Figure 3.

Inhibition of calcium cycling prevents ibandronate-induced action potential prolongation and action potential variability. A and B: Ryanodine pretreatment prevented ibandronate-induced prolongation of the action potential and 50% and 90% of repolarization (P = NS vs baseline). Data presented as percentage change from baseline. C: Representative Poincaré plots of APD₉₀ during baseline, ibandronate treated, ibandronate washout, and rynaodine pretreated + ibandronate treatment groups. D: Ibandronate washout significantly increases (P < 0.05) short-term variability at 0.5 Hz compared to baseline. Ryanodine pretreatment prevented ibandronate-induced increases in short-term variability of APD₉₀ (P = NS vs baseline).