[Cellular mechanisms of calcium regulation of cardiac rhythm in children with ectopic arrhythmias].

Regulation of intracellular calcium homeostasis by means of secondary mediators calmodulin and 4,5-inositol phosphates (products of phosphatidyl inositol hydrolysis) was studied in children with ectopic forms of arrhythmias. Alterations in the system calmodulin-Ca2+ and the activity of phosphoinosite metabolism correlated highly with clinical manifestations of the arrhythmias. The data obtained suggest that a number of molecular mechanisms and responsible for arrhythmias were realized in cell membranes and depended on a complex of intracellular messengers affected within various steps of the hormonal signal transmission.