Correlating transmural extent of acute myocardial infarction to left ventricular stain by mrifeature tracking / 中国介入心脏病学杂志

ABSTRACT

Objective The left ventricular myocardial strain of acute myocardial infarction on cardiac magnetic resonance cine imaging was measured by feature tracking technique. The relationship between left ventricular myocardial strain and the transmural extent of Myocardial Infarction was evaluated. Methods 74 patients with acute ST segment elevation myocardial infarction were included. All theses patients received primary PCI within 12 hours. After 2 to 5 days. ECG gated steady-state free precession sequences were collected. Gadolinium contrast enhanced imaging was performed on short axis. 20 patients repeated same scan after 3 to 5 months. TomTec 2D CPA and Segment software were used to analyze the images. The peak values of the regional myocardial strain indexes. The transmural extent of myocardial infarction of segment in left ventricular was measured. Results There was no significant difference of longitudinal strain in non-infarction,non-transmural infarction and transmural infarction segments at the basal and middle segments. The circumferential strain peak and the radial strain peak of non-transmural infarction segments were lower than those of the non-infarction segments. The circumferential strain of transmural infarction segments were the lowest(basal level-14.24％±9.05％,P<0.05;middle level-12.71％±8.92％,P<0.05;apical level-13.81％±11.13％, P<0.05). GLS was improved while LVDd was increased when compared the acute phase of myocardial infarction to that of 3-5 months after primary PCI. The circumferential strain and longitudinal strain of the non-transmural infarction segments was improved. The circumferential strain and radial strain of the transmural infarction segments 3-5 months later was improved as compared to the acute phase. Conclusions There was differences in myocardial strain in non-infarction,non-transmural infarction and transmural infarction segments from patients with acute ST segment elevation myocardial infarction who had accepted primary PCI. The circumferential strain and longitudinal strain of the non-transmural infarction segments were improved after 3-5 months. The circumferential strain and radial strain of the transmural infarction segments after 3-5 months was improved as compared to the acute phase. Cardiac Magnetic resonance could combine feature tracking technique with gadolinium contrast delayed enhancement technique,giving both function and tissue characteristic evaluation to the myocardial damages after acute myocardial infarction.