Do the Human Ventricles Eject Simultaneously?

SummaryOn the basis of simultaneously recorded right ventricular pressures, carotid surface pulses and ballistocardio-graphic recoils, evidence is presented that ejection from the right and left ventricles may not start simultaneously in the human. The I-wave of the ballistocardiographic record seemingly datc^ to the right heart ejection, and is not initiated by left ventricle ejection which must have started earlier.Since this paper was submitted, an abstract appeared in the Federation Proceedings stating that, in the human, a time discrepancy between the start of ejection from the 2 ventricles exists in almost all cases. The measurements were taken from electrokymograph recordings. In this series, either ventricle might precede, whereas in our series, the left ventricle usually precedes the right. The time discrepancies are somewhat larger in our series. Whether these differences are attributable to the small number of cases reported here remains to be determined.