High Frequency Ultrasound Imaging Detects Cardiac Dyssynchrony in Noninfarcted Regions of the Murine Left Ventricle Late After Reperfused Myocardial Infarction

Li, Yinbo; Garson, Christopher D.; Xu, Yaqin; French, Brent A.; Hossack, John A.

doi:10.1016/j.ultrasmedbio.2007.12.009

« Previous Next »Ultrasound in Medicine and Biology
Volume 34, Issue 7 , Pages 1063-1075, July 2008

High Frequency Ultrasound Imaging Detects Cardiac Dyssynchrony in Noninfarcted Regions of the Murine Left Ventricle Late After Reperfused Myocardial Infarction

Yinbo Li
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
Christopher D. Garson
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
Yaqin Xu
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
Brent A. French
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
- Department of Medicine, University of Virginia, Charlottesville, VA, USA
- Department of Radiology, University of Virginia, Charlottesville, VA, USA
John A. Hossack
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
- Address correspondence to: John A. Hossack, Ph.D., Department of Biomedical Engineering, MR5, 415 Lane Road, University of Virginia, P.O. Box 800759, Charlottesville, VA 22908-0759, USA.

Received 6 June 2007; received in revised form 22 November 2007; accepted 13 December 2007. published online 04 March 2008.

Abstract

Cardiac dyssynchrony in the left ventricles of murine hearts late (≥28 d) 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 (T_{peak_d}) and time to peak strain (T_{peak_s}) were calculated in 36 sectors along the myocardial circumference; then their standard deviations (SD_T_{peak_d} and SD_T_{peak_s}) were computed among noninfarcted 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_T_{peak_d} and SD_T_{peak_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 noninfarcted regions in the murine left ventricles late after MI by identifying the temporal and spatial disparity of regional myocardial contraction. (E-mail: jh7fj@virginia.edu)

Key Words: Myocardial infarction, Cardiac dyssynchrony, Contractile dysfunction, Regional left ventricular function, High resolution ultrasound