Second-degree Atrioventricular (Mobitz 1) Heart Block in a 52-hour-old Newborn: A Very Rare Case Report

Document Type : Case Report


1 Neonatal and Children Health Research Center, Golestan University of Medical Sciences, Gorgan, Iran

2 Neonatal and Children Health Research Center, Golestan University of Medical Sciences, Gorgan, Iran/Bone, Joint, and Related Tissue Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran


Background: Cardiac conduction disorders are rare syndromes in neonates and children. According to the literature atrial septal defect, especially ostium secundum type, is associated with atrioventricular (AV) block. Wenckebach conduction heart block is very rare in a neonate; however, there is a dearth of research on the prevalence of this type of heart block regarding the neonates and pediatrics literature. This disorder has only been addressed earlier in thalassaemia major and dengue fever in Pediatrics. There have been different anatomical and metabolic and genetic etiologies for this condition. Wenckebach block is a gradual delay in sending the electrical signal from the sinoatrial node to the ventricles with each beat until there is a single dropped beat, which could be uneventful or problematic later in life. This study aimed to present a deep investigation of a rare case of congenital Wenckebach conduction heart block.
Case report: The case in this study was a 52-hour-old female neonate who was diagnosed to suffer from Mobitz type 1 or Wenckebach heart block possibly due to a small ostium secundum atrial septal defect. Therefore, it was suggested to provide supportive care and regular follow-up visit.
Conclusion: Precise antenatal care and investigation are required to reduce the morbidity and mortality rate of such condition.


1. Brucato A, Jonzon A, Friedman D, Allan LD, Vignati G, Gasparini M, et al. Proposal for a new definition of congenital complete atrioventricular block. Lupus. 2003; 12(6):427-35.
2. Michaelsson M, Riesenfeld T, Jonzon A. Natural history of congenital complete atrioventricular block. Pacing Clin Electrophysiol. 1997; 20(8 Pt 2):2098-101.
3. Baruteau AE, Pass RH, Thambo JB, Behaghel A, Le Pennec S, Perdreau E, et al. Congenital and childhood atrioventricular blocks: pathophysiology and contemporary management. Eur J Pediatr. 2016; 175(9):1235-48.
4. Geva T, Martins JD, Wald RM. Atrial septal defects. Lancet. 2014; 383(9932):1921-32.
5. Chin J, Pereira S, Camacho A, Pessoa B, Bento D, Amado J, et al. Holt-Oram syndrome: a case report. Rev Port Cardiol. 2014; 33(11):737.e1-5.
6. Wu RH, Li DF, Tang WT, Qiu KY, Li Y, Liao XY, et al. Atrial septal defect in a patient with congenital disorder of glycosylation type 1a: a case report. J Med Case Rep. 2018; 12(1):17.
7. Sohoni A, Perez B, Singh A. Wenckebach block due to hyperkalemia: a case report. Emerg Med Int. 2010; 2010:879751.
8. Baruteau AE, Fouchard S, Behaghel A, Mabo P, Villain E, Thambo JB, et al. Characteristics and long-term outcome of non-immune isolated atrioventricular block diagnosed in utero or early childhood: a multicentre study. Eur Heart J. 2011; 33(5):622-9.
9. Baruteau AE, Behaghel A, Fouchard S, Mabo P, Schott JJ, Dina C, et al. Parental electrocardiographic screening identifies a high degree of inheritance for congenital and childhood non-immune isolated atrio-ventricular block. Circulation. 2012; 126(12): 1469-77.
 10. Barra SN, ProvidÊncia R, Paiva L, Nascimento J, Marques AL. A review on advanced atrioventricular block in young or middle-aged adults. Pacing Clin Electrophysiol. 2012; 35(11):1395-405.
11. Mah DY, Porras D, Bergersen L, Marshall AC, Walsh EP, Triedman JK. Incidence of and risk factors for catheterization-induced complete heart block in the pediatric cardiac catheterization laboratory. Circ Arrhythm Electrophysiol. 2014; 7(1):127-33.
12. Krause U, Backhoff D, Klehs S, Kriebel T, Paul T, Schneider HE. Catheter ablation of pediatric AV nodal reentrant tachycardia: results in small children. Clin Res Cardiol. 2015; 104(11):990-7.
13. Yildirim I, KaragÖz T, Ertuğrul İ, KaragÖz AH, Özer S. Efficacy and safety of cryoablation of parahissian accessory pathways in children: a single institution study. Pacing Clin Electrophysiol. 2013; 36(12): 1495-502.
 14. Zartner P, Christians C, Stelter JC, Hraška V, Schneider MB. Transvascular closure of single and multiple muscular ventricular septal defects in neonates and infants< 20 kg. Catheter Cardiovasc Interv. 2014; 83(4):564-70