Five groups were assayed: cold anesthesia, and 10 sec, 30 sec, 1 min or 5 min exposure to FlyNap (FN). The following heart parameters are reported: (A–C) total, anterograde and retrograde contraction rate; (D) frequency of heartbeat directional reversals; (E–F) percent time contracting in the anterograde and retrograde directions; (G–H) anterograde and retrograde period lengths. Data were analyzed by one-way ANOVA, and when P<0.05 the statistical significances between the individual FlyNap groups and the cold group (Reference group, R) are denoted using asterisks (Tukey’s multiple comparisons post-hoc test: ns, P>0.05; *, P<0.05; **, P<0.01; ***, P<0.001; ****, P<0.0001). The percentages reported above the columns report the percentage difference between that group and the cold (R) group. Bars denote the standard error of the mean. Sample sizes: Cold, 88; 10 sec FN, 30; 30 sec FN, 20; 1 min FN, 80; 5 min FN, 30.