The importance of calcium and phosphorus metabolism for the development of hypertrophic cardiomyopathies is still obscure. Therefore 52 patients with hypertrophic cardiomyopathy were subjected to detailed cardiological and laboratory examinations. Twenty-five age matched healthy subjects served as controls. The following indicators were assessed: calcium and its ionized fraction, phosphorus, chlorides and magnesium in serum and 24 h urine, as well as AST, ALT, ALP, ACP, urea, creatinine, protein electrophoresis (to check calcium values with regard to serum albumins), endogenous creatinine clearance, Palmer's chloride phosphate index and Nordin's index. In addition to tubular phosphate reabsorption, the renal phosphate threshold was assessed and finally the parathormone blood level by the RIA method. In patients with hypertrophic cardiomyopathy a significant increase of the parathormone level was found--in a total of seven patients with advanced myocardial hypertrophy (more than 30 mm). There were no significant differences in the remaining parameters. It may thus be admitted that in some instances the increased parathormone level may cause an increase of the already existing myocardial hypertrophy. However, in the broad spectrum of patients with hypertrophic cardiomyopathy it is not suited for explaining morphological findings.

Keywords: Adolescent; Adult; Aged; Calcium /metabolism/; Cardiomyopathy, Hypertrophic /metabolism/; Child; Child, Preschool; Female; Humans; Male; Middle Aged; Parathyroid Hormone /metabolism/; Phosphorus /metabolism/