To assess whether global and regional myocardial strains from three-dimensional speckle tracking echocardiography (3D-STE) correlate with myocardial infarction size (MIS) detected by single photon emission computed tomography (SPECT). Fifty-seven patients with a history of ST-segment elevation myocardial infarction (MI) within 3-6 months were enrolled, alongside 24 healthy volunteers. Left ventricular (LV) global area strain, global longitudinal strain (GLS), global radial strain, global circumferential strain, left ventricular ejection fraction (LVEF) and wall motion score index (WMSI) were measured and compared with the corresponding SPECT-detected MISs. Patients were sub-grouped into massive MIS group (MIS ≥ 12%) and small MIS group (MIS < 12%). Myocardial strains of all the LV segments were compared with the corresponding MIS. Global myocardial strain parameters, LVEF and WMSI of the patients were significantly different from the control group (all P < 0.05) and correlated well with MISs, most significantly for GLS (r = 0.728, P < 0.01). Significant differences in myocardial strain parameters were found between the massive and small MIS groups (all P < 0.05). Receiver operating characteristic curve analysis indicated that GLS had a highest diagnostic value and when the cutoff was -13.8%, the area under the curve was 0.84, with the 70.6% sensitivity and 87.5% specificity. Significant differences of myocardial strain parameters were observed between segments with and without transmural MIs (P < 0.01). 3D-STE myocardial strain parameters evaluated LV global MIS, 3D GLS had the highest diagnostic value. It also preliminarily gauged the degree of ischemia and necrosis of regional myocardial segments.
Keywords: Area; Myocardial infarction; Myocardial strain; Single photon emission computed tomography; Three-dimensional speckle tracking echocardiography.