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.