Significance of elevated MB isoenzyme with normal @entity908 kinase in XXXX .

@entity1 @entity908 @entity583
The significance of elevated levels of the MB isomer of @entity908 kinase (CK-MB) when @entity908 kinase (CK) level is normal was studied in 400 @entity1 with suspected @entity583 ( @entity583 ). In 350 @entity1 both CK and CK-MB were elevated (group 1), in 21 only CK-MB was elevated (group 2), in 24 neither enzyme was elevated (group 3) and in 5 only CK was elevated (group 4). In 57% of @entity1 in group 2 the CK level was doubled, with a characteristic enzyme curve, within the normal range, suggesting that an increase in CK had been missed because arbitrary definitions of "normal" were used. The median CK increase (60 IU/liter) in group 2 was greater than that in group 3 (23 IU/liter) (p less than 0.001). @entity1 in group 1 with small AMIs had a relative increase in CK similar to that in group 2. However, @entity1 in group 2 had a lower baseline CK level so that peak CK did not become abnormally high despite a 5-fold increase in some @entity1 . In @entity1 in group 1 with small AMIs, CK was elevated in fewer samples than CK-MB. If only 2 samples were obtained in all @entity1 , elevation of CK levels would have been missed in 63 group 1 @entity1 , erroneously increasing the number of @entity1 in group 2 fourfold (to 84 of 400, or 21%, instead of 21 of 400, or only 5%). Conversely, if @entity1 in group 2 with a doubling of CK are excluded, the prevalence of elevated CK-MB with normal CK would be only 9 of 400 (2%).(ABSTRACT TRUNCATED AT 250 WORDS)
