Evaluation of left ventricular regional systolic functions in patients with coronary artery disease by two-dimensional strain imaging: a velocity vector imaging study)

OBJECTIVES
The aim of the study was to assess left ventricular (LV) regional systolic functions in coronary artery disease (CAD) using a novel strain imaging method, namely, velocity vector imaging (VVI).

STUDY DESIGN
The study included 69 patients (51 men, 18 women; mean age 52.9±10.3 years) with CAD and 30 healthy volunteers (22 men, 8 women; mean age 58.1±13.8 years). Thirty-three patients had previous myocardial infarction (MI). In all the patients, LV wall motions were analyzed as akinetic, hypokinetic, or normokinetic using the 16-segment model of the American Heart Association. In addition, LV peak systolic strain, strain rate (SRs), and segmental ejection fraction (SEF) of all the segments were calculated by using VVI.

RESULTS
Patients with MI had significantly lower mean peak systolic strain, SRs, and SEF compared to patients without MI and controls (p=0.0001). The presence of multivessel disease was accompanied by significantly decreased peak systolic strain (p=0.04), SRs (p=0.02), and SEF (p=0.0001). Myocardial segments affected by subtotal/total occlusion (≥99%) had lower peak systolic strain (p=0.02), SRs (p=0.001), and SEF (p=0.0001) values compared to segments with less severe occlusion. In segmental analysis, longitudinal deformation was most significant in akinetic segments (p=0.0001), but hypokinetic and normokinetic segments also differed significantly with respect to deformation (for strain, p=0.01; for SRs and SEF, p=0.0001). Moreover, deformation in the normokinetic segments was more significant than normal segments of the controls (for strain, p=0.02; for SRs and SEF, p=0.0001).

CONCLUSION
Velocity vector imaging allows regional deformation analysis for quantitative assessment of regional LV systolic functions; this technique may be more reliable than conventional echocardiography in determining wall motion abnormalities.