Real-time three-dimensional speckle tracking imaging in detection of left ventricular delayed relaxation of stunned myocardium in canines

Objective To assess the left ventricular delayed relaxation of stunned myocardium with real time three-dimensional speckle tracking imaging(3D-STI) in canines.Methods Left anterior descending arteries of 12 canines were ligated to induce myocardial ischemia for 15 min,followed by reperfusion.The peak longitudinal strain(LSpeak) and strain imaging diastolic index(SI-DI) of ischemic and non-ischemic myocardium were measured and calculated using 3D-STI before ischemia,5 min and 15 min after ischemia,as well as 30 min,60 min,90 min and 120 min after reperfusion.Results LSpeak and SI-DI decreased in ischemic myocardium 5 min and 15 min after ischemia and both recovered with reperfusion time going.LSpeak returned to normal while SI-DI did not 120 min after reperfusion.In non-ischemic myocardium,LSpeak and SI-DI increased after ischemia 5 min,15 mm and both recovered 30 min after reperfusion.Conclusion 3D-STI has application value for evaluation on the delayed relaxation of regional left ventricle in stunned myocardial in canines.