Intravenous flecainide for the treatment of junctional ectopic tachycardia after surgery for congenital heart disease.

BACKGROUND: Junctional ectopic tachycardia (JET) is a life-threatening arrhythmia producing severe hemodynamic dysfunction, which may complicate the postoperative course of surgery for congenital heart disease. Strict care and a fast and effective antiarrhythmic strategy are essential, because mortality largely depends on the duration of the arrhythmia.

METHODS: Seven consecutive neonates with postoperative JET without any evidence of myocardial ischemia received intravenous flecainide after conventional therapies proved ineffective. Atrial pacing at the minimal rate for atrioventricular synchrony was followed by a 10-min intravenous infusion of 1.6 mg/kg flecainide, then continuous infusion of 0.4 mg/kg flecainide per hour. Treatment was considered effective based on restoration of sinus rhythm or a JET rate no higher than 170 bpm within 4 hours of flecainide loading. Overall mean flecainide infusion lasted 31.2 hours (range 25 to 53 hours). Side effects were assessed by monitoring plasma flecainide levels, electrocardiogram, arterial pressure, and central venous pressure.

RESULTS: Flecainide was effective in all 7 patients after an infusion duration of 3.6 +/- 1.5 hours. Sinus rhythm was restored after 7.2 +/- 9.7 hours. After 4 hours of loading, heart rate fell from 219 +/- 14 to 136 +/- 7 bpm (p < 0.0001), arterial pressure increased from 69 +/- 8 to 93 +/- 10 mm Hg (p < 0.0001), while central venous pressure decreased from 8.0 +/- 1.6 to 5.2 +/- 1.9 mm Hg (p = 0.0007). No side effect or recurrence was noted.

CONCLUSIONS: Flecainide can exert a fast antiarrhythmic effect on postoperative JET, and its infusion can be modulated to maintain the concentration within the therapeutic range, thus avoiding toxicity. We propose further consideration of flecainide for treatment of JET in neonates without myocardial ischemia.