Fig. 1. Effects of increasing input pressure P_LAt and P_RAt (Frank—Starling effect) to the left atrium (LAt: A,B) or right atrium (RAt; C,D) on central flow rates (A,C) and power output (B,D) in Python molurus heart. In each of the two cases, input pressure to the other atrium was maintained constant. All values are means ± S.E.M. (N=7); an asterisk indicates significant differences (P<0.05) between systemic or pulmonary flow rates and power outputs at a given input pressure. NS, not significantly different; sys, systemic; pul, pulmonary; tot, total.