Before revision:  Here we present a mathematical model of  RyR and IP3R channel interaction which demonstrates that cytosolic IP3 is indeed capable of increasing the duty cycle of the calcium signal in the cardiomyocyte.
After revision:  Here we present a mathematical model of functional interactions between RyR and IP3R channel interaction which demonstrates that cytosolic IP3 is indeed capable of increasing the duty cycle of the calcium signal in the cardiomyocyte.