Transients in Heart Sounds and Murmurs

A new approach to the analysis of heart sounds and murmurs has been developed. These acoustic phenomena are considered to be generated by a series of transient sounds which because of the long persistence of the low-frequency components of the sounds, tend ordinarily to fuse into a single sound. The separate events such as valve closures which produce discrete clicks, therefore tend to fuse, and time discrimination of these important events is lost. An apparatus which filters out the low frequencies has been developed. The remaining high-frequency, short duration waves can thereby be displayed as a series of separate events, each representing closure or opening of a valve. Several records obtained with this system are shown, and the potential value of this mode of analysis is discussed.