Congenital junctional ectopic tachycardia (JET) is usually initially treated with antiarrhythmic therapy, with the choice of medication guided by the degree of coexisting ventricular dysfunction. The most appropriate management of asymptomatic infants with "slow" JET (ie, 150 beats per minute [bpm]) is debatable. However, these asymptomatic patients should have close monitoring.
Numerous therapeutic options have been used for the treatment of postoperative JET, including the following:
Some propose that management of symptomatic infants with slow JET should consist of digoxin to control symptoms of cardiac failure and antiarrhythmic drugs to control the ventricular rate of the arrhythmia. However, caution should be used because development of ventricular fibrillation or faster tachycardia (≤400 bpm) during progressive digoxin loading has been described in patients with congenital JET and severe cardiac failure.
Propafenone has also been effective in preventing or controlling JET in some neonates, especially neonates with slower ventricular rates (approximately 170 bpm).
Amiodarone may successfully control ventricular rate. Furthermore, the combination of amiodarone and a class Ic antiarrhythmic drug can be used to reduce the dose of amiodarone. A multicenter study reported that success of intravenous amiodarone is dose-related.  However, so are its adverse effects. Therefore, the dose-related risks should be taken into account when treating children with incessant arrhythmias. It has been reported that prophylactic use of amiodarone being started in the operating room at the time of rewarming during cardiopulmonary bypass decreases the incidence of JET. 
True drug-refractory JET is very rare. Therefore, in patients who fail to respond to a single drug regimen, a second antiarrhythmic agent with different electrophysiological effects may be added.
Controlled hypothermia has been relatively effective in reducing JET rate in patients in the immediate postoperative period. [11, 12] These patients are often intubated and can be effectively paralyzed, sedated, and cooled. For refractory cases, adding procainamide has been effective.  Other traditional approaches include increase of ventricular preload and reduction of inotropic agents (which are also usually chronotropic) as much as possible.
The use of atrial or AV sequential pacing can help to restore AV sequence and cardiac output once the JET rate is reduced.
Multiple antiarrhythmic agents have been used and are considered somewhat effective in postoperative JET.
Occasionally, atrial high-rate pacing to the point of 2:1 AV block can provide a controlled ventricular response while continuing to suppress the JET focus. This finding suggests a relatively high insertion site of the JET focus into the AV conduction system.
Ventricular paired pacing, with or without additional atrial pacing, has been used in rare cases when patients have not responded to other therapies. This technique is potentially dangerous and requires essentially constant monitoring and adjustment by personnel who are extremely familiar with electrophysiologic procedures. During ventricular paired pacing, electrolytes and antiarrhythmic medications should be administered by constant infusions only.
A small-case series advocates for radiofrequency catheter ablation for JET if antiarrhythmic drug therapy has failed.  Success was safely achieved by plotting the entire His-bundle using a modern navigation system that would permit marking the spot of earliest retrograde conduction during tachycardia, and, later, empirically ablating that spot during sinus rhythm.
A study suggested that supplementation with magnesium sulfate during cardiopulmonary bypass reduces the incidence of postoperative JET. 
The primary functions of surgical care in postoperative JET are to correct major residual defects that may be contributing to morbidity, to ensure that atrial-based pacing can be achieved, and to provide extracorporeal life support (ie, extracorporeal membrane oxygenation [ECMO]) if required.
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