Abstract 3157: Coupling of Left Ventricular Relaxation to Systolic Contraction in Normal, Hypertrophied, and Dilated Myocardium Quantified by Speckle-Tracking Global Strain and Strain Rate Imaging
Background: It has not been fully investigated whether impairments of left ventricular (LV) relaxation precede or couple to systolic dysfunction during the disease process ranged from latent myocardial dysfunction to failing myocardium in patients with either left ventricular hypertrophy (LVH) or dilated cardiomyopathy (DCM).
Methods: To quantify global LV longitudinal (L) and circumferential (C) function, fifty-seven patients with hypertensive LVH (ejection fraction 58 ± 10 %), twenty-one patients with DCM (ejection fraction 33 ± 13 %), and fifty-seven normal controls (Controls: ejection fraction 65 ± 6 %) had echo-study with speckle-tracking strain and strain rate imaging (Vivid 7 and EchoPAC, GE Electronic) from apical 4-, 2-, long axis, and mid-ventricular short axis views. Global peak systolic strain (PSS) and peak relaxation rate (PRR) were used as indices of global LV contraction and relaxation, respectively.
Results: PRR was significantly correlated to PSS from both (L) and (C) in LVH, DCM, and Controls with linear regressions, respectively (DCM (L); r = 0.81*, (C); r = 0.81*, LVH (L); r = 0.78*, (C); r = 0.74*, Control (L); r = 0.64*, (C); r = 0.70*, *p < 0.05). Furthermore, correlations between PSS and PRR were best fit with exponential regression from (L) and linear regression from (C) all through the subjects ((L); y = 0.18e-0.099x, r = 0.84*, (C); y = −0.070x - 0.017, r = 0.79*, *p < 0.05).
Conclusion: Speckle-tracking strain and strain rate imaging exhibited the strong coupling of LV relaxation to systolic contraction ranged from the normal to failing myocardium regardless of their initiating disease process.