Ann Thorac Surg 2003;76:151
© 2003 The Society of Thoracic Surgeons
Original article: cardiovascular
Invited commentary
Ko Bando, MDa
a Department of Cardiovascular Surgery, National Cardiovascular Center, 5-7-1, Fujishirodai, Suita, Osaka 565-8565, Japan
Unlike supraventricular arrhythmias secondary to re-entry, junctional ectopic tachycardias (JET) in children are rare but more resistant to standard pharmacological therapy. A standard regimen for treatment of postoperative JET includes cooling and intravenous propafenone, procainamide, or amiodarone. Cooling seems to have an effect on rate control without affecting the junctional tachycardia itself, while intravenous amiodarone therapy holds promise for actual conversion to normal sinus rhythm. A recent study of a staged approach to JET using cooling and procainamide resulted in 71% efficacy [1]. A study by Perry and colleagues demonstrated an efficacy of 84% with intravenous amiodarone infusion [2]. However, amiodarone does have the risk of hypotension and cardiovascular collapse, and the prolonged half-life of this drug is worrisome.
In the present study, Bronzetti and colleagues [3] demonstrated that continuous infusion of intravenous flecainide resulted in 100% (7/7) efficacy, using the same definition of success (restoration of sinus rhythm or JET rate 
170/m) as Perry and colleagues. For neonates and young children immediately after complex congenital heart surgery, flecainide certainly has definite advantages including (1) promptly achieving optimal plasma concentrations, (2) a high early uptake from myocardial tissue, and (3) a short half-life (9 hrs). Although flecainide is known for the treatment of reentry tachycardia, its pharmacologic effects on the abnormal automaticity or triggered activity of JET remains to be determined. Potential side-effects of this drug, including proarrhythmic and myocardial depressive effect should be monitored by continuous EKG, central venous pressure, and plasma flecainide levels. For patients with cardiac, liver, and/or renal dysfunction, the initial IV dose should be reduced.
Although selective ablation of the tachycardia focus has reasonable success, this aggressive approach carries the risk of complete AV block, which may require permanent pacemaker implantation. Since most cases of JET are self-limiting, the excellent success of flecainide, as described in this paper, may lead to its use as a front-line medical therapy that can avoid serious complications.
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References
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- Walsh E.P., Saul J.P., Sholler G.F., et al. Evaluation of a staged treatment protocol for rapid automatic junctional tachycardia after operation for congenital heart disease. J Am Coll Cardiol 1997;29:1046-1053.[Abstract]
- Perry J.C., Knilans T.K., Marlow D., et al. Intravenous amiodarone for life-threatening tachyarrhythmias in children and young adults. J Am Coll Cardiol 1993;22:95-98.[Abstract]
- Bronzetti G., Formigari R., Giardini A., et al. Intravenous Flecainide for the treatment of junctional ectopic tachycardia after surgery for congenital heart disease. Ann Thorac Surg 2003;76:148-151.[Abstract/Free Full Text]
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