Faculty Bibliography

BACKGROUND: Acute success rates of accessory pathway ablation for Wolff-Parkinson-White (WPW) syndrome can exceed 95%, with rare failures attributed to anatomically complex epicardial connections. Right atrial appendage to right ventricle pathways have been reported, but their left-sided counterparts have only recently been described. OBJECTIVE: The purpose of this study was to report three unique cases of WPW syndrome in children with left atrial appendage and biatrial appendage connections. RESULTS: Three young patients with high-risk accessory pathways (accessory pathway effective refractory period = 190-240 ms) had unsuccessful endocardial ablations despite aggressive efforts with various catheter techniques. One patient had a left atrial appendage to left ventricular connection; the other two had biatrial appendage pathways connected to their respective ventricular surfaces. The latter two patients had a history of ventricular fibrillation: one experiencing ventricular fibrillation in the electrophysiology laboratory and the other suffering from ventricular fibrillation arrest at home. All three patients were taken to the operating room, where the appendages were noted to be diffusely adherent to their ventricles by fibrofatty connections. Dissection of the appendages led to loss of preexcitation and no further tachycardia. CONCLUSION: Surgical management of atrial appendage accessory pathways should be considered if aggressive attempts at endocardial ablation have failed.

BACKGROUND: Transvenous pacemaker and defibrillator implantation is an expanding practice in pediatric and congenital heart disease patients, and given the finite longevity of current lead designs, lead extraction is an eventuality for a significant subset of these patients. Data on the safety and efficacy of different lead extraction techniques in this specific patient population are limited. METHODS AND RESULTS: We report our experience from a single-center cohort study with a retrospective review of prospectively collected data on all lead extractions performed between January 2002 and December 2008. Lead extraction procedures involved a total of 144 patients and 203 leads. Of these, 61 patients (42%) were female and 86 (60%) had structural heart disease. Successful simple extraction, requiring the use of only a nonlocking stylet, was achieved in 59 (29%) leads. Of the remaining leads, 35 were abandoned and 109 underwent complex extraction techniques, including a radiofrequency-powered sheath used in 78 of 109 leads. Successful extraction was achieved in 80% (162/203) of all leads and 94% (103/109) of leads undergoing a complex extraction. On multivariable analysis, older lead age (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.48 to 0.82; P<0.0001), ventricular lead position (OR, 0.40; 95% CI, 0.20 to 0.79; P=0.015), and polyurethane insulation (OR, 0.34; 95% CI, 0.14 to 0.80; P=0.017) were found to be associated with a decreased likelihood of simple extraction. There were 4 major and 4 minor procedural complications involving 8 patients and no procedure-related deaths. On univariate analysis, lead age (OR, 1.28; 95% CI, 1.09 to 1.50; P=0.002) was the only factor associated with procedural complications. CONCLUSIONS: The majority of leads implanted in pediatric and congenital heart disease patients can be extracted successfully; however, the procedure carries a risk of serious complications. Older lead age, ventricular leads, and polyurethane insulation were independent predictors of the decreased likelihood of an extraction by simple traction.

BACKGROUND: Although pulmonary valve replacement (PVR) is effective in reducing right ventricular (RV) volume overload in patients with chronic pulmonary regurgitation, persistent RV dysfunction and subsequent adverse clinical outcomes have been reported. This trial was conducted to investigate whether the addition of surgical RV remodeling with exclusion of scar tissue to PVR would result in improved RV function and laboratory and clinical parameters, as compared with PVR alone. METHODS AND RESULTS: Between February 2004 and October 2008, 64 patients who underwent RV outflow tract procedures in early childhood had more than or equal to moderate pulmonary regurgitation, and fulfilled defined criteria for PVR were randomly assigned to undergo either PVR alone (n=34) or PVR with surgical RV remodeling (n=30). No significant difference was observed in the primary outcome (change in RV ejection fraction, -2+/-7% in the PVR alone group and -1+/-7% in the PVR with RV remodeling group; P=0.38) or in any of the secondary outcomes at 6-month postoperative follow-up. Multivariable analysis of the entire cohort identified preoperative RV end-systolic volume index <90 mL/m(2) and QRS duration <140 ms to be associated with optimal postoperative outcome (normal RV size and function), and RV ejection fraction <45% and QRS duration >/=160 ms to be associated with suboptimal postoperative outcome (RV dilatation and dysfunction). CONCLUSIONS: The addition of surgical remodeling of the RV to PVR in patients with chronic pulmonary regurgitation did not result in a measurable early benefit. Referral to PVR based on QRS duration, RV end-systolic volume, or RV ejection fraction may be beneficial. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00112320.

BACKGROUND: Nontransvenous (NTV) implantable cardioverter-defibrillator (ICD) systems with pericardial and/or subcutaneous coils are used in select pediatric and congenital heart disease patients who are not candidates for transvenous ICD leads. Outcomes with these hybrid configurations are not well understood. OBJECTIVE: The purpose of this study was to compare survival of NTV ICD systems to standard transvenous (TV) ICD systems. METHODS: We conducted a retrospective single-center study in which the TV group was matched to the NTV group 2:1 by type of cardiac disease and implant date. RESULTS: There were 39 patients in the NTV group and 78 matched in the TV group. Compared to the TV group, the NTV group was younger (median 7 vs 20 years) with a smaller body surface area at implant (0.9 vs 1.8 m(2); both P <.001). Median follow-up in the NTV group was 17 months. System survival at 12, 24, and 36 months was 73%, 55%, and 49% in the NTV group versus 91%, 83%, and 76% in the TV group (P = .003). A multivariable Cox proportional hazards model including group, body surface area, and age at implant revealed the NTV group to be an independent predictor of system failure (hazard ratio 2.9, P = .04). Rate of total unanticipated interventions in the NTV group was 18 versus 6 per 1,000 person-months in the TV group. In patients with NTV systems, 23% received appropriate shocks and 18% received inappropriate shocks. CONCLUSION: Survival of ICD systems using NTV defibrillation coils is significantly shorter than with TV ICD systems. Although NTV systems provide protection for this unique subset of patients, more durable options are needed.