Background and Objectives : Left Ventricular(LV) torsion is due to wringing motion of the heart, and a vital contributor to systolic and diastolic function. The purpose of this study was to examine LV torsion and untwisting for assessment of the severity in patients with acute coronary syndrome(ACS) by 2 dimensional ultrasound speckle-tracking imaging(STI), and compared these data with healthy subjects. Subjects and Methods : Forty one ACS patients and 21 healthy subjects for control group were analyzed. Standard echocardiogram before primary coronary intervention as performed. LV torsion (degree/Cm) was defined as following : (Peak torsion – torsion at time)/Peak torsion ⅹ 100. Patients were divided into three groups according involved vessel (group A : healthy subjects, n=21, group B : 1 vessel disease, n=16, group C : 2 or 3 vessel disease, n=23).
Results: LV rotation and torsion were significantly lower in group C compared with group A and B ( group A: 20.4 ± 6.5˚, 3.2 ± 0.4 ˚/Cm, group B: 15.1 ± 3.1 ˚,2.1 ± 0.2 ˚/Cm ; group C: 9.5 ± 3.4 ˚, 1.1 ± 0.3˚/Cm ; each p < 0.05). LV untwisting at mitral valve opening was also lower in group C compared with group A and B (1.3 ± 0.5˚, 0.8 ± 0.4 ˚, 0.6±0.3˚, p < 0.05). LV torsion and untwisting at mitral valve opening were correlate with LV ejection fraction (r=0.66, p < 0.001 ; r=0.39, p < 0.001, respectively). In ACS patients, N-terminal pro-B-type natriuretic peptide (NT-proBNP) level was higher in group C patients compared with group A and B (group A : 18.7 ± 10.1 pg/mL, group B : 39.9 ± 32.8 pg/mL, group C : 2478.5 ± 280.7 pg/mL. p<0.05).
Conclusion : LV torsion and untwisting were decreased in patients ith ACS, especially in multivessel disease. Increment of NT-proBNP level showed severe ACS. LV torsion and untwisting can be a general indicator of the severity in patients with ACS.
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