Cardiac anomalies in Axenfeld-Rieger syndrome.

Axenfeld-Rieger syndrome is a rare multi-system disorder associated with cardiac anomalies. All patients with a diagnosis of Axenfeld-Rieger syndrome were identified from our electronic medical record. Chart review was performed to document the presence and types of CHD. Out of 58 patients, 14 (24.1%) had CHD and a wide variety of cardiac lesions were identified.

Antitachycardia pacing reduces appropriate and inappropriate shocks in children and congenital heart disease patients.

BACKGROUND: Antitachycardia pacing (ATP) can reduce implantable cardioverter-defibrillator shocks, but its use in children and patients with congenital heart disease (CHD) is not well described. OBJECTIVE: To review the efficacy of ATP in children and patients with CHD. METHODS: We reviewed implantable cardioverter-defibrillator therapies in children and patients with CHD (aged 2-52 years) at our institution. Appropriate therapies were defined as those delivered for true ventricular tachycardia (VT) or ventricular fibrillation; other therapies were defined as inappropriate. RESULTS: During a median follow-up of 4 years (range 0.5-15 years), 17 of 79 patients (23%) received appropriate therapy and 14 received ATP for 100 episodes of VT. ATP was highly successful (88%) in terminating VT, and only 10 of 100 episodes required a shock. Shocks were effective in terminating VT/ventricular fibrillation in 21 of 24 episodes (87%). The outcomes of appropriate therapy were similar for ATP and shocks (success 88% vs 87%, failure 9% vs 8%, acceleration 3% vs 4% for ATP and shocks, respectively). Thirty-one patients (39%) received inappropriate therapy. Inappropriate ATP (without subsequent shocks) was delivered to 11 patients for the following: sinus tachycardia (19 episodes in 7 patients) with slowing of the rate after ATP, T-wave oversensing (2 episodes in 2 patients) with loss of oversensing after ATP, and reentrant supraventricular tachycardia (14 episodes in 2 patients) terminated with ventricular ATP. CONCLUSIONS: ATP is highly efficacious for VT in children and patients with CHD. In addition to reducing appropriate shocks, inappropriate shocks due to sinus or supraventricular tachycardia can be significantly reduced with ATP.

Pacemaker lead prolapse through the pulmonary valve in children.

BACKGROUND: Transvenous pacemaker leads in children are often placed with redundant lead length to allow for anticipated patient growth. This excess lead may rarely prolapse into the pulmonary artery and potentially interfere with valve function. We sought to determine the response to lead repositioning on pulmonary valve insufficiency. METHODS: Retrospective reviews of demographics, lead type, implant duration, and radiography and echocardiography. RESULTS: A total of 11 pediatric patients were identified with lead prolapse through the pulmonary valve, of which nine patients underwent procedures to retract and reposition the lead (age at implant 9 +/- 4 years, age at revision 13 +/- 4 years). The implant duration prior to revision was 4 +/- 3 years. Two leads required radiofrequency extraction sheaths for removal, two pulled back using a snare, while five leads were simply retracted and repositioned. Tricuspid regurgitation was none/trivial (three), mild (four), or moderate (two) and only two improved with repositioning or replacement. Pulmonary regurgitation preoperatively was mild (three), mild-moderate (two), or moderate (four) compared with trivial (three), mild (four), and moderate (two) after revision. Patients with longer-term implanted leads had less improvement in pulmonary insufficiency. Two patients had mild pulmonary stenosis from lead-related obstruction. CONCLUSIONS: Prolapse of transvenous pacing leads into the pulmonary artery can occur when excess slack is left for growth. Leads can often be repositioned, but may require extraction and replacement, particularly if chronically implanted and adherent to valve apparatus. Lead revision does not always resolve pulmonary insufficiency, potentially leaving permanent valve damage.

Inducible atrioventricular nodal reentry tachycardia in infants with a history of neonatal orthodromic reciprocating tachycardia.

Atrioventricular nodal reentry tachycardia (AVNRT) is an uncommon mechanism of supraventricular tachycardia in neonates in whom orthodromic reciprocating tachycardia (ORT) predominates. We report three patients with structurally normal hearts who presented with neonatal ORT, documented by transesophageal electrophysiology studies at 2 to 3 weeks of age. At follow-up study at 8-12 months of age, no infant had inducible ORT, suggesting spontaneous regression of congenital accessory pathways; however, each had inducible tachycardia consistent with the typical form of AVNRT. The clinical significance of this finding is unknown and warrants further study.