Key result
Bazett's formula for QTc calculation showed a significant positive mean bias of 21.3 ms compared to Fridericia's formula in untreated pediatric epilepsy patients, leading to overestimation of prolonged QTc.
Why the study?
Previous studies yielded conflicting findings on prolonged QT intervals in epilepsy, which could stem from the QTc calculation method used.
Does the method of QTc calculation affect the detection of prolonged QTc intervals in pediatric patients with epilepsy?
Cross-Sectional (n=86)
No
Does the method of QTc calculation affect the detection of prolonged QTc intervals in pediatric patients with epilepsy?
Mean Difference: 21.3 (95% CI 14.9–27.7)
p-value: p=<0.001
The apparent prolongation of the QTc interval in pediatric epilepsy patients is largely driven by the use of Bazett's formula, which introduces a positive bias compared to other calculation methods like Fridericia's.
QTc method agreement in pediatric epilepsy remains uncertain; leaves open optimal ECG assessment pending validation studies.
Objective: Previous studies have shown conflicting results regarding the significantly prolonged QT interval in epilepsy, which could be attributed to the method of calculating the corrected QT (QTc).This study aimed to investigate the impact of the method on the calculation of QTc by determining the agreement between these methods using the Bland-Altman plot.Methods: This cross-sectional study included 86 patients of both sexes aged <18 years.The patients were categorized into group 1 (new cases, untreated epilepsy); group 2 (sodium valproate treatment); and group 3 (levetiracetam treatment).The QTc interval of each participant was calculated using 10 different methods.Bias was assessed using Bland-Altman plot analysis.Results: The mean±standard error of QTc was within the normal range and did not show significant differences between groups 2, 3, and 1, despite the detection of significant prolonged QTc in the number of patients in each group.Bland-Altman analysis showed significant disagreement between methods with positive mean bias when using Bazett's formula compared with other formulas.Conclusion: Prolonged QTc interval was negligible in treated or untreated epileptic patients, and the overestimation of prolonged QTc was related to the calculation method used for overestimation of QTc, and a positive bias was related to the use of Bazett's formula compared with others.
No takes yet. Share an insight, caveat, or question.
Marwan S.M. Al-Nimer (2024) conducted a cross-sectional in Epilepsy (n=86). Bazett's formula vs. Fridericia's formula was evaluated on Mean bias in QTc calculation between Bazett's and Fridericia's formulas in untreated epilepsy patients (MD 21.3, 95% CI 14.9-27.7, p=<0.001). Bazett's formula for QTc calculation showed a significant positive mean bias of 21.3 ms compared to Fridericia's formula in untreated pediatric epilepsy patients, leading to overestimation of prolonged QTc.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: