inhibition of abnormal automaticity and increase in the refractory period of the AV node and His-Purkinje system Hence, amiodarone has been reported to be one of the most effective agents in managing JET after cardiac surgery in general.94,211,212 In a recent study, the preemptive use of dexmedetomidine and intravenous amiodarone in the perioperative period was associated with a significantly decreased incidence of JET as compared with placebo and without significant side effects If the JET rate is slow, pacing alone to achieve AV synchrony may be adequate to improve the hemodynamics At times cooling and pharmacologic therapy may be needed to slow the rate in order for pacing to be possible and effective Pacing using an AAI mode is preferable as this allows for normal AV conduction and less dyssynchrony than DDD pacing Complete Heart Block (Postsurgical) The incidence of complete heart block following congenital heart surgery is about 1.4% to 1.9% and is generally the consequence of surgery involving closure of a ventricular septal defect or surgery in the vicinity of the aortic valve.34,87,213 Surgical postoperative heart block tends to occur immediately after surgery or in the very early postoperative period (Fig 22.41) Early postoperative heart block can be transient, with a return to normal sinus rhythm and normal AV conduction, or it may remain a permanent If patients are going to recover following surgery, recovery will occur by postoperative day 9 in 97% of patients with transient heart block.33 Temporary epicardial pacing, preferably in an atrial sensed-ventricular paced mode, should be utilized while awaiting resolution of AV conduction, especially if the underlying rate is slow, wide complex, pauseinduced ventricular ectopy or the cardiac output is poor Use of temporary epicardial pacing and manipulations of lower rates, AV intervals, PVARP, upper rate should always be done carefully and judiciously while paying close attention to the invasive and noninvasive monitors Resolution of postoperative AV block to that of residual trifascicular block (RBBB, left axis deviation, and first-degree AV block) has been discussed and debated for years.202 Antiarrhythmic medications that cause AV block should be avoided in patients with trifascicular block.214 In patients whose postoperative heart block after a period of 7 to 10 days reverts to sinus rhythm only with RBBB and left axis deviation there is a class IIB indication for a permanent pacemaker However, at all times decisions regarding permanent pacing should include an understanding of the patient's symptoms, especially if the rates are slow, as well as the underlying hemodynamics Use of temporary wires to assess AV nodal conduction may be valuable in the postoperative period if there was concern about the robustness of the AV node In patients, with transient postoperative AV block whose recovery is not completely back to sinus rhythm and who happen to be going for a diagnostic catheterization, it may be of benefit to measure and AH and HV interval Patients with 2 : 1 AV block postsurgery with a prolonged HV interval are a more concerning subcohort FIG 22.41 Postoperative management algorithm for junctional ectopic tachycardia (JET) ECMO, Extracorporeal membrane oxygenation; IV, intravenous Supraventricular Tachycardia SVT may complicate the management of children after heart surgery This