Integrating Right Ventricular Pressure Waveform Analysis With Two-Point Volume Measurement for Quantification of Systolic and Diastolic Function: Experimental Validation and Clinical Application

Abstract

To define in an experimental model the variance, accuracy, precision, and concordance of single-beat measures of right ventricular (RV) contractility and diastolic capacitance relative to conventional reference standards, and apply the methods to a clinical data set. A retrospective, observational analysis of recorded pressure waveforms and RV volume measurements. At a university laboratory. Archived data from previous studies of anesthetized swine and awake patients undergoing clinically-indicated right-heart catheterization. Recording of RV pressure with simultaneous measurement of RV volume by conductance (swine) or 3-dimensional (3D) echocardiography (humans) during changes in contractility and/or loading conditions. Using experimental data, single-beat measures of RV contractility quantified as end-systolic elastance, and diastolic capacitance quantified as the predicted volume at an end-diastolic pressure of 15 mmHg (V15), were compared to multi-beat, preload- variant, reference standards using correlation, Bland-Altman analysis, and 4-quadrant concordance testing. This analysis indicated that the methods were not directly interchangeable with reference standards, but were sufficiently robust to suggest potential clinical utility. Clinical application supported this potential by demonstrating enhanced assessment of the response to inhaled nitric oxide in patients undergoing diagnostic right-heart catheterization. Study results supported the possibility of integrating automated RV pressure analysis with RV volume measured by 3D echocardiography to create a comprehensive assessment of RV systolic and diastolic function at the bedside.