Fig. 4. Correlation between systemic mean arterial pressure (AP) and estimated MPAP. Mean AP and estimated MPAP were determined as described in methods and then plotted as shown. Data shown are: (A) correlation of estimated MPAP and mean AP in all control subjects and (B) correlation of estimated MPAP and mean AP in all PEC subjects. Linear regression is depicted in each graph by solid line. The slopes were not significantly different from 0 in either plots by linear regression. estimated MPAP: estimated mean pulmonary arterial pressure; PEC: pre-eclampsia