Importance: Enhanced ventricular interdependence is a highly sensitive and specific criterion for the diagnosis of constrictive pericarditis (CP), but simultaneous ventricular measurements can be challenging at cardiac catheterization. Ejection times (ETs) correlate with stroke volumes and can be easily measured from arterial pressure tracings.
Objective: To assess respirophasic changes in pulmonary artery (PA) ETs and aorta (Ao) ETs as a marker for enhanced ventricular interdependence.
Design, setting, and participants: Retrospective analysis of simultaneous left-side and right-side heart catheterizations between January 2006 and January 2017 was performed. The data were analyzed in June 2020. All catheterizations were performed at the Mayo Clinic, Rochester, Minnesota. This study evaluated patients undergoing left-side and right-side heart catheterization for assessment of CP after noninvasive evaluation was inconclusive.
Main outcomes and measures: Measurements of the PA and Ao ETs were made during inspiration and expiration. Ventricular interaction was mainly assessed by evaluating the difference of ETs from expiration to inspiration as well as the difference in Ao minus the difference in PA.
Results: A total of 10 patients with surgically proven CP and 10 patients without CP (restrictive cardiomyopathy or severe tricuspid regurgitation) were identified. Of these 20 included patients, 10 (50%) were female, and the median (interquartile range) age was 59.5 (47.0-67.5) years. There were no significant differences in demographic characteristics or baseline hemodynamic measurements. In patients with CP compared with those without CP, there was a significantly greater decrease in PA ET (mean [SD], -31.8 [28.6] vs 5.1 [9.5]; P < .001) and a nonsignificantly greater increase in Ao ET (mean [SD], 19.0 [15.7] vs 10.5 [9.1]; P = 0.20) during expiration vs inspiration. Thus, the difference in Ao ET minus the difference in PA ET during expiration vs inspiration was significantly greater in those with CP compared with those without CP (mean [SD], 50.8 [22.5] milliseconds vs 5.4 [15.2] milliseconds; P < .001).
Conclusions and relevance: In this study, PA and Ao measurements of ETs throughout the respiratory cycle were a simple, easily obtainable, and accurate parameter for the diagnosis of CP.