Discussion
To the best of our knowledge this is the first observational prospective
study that monitored closely the QTc interval following CV in patients
with persistent AF using 7-day Holter monitoring. The main finding of
this study include 1) significant QTc prolongation that was detected in
47% of patients following CV, 2) the maximal median QTc prolongation
occurred during the second day (44 hours following CV), 3) there was a
substantial increase in detection rates of clinically significant QTc
prolongation using prolonged Holter monitoring compared with standard
monitoring, and 4) chronic beta blocker use was the only predictor
associated with significant QTc prolongation.