Reproducibility of corrected QT interval in pediatric genotyped long QT syndrome.
Reproducibility of corrected QT interval (QTc), especially QTc after exercise, has not been thoroughly investigated. We reviewed charts of pediatric patients who underwent treadmill-exercise stress testing without medication multiple times within 1 year. In patients with long-QT syndrome (LQTS; n = 22), the discrepancy in QTc between two treadmill exercise stress tests using Fridericia's formula was 14 ± 12 ms at rest, 13 ± 12 ms 4 min after exercise, with a maximum of 14 ± 12 ms after exercise. There was no statistically significant difference in QTc between the two tests. Intraclass correlation coefficients (ICC) were 0.84, 0.85, and 0.85, respectively. In controls (n = 13), the discrepancy in QTc was 18 ± 12 ms at rest, 14 ± 7 ms 4 min after exercise, with a maximum of 14 ± 9 ms after exercise. There was no significant difference in QTc between the two tests. ICC were 0.78, 0.80, and 0.80, respectively. QTc calculated using Bazett's formula also showed high reproducibility. Reproducibility of QTc in children is high at rest and after exercise.
['Ogawa|Yoshiharu|Y|', 'Tanaka|Toshikatsu|T|', 'Kido|Sachiko|S|']
D002648:Child D004562:Electrocardiography D005080:Exercise Test D005260:Female D005500:Follow-Up Studies D005838:Genotype D006339:Heart Rate D006801:Humans D008133:Long QT Syndrome D008297:Male D015203:Reproducibility of Results D012189:Retrospective Studies
reproducibility long QT syndrome exercise stress test Fridericia's formula Bazett's formula