A Simple Method for Intracardiac Acoustic Auscultation and Phonocardiography

Abstract

Acoustic auscultation of the cavities of the heart was carried out in 62 patients with normal hearts and with congenital or acquired heart disease. The type of instrument used is a special cardiac catheter with closed distal tip and with side openings near the tip covered by a thin latex cuff. Intracardiac sound vibrations are collected by the latex membrane, which transmits them to the column of air in the catheter and thereby to the outside of the body.The catheter can be connected either with the tubing of a binaural stethoscope, for acoustic intracardiac auscultation, or with a microphone. In the latter instance, with the help of a specially designed preamplifier, simultaneous intracardiac sounds and pulse curves can be recorded. This has a two-fold advantage: that of locating the site of recording (by the shape of the intracardiac pulse) and of correlating acoustic and mechanical intracardiac events of the cardiac cycle.The advantages of acoustic intracardiac auscultation (an aid in avoiding artifacts and locating the best area of sound production) and the practicality, reliability, and low cost of the new technic of intracardiac phonocardiography are stressed.