8/High Frequency Ultrasound Imaging Detects Cardiac Dyssynchrony in Non-Infarcted Regions of the Murine Left Ventricle Late After Reperfused Myocardial Infarction

摘要

Cardiac dyssynchrony in the left ventricles of murine hearts late (>= 28 days) after reperfused myocardial infarction (post-MI) was assessed using high frequency 30 MHz B-mode ultrasound imaging. Nine post-MI and six normal C57Bl/6 mice were studied in both short- and long-axis views. Regional time to peak displacement (Tpeak_d) and time to peak strain (Tpeak_s) were calculated in 36 sectors along the myocardial circumference; then their standard deviations (SD_Tpeak_d and SD_Tpeak_s) were computed among non-infarcted myocardial regions for each mouse, and were compared between the normal and post-MI mouse groups with Student’s t test. The comparison revealed that SD_Tpeak_d and SD_Tpeak_s were significantly larger in the post-MI hearts than in the normal hearts. The displacement uniformity ratio was determined to be 0.97±0.01 and 0.85±0.07 for radial and circumferential displacements in the normal hearts, respectively; and 0.59±0.17 and 0.64±0.24 in the post-MI hearts. In conclusion, this high resolution ultrasound image tracking method provides for the detection of cardiac dyssynchrony in the non-infarcted regions in the murine left ventricles late after MI by identifying the temporal and spatial disparity of regional myocardial contraction.