Noninvasive left ventricular stiffness in chronic mitral regurgitation both at rest and during supine ergometry

Abstract Background Adaptation to volume overload in mitral regurgitation (MR) decreases left ventricular (LV) chamber stiffness. Compromised diastolic function in MR may contribute to clinical decompensation. Purpose Aim of the study was to evaluate the effect of MR etiology on the noninvasively estimated LV stiffness both at rest (R) and supine exercise ergometry (Ex) and to interrogate potential implications for the outcome. Methods One hundred forty three asymptomatic subjects with moderate to severe MR (pts), followed up on valve clinic in a tertiary center (age 56±14), were referred for Ex. Fifty-three had myxomatous substrate (Myx), 57 fibroelastic deficiency (FD), 19 functional LV MR (LVfn) and 14 functional atrial MR (ATRfn). Cardiac events (independent decision for surgery, NYHA worsening) during a follow up of 34±25 months occurred in 24 pts. The following parameters (mean±SD) were estimated at R/Ex: Biplane LV enddiastolic volume (LVEDvol), ejection fraction, stroke volume, longitudinal strain, systolic tricuspid pressure gradient (TRPG), transmitral E/e, LV stiffness as the ratio E/e/LVEDvol (mL-1). The slope meanTRPG/cardiac output (CO) was estimated using R/Ex points. Results At R, LV stiffness was greater (thus implying decreased compliance) in ATRfn (0.21±0.16 vs 0.09±0.06 Myx/p