The value of the ultrasonic Doppler method and apexcardiography as reference tracings in phonocardiography

Abstract

The exact timing of the opening of the mitral valve and of atrial contraction was obtained by utilizing the ultrasonic Doppler. These signals were used as reference points in phonocardiography for the differentiation of the diastolic heart sounds and compared to the ACG utilized for the same purpose in 62 patients. The Doppler signal coincided with the opening snap in all patients with mitral stenosis while the 0 point of the ACG usually followed the opening snap by a time interval of up to 20 msec. The third heart sound bore a very close relationship to the end of the rapid filling wave of the ACG. The fourth heart sound was related to the atrial component of the Doppler tracing as well as the A wave of the ACG. Satisfactory Doppler tracings were obtained in all 62 patients while in 11 of these patients a satisfactory ACG could not be obtained. The ultrasonic Doppler method is a noninvasive method that can be used as a reference tracing in phonocardiography especially when a satisfactory ACG cannot be obtained. The tracings can be recorded with minimal delay and at no risk or discomfort to the patient. The ultrasonic Doppler method is the most reliable and accurate noninvasive method for the identification of the opening snap and timing of the mitral opening while the ACG is more reliable for the identification of the third heart sound.