Evaluation of left ventricular longitudinal strain in patients with lesions of left anterior descending coronary artery using three-dimensional speckle tracking technique

Abstract

Objective To explore the value of three-dimensional speckle tracking (3DT-STI) technique for evaluating end-systolic three-dimensional longitudinal strain (3DLSe) of left ventricular myocardium in patients with left anterior descending coronary artery (LAD) lesions. Methods Sixty patients with pure LAD lesions diagnosed by coronary artery angiography (CAG) in Taizhou Hospital from June 2012 to December 2014 were enrolled, including 30 patients with acute anterior wall myocardial infarction (infarction group) and 30 patients without acute anterior wall myocardial infarction (non-infarction group). Sixty patients in the control group were enrolled in Department of cardiology in Taizhou Hospital in the same period. 3DLSe within LAD blood-supplied region, adjacent region and remote region were analyzed in all cases using 3DT-STI. The 3DLSe differences of 3 groups were compared by one-way analysis of variance, and the 3DLSe differences between two groups were compared by the LSD-t test. The inter-observer and intra-observer consistency of 3DLSe of left ventricular myocardium were analyzed by Bland-Altman drawing analysis method. Results 3DLSe of all 7 segments within LAD blood-supplied region were lower in infarction group than those of non-infarction group and control group, and the differences were statistically significant (infarction group vs. control group: t values were 6.96, 7.41, 8.94, 8.23, 8.94, 12.09 and 15.99, respectively, P values were all less than 0.01; infarction group vs. non-infarction group: t values were 5.30, 5.50, 4.66, 4.32, 4.66, 7.66 and 10.11, respectively, P values were all less than 0.01); 3DLSe of middle anterior segment, middle anterior septal segment, apical anterior segment, apical septal segment and apex of heart within LAD blood-supplied region were lower in non-infarction group than those of control group, and the differences were statistically significant (t values were 3.56, 3.23, 3.02, 3.25 and 4.36, respectively, P values were all less than 0.01), but 3DLSe of basal anterior segment and basal anterior septal segment had no statistically significant difference. 3DLSe of basal inferior septal segment within LAD adjacent region had no statistically significant difference in all 3 groups. 3DLSe of basal lateral segment, middle inferior septal segment, middle lateral segment, apical inferior segment and apical lateral segment within LAD adjacent region were lower in infarction group than those of non-infarction group and control group, and the differences were statistically significant (infarction group vs. control group: t values were 4.15, 4.79, 4.58, 9.24 and 12.07, respectively, P values were all less than 0.01; infarction group vs. non-infarction group: t values were 2.66, 3.59, 4.29, 7.74 and 10.33, respectively, P values were all less than 0.01); but 3DLSe of basal lateral segment, middle inferior septal segment, middle lateral segment, apical inferior segment and apical lateral segment within LAD adjacent region had no statistically significant difference between non-infarction group and control group. 3DLSe of all 4 segments within remote region had no statistically significant difference. Bland-Altman drawing analysis method showed the mean inter-observer and intra-observer difference of 3DLSe of left ventricular myocardium were -0.3% and -0.2%, the 95% confidence interval (CI) were in the range of (-5.6%, 5.0%) and (-8.2%, 7.7%), respectively. It was demonstrated that 3DLSe of left ventricular myocardium had good inter-observer and intra-observer consistency. Conclusions 3DLSe of left ventricular myocardium can detect the subtle changes in myocardial systolic function and is more sensitive than the conventional echocardiography. It can localization and analyze quantitatively the range of myocardial ischemia or infarction and has good consistency. Key words: Echocardiography, three-dimensional; Coronary artery disease; Ventricular function, left