[Modification of the chronotropic-inotropic relations in the atrial and ventricular myocardium during external gamma-irradiation].

It has been shown of isolated muscle preparations of rat heart that external gamma-irradiation with a dose of 6 Gy reduces the contractile capacity of myocardium and changes the chronoinotropic relationships: in the auricle, the rate/power relationship and the potentiating effect of the passive interval increase, and in the ventricles, the potentiating effect decreases. Modification of the chronoinotropic relationships may be associated with changes in the calcium ion transport in the heart cells.