Fig. 5.

LV end-systolic volume index (LVESVI) (a), LV end-diastolic volume index (LVEDVI) (b), LV mass index (c), LV ejection fraction (LVEF) (d), LV eccentricity index (LVEI) in systole (e) and LV eccentricity index in diastole (f) are shown in normoxia (n = 8), Sugen–hypoxia at five weeks (n = 4) and Sugen–hypoxia at eight weeks (n = 4). LV end-diastolic and end-systolic volumes and LV mass were determined by manual planimetry and indexed to body surface area. LVEF was determined by ((LVEDV – LVESV)/LVEDV) × 100%. There were no significant differences between the normoxic group and different stages of Sugen–hypoxia in LVESVI, LVEDVI, LV mass index, and LVEF. Left ventricular eccentricity index (LVEI) was defined as the ratio of the anterior-inferior and septal–posterolateral cavity dimensions at the mid-ventricular level and was measured at both systole (e) and diastole (f). Although there were no significant differences between the three groups in the LVEI in diastole, LVEI was higher in both Sugen–hypoxic groups compared to normoxia in systole. Previous human studies had demonstrated LVEI in systole to correlate with pulmonary hypertension. The groups were compared by ANOVA, and if there was statistical significance, a Tukey HSD test was used for post hoc analysis. Results are shown as mean ± SEM.

**: p < 0.05.

LV: left ventricle; SuHx: Sugen–hypoxia.