Left ventricular unloading during reperfusion does not limit XXXX size.

@entity5045 @entity63 @entity95 @entity1188 @entity1562 @entity583 @entity1002
To determine whether venting the left ventricle during coronary reperfusion limits @entity583 size, we studied paced (200 beats/min) Langendorff @entity95 hearts, perfused with blood from a support @entity95 . A left coronary artery was occluded for 60 minutes, followed by 2 hours of reperfusion. Four experimental conditions, as follows, were used: In group 1 (control), the hearts contracted isovolumetrically on a fluid-filled balloon in the left ventricle during both occlusion and reperfusion. In group 2, the balloon was present only during occlusion, and the heart was vented during reperfusion. Hearts in group 3 were vented during occlusion and developed pressure during reperfusion. In group 4, the left ventricle was vented during occlusion and reperfusion. Perfusion pressure (91.2 +/- 0.9 mm Hg) and coronary flow (0.88 +/- 0.03 ml/min/g) were not different between groups. @entity1002 (mean of all groups) were 87.3 +/- 1.5 mm Hg systolic and 6.5 +/- 0.6 mm Hg diastolic. Infarcted @entity1562 was assessed by @entity5045 staining and expressed as a percentage of the area at risk, as measured by fluorescent particles. Venting during both @entity63 and reperfusion (n = 10) did result in significantly smaller @entity1188 than in the unvented controls (n = 10), that is, 13 +/- 5% vs. 41 +/- 6%, respectively. Venting only during reperfusion (n = 10) or occlusion (n = 11) did not significantly limit @entity1188 size (57 +/- 6% and 32 +/- 5%, respectively), as compared with controls. Thus, the clinically feasible intervention of left ventricular venting during reperfusion was not cardioprotective.
