AUSCULTATORY AND PHONOCARDIOGRAPHIC SIGNS OF PULMONARY STENOSIS

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Abstract
Seventy patients in whom the clinical diagnosis of pulmonary valvular or infundibular stenosis was made and confirmed by cardiac catheterization or angiocardiography were studied by high frequency phonocardiograms corresponding to auscultation. Simultaneous recordings were made from the pulmonary and mitral areas together with an ecg and indirect carotid pulse, the latter for identifying the aortic component of the 2nd sound by virtue of its relation to the dicrotic notch. On the basis of the findings, the patients were divided into 3 groups. Those with mild pulmonary stenosis with intact ventricular septum (11 cases) with right ventricular systolic pressure under 40 mm Hg showed a normal first sound followed by a clicking sound 0.04 second (mean) later maximal at the pulmonary area and in expiration. Also, the 2nd heart sound was abnormally split, the earlier component related to aortic valve and the later to pulmonary valve closure, the interval between the two components in expiration being 0.03-0.06 seconds. A soft pulmonary systolic murmur was present in all cases. The 2nd group were those with moderate or severe pulmonary stenosis with intact ventricular septum (33 cases) and right ventricular systolic pressures between 50-160 mm Hg. The pulmonary component of the 2nd sound was present only in 85% of the cases but it was soft and delayed in expiration from 0.05 to 0.14 seconds. A loud pulmonary systolic murmur persisted throughout systole. The 3rd group consisted of patients with Fallot''s tetralogy (26 cases) and the right ventricular systolic pressures ranged between 70-115 mm Hg. The 2nd-sound was always single and was attributed to aortic valve closure from its relation to the dicrotic incisura of the carotid tracing. The pulmonary systolic murmur was variable in intensity and duration. The authors feel that attention to the characteristics of the 2nd heart sound in the pulmonic area is of considerable help in deciding the cause of a pulmonary systolic murmur in differentiating between the above groups as well as in the differential diagnosis of other conditions.