Systolic time interval recordings in rabbits with congestive cardiomyopathy induced by chronic anthracycline administration.

Systolic time interval recordings were performed serially on 104 healthy female New Zealand White rabbits and 51 rabbits with congestive heart failure (CHF) induced by chronic anthracycline drug therapy. The results were analyzed and the comparisons were made with studies of systolic time interval recordings of CHF in persons. In the rabbit, CHF is manifested by prolongation of the isovolumic contraction time, the preejection period (PEP), and by shortening of the left ventricular ejection time (LVET). The ratio of PEP/LVET was a sensitive indicator of left ventricular failure, with values in excess of 0.466 reflecting significant cardiac dysfunction at the 95% confidence level. The mean PEP/LVET = 0.337 +/- 0.66 in healthy rabbits and PEP/LVET = 0.502 +/- 0.075 in rabbits with CHF. The PEP index increased from 0.057 +/- 0.007 in healthy rabbits to 0.074 +/- 0.007 in rabbits with heart failure. The LVET index decreased from 0.173 +/- 0.007 in healthy rabbits to 0.166 +/- 0.010 in rabbits with CHF.