Ventricular contractility and circulating catecholamine levels in control and OMX-CV–treated animals.

(A) Representative Pressure-Volume loops obtained from the left ventricle of a vehicle-treated animal during transient IVC occlusion. LV pressure is measured on the y-axis and LV volume on the x-axis. The superimposed line tangential to the end systolic pressure volume points of each family of loops defines the ESPVR. The family of loops in black and their corresponding ESPVR were obtained during the physiologic baseline, while the green loops and ESPVR were obtained from the same animal following 1 hour of hypoxic ventilation. (B) Representative Pressure-Volume loops obtained from the LV of an OMX-CV–treated animal during transient IVC occlusion. The family of loops in black and their corresponding ESPVR were obtained during the physiologic baseline, while the blue loops and ESPVR were obtained from the same animal following 1 hour of hypoxic ventilation. (C) Mean right ventricular contractility (as assessed by slope of the ESPVR relative to baseline) in vehicle- (n = 7) and OMX-CV–treated (n = 6) animals after 1 hour of hypoxic ventilation. Error bars represent the standard error of the mean; “*” denotes a significant difference between groups with p n = 7) and OMX-CV–treated (n = 6) animals after 1 hour of hypoxic ventilation. Error bars represent the standard error of the mean; “*” denotes a significant difference between groups with p n = 7) and OMX-CV–treated (n = 6) animals. Error bars represent the standard error of the mean; “*” denotes a significant difference between groups with p p S1 Table. bsln, baseline; ESPVR, end systolic pressure-volume relationship; IVC, inferior vena cava; LV, left ventricle; mmHg, millimeters mercury; OMX-CV, Omniox-cardiovascular; RV, right ventricle; Veh, vehicle.