Definitions and endpoints
Baseline QTc was defined as the median QTc during the first hour post CV. Conventional monitoring was defined as the Holter tracing at the second hour following CV. Holter monitoring was defined as tracings starting 3 hours following CV throughout the end of the monitoring period. The primary endpoint was clinically significant QTc prolongation defined as; 1) new prolongation of QTc ≥500 ms (if baseline QTc was < 480 ms) or 2) prolongation of QTc ≥10% if baseline QTc was >480 ms.