The change in the "refractory window" was assessed as a possible indicator of successful slow pathway modification in 26 pediatric patients with persistent dual-atrioventricular node physiology. The "refractory window" was defined as the difference between the fast and slow pathway effective refractory periods. A significant decrease in the refractory window (p <0.001) after successful slow pathway modification was found.

Adolescent↗

PubMed2004

Postpericardiotomy syndrome after permanent pacemaker implantation in children and young adults.

BACKGROUND: Postpericardiotomy syndrome (PPS) occurs in 10% to 50% of pediatric patients after cardiac surgery. The incidence and outcome of PPS after permanent pacemaker implantation in children is not described. METHODS: A retrospective analysis was performed of all pediatric patients who underwent isolated placement of a pacemaker between January 1984 and December 2002. Patients who underwent congenital heart surgery at the time of pacemaker implantation were excluded. PPS was diagnosed on the basis of clinical symptoms with echocardiographic confirmation of a pericardial effusion. RESULTS: Four hundred and forty-three pacemakers (237 epicardial, 206 transvenous) were implanted in 370 patients (median age 10 years, range 2 months to 24 years). Eight (2%) episodes of PPS (6 epicardial, 2 transvenous) occurred in 7 patients. The median time from implantation to PPS was 12.5 days (range 8 to 22 days). Six (75%) episodes followed primary pacemaker implantation, two occurred after subsequent lead revision. Three patients were initially treated with medical therapy (1 nonsteroidal agents, 2 steroids), and 1 required subsequent pericardiocentesis. Five patients underwent initial pericardiocentesis followed by medication. One patient had echocardiographic recurrence of a pericardial effusion 3 weeks after a nonsteroidal taper, with resolution after nonsteroidal agents were reinitiated. One patient required a pericardial window for a persistent effusion. No pacemaker was explanted. CONCLUSIONS: PPS occurred in 2% of children undergoing isolated pacemaker implantation of both epicardial and transvenous systems. PPS is usually managed successfully with medical therapy. Patients with medical treatment failure were successfully treated with pericardiocentesis or the surgical creation of a pericardial window.

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PubMed2004

Capture management efficacy in children and young adults with endocardial and unipolar epicardial systems.

AIMS: This prospective study characterized performance of the Kappa 700 Ventricular Capture Management trade mark (VCM) system for monitoring ventricular pacing threshold and adapting outputs in both endocardial and unipolar epicardial pacing systems in children and young adults. VCM bears cautionary labelling against use with epicardial leads since they have not been demonstrated appropriate for use with VCM. METHODS AND RESULTS: VCM was programmed in "Monitor Only" mode. Ventricular pacemaker thresholds were measured daily using VCM for a minimum of 2 months. Potential device longevities at nominal outputs (3.5 V, 1.0 ms) and at VCM-recommended outputs were compared. Thirty patients (median age 14.4 years (1-27 years); 15 epicardial/15 endocardial) completed the study. During the daily measurements, consistent undersensed evoked response occurred in 2 patients (Medtronic epicardial leads 4965). For the other 28 patients, programming VCM in "Adaptive" mode from implant would provide an additional 6.8 months (0-19 months) of battery life. CONCLUSION: Although not an IDE (Investigation Device Exemption) study, this study showed acceptable VCM performance in "Monitor Only" mode in 13/15 patients with unipolar epicardial leads. A 2-month "Monitor Only" observation period helps screen patients who might not benefit from VCM. VCM may provide substantial energy savings and extended battery life for children and young adults.

Adolescent↗

PubMed2004

Prospective assessment after pediatric cardiac ablation: recurrence at 1 year after initially successful ablation of supraventricular tachycardia.

OBJECTIVES: A multicenter prospective study was performed to assess the results and risks associated with radiofrequency ablation in children. This report focuses on recurrences following initially successful ablation. METHODS: Patients recruited for the study were aged 0 to 16 years and had supraventricular tachycardia due to accessory pathways or atrioventricular nodal reentrant tachycardia (AVNRT), excluding patients with more than trivial congenital heart disease. A total of 481 patients were recruited into the prospective cohort and were followed at 2, 6, and 12 months following ablation. RESULTS: There were 517 successfully ablated substrates out of 540 attempted (95.7%). Loss to follow-up for individual substrates was 3.3%, 10.6%, and 21.2% at 2, 6, and 12 months, respectively. Recurrence was observed in 7.0%, 9.2%, and 10.7% of these substrates at 2, 6, and 12 months, respectively (adjusted for loss to follow-up as an independent source of data censoring). Recurrence rate varied by substrate location (24.6% for right septal, 15.8% for right free wall, 9.3% for left free wall, and 4.8% for left septal), as well as for AVNRT versus all others (4.8% vs 12.9%) at 12 months. The recurrence rate was higher for substrates ablated using power control but was not a function of whether isoproterenol was used for postablation testing. CONCLUSIONS: Recurrence after initially successful ablation occurs commonly in children. It is least common after AVNRT ablation and most common following ablation of right-sided pathways. These results serve as a benchmark for the time course of recurrence following initially successful ablation of supraventricular tachycardia in children.

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PubMed2004

Thoratec left ventricular assist device as a bridge to recovery in a child weighing 27 kilograms.

Explore the source record for details and available documents.

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PubMed2004

Prospective assessment after pediatric cardiac ablation: demographics, medical profiles, and initial outcomes.

INTRODUCTION: A multicenter prospective study was designed and implemented to assess the short- and longer-term results and risks associated with radiofrequency (RF) ablation in children. METHODS AND RESULTS: Patients recruited for the study were aged 0 to 16 years with supraventricular tachycardia due to accessory pathways or AV nodal reentrant tachycardia (AVNRT), excluding patients with nontrivial congenital heart disease. A national registry also was established, and contributing centers were encouraged to enroll all pediatric patients, aged 0 to 21 years, undergoing ablation at their center. This report summarizes acute results of these procedures. For analysis, subjects were divided into three groups: the prospective cohort (n = 481), cohort-eligible registry participants (n = 504), and not cohort eligible registry participants (n = 1,776). Prospectively enrolled cohort patients were similar to cohort-eligible patients in terms of demographic and other patient characteristics. Overall success rates for RF ablation were high (95.7%), with higher success rates for left-sided and particularly left free-wall pathways (97.8%) than right free-wall pathways (90.8%). Complications of both electrophysiologic study and RF ablation were infrequent (4.2% and 4.0%, respectively), and there were no deaths. AV block was uncommon overall (1.2%) and was limited to ablation in AVNRT (2.1%) and septal accessory pathways (3.0%). CONCLUSION: Despite the multicenter and prospective design, the study demonstrates high success rates and low complication rates, which are comparable to prior single-center retrospective studies. These results may serve as the current best benchmark for expected results in the pediatric population, aged 0 to 16 years, both in terms of acute success rates and the occurrence of complications.

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