Heart sounds and murmurs are studied in 18 proved cases of rheumatic valvular aortic stenosis and an attempt is made to correlate their characteristics to pathologic and hemodynamic changes.
The 1st sound may be normal. Alternation is a rare finding. Faintness and low pitch are encountered in the greatest percentage of cases. Accentuation and splitting are usually due to marked exaggeration of the last component of the 1st sound (early systolic click, ejection sound).
The systolic murmur, practically constant, may be alternans. It is loudest at the 2nd and 3rd right interspaces and it radiates mostly to the suprasternal notch and to the neck; however wide differences may be found both in its location and propagation. A diamond-shaped configuration, a high frequency range, and its ending a few hundredth of a second before the aortic (or first) component of the 2nd sound are characteristic features.
The 2nd sound may have a very different amplitude; as a rule its faintness or absence are in favor of severe constriction. As the lesion progresses, left ventricular systole extends and aortic closure is delayed so that the aortic component of the 2nd sound successively draws closer to, coincides with, and occurs after the pulmonic component (reversed or paradoxical splitting).
A faint diastolic murmur is occasionally present and it is due to a minimal aortic regurgitation. When paradoxical splitting of the 2nd sound occurs and aortic closure is silent, the systolic murmur may extend beyond the pulmonic component and it can be mistaken for an early310 CALO jap. Heart J. July, 1962diastolic murmur.
Gallop sounds, either presystolic or early diastolic, may be present.