Systolic time interval recordings as a measure of cardiac function in the healthy rabbit: reference values

Results of systolic time interval recordings obtained serially on 104 female New Zealand White rabbits were analyzed for reproducibility, variation with respect to changes in heart rate (HR), and interrelationship of the various systolic time intervals. A table of values for systolic time intervals in the healthy rabbit was constructed. The preejection period (PEP), left ventricular ejection time (LVET), and PEP/LVET ratio were 0.040 +/- 0.008 s, 0.119 +/- 0.014 s, and 0.337 +/- 0.066 respectively. The major systolic time intervals, PEP and LVET, varied with respect to HR according to the regression equations: PEP = 0.057--0.000078 HR and LVET = 0.175--0.000251 HR. The QS2 interval, S1S2 interval and isovolumic contraction time also varied with changes in HR.