Objective To assess LV twisting and untwisting in patients with myocardial ischaemia at rest and myocardial infarction (MI) with different sites, searching for the value and characteristics of left ventricular twisting and untwisting in patients with CAD by speckle tracking imaging (STI).
Methods Echocardiography were performanced in 60 patients with MI (consisting of anteroseptal MI, infer-posterior MI and extensive infarction of the anterior wall), 31 patients with myocardial ischaemia and 26 control individuals who were all received coronary arteriography. It was demonstrated by coronary arteriography that stenosis of one main branch at least of coronary artery was significant (≥70%) in patient groups while it was slight (<50%) or none in control group. Twisting and untwisting were measured by STI, and the paramaters of them were torsion, torsion rate and untwisting rate.
Results The two patient groups, especially in patients with MI, had much lower parameters in torsion (6.92±3.28 vs 11.65±2.70 vs 17.16±5.42), torsion rate (45.78±19.36 vs 72.68±20.77 vs 99.51±32.13) and untwisting rate (−49.88±24.67 vs −82.91±16.37 vs −102.03±30.97) than that of control group (p<0.001). When comparing with the patients of anteroseptal and infer-posterior MI, torsion (7.82±2.03 vs 9.08±3.42 vs 4.23±2.62), torsion rate (53.76±14.85 vs 54.38±18.80 vs 30.30±19.51) and untwisting rate (−56.94±21.96 vs −59.11±25.76 vs −36.39±20.40) were significantly reduced in patients with extensive infarction of the anterior wall (p<0.05), while the differences between anteroseptal and infer-posterior MI were small. There were good correlations between torsion and LVEF, untwisting rate (r1=0.618, r2=−0.731, p<0.001 for both).
Conclusion Torsion, torsion rate and untwisting rate derived by STI were decreased not only in patients with MI but also in patients with myocardial ischaemia at rest. Besides it is the infarction extent and size rather than the site to influence the twisting and untwisting in patients with MI.