Correlation between Longitudinal Strain in the Apical Segments of the Left Ventricle at End-systole Obtained by Two-Dimensional Speckle-Tracking Echocardiography and Left Ventricular Relaxation

概要

Background:
　It is well acknowledged that left ventricular (LV) contractile performance affects LV relaxation via LV elastic recoil. Accordingly, we aimed to investigate whether the global longitudinal strain (GLS) and especially longitudinal strain at the LV apical segments at end- systole (ALS) obtained by two-dimensional speckle-tracking echocardiography could be used to assess LV relaxation.

Methods:
　We enrolled 121 patients with suspected or definite coronary artery disease in whom echocardiography and diagnostic cardiac catheterization were performed on the same day. We obtained conventional echo-Doppler parameters and GLS as well as ALS prior to catheterization. From the LV pressure recorded using a catheter-tipped micromanometer, LV functional parameters were obtained.

Results:
　In all patients, the GLS and ALS were significantly correlated with the time constant τ of LV pressure decay during isovolumic relaxation (r=0.63, P<0.001 and r=0.66, P<0.001, respectively). Receiver-operating-characteristic curve analysis for identifying impaired LV relaxation (τ ≥48 ms) revealed that ALS >–22.3% was an optimal cut-off value, with 81.7% sensitivity and 82.4% specificity. Even in patients with preserved LV ejection fraction, the same ALS value of >–22.3 % enabled to identify impaired LV relaxation with 70% sensitivity and 87.5% specificity.

Conclusions:
　Our findings indicate that contractile dysfunction at the LV apical segments slows LV relaxation via loss of LV elastic recoil, even in patients with preserved LVEF.