Figure 1.

(A) LVISP-Left ventricle isovolumetric systolic pressure curves obtained at different diastolic pressures (DP). (B) LVISP upon changes in heart rate stimulation. (C) Left ventricular curves were normalized to the DP of 10 mm Hg. Hearts were perfused using different extracellular Ca²⁺ concentrations. (D) β-adrenergic activation in the Langendorff apparatus (% of Control). Data are shown as mean ± SEM. *p < 0.05. ANOVA two-way and Tukey test. Number of animals used is indicated in parentheses.