Cine MRI evaluation of regional asynergy after experimental coronary occlusion

Academic Article

Abstract

  • To determine whether cine magnetic resonance imaging (MRI), an MR imaging technique that employs short repetition times, low flip angles, and gradient refocused echoes, can detect abnormalities in regional left ventricular wall motion, eight dogs were imaged before and after ligation of the left anterior descending artery. Cine loops containing between eight and 12 views during the cardiac cycle of a single anatomic section of the left ventricle were acquired with a temporal resolution between 33 and 42 ms per view in the short-axis, long-axis, and four-chamber imaging planes. Ten left ventricular wall segments were assessed for the presence of contraction or asynergy by two blinded observers. Severe ischemia after coronary occlusion was verified with segment length sonomicrometers. After coronary occlusion, akinesis of the anterior wall with apical asynergy or dysynergy was evident in seven of the eight dogs. In the one dog that showed no change after coronary occlusion, sonomicrometrically measured contraction did not change. A wall segment score was derived where normal contraction was given a score of 1 and akinesis a score of 0. The wall segment score for all dogs decreased after coronary occlusion from 9.8 ± 0.6 to 7.0 ± 1.3 (P < .01). Segmental contraction, as assessed by the segment length sonomicrometers, also diminished after coronary occlusion, with total percent systolic shortening decreasing from 22.2 ± 6.8% to -1.8 ± 1.3%, (P < .01). These results suggest that cine MRI may be a useful noninvasive tomographic method for detecting regional asynergy.
  • Authors

    Published In

    Author List

  • Askenase AD; Chen G; Heo J; Iskandrian AS; Helfant RH
  • Start Page

  • 91
  • End Page

  • 99
  • Volume

  • 3
  • Issue

  • 2