JTC MONITORING

It is recommended as per the ACC/AHA Guidelines to perform in-hospitalization
monitoring when initiating Sotalol.  However, this recommendation is based
upon prior studies that followed the QTc during normal, native conduction and
how it relates to proarrhythmia.  Unfortunately, the guidelines do not offer
any specific comments regarding the management of antiarrhythmic drug (AAD)
initiation in patients with ventricular conduction abnormalities, such as
those seen with ventricular pacing.  

There has been some evidence in the literature that suggest that the JT
interval (an index measurement of ventricular repolarization) is actually the
better ECG parameter (as compared to the traditional QT interval) to monitor
of repolarization risk in ventricular paced rhythms when starting Sotalol or
Dofetilide.  Thus, the it is the JT interval that may be more useful for
determining the repolarization abnormality and safety efficacy of Sotalol
(Tsai, S et al.  "QTc ompared to JTc for monitoring drug-induced
repolarization changes in the setting of ventricular pacing."  Heart Rhythm,
Vol 11, No. 3 March 2014).    In their paper, the authors conclude that there
was an excellent correlation between the measured vs derrived JTc, and that
the mean JTc for the study was 351 msec +/- 33 msec (318 - 384 msec).  In
addition, dosages were titrated down if the JTc increased > 20% over baseline.  

    -It is recommended as per the ACC/AHA Guidelines to perform in-
    hospitalization monitoring when initiating Sotalol.  However, this
    recommendation is based upon prior studies that followed the QTc
        during normal, native conduction and how it relates to
        proarrhythmia. Unfortunately, the guidelines do not offer any
        specific comments regarding the management of antiarrhythmic drug
        (AAD) initiation in patients with ventricular conduction
        abnormalities, such as those seen with ventricular pacing.  

     There has been some evidence in the literature that suggest that the
        JT interval (an index measurement of ventricular repolarization) is
    actually the better ECG parameter (as compared to the traditional QT
    interval) to monitor for repolarization risk in ventricular paced
    rhythms when starting Sotalol or Dofetilide.  Thus, the it is the JT
    interval that may be more useful for determining the repolarization
    abnormality and safety efficacy of Sotalol (Tsai, S et al.  "QTc
    compared to JTc for monitoring drug-induced repolarization changes
    in the setting of ventricular pacing."  Heart Rhythm, Vol 11, No. 3
    March 2014). In their paper, the authors conclude that there was an
    excellent correlation between the measured vs derrived JTc, and that
    the mean JTc for the study was 351 msec +/- 33 msec (318 - 384
        msec).  In addition, dosages were titrated down if the JTc increased
        > 20% over baseline.