Differentiating muscle damage from myocardial injury by means of the serum creatine kinase (CK) isoenzyme MB mass measurement/total CK activity ratio. - El Allaf,M.; Chapelle,J.P.; El Allaf,D.; Adam,A.; Faymonville,M.E.; Laurent,P.; Heusghem,C. (Clin Chem, 1986)