Evaluating The Dyssynchrony Of Post-infarction Heart Failure Rats' Left Intraventricular With Quantitative Tissue Velocity Imaging And Tissue Tracking Imaging

Objective To explore the value of the Quantitative Tissue Velocity imaging and Tissue Tracking Imaging in evaluating the dyssynchrony of post-infarction heart failure rats'left intraventricular and lay a foundation for the resynchronization therapy.Methods A total of 70 male SD rats were randomly assigned to 4 groups:4 weeks after operation group and 8 weeks after operation group, including 25 rats of each group, their anterior descending branch of left coronary artery was ligated. Sham operation group, including 10 rats, had thoracotomy and open the pericardium as the same, but did not ligate the artery. Control group, including 10 rats, without any treatment. The change of regional myocardial systolic movement of rats was examined with QTVI and TTI. Combined with the electrocardiogram, the index of the rat's left intraventricular dyssynchrony was calculated. Both repeatability and discrepancy of the results were analyzed.Result①Compare with the control group and the sham operation group, the ejection fraction (EF) and fractional shortening (FS) were getting lower as the process of the heart failure in the operation group.②In the operation group, the systolic peak velocity of all segments of left ventricular except the inferior wall and the base segments of lateral wall were lower than the sham operation group and the control group in 4 weeks after surgery. In 8 weeks after surgery, compared with the sham operation group and the control group, the systolic peak velocity of all segments were lower in the operation group. Compare with the control group and the sham operation group, as the process of the time, the systolic peak velocity of all segments getting lower and lower in the operation group.③One day before the surgery, all of the index of the rat's left intraventricular dyssynchrony were not significant differences in each group. In the operation group, all of the dyssynchrony indexes were getting longer than the sham operation group and the control group in 4 weeks after surgery except the inferior wall Intra-△Ts. In 8 weeks after surgery, all of the indexes were getting longer than the sham operation group and the control group. As the process of the heart failure, all of the indexes were getting longer and longer in the operation group, while the changes of the dyssynchrony index were not significant difference in the sham operation group and the control group as the process of time.④In the operation group, the systolic peak displacement of base and mid segments of interventricular septum and left ventricular anterior wall were lower than the sham operation group and the control group in 4 weeks after surgery. In 8 weeks after surgery, compared with the sham operation group and the control group, the systolic peak displacement of all segments were lower in the operation group. As the process of the time, the systolic peak displacement of all segments were getting lower and lower in the operation group while the changes of the sham operation group and the control group were not significant difference.⑤The discrepancy of all results among intra-investigator and inter-investigator was not more than 16%.Conclusion It can early and exactly quantitative evaluate the change of the post-infarction heart failure rats'regional myocardial systolic motion with QTVI and TTI from the long axis of the heart. Each index has a good repeatability. Combined with the electrocardiogram, the dyssynchrony of left intraventricular could be estimated. The cardiac dyssynchrony was closely related to the Severity of heart failure.