[Polyploidization mechanisms of the cardiac myocytes in the mouse].

Ventricular cardiomyocytes of 5-6 day-old mice are mostly polyploid. At this time 60% of the cardiomyocytes become binuclear and another 10% mononuclear polyploids. The binuclear cardiomyocytes emerge as a result of acytokinetic mitosis, while mononuclear tetraploids as a result of the cessation of the mitosis at the initial stages.