ECG Screening of Pediatric Patients With Functional GI Disorders Prior to Tricyclic Antidepressant Therapy Has Small Clinical Impact

Electrocardiogram (ECG) assessments among pediatric patients with functional gastrointestinal disorders (FGIDs) who are considering low-dose tricyclic antidepressants (TCAs) may have limited utility, according to results of a retrospective review of medical records published in the Journal of Pediatric Gastroenterology.

Medical charts of all patients (N=233) who visited an outpatient pediatric gastroenterology center affiliated with Duke University between 2011 and 2018 were retrospectively reviewed. In anticipation of starting TCAs, outcomes of baseline ECG were assessed.

Patients were aged mean 13.4 (standard deviation [SD], 3.1) years, 64.8% were girls, 71.2% were White, most had painful irritable bowel syndrome (55.4%), and 82.4% were found to have normal ECG characteristics. Patients who were ultimately prescribed amitriptyline (n=196) were older (P =.004).

Abnormal ECGs were observed among 8 patients and 4 did not start amitriptyline due to ECG findings. Corrected QT (QTc) interval was prolonged in 1 patient and was borderline among 2 patients. No correlation between QTc interval and starting dose of amitriptyline was observed (R² = 0.0004; P =.792).

A total of 8 patients were referred to a cardiologist due to their ECG findings. Of these patients, 7 were cleared to use amitriptyline; it remains unclear whether the other patient was cleared, as they sought care outside the health system.

Among the 7.7% of patients who were reassessed by ECG while taking TCAs, QTc interval increased from a mean of 413.4 (SD, 22.2) ms by an average of 10.1 (SD, 24.9) ms. No correlation was observed between amitriptyline dosage and QTc interval increase (R² = 0.0013; P =.897).

This study was limited by only having access to medical records collected within the Duke University Medical System. It remains unclear whether any of these patients sought other medical or emergency care during the study period.

The study authors concluded that the utility in prescreening patients by ECG before starting TCAs remains unclear, as there was little evidence that ECG findings altered therapeutic decisions. Additionally, low-dose TCAs did not appear to increase risk for serious adverse cardiac outcomes. For the patients who had normal baseline ECG, repeated assessment by ECG is likely not necessary.

Reference

Klein LJ, Chamberlain RC, Bonello K, Milazzo AS, Noel RJ. Electrocardiogram before tricyclic antidepressant use: minimal impact in pediatric functional gastrointestinal disorders. J Pediatr Gastroenterol Nutr. 2021;73(4):523-528. doi:10.1097/MPG.0000000000003226