Impact of early and standardized treatment with amiodarone on therapeutic success and outcome in pediatric patients with postoperative tachyarrhythmia.

Abstract

Effects of timing of inception of amiodarone antiarrhythmic treatment after corrective surgery for congenital heart defects are not yet well defined. In a 10-year prospective observational study, 71 of 2651 patients (2885 procedures, 2106 bypass procedures) received amiodarone for newly detected postoperative atrial (n = 70) or ventricular (n = 7) tachyarrhythmia: early treatment (initiation within 60 minutes of arrhythmia detection) and late treatment (after that). From an interim analysis, a treatment protocol was established (32 patients). Inotropic requirements were monitored, as were heart rate, blood pressure, central venous pressure, and sedation requirements. With early treatment (n = 29), delay before start of amiodarone was 40.7 +/- 21.9 minutes, versus 227.7 +/- 228.1 minutes (P < .001) with late treatment (n = 42). There were significant benefits of early treatment for times to rate (155.9 +/- 299.8 vs 407.6 +/- 376.9 minutes, (P < .001) and rhythm control (400.4 +/- 845 vs 1038.5 +/- 1158.4 minutes, P < .001), reduction in dose needed for rate control (28.2 +/- 45.2 vs 66.5 +/- 137.5 mg, P < .025), and significant reduction in pediatric cardiac intensive care unit stay (3.32 +/- 1.9 vs 5.26 +/- 4.27 days, P < .01). There were continuous improvements in heart rate, blood pressure, and filling pressures without additional inotropic requirements or side effects. Early treatment of postoperative tachyarrhythmia with amiodarone according to a standardized treatment protocol is safe and has beneficial effects on arrhythmia control and pediatric cardiac intensive care unit stay.