The ratio of right ventricular volume to left ventricular volume reflects the impact of pulmonary regurgitation independently of the method of pulmonary regurgitation quantification

Abstract

BackgroundPrevious studies have advocated quantifying pulmonary regurgitation (PR) by using PR volume (PRV) instead of commonly used PR fraction (PRF). However, physicians are not familiar with the use of PRV in clinical practice. The ratio of right ventricle (RV) volume to left ventricle volume (RV/LV) may better reflect the impact of PR on the heart than RV end-diastolic volume (RVEDV) alone. We aimed to compare the impact of PRV and PRF on RV size expressed as either the RV/LV ratio or RVEDV (mL/m2). MethodsConsecutive patients with repaired tetralogy of Fallot were included (n=53). PRV, PRF and ventricular volumes were measured with the use of cardiac magnetic resonance. ResultsRVEDV was more closely correlated with PRV when compared with PRF (r=0.686, p<0.0001, and r=0.430, p=0.0014, respectively). On the other hand, both PRV and PRF showed a good correlation with the RV/LV ratio (r=0.691, p<0.0001, and r=0.685, p<0.0001, respectively). Receiver operating characteristic analysis showed that both measures of PR had similar ability to predict severe RV dilatation when the RV/LV ratio-based criterion was used, namely the RV/LV ratio>2.0 [area under the curve (AUC)PRV=0.770 vs AUCPRF=0.777, p=0.86]. Conversely, with the use of the RVEDV-based criterion (>170mL/m2), PRV proved to be superior over PRF (AUCPRV=0.770 vs AUCPRF=0.656, p=0.0028]. ConclusionsPRV and PRF have similar significance as measures of PR when the RV/LV ratio is used instead of RVEDV. The RV/LV ratio is a universal marker of RV dilatation independent of the method of PR quantification applied (PRF vs PRV).