Figure 4.

Arrhythmogenic effects of D-sotalol and ranolazine. TdP was induced by challenge with phenylephrine, which was administered as an intravenous bolus of 10–50 μg kg⁻¹. (a) D-Sotalol 8 mg kg⁻¹ bolus followed by continuous infusion of 4 mg kg⁻¹ h⁻¹ and phenylephrine 10 μg kg⁻¹ bolus. (b) D-Sotalol 8 mg kg⁻¹ bolus followed by continuous infusion of 4 mg kg⁻¹ h⁻¹ and phenylephrine 40 μg kg⁻¹ bolus. (c) Ranolazine 3 mg kg⁻¹ and phenylephrine 20 μg kg⁻¹ bolus. (d) Ranolazine 15 mg kg⁻¹ and phenylephrine 50 μg kg⁻¹ bolus. The bar graphs on the right-hand panel of each ECG illustrate the number of animals (in %; n=6 in each group) developing TdP in each series of experiments.