No abstract

SUMMARY. We have compared measurement of cardiac troponin T by enzyme linked immunosorbent assay with creatine kinase MB isoenzyme (CK-MB) concentration measurement in 219 Royal Marine commandos with no evidence of cardiovascular disease who have elevated creatine kinase (CK) produced by arduous physical training. CK was elevated up to 22.6 times and CK-MB mass up to 6.6 times the upper reference limit. Only two commandos had detectable cardiac troponin T, with neither exceeding the upper reference limit of 0.2 /lg/L. At decision thresholds optimized for diagnosis of acute myocardial infarction in previous published work, 58.3070 of the total CK activity, 13.8% of the CK-MB concentration/CK activity ratio and 1.6% of CK-MB concentration measurements showed elevated values but no elevations in cardiac troponin T occurred. Cardiac troponin T is currently the investigation of choice for the differential diagnosis of patients with an elevated CK due to skeletal muscle trauma to exclude myocardial damage. Additional key phrases: CK-MB mass; myocardial infarction; cardiac enzymes; relative index; skeletal muscle traumaThe differential diagnosis in patients presenting with chest pain where there may be skeletal muscle trauma creates a problem for the laboratory. A range of approaches have been suggested including creatine kinase (CK) isoenzyme separation, creatine kinase MB (CK-MB) isoenzyme/total CK activity ratio, 1 CK-MB concentration measurement and CK-MB mass/total CK activity ratio.? We have compared the diagnostic performance of proposed strategies for the differentiation of skeletal and cardiac muscle damage with measurement of cardiac troponin T (cTnT) in the situation of extreme elevation of CK due to arduous physical training. METHODSRoyal Marine recruits were studied during commando training. All had been pre-screened Correspondence: Dr P 0 Collinson. 450by full physical examination and electrocardiography both at entry, following basic training and during the training programme. None had any cardiac symptoms at any time.Two hundred and nineteen men were examined, age range 18 to 26 years, median 20.8 years, in four troops (training cohorts). Serial blood samples were obtained from individuals during training at I, 12, 19, 24 and 29 weeks. Serum was separated and stored at -70 DC prior to estimation for aspartate transaminase activity (AST), CK activity, CK-MB concentration and cTnT.AST and CK were measured on all samples. Samples for further study were selected from those periods of training corresponding to maximal physical exertion. One hundred and twenty-nine samples were selected at week 24 and 106 at week 29. On week 29 samples were taken following one of the final qualification assignments. This comprised a 30 mile route march, in full webbing, carrying a 40lb (18 kg) pack,

No abstract

No abstract

No abstract