Alternations of left ventricular torsion of myocardial ischemia before and after reperfusion assessed by speckletracking imaging

Objective To evaluate the alternations of left ventricular (LV) torsion of myocardial ischemia before and after reperfusion using speckle tracking imaging (STI).Methods Fourteen open-chest pigs underwent randomizedly 1 minute (group A) or 15 minutes (group B) of left anterior descending (LAD) ligation and followed up for 1 week.Torsion of LV in both groups were quantified by STI before LAD occlusion,LAD occlusion immediately,and 1-,5-,30-,60-,90-minute and 1-week after reperfusion.Results One minute after reflow,decreased peak apical rotation and peak LV torsion fully recovered in the inner layer in group A.In contrast,there was a brief resumption in group B during 30min after reflow from (6.5 ± 0.8)° to (3.4 ± 1.2)°( P ＜0.01 ) and from (7.8 ± 1.0)° to (6.1 ± 1.1 ) ° ( P ＜0.01 ),respectively.Peak LV subepicardial torsion increased gradually after reperfusion.Conclusions As a result of various durations of ischemia,peak torsion in subendocardium and subepicardium change differently before and after reflow.STI may be suitable for evaluation of the extent of ischemia by noninvasive quantification of torsion in subendocardium and subepicardium.Therefore,duration of assessment of myocardial ischemia can be prolonged. Key words: Echocardiography;  Myocardial ischemia;  Myocardial reperfusion;  Torsion;  Speckle tracking imaging