Ventricular Inhomogeneity and Beat-to-beat QT Interval Variability after Surgical Repair of Tetralogy of Fallot.
- Author:
Su Hyun KIM
1
;
Myung Kul YUM
;
Nam Su KIM
;
Chang Ryul KIM
;
Chul Burm LEE
;
Chung Ill NOH
;
Hee Soo KIM
Author Information
1. Department of Pediatrics, Hanyang University Kuri Hospital, Korea.
- Publication Type:Original Article
- Keywords:
Tetralogy of fallot;
Ventricular arrhythmia;
Temporal ventricular repolarization inhomogeneity;
QT variability index
- MeSH:
Arrhythmias, Cardiac;
Electrocardiography;
Heart Rate;
Humans;
Tetralogy of Fallot*
- From:Journal of the Korean Pediatric Society
2001;44(4):418-425
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: The object of this study is to determine whether QT interval variability in patients with postoperative tetralogy of Fallot increases. METHODS: We enrolled 41 patients who had total correction of tetralogy of Fallot, and 31 healthy controls. They were 6-12 years old. Patients were divided into 2 groups : arrhythmia-positive patients(n=10) who had ventricular premature contractions more than 30/hour or who had couplets, and arrhythmia-negative patients(n=31). We selected the 10-minute arrhythmia-free portion of 24-hour ambulatory ECG recorded during sleep(1-3AM). We selected the 2nd beat of recordings for a template, then found the QT interval for each beat. The method was that T-wave shape best matches template T-wave under the time-stretch model. The mean heart rate and variance and mean QT interval and variance were computed and then a QT variability index(QTVI)-which represents the log ratio between QT interval variability and heart rate variability-was derived. RESULTS: Postoperative tetralogy of Fallot patients with/without ventricular arrhythmia showed significantly increased QTVI compared with the control(-0.481+/-0.310/-0.661+/-0.376 vs -1.200+/-0.380, P<0.0001). There was a trend that QTVI in patients with ventricular arrhythmia increased more than in patients without ventricular arrhythmia, but there were no statistical significances. CONCLUSION: QT interval variability increased in repaired tetralogy of Fallot patients with/without ventricular arrhythmia compared with the control. And this finding indicates that inhomogeneity of temporal ventricular repolarization exists in repaired tetralogy of Fallot patients.
