Table 1.

The three mechanisms of RyR inhibition have different consequences on mean spark duration and spark frequency

	Standard Parameters	Tetracaine (τC↑)	Flecainide (τO↓)	Dual Mechanism (τC↑ and τO↓)
Corresponding figure	Fig. 12A	Fig. 12B	Fig. 12C	Fig. 12D
kco, μM−2·s−1	4.5	0.5	4.5	1.5
koc, s−1	500	500	4,500	1,500
Fraction of open channels	9.6 × 10−4	2.0 × 10−4	*	*
Score	0.51	0.59	*	*
Sarcoplasmic reticulum [Ca2+], μM	342	1112	*	*
Duration, ms	18.2	26.7	2.97	8.90
Frequency, sparks/s	0.043	6.5 × 10−4	0.053	0.0059

Shown are results for the whole cell model with standard parameters and modified Ca²⁺ activation rate constant (k_co), which represents the application of tetracaine and led to an increase in ryanodine receptor (RyR) open time (cf. solid and open circles in Fig. 3, respectively). When the same level of RyR inhibition was modeled as a decrease in open dwell time (τ_O↓), as may occur upon the application of flecainide, or a dual mechanism (τ_C↑ and τ_O↓), the mean spark duration changed.

^*Results identical to the tetracaine case.