Study Limitations
Because of the small cohort size, conclusions about changes in the QT/QTc interval during and after infusion are tempered by large intra- and inter-patient variability in the QT/QTc interval. The PEAKS registry is a multi-center registry currently being established of patients receiving IV sotalol initiation that will further refine understanding of QT prolongation during and after infusion, with both clinical and pharmacokinetic-pharmacodynamic data.11This study’s cohort also tended to be healthier, with overall preserved kidney function and low normal LVEF, and data may not be as generalizable to those with decreased renal clearance or more significantly depressed ejection fractions for whom sotalol can be more dangerous. There were also significantly more women in the PO sotalol load group, which may bias QT interval comparisons given the known differences in repolarization between genders.12Lastly, patients were only followed until discharge and longer-term safety outcomes are not available. These longer-term outcomes are presumed to be similar to patients loaded with oral sotalol.