Nuclear magnetic resonance analysis of acute myocardial infarction in @entity235 : the effects of transient XXXX of varying duration and reperfusion on spin lattice relaxation times.

@entity235 @entity4358 @entity741 @entity63
The purposes of this study were to evaluate the effects of acute @entity741 with reperfusion on T1 (spin-lattice) nuclear magnetic resonance (NMR) relaxation times in a @entity235 model and correlate these changes with bulk myocardial water content (% @entity4358 ). In 15 @entity235 the left anterior descending coronary artery was occluded for either 40 minutes (n = 5), 1 hour (n = 5), or 2 hours (n = 5). In 15 additional @entity235 , matched occlusion periods were followed by 3 hours of reperfusion. T1 of tissue from normal and @entity63 myocardium was measured in vitro with a 2.5 kg NMR spectrometer. In the reperfusion animals, the 2-hour group showed significant increases in % @entity4358 and T1 when the @entity63 segment of myocardium was evaluated (both p less than 0.01). All but one animal in the 1-hour (reperfusion) group showed increases in both % @entity4358 or T1 in the @entity63 segment of myocardium when compared to control segments. The mean values from the @entity63 myocardium in the 1-hour group were significantly higher than the values from the matched control segment for % @entity4358 (p less than 0.05) and T1 (p less than 0.05). In the group undergoing 40 minutes of @entity63 followed by 3 hours of reperfusion, neither % @entity4358 nor T1 changed significantly. In the nonreperfused animals, neither T1 nor % @entity4358 content increased significantly after 40 minutes. Significant increases were seen in the 1-hour (p less than 0.05) and 2-hour groups (without reperfusion) (p less than 0.01). In addition, the 2-hour occlusion followed by reperfusion animals had significantly greater T1 relaxation times and % @entity4358 than control @entity63 animals.(ABSTRACT TRUNCATED AT 250 WORDS)
