Patterns of Electrocardiographic Abnormalities in Children with Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM), a common cardiomyopathy in children, is an important cause of morbidity and mortality. Early recognition and appropriate management are important. An electrocardiogram (ECG) is often used as a screening tool in children to detect heart disease. The ECG patterns in children with HCM are not well described.ECGs collected from an international cohort of children, and adolescents (≤ 21 years) with HCM were reviewed. 482 ECGs met inclusion criteria. Age ranged from 1 day to 21 years, median 13 years. Of the 482 ECGs, 57 (12%) were normal. The most common abnormalities noted were left ventricular hypertrophy (LVH) in 108/482 (22%) and biventricular hypertrophy (BVH) in 116/482 (24%) Of the patients with LVH/BVH (n = 224), 135 (60%) also had a strain pattern (LVH in 83, BVH in 52). Isolated strain pattern (in the absence of criteria for hypertrophy) was seen in 43/482 (9%). Isolated pathologic Q waves were seen in 71/482 (15%). Pediatric HCM, 88% have an abnormal ECG. The most common ECG abnormalities were LVH or BVH with or without strain. Strain pattern without hypertrophy and a pathologic Q wave were present in a significant proportion (24%) of patients. Thus, a significant number of children with HCM have ECG abnormalities that are not typical for "hypertrophy". The presence of the ECG abnormalities described above in a child should prompt further examination with an echocardiogram to rule out HCM.

Impact of Obesity on Left Ventricular Thickness in Children with Hypertrophic Cardiomyopathy.

Obesity is associated with additional left ventricular hypertrophy (LVH) in adults with hypertrophic cardiomyopathy (HCM). It is not known whether obesity can lead to further LVH in children with HCM. Echocardiographic LV dimensions were determined in 504 children with HCM. Measurements of interventricular septal thickness (IVST) and posterior wall thickness (PWT), and patients' weight and height were recorded. Obesity was defined as a body mass index (BMI) ≥ 99th percentile for age and sex. IVST data was available for 498 and PWT data for 484 patients. Patient age ranged from 2 to 20 years (mean ± SD, 12.5 ± 3.9) and 340 (68%) were males. Overall, patient BMI ranged from 7 to 50 (22.7 ± 6.1). Obesity (BMI 18-50, mean 29.1) was present in 140 children aged 2-19.6 (11.3 ± 4.1). The overall mean IVST was 20.5 ± 9.6 mm and the overall mean PWT was 11.0 ± 8.4 mm. The mean IVST in the obese patients was 21.6 ± 10.0 mm and mean PWT was 13.3 ± 14.7 mm. The mean IVST in the non-obese patients was 20.1 ± 9.5 mm and mean PWT was 10.4 ± 4.3 mm. Obesity was not significantly associated with IVST (p = 0.12), but was associated with increased PWT (0.0011). Obesity is associated with increased PWT but not IVST in children with HCM. Whether obesity and its impact on LVH influences clinical outcomes in children with HCM needs to be studied.

Radiofrequency ablation versus cryoablation for atrioventricular nodal re-entrant tachycardia in children: a value comparison.

BACKGROUND: It is unclear whether cryoablation or radiofrequency ablation offers better value for treating atrioventricular nodal re-entrant tachycardia in children. We aimed to compare the value of these procedures for treating atrioventricular nodal re-entrant tachycardia in children, with value being outcomes relative to costs. METHODS: We performed a retrospective cohort study of all atrioventricular nodal re-entrant tachycardia ablations for children (age⩽18 years) from July, 2009 to June, 2011 at our institution. Costs included fixed costs, miscellaneous hospital costs, and labour costs, and key outcomes were acute and long-term success (6 months) of the ablations. We conducted T-tests and regression analyses to investigate the associations between the ablation procedure type and the cost and success of the ablations. RESULTS: Of 96 unique cases performed by three paediatric electrophysiologists, 48 were cryoablation only, 42 radiofrequency ablation only, and six were a combination. Acute success was 100% for the cryoablation only and radiofrequency ablation only cases and 83% for the combination cases. There were no notable adverse events. The average total cost was $9636 for cryoablation cases, $9708 for radiofrequency ablation cases, and $10,967 for combination cases (p=0.51 for cryoablation only versus radiofrequency ablation only). The long-term success rate was 79.1% for cryoablation only, 92.8% for radiofrequency ablation only, and 66.7% for the combination (p=0.01 for cryoablation only versus radiofrequency ablation only), but long-term success varied notably by provider. CONCLUSIONS: Cryoablation and radiofrequency ablation offer similar value in the short term for the treatment of atrioventricular nodal re-entrant tachycardia in children. Differences in long-term success may vary substantially by physician, and thus may lead to differences in long-term value.

Health related quality of life and social support in pediatric patients with pacemakers.

Prior research evaluating health-related quality of life (HRQOL) among pediatric patients with internal cardiac devices has primarily focused on children with cardiac defibrillators, with scant attention devoted to pacemaker recipients. Social support has been conceptualized as a protective factor that partially accounts for differences in HRQOL. This study compares the HRQOL of children with pacemakers with that of healthy children, and examines associations between HRQOL and social support. Twenty-seven pediatric pacemaker recipients completed measures of HRQOL and social support. Their parents also completed measures of child HRQOL. High concordance was found for child and parent-proxy reports of child HRQOL. Children with pacemakers and their parents both reported relatively low child HRQOL when compared to published normative data for healthy children and parents of healthy children. Family and friends emerged as the sources of support positively associated with the greatest number of HRQOL domains. In conclusion, these findings suggest that pediatric pacemaker recipients experience lower levels of HRQOL compared to healthy peers, and that social support from those closest to the child is associated with their perceived HRQOL.

Implanted defibrillators in young hypertrophic cardiomyopathy patients: a multicenter study.

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disease, with an annual risk of sudden cardiac death (SCD) estimated at 1 %. Limited data are available regarding both the risk of SCD in the young HCM population and the use of implantable cardioverter-defibrillators (ICDs). This retrospective study included all patients with HCM who underwent ICD implantation for primary or secondary prevention of SCD before the age of 30 years at five institutions between 1995 and 2009. There were 99 devices implanted in 73 patients. Appropriate shocks occurred for 11 % of all the patients. None of the previously identified conventional risk factors for SCD in HCM patients were associated with increased risk of appropriate shocks in the young study cohort. During a median follow-up period of 2.4 years, inappropriate shocks occurred for 22 % of the patients. Older age at implant was associated with a decreased risk of inappropriate shock. Those who underwent implantation in the earlier decade had a higher incidence of inappropriate shocks. Late complications including lead fracture or dislodgement, generator malfunction, and infection occurred for 32 % of the patients. Three patients died (4 %), one of whom had an arrhythmic sudden death. A greater proportion of primary prevention implantations was performed for patients from the latter decade. Over time, ICD use in young HCM patients has become increasingly primary prevention oriented. Shock rates mirror those reported in adult series, and there is a substantial incidence of device complications.

Cryoablation therapy for atrioventricular nodal reentrant tachycardia in children: a multicenter experience of efficacy.

Atrioventricular nodal reentrant tachycardia (AVNRT), a common tachycardia in children, is routinely treated by catheter ablation using radiofrequency or cryothermal energy. Acute success rates of 95-97 % are reported for cryoablation, similar to those achieved with radiofrequency ablation (RFA). However, early studies reported higher recurrence rates after cryoablation for treatment of AVNRT than those reported for RFA. This study evaluated the success and recurrence rates for cryoablation in a current cohort of pediatric patients across several institutions. Patients 21 years old or younger with AVNRT who underwent cryoablation at five participating centers between 2004 and 2009 were retrospectively reviewed. Patient demographics and procedural data were extracted from patient records and analyzed. A total of 434 patients with AVNRT who underwent cryoablation were identified. Cryoablation was used as the exclusive ablation method for 379 patients. For 97 % (368/379) of these patients, cryoablation was acutely successful. A higher acute success rate was found with the 6-mm-tip catheter (99 %) than with the 4-mm-tip catheter (91 %) (p < 0.01). Recurrence was experienced by 7.3 % of the patients. Recurrence was more likely for those treated with the 4-mm-tip catheter (6/42, 14 %) than for those who had the larger catheters (12/204, 6 %) No patient experienced permanent heart block. Success and recurrence rates for this cohort of patients were similar to those reported for RFA used to treat AVNRT in pediatric patients. The findings show a higher success rate and a lower recurrence rate after cryoablation with a 6-mm-tip catheter than after use of the 4-mm-tip catheter, with an associated excellent safety profile.

Risk factors for lethal arrhythmic events in children and adolescents with hypertrophic cardiomyopathy and an implantable defibrillator: An international multicenter study.

BACKGROUND: Predictors of risk of lethal arrhythmic events (LAE) is poorly understood and may differ from adults in children with hypertrophic cardiomyopathy (HCM). OBJECTIVE: The purpose of this study was to determine predictors of LAE in children with HCM. METHODS: A retrospective data collection was performed on 446 children and teenagers 20 years and younger (290 [65%] male; mean age 10.1 ± 5.7 years) with idiopathic HCM from 35 centers. Patients were classified as group 1 (HCM with LAE) if having a secondary prevention implantable cardioverter-defibrillator (ICD) or primary prevention ICD with appropriate interventions or group 2 (HCM without LAE) if having a primary prevention ICD without appropriate interventions. RESULTS: There were 152 children (34%) in group 1 and 294 (66%) in group 2. Risk factors for group 1 by univariate analysis were septal thickness, posterior left ventricular (LV) wall thickness, lower LV outflow gradient, and Q wave > 3 mm in inferior electrocardiographic leads. Factors not associated with LAE were family history of SCD, abnormal blood pressure response to exercise, and ventricular tachycardia on ambulatory electrocardiographic monitoring. Risk factors for SCD by multivariate analysis were age at ICD placement (hazard ratio [HR] 0.9; P = .0025), LV posterior wall thickness z score (HR 1.02; P < .005), and LV outflow gradient < 30 mm Hg (HR 2.0; P < .006). LV posterior wall thickness z score ≥ 5 was associated with LAE. CONCLUSION: Risk factors for LAE appear different in children compared to adults. Conventional adult risk factors were not significant in children. Further prospective studies are needed to improve risk stratification for LAE in children with HCM.

Long-term risk of fatal malignancy following pediatric radiofrequency ablation.

Children undergoing radiofrequency ablation (RFA) are believed to be at increased risk of developing malignancy caused by radiation, although the magnitude of this risk is incompletely understood. We previously reported a strategy to reduce radiation exposure during pediatric RFA. In a cohort of 15 subjects (median age 12 years, range 9 to 17), radiation was measured using dosimeters at 5 sites. The risk of malignancy using measured radiation absorbed dose was calculated. International Council for Radiation Protection 60 risk estimates were applied to calculate absorbed organ doses. Median duration of combined biplane fluoroscopy was 14.4 minutes. Of the 5 dosimeter locations, the right scapular location had the highest median radiation exposure (43 mGy). Incorporating data from the 5 dosimeters, the risk model calculated that the organ with the greatest absorbed dose and at greatest risk of malignancy was the lung, followed by bone marrow, then breast. Thyroid and ovary exposures were negligible. The increased lifetime risk of fatal malignancy was 0.02% per single RFA procedure. In conclusion, with appropriate measures to reduce radiation exposure, the increased risk of malignancy after a single RFA procedure in children is low. These data should be of help counseling families and will contribute to analysis of the relative risk reduction benefits of such novel imaging approaches as a magnetic resonance imaging-based catheterization laboratory.

Acute pacing-induced dyssynchronous activation of the left ventricle creates systolic dyssynchrony with preserved diastolic synchrony.

INTRODUCTION: Patients with heart block have conventionally received a pacemaker that stimulates the right ventricular apex (RVA) to restore heart rate control. While RVA pacing has been shown to create systolic dyssynchrony acutely, dyssynchrony can also occur in diastole. The effects of acute RVA pacing on diastolic synchrony have not been investigated. RVA pacing acutely impairs diastolic function by increasing the time constant of relaxation, decreasing the peak lengthening rate and decreasing peak negative dP/dt. We therefore hypothesized that acute RVA pacing would cause diastolic dyssynchrony in addition to creating systolic dyssynchrony. METHODS AND RESULTS: Fourteen patients (13 +/- 4 years old) with non-preexcited supraventricular tachycardia underwent ablation therapy with subsequent testing to confirm elimination of the tachycardia substrate. Normal cardiac structure and function were then documented on two-dimensional echocardiography and 12-lead electrocardiography prior to enrollment. Tissue Doppler images were collected during normal sinus rhythm (NSR), right atrial appendage pacing (AAI), and VVI-RVA pacing during the postablation waiting interval. Systolic and diastolic dyssynchrony were quantified using cross-correlation analysis of tissue Doppler velocity curves. Systolic dyssynchrony increased 81% during RVA pacing relative to AAI and NSR (P < 0.01). Diastolic synchrony was not affected by the different pacing modes (P = 0.375). CONCLUSION: Acute dyssynchronous activation of the LV created by RVA pacing resulted in systolic dyssynchrony with preserved diastolic synchrony in pediatric patients following catheter ablation for treatment of supraventricular tachycardia. Our results suggest that systolic and diastolic dyssynchrony are not tightly coupled and may develop through separate mechanisms.

Congenital sick sinus syndrome caused by recessive mutations in the cardiac sodium channel gene (SCN5A).

Sick sinus syndrome (SSS) describes an arrhythmia phenotype attributed to sinus node dysfunction and diagnosed by electrocardiographic demonstration of sinus bradycardia or sinus arrest. Although frequently associated with underlying heart disease and seen most often in the elderly, SSS may occur in the fetus, infant, and child without apparent cause. In this setting, SSS is presumed to be congenital. Based on prior associations with disorders of cardiac rhythm and conduction, we screened the alpha subunit of the cardiac sodium channel (SCN5A) as a candidate gene in ten pediatric patients from seven families who were diagnosed with congenital SSS during the first decade of life. Probands from three kindreds exhibited compound heterozygosity for six distinct SCN5A alleles, including two mutations previously associated with dominant disorders of cardiac excitability. Biophysical characterization of the mutants using heterologously expressed recombinant human heart sodium channels demonstrate loss of function or significant impairments in channel gating (inactivation) that predict reduced myocardial excitability. Our findings reveal a molecular basis for some forms of congenital SSS and define a recessive disorder of a human heart voltage-gated sodium channel.

Distinguishing benign syncope from life-threatening cardiac causes of syncope.

Syncope, defined as the temporary loss of consiousness and postural tone resulting from an abrupt transient decrease in cerebral blood flow, is a common usually benign self-limiting event. However, rarely, it may be the first warning sign of a serious condition including arrhythmias, structural heart disease, or non-cardiac disease. This article presents a differential diagnosis of syncope in children with an emphasis on neurocardiogenic syncope, details important positives and negatives in the history and physical exam that would suggest cardiac syncope and gives recommendations on when to refer a child for syncope to a pediatric cardiologist.

Radiofrequency modification for inducible and suspected pediatric atrioventricular nodal reentry tachycardia.

INTRODUCTION: AV Node Reentry Tachycardia (AVNRT) is the second most common supraventricular tachycardia (SVT) undergoing pediatric radiofrequency ablation behind accessory pathway reentry tachycardias. AVNRT can be difficult to induce during electrophysiology study (EPS) and dual atrioventricular nodal (AVN) pathways physiology may not be demonstrated in young patients. PURPOSE: This report is the largest single center long term pediatric experience of radiofrequency modification of slow AVN input fibers for inducible or suspected (non-inducible) AVNRT. RESULTS: One hundred thirty-two patients underwent slow input AVN modification from 1993 to 2002. The mean patient age was 13.7 years (4-20 yrs) with 62M/70F. Outpatient tachycardia was documented by ambulatory monitoring in all patients. AVNRT was induced in 98/132 patients during EPS (group A) with mean SVT cycle length of 324 msec (230-570 msec). Initial AVN modification (group A) was successful in 97/98 patients (99%). During 34/132 EPS, AVNRT was non-inducible; dual AVN physiology was present in 19/34 (group B), and 15/34 did not show evidence for dual AVN physiology (group C). These 34 patients underwent empiric AVN modification following discussion with patients' families. Freedom of recurrence from SVT at 1 year was 96% for group A (94/98), 89% (17/19) for group B and 93% (14/15) for group C. 1 major and 6 minor complications occurred. CONCLUSIONS: AVN modification for AVNRT can be performed safely and effectively in pediatric patients with good long-term results. Empiric slow pathway AVN modification for non-inducible SVT results in a high rate of freedom from recurrence of tachycardia.

Initial experience with cardiac resynchronization therapy for ventricular dysfunction in young patients with surgically operated congenital heart disease.

Data regarding cardiac resynchronization therapy (CRT) in pediatric patients are limited. The first reported use of CRT in a young patient with congenital heart disease showed promising early results with improvement in New York Heart Association classification, aerobic capacity, and ventricular contractility 1 month after implant. Other reports have shown acute benefits of CRT in young patients with postoperative right bundle branch block after surgery for congenital heart defects. To date, however, there are no published data regarding CRT for the long-term management of systemic ventricular dysfunction in the young with associated congenital heart disease. This report describes our initial experience with CRT in these patients.

Efficacy of atrial antitachycardia pacing using the Medtronic AT500 pacemaker in patients with congenital heart disease.

Patients with congenital heart disease are vulnerable to atrial tachyarrhythmias, especially after atrial surgeries. We evaluated the efficacy of atrial arrhythmia detection and antitachycardia pacing (ATP) using the Medtronic AT500 pacemaker in 28 patients with congenital heart disease (age 30 +/- 18 years). Of 15 patients with atrial arrhythmias, 14 had atrial tachycardia events that were appropriately detected. ATP was enabled for 167 treatable episodes, successfully converting 90 (54%). Rhythms classified as ventricular tachycardia were detected 127 times, yet most were actually atrial or sinus tachycardia with 1:1 atrioventricular conduction. Atrial tachycardias in congenital heart disease are amenable to ATP algorithms in the AT500 pacemaker.

Novel electrocardiographic screening criterion for hypertrophic cardiomyopathy in children.

Electrocardiography is often advocated as a screening tool in children for hypertrophic cardiomyopathy (HC). We sought to establish an electrocardiographic screening tool to identify children with HC. We hypothesized that a pediatric-specific electrocardiographic criterion would perform better than the popular criteria used for screening children for left ventricular hypertrophy and HC. The earliest available electrocardiogram for children (n=108) with HC (ages 7 to 21 yrs) was reviewed. We sought to compare the diagnostic accuracy of 4 screening algorithms: (1) Sokolow-Lyon criterion (SV1+RV5/RV6>35 mm), (2) Cornell criterion (RaVL+SV3>28 mm in men, 20 mm in women), (3) total 12-lead voltage criterion (R wave to the nadir of Q/S wave>175 mm), and (4) pediatric-specific criterion (RaVL+SV2>23 mm). The same criteria were applied to a cohort of age-matched and gender-matched controls without cardiac disease. Statistically significant correlations were found between children with HC and positive screen using all 4 criteria. However, comparison of receiver operating characteristic demonstrated an area under the curve of 0.67 for Sokolow-Lyon criterion, 0.70 for Cornell criterion, 0.83 for total 12-lead criterion, and 0.82 for pediatric-specific criterion. Pediatric-specific criterion had superior sensitivity in gene-positive children and superior overall specificity than total 12-lead criterion. In conclusion, our study demonstrates that the pediatric-specific criterion employing leads RaVL+SV2 is more accurate in identifying children with HC in comparison with other popular screening criteria.

Perceived self-competence, psychosocial adjustment, and quality of life in pediatric patients with pacemakers.

OBJECTIVES: To compare participants' self-competence levels to normative data and examine self-competence as a potential protective factor against poorer health-related quality of life (HRQOL) and psychosocial adjustment in children with pacemakers. METHODS: Twenty-seven children between the ages of 8 and 18 years and their caregivers were recruited from a pediatric pacemaker clinic. Participants completed self-report and parent-proxy measures of children's health-related quality of life (HRQOL), self-competence, and psychosocial functioning, which included externalizing and internalizing symptoms, adaptive skills, and behavioral symptoms. RESULTS: Participants reported significantly lower levels of self-competence compared to healthy norms. Self-competence was significantly and positively correlated with most HRQOL domains. Few significant correlations emerged between self-competence and various domains of psychosocial functioning. CONCLUSION: Self-competence may function as a protective factor against lower HRQOL in children with pacemakers. There was less evidence that self-competence may play a protective role against lower adaptive skills and higher externalizing, internalizing, and behavioral symptoms. Clinical implications of these findings, limitations of the study, and areas for future research are discussed.

Catheter ablation of primary supraventricular tachycardia substrate presenting as atrial fibrillation in adolescents.

BACKGROUND: Atrial fibrillation is rarely encountered in children and adolescents, and these cases are usually secondary to myocardial diseases, electrical abnormalities, or scar related in postoperative congenital heart disease patients. Untreated sustained atrial fibrillation may lead to tachycardia-induced cardiomyopathy and/or systemic thromboembolization. OBJECTIVE: The objective here is to describe our findings in four adolescent patients presenting with recurrent atrial fibrillation. DESIGN: We report here the results of the findings in four patients who presented with recurrent clinical atrial fibrillation. RESULTS: Each of the four underwent electrophysiologic study that revealed a primary reentry or automatic supraventricular tachycardia (SVT) substrate, which was able to be treated with radiofrequency ablation. In three of the four cases, elimination of the primary substrate prevented subsequent recurrence of SVT symptoms or documented SVT and/or atrial fibrillation. CONCLUSION: Children and adolescents presenting with atrial fibrillation warrant an exhaustive search for a treatable primary cause of myocardial or electrical disease. If present, a primary SVT substrate may be successfully ablated to prevent recurrence of atrial fibrillation and any associated complications. Pulmonary vein isolation is rarely indicated in adolescents and should be avoided.

Does ablation of supraventricular tachycardia in children with a structurally normal heart improve quality of life?

INTRODUCTION: Ablation has become first-line therapy for managing many pediatric patients with atrioventicular accessory pathway or atrioventricular nodal-mediated supraventricular tachycardia (SVT). Studies to date have all focused on elimination of the SVT substrate; yet, there are no studies to document whether this results in improved quality of life (QoL) scores. OBJECTIVE: The objective of this study was to evaluate whether a successful catheter ablation improved QoL scores in pediatric patients. PATIENT AND METHODS: Pediatric patients between the age of 5 and 18 years with structurally normal hearts and re-entry SVT that were referred to the electrophysiology laboratory between October 2004 and June 2006 at the Children's Healthcare of Atlanta were eligible to be enrolled in the study. The Pediatric Quality of Life Inventory cardiac model questionnaire was administered to patients prior to and 6 months following catheter ablation. Areas evaluated were physical, emotional, social, school, and psychosocial function. The paired t-test was used to test the difference between pre- and post-time points for the study groups. P value <.05 was considered significant. RESULTS: Forty-three patients consented to initial enrollment and returned the initial questionnaires. Seven patients did not have ablations performed during the electrophysiology study and therefore were excluded from further analysis. Complete pre- and post-ablation data were available for 27 patients. Comparing pre-ablation data with post-ablation data, there was significant improvement in all measured areas following successful elimination of tachycardia substrate. Patients reported lowest social and physical functioning scores pre-ablation. The greatest reported improvement post-ablation was in physical functioning. CONCLUSION: Successful elimination of SVT substrate results in improved pediatric QoL scores as reported by patients.

Electrocardiographic screening in children with attention-deficit hyperactivity disorder.

Some investigators have suggested that children receiving stimulant medications to manage attention-deficit hyperactivity disorder should undergo screening electrocardiography to identify asymptomatic cardiac disease. However, no study to date has examined the efficacy and costs of this strategy. In the present study we sought to determine the utility of electrocardiographic screening in children with attention-deficit hyperactivity disorder. We reviewed the clinical experience of electrocardiographic screening of subjects with attention-deficit hyperactivity disorder <21 years of age from April to September 2008. Additional cardiac care and testing that resulted from an abnormal initial electrocardiogram were recorded. Screening electrocardiograms were obtained in 1,470 children with attention-deficit hyperactivity disorder and were interpreted as abnormal in 119 subjects (8.1%). Further evaluation of these 119 subjects included 63 transthoracic echocardiograms, 5 stress tests, and 9 Holter monitor studies. Cardiac disease was identified in 5 subjects (0.3% of entire cohort), yielding a positive predictive value of 4.2%. Cardiac diagnoses included ventricular pre-excitation syndrome (n = 2), bicuspid aortic valve (n = 2), and moderate secundum atrial septal defect (n = 1). The mean cost of electrocardiographic screening including further testing for subjects with abnormal initial screen results was $58 per child. The mean cost to identify a true-positive result was $17,162. In conclusion, electrocardiographic screening for children with attention-deficit hyperactivity disorder can successfully identify cardiac disease in otherwise asymptomatic subjects, although the positive predictive value is low. Ongoing studies are needed to know what role electrocardiographic screening should play in the management of children with attention-deficit hyperactivity disorder.

Outcomes following electroanatomic mapping and ablation for the treatment of ectopic atrial tachycardia in the pediatric population.

Ectopic atrial tachycardia (EAT) is often resistant to medical therapy, with radiofrequency ablation (RFA) being a preferred treatment option. Three-dimensional (3-D) electroanatomic mapping was introduced as a tool for improved substrate localization, although there are no published data with this technology in pediatric patients with EAT. The objective of this study was to examine our experience with 3-D mapping and standard mapping in this patient population. We used retrospective chart review of pediatric patients with EAT requiring RFA from 1993 to 2004. We analyzed the method of ablation, acute success and recurrence rates, procedure and fluoroscopy times, and cardiac function. Twenty-five patients underwent 31 RFA procedures. All patients had been followed for >6 months (6 months to 7 years). Standard mapping (Group 1) was used in 11 patients (5F/6M, 1.4-11.8 years) who underwent 13 RFA procedures; 3-D mapping (Group 2, October 2000-2004) was used in 16 patients (8 F/8M, 2.7-17 years) who underwent 18 RFA procedures. Left-sided focus was present in 6/13 in Group 1 and 7/18 in Group 2 (all transeptal, NS). There was a trend toward fewer lesions with 3-D mapping (15 +/- 14, median 9.5 in Group 1; 8 +/- 6, median 6.5 in Group 2, NS). Acute success was more likely for patients in which 3-D mapping was utilized (10/13 Group 1 vs. 18/18 Group 2, p < 0.04). Recurrence or persistence of tachycardia at follow-up (2 weeks to 1 year) was documented in 7/13 cases in Group 1, compared to only 2/18 cases in Group 2 (p = 0.01). Six patients underwent repeat RFA: two patients using standard mapping (one failure, one success) and four patients using 3-D mapping [all acute and long-term (>1 year) success]. Procedure times (232 +/- 84 vs. 268 +/- 72 min, skin-to-skin) and fluoroscopy times (47 +/- 24 vs. 40 +/- 20 min) were similar (NS). Of the 25 pts, 17 (7 in Group 1, 10 in Group 2, NS) presented with cardiomyopathy [Ejection fraction (EF), 38.6 +/- 12.1%]. Successful RFA resulted in improved EF (61.1 +/- 11.6%, p < 0.0001) in the 14 patients in whom pre-RFA and post-RFA echocardiograms were available. Compared to standard techniques, 3-D electroanatomic mapping has resulted in no acute failures, statistically reduced recurrence rates, and improved overall success in the management of EAT.