Evaluation of Longitudinal Tissue Velocity and Deformation Imaging in Akinetic Nonviable Inferobasal Segments of Left Ventricular Myocardium by Dobutamine Stress Echocardiography

Abstract

To study tissue velocity imaging (TVI) and strain rate imaging (SRI) indices in akinetic nonviable and normal left ventricular (LV) inferobasal segment and effect of dobutamine infusion on these indices in nonviable segments. The study population consisted of two groups: 25 patients (mean age 60.75 +/- 8.69 years) with left ventricular akinetic inferobasal nonviable segment determined by dobutamine stress echocardiography (DSE) and 14 normal coronaries (mean age 56.67 +/- 11.90 years) with normal echocardiography as control group. The following TVI and SRI parameters were measured in patient and control group: ejection phase velocity (Sm [cm/sec]), peak systolic strain (ST [%]), and strain rate (SR [per second])). Ejection fraction was significantly lower in patient group (29.40%+/- 5.46% vs. 55.00%+/- 3.39%; P < 0.001). Several differences were observed in patients with nonviable inferobasal segments compared to control group: Sm was reduced (3.58 +/- 1.08 cm/sec vs. 5.56 +/- 1.28 cm/sec; P < 0.001); SR and ST were significantly decreased (-0.39 +/- 0.20/second vs. -1.44 +/- 0.64/second, and -3.86%+/- 4.12% vs. -17.64%+/- 7.44%, respectively; P < 0.001 in both). The range of SR for nonviable segments (-0.04 to -0.77/second) did not overlap with that of the normal segments (-0.80 to -3.0/second). This range for Sm and ST overlapped with those of the normal segments. All TVI and SRI parameters are reduced in akinetic nonviable inferobasal compared with normal segments. According to findings of this study, resting strain rate has a potential to discriminate nonviable inferobasal from normal segments.