Global longitudinal strain measured by two-dimensional speckle tracking echocardiography is closely related to myocardial infarct size in chronic ischaemic heart disease

Abstract

2D-STE (two-dimensional speckle tracking echocardiography) is a novel echocardiographic modality that enables angle-independent assessment of myocardial deformation indices. In the present study, we tested whether peak systolic ϵ∥ (longitudinal strain) values measured by 2D-STE could identify areas of MI (myocardial infarction) as determined by CE MRI (contrast-enhanced magnetic resonance imaging). Conventional echocardiographic apical long-axis recordings were performed in 38 patients, 9 months after a first MI. Peak systolic ϵ∥ measured by 2D-STE in 16 left ventricle segments was compared with segmental infarct mass and transmurality assessed by CE MRI. Segmental values were averaged to global and territorial values for assessment of global function and myocardial function in the coronary distribution areas. CE MRI identified transmural infarction in 27 patients, and a mean infarct size of 36±25 g. Peak systolic ϵ∥ correlated with the infarct mass at the global level (r=0.84, P<0.001). A strain value of −15% identified infarction with 83% sensitivity and 93% specificity at the global level and 76% and 95% at the territorial level, and a strain value of −13% identified transmural infarction with 80% sensitivity and 83% specificity at the segmental level. Global infarct mass correlates with the wall motion score index (r=0.70, P<0.001), and left ventricular ejection fraction measured by MRI or echocardiography (r=−0.71 and −0.58, both P<0.001). In chronic infarction, peak systolic ϵ∥ measured by 2D-STE correlates with the infarct mass assessed by CE MRI at a global level, and separates infarcted from non-infarcted tissue. Global strain is an excellent predictor of myocardial infarct size in chronic ischaemic heart disease.