Use of the Electrokymograph for Estimation of Pulmonary Pressure

¹ From the Department of Physiology, University of Miami School of Medicine, Coral Gables, Florida

The velocity of the pulmonary pulse wave in patients assumed to have pulmonary hypertension is faster than that of normal subjects. Individual measurements show such a wide variation that estimates of pulmonary hypertension by this method would not be reliable. The simplest and probably the best use to make of pulse velocity is a comparison between the time of arrival of carotid and pulmonary conus pulse. In normal subjects the conus pulse precedes the carotid, whereas in pulmonary hypertension it very often follows. The shape of the systolic portion of pulmonary conus electrokymographic curves appears to change in pulmonary hypertension. In normal subjects the area of the first sixth of the electrokymographic curve is about 0.6 the size of the second sixth, whereas in our series of patients assumed to have pulmonary hypertension the first sixth averaged 0.8 the size of the second sixth.