OBJECTIVE: @entity337 after @entity63 and reperfusion may compromise the normal postischemic coronary perfusion and additionally jeopardize the recovery of the myocytes. We investigated whether such a form of @entity697 occurs in the routine operative setting despite the use of protective measures. For this purpose, we measured pressure-flow relations in the coronary vasculature during heart operations before and after @entity63 and after reperfusion and their reaction to the @entity842 donor @entity1242 . METHODS: Forty-eight @entity1 with a low risk profile scheduled for routine coronary artery bypass surgery were included. During normothermic extracorporeal circulation, the fibrillating heart was completely excluded from bypass by clamping of the ascending aorta and snaring of the caval veins. It was relieved of blood by opening the right atrium and venting the left atrium and ventricle to avoid distention. The coronary vessels were perfused under controlled flow, and the perfusion pressures were monitored. This protocol was performed in 24 @entity1 before and immediately after @entity63 and after a reperfusion period. RESULTS: Compared with the preischemic control, vascular resistance was decreased by 17% (P <.003) immediately after @entity63 but increased again by 46% (P <.0001) during an average of 25 minutes of reperfusion and, even more important, by 23% (P <.028) in comparison with the preischemic values. In two groups of 12 @entity1 , @entity1242 was added to the perfusate either in a dosage of 3 microg. kg. @entity1009 ) or as a bolus injection of 2 mg. Low-dose @entity1242 did not reduce the elevated postreperfusion resistances significantly, but bolus injection did (P <.0002). Coronary vessel resistance increased during reperfusion in particular in @entity1 with a history of @entity101 . CONCLUSION: Coronary vasoconstriction during postischemic reperfusion is regularly present in the routine operative setting in cardiac surgery, despite myocardial protection measures. The amount of vasoconstriction varies considerably and is particularly increased in @entity1 with @entity101 . The @entity842 donor @entity1242 can normalize the elevated resistances, but only in high dosages. This demonstrates a preserved ability of vascular smooth muscle to relax. The phenomenon had no sequelae in our low-risk @entity1 having elective operations. However, it may gain significance in the case of severe left @entity1283 and in @entity1 at risk with both a postoperative @entity998 and reduced mean arterial pressures during reperfusion.

Changes in coronary vessel resistance during postischemic reperfusion and effectiveness of XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity697 :: ('MESH:D000208', 'Disease') :: ['acute endothelial dysfunction'] @entity101 :: ('MESH:D006973', 'Disease') :: ['hypertension'] @entity1242 :: ('MESH:D005996', 'Chemical') :: ['nitroglycerin'] @entity63 :: ('MESH:D007511', 'Disease') :: ['ischemia'] @entity1009 :: ('966', 'Gene') :: ['min(-1'] @entity1283 :: ('MESH:D006332', 'Disease') :: ['heart hypertrophy'] @entity998 :: ('MESH:D002303', 'Disease') :: ['low-output syndrome'] @entity337 :: ('MESH:D001022', 'Disease') :: ['Microvascular incompetence'] @entity842 :: ('MESH:D009569', 'Chemical') :: ['nitric oxide']
@entity1242 :: (MESH:D005996,Chemical) :: ['nitroglycerin']
