Preoperative QTc duration, ms Postoperative QTc duration, ms δQTc* duration, ms Gender 406 537 131 female 409 524 115 female 412 511 99 female 418 505 87 female 421 505 84 female 422 525 103 female 433 550 117 female 438 509 71 male 447 512 65 female 448 516 68 male 452 518 66 male 458 505 47 female 460 510 50 male 466 518 52 male 469 541 72 male 473 535 62 female 473 551 78 male 474 508 34 male 474 530 56 male 477 596 119 male 483 519 36 male 485 508 23 male 508 551 43 male 531 512 -19 male 540 574 34 male 543 560 17 male 550 520 -30 male 655 533 -122 female *δQTc=difference in corrected QT interval duration postoperatively and preoperatively. QTc was calculated using the Bazzett’s formula.

Table 2a: Pre- and post-operative QTc interval duration for patients with the most prolonged QTc intervals measured (>500 ms).