Abstract
Introduction: Right bundle branch block (RBBB) is a conduction abnormality well-described in adults, but its prevalence and clinical significance in children remain poorly understood, particularly in Nepal. This study aimed to determine the prevalence of RBBB among school children in Kathmandu and assess associated structural cardiac abnormalities by echocardiography.
Methods: A school-based descriptive cross-sectional study was conducted among 160 students (grades 6–10) in Kathmandu, Nepal, from July to December 2025. Participants underwent clinical examination and 12-lead electrocardiography. Children with RBBB underwent transthoracic echocardiography. Data were analyzed using PSPP version 2.1.1, with p<0.05 considered statistically significant.
Results: RBBB was identified in 10 children (6.25%), predominantly incomplete (n=9, 5.63%), while complete RBBB was rare (n=1, 0.62%). There were no significant differences in age, gender distribution, or electrocardiographic parameters (PR interval, QTc interval, QRS duration) between children with and without RBBB. Echocardiography was normal in seven children (70%). Structural abnormalities were observed in three children (30%): mild mitral regurgitation with mitral valve prolapse in two (20%, both with incomplete RBBB) and a large secundum atrial septal defect with right ventricular dilatation in one (10%, the child with complete RBBB).
Conclusions: RBBB was uncommon among school children, with incomplete RBBB predominating. Although most children with RBBB had normal echocardiograms, structural abnormalities were identified in a small number of cases. These echocardiographic findings are exploratory and hypothesis-generating, requiring confirmation in larger, adequately powered studies.
References
1. Harkness WT, Hicks M. Right bundle branch block. StatPearls [Internet]. Treasure Isand (FL): StatPearls Publishing: 2023. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507872/
2. Surawicz B, Childers R, Deal BJ, Gettes LS, Bailey JJ, Gorgels A, et al. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part III: intraventricular conduction disturbances: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society. Endorsed by the International Society for Computerized Electrocardiology. J Am Coll Cardiol. 2009;53(11):976-81. PMID: 19281930 DOI: https://doi.org/10.1016/j.jacc.2008.12.013
3. Cuesta AG, García AV, Fernández JU, Jover EB. Ventricular conduction disorders in pediatrics: Bundle branch blocks- update. International Journal of Pediatric Research. 2023;9:104. DOI: https://doi.org/10.23937/2469-5769/1510104
4. Gelband H, Waldo AL, Kaiser GA, Bowman FO, Malm JR, Hoffman BF. Etiology of right Bundle-Branch block in patients undergoing total correction of tetralogy of Fallot. Circulation. 1971;44(6):1022-33. PMID: 5127831 DOI: https://doi.org/10.1161/01.cir.44.6.1022
5. Sharma S, Whyte G, Elliott P, Padula M, Kaushal R, Mahon N, et al. Electrocardiographic changes in 1000 highly trained junior elite athletes. Br J Sports Med. 1999;33(5):319-24. PMID: 10522633 DOI: https://doi.org/10.1136/bjsm.33.5.319
6. Harbison AL, Hill AC, Motonaga KS, Miyake CY, Dubin AM. Do pediatric electrophysiologists read pre-participation screening electrocardiograms accurately than general more pediatric cardiologists? J Pediatr. 2013;163(6):1775-7. PMID: 23993128 DOI: https://doi.org/10.1016/j.jpeds.2013.07.034
7. Sridhar AR, Padala SK. Isolated right bundle branch block in asymptomatic patients: not inconsequential as previously thought? Heart. 2019;105(15):1136-37. PMID: 31129610 DOI: https://doi.org/10.1136/heartjnl-2019-314751
8. Narula OS, Samet P. Right bundle branch block with normal, left or right axis deviation. The American Journal of Medicine. 1971;51(4):432-55. DOI: https://doi.org/10.1016/0002-9343(71)90250-6
9. Hill AC, Miyake CY, Grady S, Dubin AM. Accuracy of interpretation of preparticipation screening electrocardiograms. The Journal of Pediatrics. 2011;159(5):783-88. DOI: https://doi.org/10.1016/j.jpeds.2011.05.014
10. Meziab O, Abrams DJ, Alexander ME, Bevilacqua L, Bezzerides V, Mah DY et al. Utility of incomplete right bundle branch block as an isolated ECG finding in children undergoing initial cardiac evaluation. Congenit Heart Dis. 2018;13(3):419-27. PMID: 29431296 DOI: https://doi.org/10.1111/chd.12589
11. Niwa K, Warita N, Sunami Y, Shimura A, Tateno S, Sugita K. Prevalence of arrhythmias and conduction disturbances in large population-based samples of children. Cardiol Young. 2004;14(1):68-74. PMID: 15237674 DOI: https://doi.org/10.1017/s104795110400112x
12. Pelliccia A, Culasso F, Di Paolo FM, Accettura D, Cantore R, Castagna W, et al. Prevalence of abnormal electrocardiograms in a large, unselected population undergoing pre-participation cardiovascular screening. Eur Heart J. 2007;28(16):2006-10. PMID: 17623682 DOI: https://doi.org/10.1093/eurheartj/ehm219
13. MacLachlan H, Antonakaki D, Bhatia R, Fyyaz S, Chatrath N, Androulakis E, et al. Prevalence and clinical significance of electrocardiographic complete right bundle branch block in young individuals. Eur J Prev Cardiol. 2025;32(12):1054-1061. PMID: 38412448 DOI: https://doi.org/10.1093/eurjpc/zwae082
14. Eriksson P, Hansson PO, Eriksson H, Dellborg M. Bundle-branch block in a general male population: the study of men born 1913. Circulation. 1998;98(22):2494–500. PMID: 9832497 DOI: https://doi.org/10.1161/01.cir.98.22.2494
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