A Case of Congenital Junctional Ectopic Tachycardia: Prenatal Diagnosis and Successful Radiofrequency Catheter Ablation in Infancy

Junctional Tachycardia

Junctional tachycardia (JT) is typically considered to have an automatic mechanism originating from the distal atrioventricular node. When there is 1:1 retrograde conduction via the fast pathway, JT would resemble the typical form of atrioventricular nodal re-entrant tachycardia (AVNRT). Atrial pacing maneuvers have been proposed to exclude AVNRT and suggest a diagnosis of JT. However, after excluding AVNRT, one should consider the possibility of an infra-atrial narrow QRS re-entrant tachycardia, which can exhibit features that resemble AVNRT as well as JT. Pacing maneuvers and mapping techniques should be performed to assess for infra-atrial re-entrant tachycardia before concluding that JT is the mechanism of a narrow QRS tachycardia. Distinguishing JT from typical AVNRT or infra-atrial re-entrant tachycardia has notable implications regarding the approach to ablation of the tachycardia. Ultimately, a contemporary review of the evidence on JT raises some questions as to the mechanism and source of what has traditionally been considered JT.

Functional assessment of atrial wall excursion and foramen ovale flap tracings in 3rd trimester as predictor of short-term hemodynamic stability in congenital heart defects fetuses

OBJECTIVES

Right atrium and left atrium of the fetal heart play a fundamental role in fetal heart circulatory physiology.

METHODS

Excursion of fetal atria walls and tracings of foramen ovale (FO) flap movement were analyzed by M-mode echocardiography by new FO index to determine fetal and neonatal outcome in the first week and month of life in various congenital heart defects. The study group was divided into 3 subgroups: group A: neonates stable after birth (all on I.V. prostaglandin infusion) for at least 7 days, group B: neonates unstable after birth (despite I.V. prostaglandin infusion) requiring catheterization procedure or early cardiac surgery <6th day of life and group C: fetuses with in utero demise.

RESULTS

The average values of FO index: group A - 32, group B - 20, group C - 12.Schaffe test showed statistical difference of FO index between group A and B (p=0.029) and group A and C (p=0.001), but no difference between group B and C (p=0.24) The FO index of stability was determined by ROC curve analysis. Cut-off point distinguishing between postnatal stability and postnatal instability + in utero demise constituted FO index=25 (specificity 82%; sensitivity 90%).

CONCLUSIONS

Prenatal features of atrial M-mode echocardiography shortly before birth might be helpful to predict the short term prognosis of fetal hemodynamic stability or instability shortly after birth regardless of the type of congenital heart defects (CHD).

Transplacental fetal therapy for junctional ectopic tachycardia

Junctional ectopic tachycardia (JET) is a rare type of tachyarrhythmia. A 39-year-old woman was transferred to our hospital for fetal tachyarrhythmia at 32 weeks' gestation. Fetal cardiac sonography revealed atrial and ventricular rates of 120-130 and 175-230 bpm, respectively, without 1:1 atrioventricular relationship. As ventricular tachycardia was considered to be the most probable diagnosis, transplacental therapy with digoxin and sotalol was done with partial response. Diagnosis of JET was made after birth. Although fetal JET is rare and prenatal diagnosis and treatment of this condition is still a challenge, differential diagnosis of fetal tachyarrhythmia should include this disorder.

Case report: an infant with congenital junctional ectopic tachycardia requiring extracorporeal mechanical oxygenation

PURPOSE OF REVIEW

A case report of an infant with hemodynamic compromise and impending collapse due to congenital junctional ectopic tachycardia. Medical therapy was maximized and he required the rapid initiation of extracorporeal life support, in order to achieve hemodynamic stability.

RECENT FINDINGS

This case report briefly reviews the presentation and treatment options for congenital junctional ectopic tachycardia, as well as the indications for initiation of mechanical support for this potentially lethal condition.

SUMMARY

Congenital junctional ectopic tachycardia is a rare though often fatal arrhythmia of the newborn or infant. Medical treatment options may be limited, or may require time to attain efficacy. Despite aggressive escalation of antiarrhythmic therapy, mechanical support in the form of extracorporeal mechanical oxygenation is a viable option, until the arrhythmia is well controlled and the myocardium recovers function.