Iranian Heart Association Iranian Heart Journal 6 1.2 2005 03 01 QT DISPERSION IN CHILDREN WITH CONGENITAL HEART DISEASE AFTER OPEN-HEART SURGERY 55 59 84127 EN S. RAFIAN Department of Cardiology, Shaheed Beheshti University of Medical Sciences, Saadat Abad, Modarres General Hospital, Tehran, Iran A. KIANI Journal Article 2019 03 07 Background- A number of publications has shown a relation between increased QT dispersion and death from a cardiac cause. However, there are no published data on the value of QT interval dispersion after open-heart surgery in the pediatric age group.<br />Methods- Three electrocardiograms (pre-operation, on the day of operation and the second day post-operation) were obtained from 18 children (11 males, 7 females), three to 14years of age. Measurements were carried out from standard 12-lead ECGs recorded at a speed of 25 mmls at rest. The QT and preceding RR intervals of at least one sinus beat (range one to three) were measured in a range of nine to 12 leads, and the mean QT and RR intervals were calculated. The corrected QT interval was calculated by Bazetl's method (QTc = QT/√RR). QT intervals were measured from the onset of the QRS complex to the end of the T wave. Dispersion of the QT and QTc were defined by the difference between the maximum and minimum QT and QTc intervals occurring in any of the 12 leads.<br />Results-The mean QT dispersion in patients before surgery was 53±22ms, 72±31ms on the day of operation and 65±27 one day after operation, and mean QTc dispersion before surgery was 62±22ms, 95±27ms on the day of operation and 97±41ms on the day after operation. There was a significant increase in mean QT and QTc immediately after surgery (p<0.001). Although it decreased on the first day after surgery, it remained significantly high as compared to before surgery (p<0.02).<br />Conclusion- QT interval dispersion may increase after open-heart surgery, which may result in death following an arrhythmia. Open-heart surgery may have an independent role in the genesis of QT dispersion prolongation and should be considered as one of the mechanisms of arrhythmia after surgery.   https://journal.iha.org.ir/article_84127_0dd6eb662d25346ecd4c72a92cf10033.pdf