[Phonomechanographic evaluation of the severity of pulmonary stenosis]

Abstract

External phonomechanographic methods allow us to obtain a fairly precise estimate of the degree of obstruction to the pulmonary outflow, whether such an obstruction is a single entity or associated with another intracardiac malformation. The greatest precision in this field is obtained with the cases of pure pulmonary stenosis. The findings on phonomechanographic investigation of 54 cases with pulmonary stenosis have been compared with the results of the haemodynamic tests (catheterisation and angiography) as well as with the anatomical findings after a surgical cure had been effected in a certain number of cases. This study has allowed us to pick out five phonomechanographic criteria of severity of pulmonary stenosis: an increased reduplication of the second sound, lenghening of the interval between the Q wave of the electrocardiogram and the maximum portion of the systolic murmur, an increase in Furuta's ratio and also in the amplitude of the jugular venous a-wave as a function of the total height t (the a/t ratio), but most especially the "corrected" Furuta ratio as a function of the length of the ejection phase of the right ventricle, as this has been shown to possess the best correlation with the right ventricular systolic pressures.