Before revision:  Here we present a mathematical model of functional interactions between RyR and IP3R channels which demonstrates that IP3-mediated Ca2+ release in the cytosol 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 channels on the Ca2+ release in the cytosol is indeed capable of increasing the duty cycle of the calcium signal in the cardiomyocyte.