Abstract 9217: 4-Dimensional Speckle Tracking Imaging Shows the Reduction of Left Ventricular Apex Rotation and Twist for Open Chest Pigs with Myocardial Ischemia
Background: Studies have shown that myocardial infarction (MI) has significant impact on left ventricular (LV) twist and rotation, which is considered to be a sensitive index of cardiac performance. We used a new 4-dimensional (4D) speckle tracking imaging (STI) program to study the change in LV segment rotation and twist for pig models with MI.
Methods: Seven pigs were sedated, followed by median sternotomy and opening of the pericardium. The middle left anterior descending coronary artery was partially ligated to produce 4 periods of LAD ischemia per animal. Apical long axis full volume 4D image loops were acquired with frame rate maximized on a Toshiba Applio® Artida® System at pre- and post-MI. Data were analyzed offline for LV segment rotation and twist in the apex and base using a new Toshiba 4D STI program.
Results: Compared with baseline, ischemic apical rotation and twist were reduced (rotation: from 6.89° ± 2.19° to 3.22° ± 0.70°, P=0.001; twist: from 7.56° ± 2.36° to 5.80° ± 1.09°, P<0.05). The base rotation and twist was not statistically different between baseline and ischemia (rotation: from 3.22° ± 1.22° to 2.83° ± 1.98°, P=0.67; twist: from 2.20° ± 0.97° to 1.77° ± 0.38°, P=0.29). Close correlation was also found between rotation and twist (r2 = 0.625, p<0.001) for all steady states.
Conclusions: Myocardial ischemia in the distal LAD region reduces apical rotation and twist, which can be defined by this new 4D STI program.
- © 2010 by American Heart Association, Inc.