Novel echocardiographic assessment of right ventricular function utilizing dynamic base to apex fractional shortening

Background The right ventricle (RV) has a unique geometry and mechanical function that make it hard to evaluate by transthoracic echocardiography (TTE). Tricuspid annular plane systolic excursion (TAPSE) is commonly utilized for RV function assessment but is limited since it evaluates the RV base independent of the motion of the rest of the heart. We evaluated a novel measurement of RV base to apex fractional shortening (BAFS) between systole and diastole, which accounts for global cardiac motion, to see if it could accurately assess RV function. Methods We screened patients with cardiac MRI (CMR) between 06/2018 to 07/2019 in our system for presence of TTE within 1 month of CMR and chose 120 to evaluate. We excluded any studies without TAPSE, apical 4 chamber view or with incomplete CMR data. We reviewed studies and calculated RV BAFS by measuring distance from RV base to RV apex in diastole and systole and calculating relative change. We documented recorded TAPSE from TTE and RV Ejection Fraction (RVEF) from CMR. We then compared RV BAFS values from studies with RVEF \u3e55% to those with RVEF \u3c45%. Results Of the 120 TTEs and CMRs reviewed, 89 were included for interpretation. When comparing studies with RVEF \u3c45% to those with RVEF \u3e55%, the average RV BAFS was 15% vs. 24% (P\u3c0.005). This correlated with TAPSE, which had average values of 1.7 vs 2.1 (cm) respectively. Utilizing a specific cut off for RV BAFS of \u3c18% was associated with a 76% specificity and 69% sensitivity for predicting RVEF \u3c45%. We found RV BAFS to be easily obtainable across multiple investigators with good reproducibility. Conclusion The RV continues to be a difficult chamber to evaluate by TTE. Other potential parameters, such as TAPSE, Fractional area change and 3D echocardiography are all limited by requiring adequate image acquisition that cannot be obtained on every patient. A new metric that is reliably obtainable could greatly aid in day to day evaluation of RV function. This study demonstrates that RV BAFS has excellent correlation with RV assesment by CMR, has the potential to be a specific marker of RV dysfunction and can be easily performed on standard TTE images available to all echocardiography labs