Fig. 2.

Percent changes in key cardiac function parameters: heart rate (HR), fractional shortening (FS), ejection fraction (EF), cardiac output (CO), and stroke volume (SV). A: mouse HR increased similarly to that of NMRs. However, NMRs exhibited significantly greater percent changes in FS (B), EF (C), CO (D), and SV (E). Overall, these data may be evidence of a greater cardiac reserve in the NMR. All values are means ± SE. Sample sizes are n = 10 (5/sex) animals for each species. N.S. denotes P > 0.05.