Clinical Physiology and Functional Imaging 2015-07-01

A study to determine the contribution to right ventricle stroke volume from pulmonary and tricuspid valve displacement volumes.

Stina Jorstig, Kent Emilsson, Mats Lidén, Per Thunberg

Index: Clin. Physiol. Funct. Imaging 35 , 283-90, (2015)

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Abstract

Describing the systolic function of the right ventricle (RV) is a difficult task due to the complex shape and orientation of the RV. The purpose of this study was to investigate the extent to which the volumes encompassed by the pulmonary and tricuspid valve displacements contribute to the total right ventricle stroke volume (RVSV).Twelve healthy volunteers were examined using cardiac magnetic resonance (CMR). Two series of time-resolved axially rotated MR images were acquired that encompassed the tricuspid valve and the pulmonary valve, respectively. The volume related to each valve movement, the tricuspid plane displacement (TPD) and the pulmonary plane displacement (PPD), was determined by delineation in diastole and systole. These volumes, RVSV(TPD) and RVSV(PPD) , were compared to the stroke volume to determine the contributions to the total stroke volume from the TPD and the PPD. The remaining volume of the total RVSV was referred to as RVSV(Other) . An initial in vitro study was carried out to validate the accuracy of volume measurements using axially rotated images.In vitro measurements indicated that the method for volumetric measurements using axially rotated images was a very accurate one, with a mean difference of 0·04 ± 0·10 ml. The in vivo measurements of RVSV(TPD) , RVSV(PPD) and RVSVOther were 45 ± 10%, 13 ± 2% and 42 ± 11%, respectively.Right ventricle stroke volume is determined by different individual volume changes as follows: RVSV(TPD) together with RVSVOther contributes to almost the entire RVSV in nearly equal proportions, while RVSV(PPD) contributes only a small amount and is approximately 30% of either RVSV(TPD) or RVSV(Other) .© 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.