Junctional ectopic tachycardia in infants and children

Abstract

Tachyarrhythmias originating in the atrioventricular (AV) node and AV junction including the bundle of His complex (BH) are called junctional tachycardia (JT) or junctional ectopic tachycardia (JET). Congenital JET (CJET) is a rare arrhythmia that occurs in patients without a preceding cardiac surgery and can be refractory to medical therapy and associated with high morbidity and mortality. CJET has a high rate of morbidity and mortality with death occurring in 35% of cases. JET occurring within 72 hours after cardiac surgery is referred to as postoperative JET (POJET) and caused by direct trauma, ischemic, or stretch injury to the AV conduction tissues during surgical repair of congenital heart defects. Focal junctional tachycardia (FJT) is also known as automatic junctional tachycardia and includes paroxysmal or non‐paroxysmal forms. We discuss a staged approach to therapy with improved pharmacological therapies and the use of catheter‐based therapies.

Narrow QRS complex tachycardia with VA dissociation and episodes of blocked sinus P wave: What is the mechanism?

“…The above findings strongly support a diagnosis of a focal Hisian or Junctional tachycardia. This also fits the clinical characteristics of the tachycardia that showed a gradual onset (“warming up” phase), gradual termination (“cooling down” phase) and rate variability 2 …”

“…Unfortunately this maneuver would have been difficult to interpret in our case due to the high rate variability during tachycardia, so we used the unipolar His signal to help in the differential diagnosis (Figure 3). Differently from a junctional or Hisian tachycardia where an automatic focus centrifugally fires from the proximal His bundle, leading to a QS morphology of its earliest unipolar activation, 2 in nodoventricular or nodofascicular pathways mediated tachycardias the His bundle is part of a reentrant circuit and its unipolar activation should show a RS morphology since the depolarization comes from the ventricle to the AV node and His bundle. AV node reentry tachycardia with block in an upper common pathway was also ruled out for a number of reasons.…”

“…This also fits the clinical characteristics of the tachycardia that showed a gradual onset ("warming up" phase), gradual termination ("cooling down" phase) and rate variability. 2 The majority of AV blocks observed during the case involved sinus P-waves that followed junctional premature beats with exit block (Figure 2 Due to the high risk of AV block and the young age of the patient, we did not perform any ablation but tested the efficacy of flecainide that was found to effectively treat the AV junctional tachycardia and relieve patient symptoms.…”

Early postoperative arrhythmias in patients undergoing congenital heart surgery

“…[ 15 - 17 ] It has been suggested that being younger than six months old, prolonged CPB and aortic crossclamp time, myocardial ischemia/injury, postoperative use of dopamine or milrinone, acidosis, electrolyte disturbance (hypomagnesemia, hypokalemia or hypocalcemia), and hypovolemia may be possible risk factors. [ 15 - 17 ] The type of cardiac surgery is also another factor, particularly those involving the crux of the heart including TOF, AV canal, and VSD repair. However, JET was also reported after operations such as arterial switch and aortic arch surgeries in which the operation sites were far from the AV node.…”

Infective endocarditis of an aortic bioprosthesis causing life-threatening incessant junctional tachycardia: a case report

“…Junctional ectopic tachycardia has most often described in children, either as a congenital arrhythmia or after cardiac surgery. 5 Post-operative JET is attributed to direct trauma or stretch injury to the AVN, which was most probably the mechanism in our patient. Junctional ectopic tachycardia in an adult with structurally normal hearts is exceedingly rare.…”