Adjuvant therapy in management of pediatric inappropriate sinus tachycardia: A Systematic Review

Background: Inappropriate sinus tachycardia (IST) in children and adolescents is an underrecognized autonomic disorder characterized by a persistently elevated heart rate, often leading to palpitations, fatigue, and impaired quality of life. Conventional pharmacologic therapies, such as beta-blockers and ivabradine, are frequently limited by incomplete efficacy or adverse effects. Omega-3 polyunsaturated fatty acids (PUFAs) have been proposed as a safe adjunctive therapy due to their autonomic and antiarrhythmic properties. Objective: This systematic review aimed to evaluate the evidence on omega-3 supplementation for heart rate control, heart-rate variability (HRV), and clinical outcomes in pediatric IST. Methods: Following PRISMA 2020 guidelines, a systematic search of PubMed, Scopus, Web of Science, and Cochrane Library was conducted (2015–2025). Eligible studies included randomized controlled trials, cohort studies, case–control studies, and systematic reviews/meta-analyses reporting omega-3 supplementation in pediatric IST. Outcomes of interest were mean 24-hour heart rate, HRV indices, symptom improvement, and adverse events. Results: A total of 267 records were identified; after removal of duplicates and exclusions, 10 studies met inclusion criteria. Omega-3 supplementation was associated with a mean reduction in 24-hour heart rate of 6–10 bpm and significant improvements in HRV. Pediatric studies reported good tolerability, with mild gastrointestinal symptoms as the most common adverse events. Conclusion: Omega-3 supplementation shows promise as a safe, adjunctive therapy for pediatric IST, with consistent evidence for heart rate reduction and improved autonomic regulation. However, current evidence is limited, and larger randomized trials are required to confirm efficacy and define optimal dosing strategies.