Abstract 14641: The Search for Metrics of Systolic-Diastolic Coupling: Distance is Better Than Speed

IntroductionSystole and diastole are integrally linked. Systolic contraction engages compressive forces resulting in stored energy recovered during early diastolic recoil. Alterations in coupling may unmask subclinical impairments in cardiac relaxation seen in early stages of heart failure. Understanding of coupling and how it is affected by loading conditions is limited.HypothesisWe hypothesize annular systolic excursion and early diastolic recoil distances but not velocities remain coupled across cardiac loading conditions.MethodsHealthy subjects (n =61, age 53 ± 5 years) underwent right heart catheterization and alteration of cardiac preload with lower body negative pressure (LBNP) (-15 mm Hg and -30mm Hg) and normal saline infusion (+15 mL/kg/min, +30 mL/kg/min). Echocardiography with tissue Doppler Imaging (TDI) of the mitral annulus, including systolic velocity (s’), systolic excursion (s’ velocity time integral [VTI]), early diastolic velocity (e’) and early diastolic recoil (e’ VTI) was performed. Coupling was defined ase’/s’ representing velocities and e’ VTI/s’ VTI, representing distance.ResultsDuring LBNP, s’ increased (Δ0.39±0.51 cm/sec, p