Assessment of Right Ventricular Pressure-Volume Relationships Using 256-Slice CT in an Experimental Model of Acute Pulmonary Hypertension

Abstract

Purpose Acute increase of right ventricular afterload is a severe problem in case of acute precapillary pulmonary hypertension due to acute respiratory distress syndrome or acute lung injury (ALI), which in turn may lead to right ventricular failure. Pressure-volume relationship is the gold standard to assess ventricular function in load independent manner, which however usually requires complex invasive conductance catheter measurements. This study was performed to determine whether a less invasive method of synchronized CT-right ventricular pressure measurement adequately describe right ventricular pressure-volume relationships. Methods and Materials In 6 swine hearts acute increase of right ventricular afterload was established by inducing an ALI using repetitive bronchoalveolar lavage. Heart rate (HR), central venous pressure (CVP), right ventricular systolic and end-diastolic pressure (RVESP, RVEDP) and volume (RVESV, RVEDV) as well as pressure-volume loops were measured using synchronized 256 slice CT-right ventricular pressure-volume measurements at baseline and after induction and validation of ALI and subsequent pulmonary hypertension. Results HR and CVP did not change after induction of ALI (73.34±7.91 vs. 78.17±12.59 bpm; p=0.77 and 10.4±1.03 vs. 11.35±1.02 mmHg; p=0.55). RVESP significantly increased (22.23±1.46 vs. 28.7±3.31 mmHg; p Conclusions The assessment of pressure-volume-relationships by synchronized 256 slice CT measurement is feasible and provides a les-invasive approach. Pressure-volume-analyzes reveals both homeometric (increase of inotropy) and heterometric (Frank-Starling-Mechanism) adaption of the right ventricle in ALI.