Preliminary evaluation of left ventricular strain and torsion in clinical cardiac function classification in coronary artery disease

AIM To study left ventricular myocardial strain and torsion using 2D speckle tracking technology (2D-STI) and to explore the value of myocardial strain and torsion in quantitative assessment of the New York Heart Association (classification) accumulated points (NYHA-AP) in coronary artery disease (CAD). METHODS Fifty-six patients with CAD were divided into normal clinical heart function group (group A, n=30) and dysfunctional clinical cardiac group (group B, n=26). Thirty subjects without CAD were recruited as normal control group (group C). Left ventricular ejection fraction (LVEF), left ventricular myocardial global longitudinal strain (GLS), global radial strain (GRS) and left ventricular myocardial systolic torsion angle (TA) were detected and compared between groups. RESULTS LVEF, GLS, GRS and TA in CAD group were lower (P<0.05) than those in the control group. There was no correlation between LVEF and GLS in group A (P>0.05), GLS and LVEF were positively correlated in group B, and GLS, GRS and TA in group B were lower than those in group A (P<0.05). LVEF had no correlation with NYHA-AP in group A but were positively correlated in Group B. Sensitivity and specificity of the cut-off point of GLS-15.05% for determining NYHA class I-II grade were, respectively, 88.45% and 70%. CONCLUSION 2D-STI has unique advantages in evaluating regional myocardial function. Clinical cardiac function classification and LVEF are not synchronized and myocardial strain and torsion are correlated with clinical cardiac function. Regional myocardial function variation develops simultaneously with clinical cardiac function. Myocardial strain and torsion decreases even if NYHA is still good or to a lesser degree. Decreased myocardial strain and torsion indicate the development of heart dysfunction.