Intermittent brief periods of XXXX have a cumulative effect and may cause @entity296 .

@entity5045 @entity1 @entity296 @entity2749 @entity63 @entity235 @entity908 @entity1563 @entity39 @entity661
We investigated the effects of brief intermittent periods of @entity63 on @entity296 . Brief periodic @entity1563 were produced up to 18 times by inflating and deflating the balloon of an intracoronary No. 2F catheter for periods of 15, 10 or 5 minutes, followed by 15-minute periods of reperfusion. @entity908 kinase (CK) release, @entity5045 staining, and light and electron microscopy were used to detect the presence of @entity296 . For the study of CK release, blood was taken from the great cardiac vein and the aorta before and at 5-minute intervals during each left anterior descending coronary occlusion, as well as during and 1, 5, 10 and 15 minutes @entity661 . In seven of 24 @entity235 with 15-minute occlusions, in five of 21 @entity235 with 10-minute occlusions, and in three of 32 @entity235 with 5-minute occlusions, small but distinct areas of @entity39 were present. In all @entity235 with morphologic proof of @entity39 , there was periodic release of CK into the great cardiac vein, which peaked immediately after reperfusion, reflecting CK washout. Thus, brief periods of @entity63 , which when single do not cause @entity39 , have a cumulative effect and may cause @entity296 . This mechanism of @entity39 may be relevant clinically in @entity1 with frequent @entity2749 . Since many @entity235 of this study did not have any @entity296 , the findings also suggest that intermittent reperfusion has a beneficial effect and may prevent @entity39 , even when total occlusion time exceeds 200 minutes.
