The Right Ventricular Free Wall Strain and Functional Capacity Assessed
by 6 Minutes Walk Test in Heart Faiure Patients with Reduced Ejection
Fraction
Abstract
Introduction The correlation of the right ventricular (RV) systolic
function and functional capacity (FC) assessed by cardiopulmonary
exercise testing (CPET) in HFrEF patients were demonstrated in previous
studies In this study, we aimed to determine the correlation of RV free
wall strain (RVfwlS) , left ventricular (LV) strain parameters and other
standart echocardiographic parameters with the FC assessed by the 6
minutes walk test 6MWT in HfrEF patients. Also, according to the
calculated RVfwlS, the differences among HFrEF patients were examined.
Method Dilated cardiomyopathy patients with an EF lower than 40 %
included in our study. After echocardiographic examinations, and venous
blood sampling for NT-pro-BNP, the 6MWT performed for each participant
by a physician blinded to echocardiographic examination. Results 50
patients with a mean EF of 28,78 ± 6,0 % were included. The distance
walked in 6MWT ( 6MWT-dis) was significantly correlated with the
NT-pro-BNP levels, E/Em-mean, left atrial volume index, RvfwlS, Sc
(circumferential strain) and the Sl (longitudinal strain) . The Sc and
the RVfwlS were found to be the independent predictors of the 6MWT-dis
in multivariate analysis. According to mean RvfwlS which was -18,50 ±
4,83, we grouped patients; Group 1 (n= 26) RvfwlS > -18.5%
and Group 2 (n=24) RVfwlS < -18.5%. The Group 2 patients have
higher NT-pro-BNP levels (p<0.01) , lower 6MWT-dis
(p<0.01), higher E/Em-mean (p<0.01) and lower Sl
(p<0.01). Conclusion The low RVfwlS in HFrEF patients could
indicate cumulative exposure of RV to chronic increased LV filling
pressures due to LV remodelling and dilatation.