Simulated rabbit model prediction of CASQ2 reductions with 1 µM simulated isoproterenol. The time course of action potentials is in the top rows, and calcium transients are in the third row at 2.35 Hz. Voltage and Ca2+ transient dynamics over a range of physiological frequencies is shown below each simulated time course at 2.35 Hz: the voltage maxima are binned for each pacing frequency between 0.5 and 3 Hz during the second half of a 2-minute simulation time course. (A) Control, (B) CASQ2 25% reduction, (C) 50% reduction, and (D) 75% reduction. Cai = intracellular calcium concentration, CASQ2 = cardiac calsequestrin 2, Vm= membrane voltage.