Long-term follow-up of arrhythmias in pediatric orthotopic heart transplant recipients: incidence and correlation with rejection.

BACKGROUND: Arrhythmias in adult orthotopic heart transplant (OHT) recipients are common and have been used as predictors of rejection. Because of the paucity of information in pediatric OHT recipients, the purpose of this study was to determine the incidence and correlation of arrhythmias with rejection or with coronary artery disease (CAD) in children. METHODS: We retrospectively reviewed the records, electrocardiograms (ECGs), and 24-hour ambulatory ECGs of patients who underwent OHT from January 1984 to December 1999. We excluded arrhythmias occurring in the first 2 weeks after OHT. RESULTS: Sixty-nine patients underwent OHT, received triple-immunosuppression therapy, were discharged home, and have been followed for a mean of 4.7 years (0.3-13 years). Each patient had an average of 10 ECGs and three 24-hour ECGs. Twenty-six patients had 33 arrhythmias: sinus bradycardia (n = 9), atrial tachycardia (n = 9), ventricular tachycardia (n = 3), and Wenckebach periodicity (n = 6). Sinus bradycardia was treated with theophylline in 8 patients, and 2 required pacemakers. Atrial tachycardias (atrial flutter in 4 patients and atrial ectopic tachycardia in 5) were treated with digoxin, propranolol, or procainamide. Ventricular tachycardia was treated with mexiletine, lidocaine, and amiodarone. There were 65 episodes of rejection, 20 of which were moderate/severe (> or =3B). Only Wenckebach was associated with the presence of either rejection or CAD (p < 0.05). CONCLUSIONS: We noted clinically significant arrhythmias in 38% of the pediatric OHT recipients. Sinus bradycardia, atrial tachyarrhythmias, and ventricular tachycardia occurred with the same frequency. Only new-onset Wenckebach periodicity was noted in the presence of either CAD or rejection. No arrhythmia was of negative predictive value for rejection or CAD. From this data, we suggest that new-onset Wenckebach prompt evaluation for rejection or CAD.

A prospective evaluation of nesiritide in the treatment of pediatric heart failure.

This study sought to determine the potential of recombinant B-type natriuretic peptide (nesiritide) for the treatment of pediatric decompensated heart failure. Nesiritide is a widely used and effective treatment for decompensated heart failure (HF) in adults, but its safety and efficacy in pediatric patients is unclear. Outcomes of 55 separate nesiritide infusions of varying durations in 32 patients (13 males and 19 females; mean age, 8.01 years; range, 0.01-20.4) were evaluated prospectively. All patients received nesiritide in the intensive care unit. The starting dose (0.01 microg/kg/min) was titrated to a maximum of 0.03 microg/kg/min. All patients were monitored for clinical signs and symptoms, hemodynamics, urine output, electrolytes, oxygen requirements, and oral intake. Functional status was assessed by patients and/or their parents. All patients successfully underwent initiation and titration of nesiritide infusion. No hypotension or arrhythmias were noted during 478 cumulative days of therapy. Nesiritide was given safely with vasoactive medications. Mean urine output improved from 2.35 +/- 1.71 cc/kg/hr on the day before nesiritide initiation (baseline) to 3.10 +/- 1.94 cc/kg/hr on day 4 of treatment (p < 0.01). Serum creatinine decreased from 1.04 to 0.92 mg/dl (p = 0.096), mean central venous pressure from 13 to 7 mmHg (p = 0.018), and mean weight from 30.4 to 29.7 kg (p < 0.001) with therapy. Thirst, as subjectively assessed by patients old enough to respond, decreased with infusion in 31 of 42 cases (74%). Mean New York Heart Association functional class improved significantly (p < 0.001). Nesiritide infusion, alone or in combination, is a safe treatment for decompensated HF in pediatric patients. It is associated with decreased thirst and improved urine output and functional status, and it may be efficacious in the treatment of pediatric HF.