Incidence and outcome of arrhythmias and electrical disease in patients with Trisomy 18.

Patients with Trisomy 18 have a high incidence of cardiac anomalies and are associated with early death. Because of early mortality, electrical system disease and arrhythmia has been difficult to delineate and the incidence remain unknown. We sought to describe the association and clinical outcomes of electrical system disease and cardiac tachy-arrhythmias in patients with Trisomy 18. This was a retrospective, single institutional study. All patients with Trisomy 18 were included in the study. Patient characteristics, congenital heart disease (CHD), conduction system and clinical tachy-arrhythmia data were collected on all patients. Outcomes including cardiac surgical interventions, electrical system interventions and death were collected until the time of study. Patients with tachy-arrhythmias/electrical system involvement were compared to those without to identify potential associated variables. A total of 54 patients with Trisomy 18 were included in analysis. The majority of patients was female and had associated CHD. AV nodal conduction system abnormalities with either first or second degree AV block were common (15%) as was QTc prolongation (37%). Tachy-arrhythmias were common with 22% of patients having at least one form of tachy-arrhythmia and associated with concomitant conduction system disease (p = 0.002). Tachy-arrhythmias were typically treatable with monitoring or medication with eventual resolution without need for procedural intervention. Although early death was common, there were no causes of death associated with tachy-arrhythmia or conduction system disease. In conclusion, patients with Trisomy 18 have a high incidence of conduction system abnormalities and burden of clinical tachy-arrhythmias. Although frequent, electrical system disease did not affect patient outcome or difficultly of care delivery.

Outcomes in Infants with Supraventricular Tachycardia: Risk Factors for Readmission, Recurrence and Ablation.

Supraventricular tachycardia (SVT) is the most common arrhythmia in infants. Once diagnosed, infants are admitted for antiarrhythmic therapy and discharged after observation. There are limited data on risk factors for readmission and readmission rates, while on medication. The objective of this study was to investigate risk factors for readmission and outcomes in infants diagnosed with SVT. This is a single-center retrospective study over a 10-year period of infants under 6 months of age with documented SVT. Infants with congenital heart disease requiring surgical or catheter intervention, gestational age less than 32 weeks or diagnosis of atrial flutter or fibrillation were excluded. The primary outcome was readmission within 31 days of hospital discharge. Long term need for ablation and eventual discontinuation of medications were assessed. Ninety patients were included. Beta blockers were the initial therapy in 66 and 28 required a medication change. Nineteen were readmitted within 31 days of discharge. The only clinical factor associated with early readmission was presence of ventricular pre-excitation (6/19 vs. 8/71, p = 0.03). Patients who were readmitted within 31 days had a longer length of treatment (12 [11.5, 22.0] vs. 10 [7.5, 12.0] months, p = 0.007) and were more likely to undergo ablation (4/19 vs. 2/71, p = 0.017). In this cohort of infants with SVT, readmission was common and ventricular pre-excitation was identified as a risk factor for readmission. Infants who were readmitted within 31 days of discharge had longer length of antiarrhythmic therapy and were more likely to undergo catheter ablation.

Progressive QRS Duration and Ventricular Dysfunction in Pediatric Patients with Chronic Ventricular Pacing.

Pacemakers are a mainstay of therapy for patients with congenital and acquired heart block, but ventricular pacing is related to ventricular dysfunction. We sought to evaluate patient and device characteristics associated with ventricular dysfunction in pediatric patients with chronic ventricular pacing. This was a retrospective cohort of pediatric patients with heart block and chronic ventricular pacing. Patient, ECG, and device characteristics were analyzed to determine factors associated with ventricular dysfunction. Longitudinal ECG and echocardiogram parameters were obtained to track changes in QRS and systemic ventricular systolic function over time. In total, 82 patients were included (median age at implant 0.81 years). Over a follow-up time of 6.1 years, 18% developed ventricular dysfunction. Patients with dysfunction had greater current QRS duration (p = 0.002) compared to those with preserved function with a similar time from device implantation. There was no difference between lead location or age at device implantation. QRS duration increased with time from implant and the resultant ΔQRS was associated with ventricular dysfunction (p = 0.01). QRS duration >162 ms was associated with a 5.8 (2-9)-fold increased risk for dysfunction. Transvenous leads were associated with longer QRS duration with no difference compared to epicardial leads in development of ventricular dysfunction. This study demonstrated that the absolute paced QRS duration and Δpaced QRS were association with long-term ventricular dysfunction independent of how long a given patient was paced. Patients in high-risk categories may benefit from close echocardiographic monitoring. Whether permissive junctional rhythm or His bundle/biventricular pacing decreases the rate of dysfunction needs further study.

Can noninvasive testing identify benign patterns of suggested pre-excitation on electrocardiogram?

BACKGROUND: The presence of anterograde conduction through an accessory pathway (AP) has been linked to sudden cardiac death. Unfortunately, pre-excitation associated with classic pathways can be difficult to differentiate from benign APs such as nodofascicular fibers. OBJECTIVE: Identifying characteristics on electrocardiogram (ECG) and exercise that differentiate classic and benign AP connections in suggested pre-excitation patterns. METHODS: Retrospective review of patients presenting between 1995 and 2017 with ventricular pre-excitation on ECG, determined to have either typical left-lateral AP during electrophysiology study (EPS), or benign, or no AP determined by either transesophageal electrophysiology study (TEP), or EPS. RESULTS: A total of 96 patients were included, 14.2 years (4-24), 45% female, 90% Caucasian. Of these, 60 (63%) had a classic APs identified on EPS and 58 (97%) underwent successful ablation. Conversely, 36 (37%) had benign pathways identified. ECG findings differed between the groups: PR-interval 102 versus 120 ms (P < .0001), QRS-duration 110 versus 102 ms (P < .0001), QRS-axis 74 versus 59 degrees (P = .0005), and QRS onset to peak R/S in limb leads 64 versus 42 ms (P < .0001), and precordial leads 66 versus 46 ms (P < .0001). Change in QRS duration during exercise differed between the groups: 25 versus 2 ms (P < .0001) and ECG characteristics identified the presence of an AP with 97% sensitivity and 94% negative predictive value. CONCLUSION: Classic and benign APs exhibit different ECG characteristics, though clinical overlap does not allow for absolute differentiation. These data may help with risk stratification decision making though does not obviate the need for additional invasive testing.

Patient understanding of disease and the use and outcome of implantable cardioverter defibrillators in hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden cardiac death (SCD) in young individuals. Implantable cardioverter defibrillators (ICD) are the primary therapy for sudden death prevention; however, are associated with both physical and psychological complications. We sought to determine factors associated with ICD understanding and patient satisfaction. This was a cross-sectional study, using patient/parent answered questionnaires distributed to patients enrolled in the Hypertrophic Cardiomyopathy Association. Patient characteristics and satisfaction data were obtained via questionnaire. Patients were compared based on age at diagnosis and presence of ICD. ICD patients with high satisfaction were compared to those with low satisfaction to determine factors associated with poor satisfaction. A total of 538 responses were obtained (53 ± 16 years); 46% were females. Seventy patients (13%) were diagnosed with HCM < 18 years of age and 356 (66%) had an ICD. Compared to those without an ICD, patients with ICDs were younger at age of diagnosis (P = 0.001) and time of study (P = 0.008). Patients with ICDs were more likely to have presented with syncope and have family history of ICD, SCD, or HCM-related death. Nineteen patients (5%) felt that issues surrounding their ICD outweighed its benefit. Compared to patients with a favorable satisfaction, the only significant difference was the preimplant ICD discussion (P < 0.001) and history of lead replacement (P = 0.01). In conclusion, the majority of HCM patients with ICDs are satisfied with their ICD management and feel the benefits of ICDs outweigh issues associated with ICDs. Additionally, these data highlight the importance of the preimplant patient-physician discussion around the need for ICD prior to implantation.

Risks and outcomes of direct current cardioversion in children and young adults with congenital heart disease.

OBJECTIVES: Evaluate the efficacy, outcomes, and complications associated with direct current cardioversion (DCCV) in the treatment of arrhythmias in pediatric and adult congenital heart disease (CHD) populations and identify patient and procedural characteristics associated with adverse events. BACKGROUND: Pediatric and adult patients with CHD are at risk of atrial arrhythmias. DCCV is effective but is associated with potential complications. METHODS: In this single-center retrospective series, patients who underwent DCCV between January 2010 and May 2015 were identified and categorized as pediatric (<18 years) or adult (> 18 years). Records were reviewed for demographic, arrhythmic, and CHD-specific characteristics; acute efficacy; and 3-month arrhythmia recurrence. Complications were categorized as life-threatening (LT) or non-life-threatening (NLT). Univariate followed by multiple variable and logistic regression (LR) analyses were used to identify characteristics associated with complications. RESULTS: We identified 104 patients with 152 discrete DCCV events with median age 17.4 years (0.15-62.2). DCCV efficacy was 89% with 3-month recurrence of 46%. There were 52 complications among 24 patients, median age 17.7 years (0.15-49). Risks associated with NLT complications are as follows: moderate-severe systolic dysfunction (8/152 encounters, P = < 0.01) and more than one shock per DCCV encounter (P = < 0.01). Six of eight encounters with moderate-severe systolic dysfunction were <18 years (P = 0.1). Risks for LT complications included age >18 years and associated NLT complication. Adults had more frequent arrhythmia recurrence within 3 months than children (P = < 0.01). CONCLUSIONS: DCCV is effective for arrhythmias but is associated with frequent recurrence, particularly in adult patients. Complications associated with DCCV may be greater than previously reported. Additional support and precautions should be in place for those at greatest risk.

Wearable cardioverter defibrillators in schools: A guide for parents and educators.

Keeping children safe is a goal for everyone. To stay safe, some children need a wearable cardioverter defibrillator (WCD). WCDs protect individuals who are at risk for life-threatening arrhythmias. The LifeVest® (ZOLL, Pittsburgh, PA, USA) is a WCD that identifies, records, and treats potentially life-threatening abnormal heartbeats, or arrhythmias. The WCD will provide electrical energy to the heart with up to five high-energy shocks if a potentially dangerous cardiac arrhythmia is detected. This type of arrhythmia, if not treated within a short time period (less than 2 minutes), can result in disruption of blood flow to the brain and other vital organs (that is, a sudden cardiac arrest), and death can occur within minutes. A shock delivered by the LifeVest can terminate an arrhythmia and restore a normal heart rhythm and blood flow to the body. In December 2015, the Food and Drug Administration approved the LifeVest for patients under 18 years old. The purpose of this guide is to serve as a resource for parents and educators, to promote awareness of the LifeVest, and to answer questions about the safety of the LifeVest in schools.

Early Repolarization in Normal Adolescents is Common.

In adults with structurally normal hearts, the early repolarization pattern (ERP) on electrocardiogram (ECG) may be associated with an increased risk of sudden cardiac death. The prevalence and significance of the ERP in children is unknown. This study examines the prevalence of the ERP, the population in which it is found, and whether there exists any correlation with increased LV mass or family history of significant cardiac events. This was a secondary review of data obtained from healthy adolescents undergoing a limited ECG and transthoracic echocardiogram (TTE) as part of a cardiac screening study. Subjects were excluded if ECG revealed known arrhythmic syndromes or TTE revealed structural abnormalities. ERP was defined as (1) notching or slurring of the terminal QRS; (2) elevation of the QRS-ST junction ≥1 mV; and (3) upwardly concave positive T-wave. Left ventricular (LV) mass was defined as mass/height2.7. Patient demographics, LV mass, family history of sudden death, arrhythmia, and/or ICD/pacemaker placement were compared for subjects with and without ERP on ECG. Data from 575 subjects (median age 15, range 13-18; 36% female; 93% Caucasian) were reviewed. The incidence of ERP was 40% (n = 228) and was seen in the inferior, lateral, or combination of these leads in 42, 10, and 48% of subjects with ERP, respectively. There was no difference in gender (p = 0.7), race (p = 0.7), age (p = 0.3), history of syncope (p = 0.2), LV mass (p = 0.8), family history of (a) sudden death (p = 0.5), (b) arrhythmia (p = 0.2), or (c) ICD/pacemaker requirement (p = 0.8) in subjects with ERP versus those without. However, a greater percentage of patients with ERP were noted to play football, when compared to those without ERP (34 vs. 13%, p < 0.001). ERP is common in healthy adolescents, and does not correlate with concerning personal/family history or elevated LV mass. Longitudinal studies are required to determine whether ERP in childhood confers an increased mortality risk.

Arrhythmic Burden and Ambulatory Monitoring of Pediatric Patients with Cardiomyopathy.

BACKGROUND: Pediatric patients with cardiomyopathy (CM) are at risk for sudden cardiac death (SCD), likely driven by arrhythmic etiologies. OBJECTIVES: Describe arrhythmia burden and Holter utility in pediatric CM including: hypertrophic CM (HCM), dilated CM (DCM), and restrictive CM (RCM). METHODS: Retrospective cohort study of patients <21 years with CM. Patient demographics, arrhythmic history, and genetic status were reviewed including outcomes of death, aborted SCD, and device shocks. Holter findings were analyzed over the prior 5 years including clinically significant findings and resulting changes to management. Analysis for the composite outcomes of death, aborted SCD, and appropriate shock were performed using logistic regression with backward elimination. RESULTS: One hundred and forty-six patients were included: 83 HCM, 54 DCM, and nine RCM (mean 13 ± 6 years). A total of 23% of patients had defibrillators. There were six deaths (two SCD), four patients with appropriate device therapies, and four aborted SCD episodes. In total, 305 Holter monitors were reviewed. Six Holters had significant findings, all nonsustained ventricular tachycardia. Two Holters resulted in changes in management, both defibrillator implantations. Twelve patients had one or more of the conditions defining the composite outcome. Using logistic regression, clinical history of ventricular arrhythmia, frequent premature ventricular complexes, and CM type were included as potential independent predictors in the final model and clinical ventricular arrhythmia and RCM disease were associated with the composite outcome. CONCLUSIONS: SCD and device therapies were relatively rare. Routine Holter screening rarely demonstrated significant findings or changed clinical care. Clinical history of ventricular arrhythmia was associated with poor clinical outcome.

Variation in Antiarrhythmic Management of Infants Hospitalized with Supraventricular Tachycardia: A Multi-Institutional Analysis.

Supraventricular tachycardia (SVT) is the most frequent form of symptomatic tachyarrhythmia in infants. The purposes of this study were to describe practice patterns of the management of infants hospitalized with SVT and factors associated with 30-day hospital readmission. This was a multi-institutional, retrospective review of the pediatric health information system database of SVT hospitalizations from 2003 to 2013. High-volume centers (HVC) were defined as those at the upper quartile of admissions. Infants with an ICD-9 code of paroxysmal SVT were included. Antiarrhythmics investigated included amiodarone, atenolol, digoxin, esmolol, flecainide, procainamide, propafenone, propranolol, and sotalol. Frequency of antiarrhythmic use based on center volume was the primary end point. Rate of 30-day SVT readmission was the secondary end point. Analysis of factors associated with readmission was assessed by Chi-square analysis and expressed as odds ratio and 95 % confidence interval. A total of 851 patients (60 % male, 44 % neonates) were hospitalized at 43 hospitals. Propranolol, digoxin, and amiodarone were the most frequently utilized antiarrhythmics. HVCs represented 12 hospitals comprising 494 (58 %) patients. Although HVCs were more likely to utilize propranolol (OR 2.5, CI 1.5-4.1), there was no significant difference in the 30-day readmission rate between patients treated at HVCs versus non-HVCs (p = 0.9). The majority of infants with SVT are treated with a small number of antiarrhythmic medications during index hospitalization. Although hospital-to-hospital variation in antiarrhythmic choice exists, there appears to be no difference in readmission. The remaining practice variation may be related to intrinsic patient characteristics.

Missing LINQ: extrusion of a new-generation implantable loop recorder in a child.

Cardiac rhythm monitoring has been facilitated by the use of implantable loop recorders. New models of these devices are 87% smaller than before allowing for easier implantation and use in the paediatric population. Recommendations are for closure with adhesive. We report a device extrusion in a 6-year-old patient. Based on this, our practice has changed to include subcutaneous sutures this complication.

Cryoablation of anteroseptal accessory pathways with a his bundle electrogram on the ablation catheter.

BACKGROUND: Radiofrequency catheter ablations of anteroseptal (AS) accessory pathways (AP) in pediatric patients have higher incidence of atrioventricular (AV) block than other AP locations. We report our experience using cryoablation in pediatric patients where a His bundle electrogram was noted on the ablation catheter at the site of the successful ablation. METHODS AND RESULTS: We retrospectively reviewed all patients ≤21 years that underwent cryoablation for an AS AP from 2005 to 2012 at our institution (n=70). Patients with a His bundle electrogram noted on the cryoablation catheter at the location of the successful lesion were identified (n=6, 8.5%). All six patients had ventricular preexcitation. Median age of 15.9 years (7.2 - 18.2). AV nodal function was monitored during the cryoablation with intermittent rapid atrial pacing conducted through the AV node (n=2), with atrial extra-stimulus testing (n=2), or during orthodromic reentrant tachycardia (n=2). Acute success occurred in all patients. Two patients had early recurrence of AP conduction. Both patients underwent a second successful cryoablation, again with a His bundle electrogram on the cryoablation catheter. At a median follow-up of 13 months (3 to 37 months) there was no recurrence of accessory pathway conduction and AVN function was normal. CONCLUSION: In a small number of pediatric patients with AS AP with a His bundle electrogram seen on the ablation catheter, the use of cryotherapy was safe and effective for elimination of AP conduction without impairment of AV nodal conduction.

Symptomatic upper-extremity deep venous thrombosis after pacemaker placement in a pediatric patient: how to treat?

Symptomatic upper-extremity deep venous thrombosis (UEDVT) after pacemaker placement in adults has been reported, but the occurrence of UEDVT in pediatric patients is poorly defined, and no treatment guidelines exist. This report describes a 14-year old girl with a history of complete atrioventricular block who experienced a symptomatic UEDVT 8 months after placement of a transvenous pacemaker. The girl was treated initially with anticoagulation including subcutaneous enoxaparin and a heparin drip, which did not resolve the venous obstruction. In the interventional laboratory, a venogram demonstrated complete obstruction of the left subclavian vein, which was treated successfully with catheter-directed alteplase, direct thrombus removal by manual suctioning, and balloon angioplasty. Warfarin therapy was continued for an additional 6 months, with follow-up venous ultrasounds demonstrating left subclavian vein patency. Soon after completing warfarin therapy, the girl presented with minimal edema of her left distal extremity and was thought to have post-thrombotic syndrome, which resolved quickly. She continued to receive aspirin therapy, with no recurrence of symptoms. In conclusion, symptomatic UEDVT after pacemaker placement in a pediatric patient can be treated successfully with both anticoagulation and interventional therapies. Further studies are needed to evaluate the incidence of thrombus formation among children with transvenous pacemaker placement together with the development of guidelines based on the safety and effectiveness of differing treatments.

Transesophageal pacing studies reduce readmission but prolong initial admission in infants with supraventricular tachycardia: A cost-comparison analysis.

Background: Supraventricular tachycardia (SVT) is a common arrhythmia. Infants with SVT are often admitted to initiate antiarrhythmics. Transesophageal pacing (TEP) studies can be used to guide therapy prior to discharge. Objective: The objective of this study was to investigate the impact of TEP studies on length of stay (LOS), readmission, and cost in infants with SVT. Methods: This was a 2-site retrospective review of infants with SVT. One site (Center TEPS) utilized TEP studies in all patients. The other (Center NOTEP) did not. Patients with structural heart disease, patients with gestational age <34 weeks, and patients diagnosed after 6 months were excluded. At Center TEPS, repeat TEP studies were performed after titration of medication until SVT was not inducible. Primary endpoints were LOS and readmission for breakthrough SVT within 31 days of discharge. Hospital reimbursement data were utilized for cost-effectiveness analysis. Results: The cohort included 131 patients, 59 in Center TEPS and 72 in Center NOTEP. One patient was readmitted in Center TEPS vs 17 in Center NOTEP (1.6% vs 23.6%; P ≤ .001). Median LOS was longer for Center TEPS at 118.0 (interquartile range [IQR] 74.0-189.5) hours vs Center NOTEP at 66.9 (IQR 45.5-118.3) hours (P = .001). Twenty-one patients had multiple TEP studies. Median length of readmission for Center NOTEP was 65 (IQR 41-101) hours. Including readmission costs, utilization of TEP studies resulted in a probability-weighted cost of $45,531 per patient compared with $31,087 per patient without TEP studies. Conclusion: Utilization of TEP studies was associated with decreased readmission rates but longer LOS and greater cost compared with SVT management without TEP studies.

Predictors and Outcomes of Arrhythmia on Stage I Palliation of Single Ventricle Patients.

BACKGROUND: Arrhythmias are common in single ventricle patients though their effect on outcomes during stage I palliation (S1P) is unclear. OBJECTIVES: The authors sought to study associated risks for arrhythmia in patients undergoing S1P for single ventricle disease and evaluate the outcome of arrhythmias and their treatment strategies on survival. METHODS: Retrospective patient, surgical, medication, and arrhythmia data were obtained from the NPC-QIC (National Pediatric Cardiology Quality Improvement Collaborative) database. Bivariate analysis of variables associated with arrhythmias, as well as those associated with survival, was performed at the time of stage II palliation. Appropriate variables were included in multivariate modeling. RESULTS: Of the 2,048 patients included in the study, 36% had arrhythmia noted during their S1P hospitalization, with supraventricular tachycardia (12%) and focal atrial tachycardia (11%) the most common. At S1P discharge, 11% of patients were on an antiarrhythmic medication. Arrhythmias were associated with lower survival and increased hospital length of stay. Heterotaxy syndrome, younger age at S1P, male sex, and additional anomalies were associated with increased risk of arrhythmia in multivariable modeling (P ≤ 0.01). Arrhythmia and female sex were associated with increased mortality, whereas antiarrhythmic medication and digoxin use were associated with decreased mortality (P ≤ 0.003, model area under the curve = 0.79). The use of antiarrhythmic medications within the subcohort of arrhythmia patients was also associated with decreased risk of mortality (P < 0.0001; odds ratio: 2.0-7.2). CONCLUSIONS: Arrhythmias are common during admission for S1P and associated with poor outcomes. The use of antiarrhythmic medications may improve survival, though future studies are needed.

Continuous Arrhythmia Monitoring in Pediatric and Adult Patients With Left Ventricular Noncompaction.

Patients with left ventricular noncompaction (LVNC) are at risk of clinically significant arrhythmias and sudden death. We evaluated whether implantable loop recorders could detect significant arrhythmias that might be missed in these patients during annual Holter monitoring. Selected pediatric and adult patients with LVNC who consented to implantable loop recorder placement were monitored for 3 years (study duration, 10 April 2014-9 December 2019). Fourteen subjects were included (age range, 6.5-36.4 yr; 8 males). Of 13 patients who remained after one device extrusion, one underwent implantable cardioverter-defibrillator placement. Four patients (31%) had significant arrhythmias: atrial tachycardia (n=2), nonsustained ventricular tachycardia (n=1), and atrial fibrillation (n=1). All 4 events were clinically asymptomatic and not associated with left ventricular ejection fraction. In addition, a high frequency of benign arrhythmic patterns was detected. Implantable loop recorders enable continuous, long-term detection of important subclinical arrhythmias in selected patients who have LVNC. These devices may prove to be most valuable in patients who have LVNC and moderate or greater ventricular dysfunction.

Multicenter Outcomes of Catheter Ablation for Atrioventricular Reciprocating Tachycardia Mediated by Twin Atrioventricular Nodes.

OBJECTIVES: This study sought to describe the electrophysiologic properties and catheter ablation outcomes for atrioventricular reciprocating tacchycardia via twin atrioventricular nodes (T-AVRT). BACKGROUND: Although catheter ablation for T-AVRT is an established entity, there are few data on the electrophysiological properties and outcomes of this procedure. METHODS: An international, multicenter study was conducted to collect retrospective procedural and outcomes data for catheter ablation of T-AVRT. RESULTS: Fifty-nine patients with T-AVRT were identified (median age at procedure, 8 years [interquartile range: 4.4-17.0 years]; 49% male). Of these, 55 (93%) were diagnosed with heterotaxy syndrome (right atrial isomerism in 39, left atrial isomerism in 8, and indeterminate in 8). Twenty-three (39%) had undergone Fontan operation (12 extracardiac, 11 lateral tunnel). After the Fontan operation, atrial access was conduit or baffle puncture in 15 (65%), fenestration in 5 (22%), and retrograde in 3 (13%). Acute success was achieved in 43 (91%) of 47 attempts (targeting an anterior node in 23 and posterior node in 24). There was no high-grade AV block or change in QRS duration. Over a median of 3.8 years, there were 3 recurrences. Of 7 patients with failed index procedure or recurrent T-AVRT, 6 (86%) were associated with anatomical hurdles such as prior Fontan or catheter course through an interrupted inferior vena cava-to-azygous vein continuation (P = 0.11). CONCLUSIONS: T-AVRT can be targeted successfully with low risk for recurrence. Complications were rare in this population. Anatomical challenges were common among patients with reduced short and long-term efficacy, representing opportunities for improvement in procedural timing and planning.

Cumulative In-Hospital Costs Associated With Single-Ventricle Palliation.

Background: In the SVR (Single Ventricle Reconstruction) Trial, 1-year survival in recipients of right ventricle to pulmonary artery shunts (RVPAS) was superior to that in those receiving modified Blalock-Taussig-Thomas shunts (MBTTS), but not in subsequent follow-up. Cost analysis is an expedient means of evaluating value and morbidity. Objectives: The purpose of this study was to evaluate differences in cumulative hospital costs between RVPAS and MBTTS. Methods: Clinical data from SVR and costs from Pediatric Health Information Systems database were combined. Cumulative hospital costs and cost-per-day-alive were compared serially at 1, 3, and 5 years between RVPAS and MBTTS. Potential associations between patient-level factors and cost were explored with multivariable models. Results: In total, 303 participants (55% of the SVR cohort) from 9 of 15 sites were studied (48% MBTTS). Observed total costs at 1 year were lower for MBTTS ($701,260 ± 442,081) than those for RVPAS ($804,062 ± 615,068), a difference that was not statistically significant (P = 0.10). Total costs were also not significantly different at 3 and 5 years (P = 0.21 and 0.32). Similarly, cost-per-day-alive did not differ significantly for either group at 1, 3, and 5 years (all P > 0.05). In analyses of transplant-free survivors, total costs and cost-per-day-alive were higher for RVPAS at 1 year (P = 0.05 for both) but not at 3 and 5 years (P > 0.05 for all). In multivariable models, aortic atresia and prematurity were associated with increased cost-per-day-alive across follow-up (P < 0.05). Conclusions: Total costs do not differ significantly between MBTTS and RVPAS. The magnitude of longitudinal costs underscores the importance of efforts to improve outcomes in this vulnerable population.

Predictors and outcomes of heart block during surgical stage I palliation of patients with a single ventricle: A report from the NPC-QIC.

BACKGROUND: Mortality in cohorts with a single ventricle remains high with multiple associated factors. The effect of heart block during stage I palliation remains unclear. OBJECTIVE: The purpose of this study was to study patient and surgical risks of heart block and its effect on 12-month transplant-free survival in patients with a single ventricle. METHODS: Patient, surgical, outcome data and heart block status (transient and permanent) were obtained from the National Pediatric Cardiology Quality Improvement Collaborative single ventricle database. Bivariate analysis was performed comparing patients with and without heart block, and multivariate modeling was used to identify variables associated with block. One-year outcomes were analyzed to identify variables associated with lower 12-month transplant-free survival. RESULTS: In total, 1423 patients were identified, of whom 28 (2%) developed heart block (second degree or complete) during their surgical admission. Associated risk factors for block included heterotaxy syndrome (odds ratio [OR] 6.4) and atrial flutter/fibrillation (OR 3.8). Patients with heart block had lower 12-month survival, though only in patients with complete heart block as opposed to second degree block. At 12 months of age, 43% (12/28) of patients with heart block died and were more likely to experience mortality at 12 months than patients without block (OR 4.9; 95% confidence interval 1.4-17.5; P = .01). CONCLUSION: Although rare, complete heart block after stage I palliation represents an additional risk of poor outcomes in this high-risk patient population. Heterotaxy syndrome was the most significant risk factor for the development of heart block after stage I palliation. The role of transient block in outcomes and potential rescue with long-term pacing remains unknown and requires additional study.

Outcomes of Implantable Loop Monitoring in Patients <21 Years of Age.

Rhythm-symptom correlation in pediatric patients with syncope/palpitations or at risk cohorts can be difficult, but important given potential associations with treatable or malignant arrhythmia. We sought to evaluate the use, efficacy and outcomes of implantable loop recorders (ILR) in pediatrics. We conducted a retrospective study of pediatric patients (<21 years) with implanted ILR. Patient/historical characteristics and ILR indication were obtained. Outcomes including symptom documentation, arrhythmia detection and ILR based changes in medical care were identified. Comparison of outcomes were performed based on implant indication. Additional sub-analyses were performed in syncope-indication patients comparing those with and without changes in clinical management. A total of 116 patients with ILR implant were identified (79 syncope/37 other). Symptoms were documented 58% of patients (syncope 68% vs nonsyncope 35%; p = 0.002). A total of 37% of patients had a documented clinically significant arrhythmia and 25% of patients had a resultant change in clinical management independent of implant indication. Arrhythmia type was dependent on implant indication with nonsyncope patients having more ventricular arrhythmias. Pacemaker/defibrillator implantation and mediation management were the majority of the clinical changes. In conclusion, IRL utilization in selected pediatric populations is associated with high efficacy and supports clinical management. ILR efficacy is similar regardless of indication although patients with nonsyncope indications had a higher frequency of ventricular arrhythmias as opposed to asystole and heart block in syncope indications. The majority of arrhythmic findings occurred in the first 12 months, and new technology that would allow for less invasive monitoring for 6 to 12 months may be of value.