Predicting new-onset of postoperative atrial fibrillation in patients undergoing cardiac surgery using semi-automatic reading of perioperative electrocardiograms

P10

Predicting new-onset of postoperative atrial fibrillation in patients undergoingcardiac surgery using semi-automatic reading of perioperative electrocardiograms. Jiwei Gu, Claus Graff, Jacob Melgaard, Søren Lundbye-Christensen, Erik Berg Schmidt, Christian Torp-Pedersen, Kristinn Thorsteinsson, Jan Jesper Andreasen. Aalborg, DenmarkBackground: Postoperative new onset atrial fibrillation (POAF) is the most common arrhythmia after cardiac surgery. The aim of this study was to evaluate if semi-automatic readings of perioperative electrocardiograms (ECGs) is of any value in predicting POAF after cardiac surgery.Methods: This is a retrospective observational study. A total of 100 patients who underwent cardiac surgery at our institution between January 1, 2010 and December 31, 2014 were included. POAF was defined as new onset atrial fibrillation requiring treatment, documented by ECG or continuous ECG monitoring. A semi-automatic machine capable of reading differentparameters of digitalized ECG’s was used to read both lead specific (P/QRS/T amplitudes/intervals) and global measurements (P-duration/QRS-duration/PR-interval/QT/Heart Rate/hypertrophy).Results: We divided the patients into two groups: 50 consecutive patients with POAF and 50 patients who did not develop POAF (NOPOAF). A total of 72% and 66% were males and median age was 69, 8±9.56 years and 65, 5±10, 34 years in the POAF and NOPOAF group, respectively. The types of operation in each group included coronary artery bypass grafting (70%,58%) and valve surgery (30%,42%), respectively. The only measurements which consistently showed difference between POAF and NOPOAF were: P-duration, PR-interval, QRS-duration and left atrial enlargement (LAE). POAF versus NOPOAF (milliseconds): P-duration (127 vs 120, p=<0.05), PR-interval (198 vs 179, p=<0.05), QRS-duration (127 vs 115, p=<0.05), LAE (28 subjects versus 9 subjects, p<0.05).Conclusion: Semi-automatic readings of digitalized perioperative ECGs showed differences regarding the P-duration, PR-interval, QRS-duration and signs of LAE between patients who develop and patients who do not develop POAF following cardiac surgery with higher values in the POAF group. These results indicate that POAF may be linked to slow propagation during depolarization. It may occur if the left atrial is enlarged. Prediction of POAF should focus on assessing delayed propagation in the atria, possibly a combination of echocardiogram and ECG.