Evaluation of right ventricular contractile reserve in healthy subjects using stress echocardiography

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background The assessment of right ventricular (RV) systolic functional augmentation in healthy subjects is not well described. The objective of this study was to evaluate normal augmentation of RV systolic functional parameters in relation to maximum predicted oxygen uptake (VO2) during stress echocardiography in healthy adults. Methods Untrained healthy volunteers were recruited prior starting their first time London Marathon and underwent cardiopulmonary exercise test with echocardiography focussed on left ventricular assessment. Patients with satisfactory RV windows were included in this analysis. 20 participants with good RV delineation were evaluated retrospectively at baseline and at peak level of exercise. We defined RV systolic function by tricuspid lateral annular systolic velocity (RVS’) using Doppler tissue imaging, Tricuspid Annular Plane Systolic Excursion (TAPSE) using M-mode echocardiography, and Fractional Area Change (FAC) using 2D echocardiography to calculate the percentage of change in RV area between systole and diastole. All parameters were evaluated at baseline and at peak stress. Results There was statistically significant augmentation of all RV systolic functional parameters between baseline and peak stress (10.3 ± .8 vs 16.4 ± .7 cm/s, p <.000), (21 ± 2.6 vs 32 ± 3.3, mm, p <.000) and (41 ± 2.7, % vs 55 ± 5.1, %, p<.000) for RVS’, TAPSE and FAC respectively. At peak stress, RVS’ increased by 59 ± 11.1, %, TAPSE by 53 ± 15.4, %, and FAC by 34 ± 11.8, %. Mean peak VO2 was 107 ± 17, %. The augmentation of RV longitudinal function showed moderate correlation with peak VO2 throughout exercise for the RVS’ and TAPSE (r= .54, p 0.001), (r=.45, p0.04) respectively, and this was not observed in FAC (r=.15, p>.05). Conclusion In normal individuals, we have demonstrated that the RV augments by 59% for RVS’, 53% for TAPSE, and 34% for FAC. Longitudinal RV augmentation by RVS’ and TAPSE was correlated with maximum exercise capacity suggesting that these parameters could be able to predict VO2 peak values in larger context. Abstract Figure.