from the publisher and the authors.)

Figure 10-70: (Left) The base and apex phonocardiograms are recorded simultaneously with the aortic valve echocardiogram. The first high-frequency component of A2 is coincident with the completion of closure of the aortic valve. (Right) Base and apex phonocardiograms are recorded with the pulmonary valve echocardiogram. The first high-frequency component of P1 is coincident with the completion of closure of the pulmonic valve. (From Shaver JA, et al. Normal and abnormal heart sounds in cardiac diagnosis: I. Systolic sounds. CurrProbl Cardiol 1985: 10:43. Reproduced with permission from the publisher and the authors.)

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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...

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