Utility of smart watches for identifying arrhythmias in children.

BACKGROUND: Arrhythmia symptoms are frequent complaints in children and often require a pediatric cardiology evaluation. Data regarding the clinical utility of wearable technologies are limited in children. We hypothesize that an Apple Watch can capture arrhythmias in children. METHODS: We present an analysis of patients ≤18 years-of-age who had signs of an arrhythmia documented by an Apple Watch. We include patients evaluated at our center over a 4-year-period and highlight those receiving a formal arrhythmia diagnosis. We evaluate the role of the Apple Watch in arrhythmia diagnosis, the results of other ambulatory cardiac monitoring studies, and findings of any EP studies. RESULTS: We identify 145 electronic-medical-record identifications of Apple Watch, and find arrhythmias confirmed in 41 patients (28%) [mean age 13.8 ± 3.2 years]. The arrythmias include: 36 SVT (88%), 3 VT (7%), 1 heart block (2.5%) and wide 1 complex tachycardia (2.5%). We show that invasive EP study confirmed diagnosis in 34 of the 36 patients (94%) with SVT (2 non-inducible). We find that the Apple Watch helped prompt a workup resulting in a new arrhythmia diagnosis for 29 patients (71%). We note traditional ambulatory cardiac monitors were worn by 35 patients (85%), which did not detect arrhythmias in 10 patients (29%). In 73 patients who used an Apple Watch for recreational or self-directed heart rate monitoring, 18 (25%) sought care due to device findings without any arrhythmias identified. CONCLUSION: We demonstrate that the Apple Watch can record arrhythmia events in children, including events not identified on traditionally used ambulatory monitors.

Wearable devices, such as smart watches, have become popular for the monitoring of health, particularly for people with heart conditions. Wearable devices have been well-studied in adults, however there is less information available on their effectiveness in monitoring children's health. We reviewed the heart electrical recordings of a group of children who submitted recordings obtained from their Apple Watches during moments when they felt as though their heart's rhythm was abnormal. The Apple Watches captured rhythm abnormalities that matched the diagnoses obtained using heart monitors used clinically. This study shows that use of Apple Watches can enable clinicians to identify abnormalities that many traditional at-home monitoring devices do not detect. Thus, wearable devices, such as the Apple Watch, could be used to help identify heart rhythm disorders in children.

Outcomes After Development of Ventricular Arrhythmias in Single Ventricular Heart Disease Patients With Fontan Palliation.

BACKGROUND: With the advent of more intensive rhythm monitoring strategies, ventricular arrhythmias (VAs) are increasingly detected in Fontan patients. However, the prognostic implications of VA are poorly understood. We assessed the incidence of VA in Fontan patients and the implications on transplant-free survival. METHODS: Medical records of Fontan patients seen at a single center between 2002 and 2019 were reviewed to identify post-Fontan VA (nonsustained ventricular tachycardia >4 beats or sustained >30 seconds). Patients with preFontan VA were excluded. Hemodynamically unstable VA was defined as malignant VA. The primary outcome was death and heart transplantation. Death with censoring at transplant was a secondary outcome. RESULTS: Of 431 Fontan patients, transplant-free survival was 82% at 15 years post-Fontan with 64 (15%) meeting primary outcome of either death (n=16, 3.7%), at a median 4.6 (0.4-10.2) years post-Fontan, or transplant (n=48, 11%), at a median of 11.1 (5.9-16.2) years post-Fontan. Forty-eight (11%) patients were diagnosed with VA (90% nonsustained ventricular tachycardia, 10% sustained ventricular tachycardia). Malignant VA (n=9, 2.0%) was associated with younger age, worse systolic function, and valvular regurgitation. Risk for VA increased with time from Fontan, 2.4% at 10 years to 19% at 20 years. History of Stage 1 surgery with right ventricular to pulmonary artery conduit and older age at Fontan were significant risk factors for VA. VA was strongly associated with an increased risk of transplant or death (HR, 9.2 [95% CI, 4.5-18.7]; P<0.001), with a transplant-free survival of 48% at 5-year post-VA diagnosis. CONCLUSIONS: Ventricular arrhythmias occurred in 11% of Fontan patients and was highly associated with transplant or death, with a transplant-free survival of <50% at 5-year post-VA diagnosis. Risk factors for VA included older age at Fontan and history of right ventricular to pulmonary artery conduit. A diagnosis of VA in Fontan patients should prompt increased clinical surveillance.

Posttraumatic stress disorder in pediatric patients with implantable cardioverter-defibrillators and their parents.

BACKGROUND: An implantable cardioverter-defibrillator (ICD) in the pediatric patient (and the precipitating events that led to ICD placement) can be traumatic for patients and their families and may lead to posttraumatic stress disorder (PTSD). OBJECTIVES: This study aimed to estimate the prevalence of PTSD in pediatric patients with an ICD and their parents and identify the factors associated with PTSD incidence. METHODS: Pediatric participants with an ICD aged 8-21 years and parents of children aged 0-21 years completed surveys that included demographic characteristics and PTSD measures. Pediatric participants completed additional psychosocial measures, such as anxiety and depression self-report questionnaires. RESULTS: Fifty youth (30% female) and 43 parents (70% female) completed the measures. Six of 50 youth (12%) met the screening criteria for a likely PTSD diagnosis, while 20 of 43 parents (47%) met the cutoff for PTSD on the screening measure. Children with PTSD were more likely to have had a secondary prevention ICD (83% vs 17%; P = .021), meet the clinical cutoff for depression (67% vs 16%; P = .005), and had higher shock anxiety scores (31.7 vs 17.9; P = .003) than children without PTSD. Female gender (57% vs 23%; P = .043) and patient depression (31% vs 5%; P = .042) were associated with PTSD in parents. CONCLUSION: Parents were found to be more likely to meet the criteria for PTSD than youth. In youth, PTSD was associated with medical and psychosocial factors, whereas PTSD in parents was associated with being female and child depression. Clinic-based screenings and management planning of emotional functioning are warranted to address psychological distress in patients and parents.

Implantable Cardioverter Defibrillators in Infants and Toddlers: Indications, Placement, Programming, and Outcomes.

BACKGROUND: Limited data exist regarding implantable cardioverter defibrillator (ICD) usage in infants and toddlers. This study evaluates ICD placement indications, procedural techniques, programming strategies, and outcomes of ICDs in infants and toddlers. METHODS: This is a single-center retrospective review of all patients ≤3 years old who received an ICD from 2009 to 2021. RESULTS: Fifteen patients received an ICD at an age of 1.2 years (interquartile range [IQR], 0.1-2.4; 12 [80%] women; weight, 8.2 kg [IQR, 4.2-12.6]) and were followed for a median of 4.28 years (IQR, 1.40-5.53) or 64.2 patient-years. ICDs were placed for secondary prevention in 12 patients (80%). Diagnoses included 8 long-QT syndromes (53%), 4 idiopathic ventricular tachycardias/ventricular fibrillations (VFs; 27%), 1 recurrent ventricular tachycardia with cardiomyopathy (7%), 1 VF with left ventricular noncompaction (7%), and 1 catecholaminergic polymorphic ventricular tachycardia (7%). All implants were epicardial, with a coil in the pericardial space. Intraoperative defibrillation safety testing was attempted in 11 patients (73%), with VF induced in 8 (53%). Successful restoration of sinus rhythm was achieved in all tested patients with a median of 9 (IQR, 7.3-11.3) J or 0.90 (IQR, 0.68-1.04) J/kg. Complications consisted of 1 postoperative chylothorax and 3 episodes of feeding intolerance. VF detection was programmed to 250 (IQR, 240-250) ms with first shock delivering 10 (IQR, 5-15) J or 1.1 (IQR, 0.8-1.4) J/kg. Three patients (20%) received appropriate shocks for ventricular tachycardia/VF. No patient received an inappropriate shock. There were 2 (13%) ventricular lead fractures (at 2.6 and 4.2 years post-implant), 1 (7%) pocket-site infection, and 2 (13%) generator exchanges. All patients were alive, and 1 patient (7%) received a heart transplant. CONCLUSIONS: ICDs can be safely and effectively placed for sudden death prevention in infants and toddlers with good midterm outcomes.

Identifying an appropriate endpoint for cryoablation in children with atrioventricular nodal reentrant tachycardia: Is residual slow pathway conduction associated with recurrence?

BACKGROUND: Cryoablation is increasingly used to treat atrioventricular nodal reentrant tachycardia (AVNRT) due to its safety profile. However, cryoablation may have higher recurrence than radiofrequency ablation (RFA), and the optimal procedural endpoint remains undefined. OBJECTIVE: The purpose of this study was to identify the association of cryoablation procedural endpoints with postprocedural AVNRT recurrence. METHODS: We performed a single-center, retrospective analysis of pediatric patients following successful first-time cryoablation for AVNRT between January 1, 2011, and December 31, 2019. Preablation inducibility of AVNRT was recorded. Procedural endpoints, including slow pathway (SP) conduction (presence of jump or echo beats) with and without isoproterenol, were identified. Recurrence was established from clinical notes and/or direct patient contact. RESULTS: Of 256 patients, 147 (57%) were assessed on isoproterenol precryoablation, and 171 (47%) were assessed on isoproterenol postcryoablation. Mean cryolesion time was 2586 ± 1434 seconds. Following ablation, 104 (41%) had some evidence of residual SP conduction. With median follow-up time of 1.9 [0.7-3.7] years, recurrence occurred in 14 patients (5%). Complete elimination of SP conduction (with and without isoproterenol) had a hazard ratio for recurrence of 1.26 (95% confidence interval [CI] 0.42-3.8; P = .68) on univariate analysis and 1.39 (95% CI 0.36-5.4; P = .63) on multivariate analysis (including demographics, ablation time, 8-mm cryocatheter, and baseline inducibility). CONCLUSION: The observed AVNRT recurrence rate after cryoablation was comparable to that of RFA. The presence of residual SP conduction was not associated with recurrence. This suggests that jump or single echo beat may be an acceptable endpoint in AVNRT cryoablation.

HRS White Paper on Clinical Utilization of Digital Health Technology.

This collaborative statement from the Digital Health Committee of the Heart Rhythm Society provides everyday clinical scenarios in which wearables may be utilized by patients for cardiovascular health and arrhythmia management. We describe herein the spectrum of wearables that are commercially available for patients, and their benefits, shortcomings and areas for technological improvement. Although wearables for rhythm diagnosis and management have not been examined in large randomized clinical trials, undoubtedly the usage of wearables has quickly escalated in clinical practice. This document is the first of a planned series in which we will update information on wearables as they are revised and released to consumers.

Pectoral nerve blocks decrease postoperative pain and opioid use after pacemaker or implantable cardioverter-defibrillator placement in children.

BACKGROUND: Pectoral nerve blocks (PECs) can reduce intraprocedural anesthetic requirements and postoperative pain. Little is known about the utility of PECs in reducing pain and narcotic use after pacemaker (PM) or implantable cardioverter-defibrillator (ICD) placement in children. OBJECTIVE: The purpose of this study was to determine whether PECs can decrease postoperative pain and opioid use after PM or ICD placement in children. METHODS: A single-center retrospective review of pediatric patients undergoing transvenous PM or ICD placement between 2015 and 2020 was performed. Patients with recent cardiothoracic surgery or neurologic/developmental deficits were excluded. Demographics, procedural variables, postoperative pain, and postoperative opioid usage were compared between patients who had undergone PECs and those who had undergone conventional local anesthetic (Control). RESULTS: A total of 74 patients underwent PM or ICD placement; 20 patients (27%) underwent PECs. There were no differences between PECs and Control with regard to age, weight, gender, type of device placed, presence of congenital heart disease, type of anesthesia, procedural time, or complication rates. Patients who underwent PECs had lower pain scores at 1, 2, 6, 18, and 24 hours compared to Control. PECs patients had a lower mean cumulative pain score [PECs 1.5 (95% confidence interval [CI] 0.8-2.2) vs Control 3.1 (95% CI 2.7-3.5); P <.001] and lower total opioid use [PECs 6.0 morphine milligram equivalent (MME)/m2 (95% CI 3.4-8.6) vs Control 15.0 MME/m2 (95% CI 11.8-18.2); P = .001] over the 24 hours postimplant. CONCLUSION: PECs reduce postoperative pain scores and lower total opioid usage after ICD or PM placement. PECs should be considered at the time of transvenous device placement in children.

Impact of Cardiac Resynchronization Therapy on Heart Transplant-Free Survival in Pediatric and Congenital Heart Disease Patients.

BACKGROUND: Cardiac resynchronization therapy (CRT) studies in pediatric or congenital heart disease patients have shown an improvement in ejection fraction and heart failure symptoms. However, a survival benefit of CRT in this population has not been established. This study aimed to evaluate the impact of CRT upon heart transplant-free survival in pediatric and congenital heart disease patients, using a propensity score-matched (PSM) analysis. METHODS: This single-center study compared CRT patients (implant date, 2004-2017) and controls, matched by 1:1 PSM using 21 comprehensive baseline indices for risk stratification. CRT patients were <21 years of age or had congenital heart disease, had systemic ventricular ejection fraction <45%, symptomatic heart failure, and had significant electrical dyssynchrony, all before CRT implant. Controls were screened from nonselective imaging and ECG databases. Controls were retrospectively enrolled when they achieved the same inclusion criteria at an outpatient clinical encounter, within the same time period. RESULTS: Of 133 patients who received CRT during the study period, 84 met all study inclusion criteria. One hundred thirty-three controls met all criteria at an outpatient encounter. Following PSM, 63 matched CRT-control pairs were identified with no significant difference between groups across all baseline indices. Heart transplant or death occurred in 12 (19%) PSM-CRT subjects and 37 (59%) PSM-controls with a median follow-up of 2.7 years (quartiles, 0.8-6.1 years). CRT was associated with markedly reduced risk of heart transplant or death (hazard ratio, 0.24 [95% CI, 0.12-0.46]; P<0.001). There was no CRT procedural mortality and 1 system infection at 54 months post-implant. CONCLUSIONS: In pediatric and congenital heart disease patients with symptomatic systolic heart failure and electrical dyssynchrony, CRT was associated with improved heart transplant-free survival. Visual Overview: A visual overview is available for this article.

An exploratory assessment of pediatric patient and parent needs after implantable cardioverter defibrillator implant.

BACKGROUND: Placement of an implantable cardioverter defibrillator (ICD) is often accompanied by psychological adjustment issues in pediatric patients and their parents. Although anxiety, depression, and lowered quality of life have been seen in these patients, no studies have investigated patient or parent reported needs. This exploratory study describes the needs of pediatric ICD patients and parents and assesses whether patient factors of age, gender, depression, and anxiety are associated with specific needs. METHODS: ICD patients ages 8-21 years and their parents completed a needs analysis survey assessing various domains of functioning. Patients also completed self-reported measures of depression and anxiety. RESULTS: Thirty-two patients (28% female) and their parents (72% mothers) completed the survey. Patients' most frequently endorsed needs involved educational issues: understanding their cardiac event/diagnosis (34%), medications (34%), and how the ICD would change their lifestyle (31%). Parents' most frequently endorsed needs involved family issues; almost half of parents (47%) were concerned about their children's frustration with their overprotectiveness and 28% were concerned with their child feeling depressed or anxious. Patients who reported feeling overprotected (12.1 ± 3.4 vs 17.4 ± 3.5 years; P = .001) were significantly younger than those who did not. Experiencing peer issues was more frequently endorsed by females than males (33% of females vs 4% of males; P = .026). CONCLUSIONS: ICD patients and parents endorsed markedly different needs. Patients focused on understanding their ICD, whereas parents were more focused on their children's emotional needs. Novel ways of educating patients about their device and clinic-based screenings of emotional functioning may serve to meet these needs.

Validation of a novel automated signal analysis tool for ablation of Wolff-Parkinson-White Syndrome.

BACKGROUND: In previous pilot work we demonstrated that a novel automated signal analysis tool could accurately identify successful ablation sites during Wolff-Parkinson-White (WPW) ablation at a single center. OBJECTIVE: We sought to validate and refine this signal analysis tool in a larger multi-center cohort of children with WPW. METHODS: A retrospective review was performed of signal data from children with WPW who underwent ablation at two pediatric arrhythmia centers from 2008-2015. All patients with WPW ≤ 21 years who underwent invasive electrophysiology study and ablation with ablation signals available for review were included. Signals were excluded if temperature or power delivery was inadequate or lesion time was < 5 seconds. Ablation lesions were reviewed for each patient. Signals were classified as successful if there was loss of antegrade and retrograde accessory pathway (AP) conduction or unsuccessful if ablation did not eliminate AP conduction. Custom signal analysis software analyzed intracardiac electrograms for amplitudes, high and low frequency components, integrated area, and signal timing components to create a signal score. We validated the previously published signal score threshold 3.1 in this larger, more diverse cohort and explored additional scoring options. Logistic regression with lasso regularization using Youden's index criterion and a cost-benefit criterion to identify thresholds was considered as a refinement to this score. RESULTS: 347 signals (141 successful, 206 unsuccessful) in 144 pts were analyzed [mean age 13.2 ± 3.9 years, 96 (67%) male, 66 (45%) left sided APs]. The software correctly identified the signals as successful or unsuccessful in 276/347 (80%) at a threshold of 3.1. The performance of other thresholds did not significantly improve the predictive ability. A signal score threshold of 3.1 provided the following diagnostic accuracy for distinguishing a successful from unsuccessful signal: sensitivity 83%, specificity 77%, PPV 71%, NPV 87%. CONCLUSIONS: An automated signal analysis software tool reliably distinguished successful versus unsuccessful ablation electrograms in children with WPW when validated in a large, diverse cohort. Refining the tools using an alternative threshold and statistical method did not improve the original signal score at a threshold of 3.1. This software was effective across two centers and multiple operators and may be an effective tool for ablation of WPW.

A Prospective Assessment of Optimal Mechanical Ventilation Parameters for Pediatric Catheter Ablation.

Catheter stability, an important factor in ablation success, is affected by ventilation. Optimal ventilation strategies for pediatric catheter ablation are not known. We hypothesized that small tidal volume and positive end-expiratory pressure are associated with reduced ablation catheter movement at annular positions. Subjects aged 5-25 years undergoing ablation for supraventricular tachycardia (SVT) or WPW at two centers from March 2015 to September 2016 were prospectively enrolled and randomized to receive mechanical ventilation with either positive end-expiratory pressure of 5 cm H2O (PEEP) or 0 cm H2O (ZEEP). Movement of the ablation catheter tip at standard annular positions was measured using 3D electroanatomic mapping systems under two conditions: small tidal volume (STV) (3-5 mL/kg) or large TV (LTV) (6-8 mL/kg). 58 subjects (mean age 13.8 years) were enrolled for a total of 266 separate observations of catheter movement. STV ventilation was associated with significantly reduced catheter movement, compared to LTV at all positions (right posteroseptal: 2.5 ± 1.4 vs. 5.2 ± 3.1 mm, p < 0.0001; right lateral: 2.7 ± 1.6 vs. 6.3 ± 3.5 mm, p < 0.0001; left lateral: 1.8 ± 1.0 vs. 4.3 ± 1.9 mm, p < 0.0001). The presence or absence of PEEP had no effect on catheter movement. In multivariable analysis, STV was associated with a 3.1-mm reduction in movement (95% CI 2.6-3.5, p < 0.0001), adjusting for end-expiratory pressure, annular location, and patient size. We conclude that STV ventilation is associated with reduced ablation catheter movement compared to a LTV strategy, independent of PEEP and annular position.

Antibiotic Prophylaxis Practices in Pediatric Cardiac Implantable Electronic Device Procedures: A Survey of the Pediatric And Congenital Electrophysiology Society (PACES).

Cardiac implantable electronic device (CIED) infections are associated with significant morbidity in the pediatric device population, with a tenfold higher risk of infection in children compared to adults. The 2010 American Heart Association (AHA) guidelines recommend a single dose of systemic antibiotic (ABX) prophylaxis prior to CIED implantation and no post-operative (OP) ABX. However, there is limited data regarding adherence to this recommendation among the pediatric community. To assess current clinical practices for CIED ABX prophylaxis in pediatrics; whether the AHA guidelines are being followed; and if not, the reasons for non-adherence. An anonymous web-based survey was sent to physician members of the Pediatric And Congenital Electrophysiology Society regarding ABX prophylaxis for new CIED implants and reoperations. 75 (25%) members responded. Only 7% of respondents follow the 2010 AHA guidelines. While all respondents give pre-OP IV ABX, 64% routinely treat patients with 24-h post-OP IV ABX with additional oral or IV therapy. 69% of respondents are cognizant of the guidelines but 88% of those cognizant do not follow the guidelines for a variety of reasons including lack of data and different substrate (pediatric patients). 79% stated that pediatric-specific data would be required for them to change their practice and follow the published guidelines. The majority of pediatric EP physicians who responded to this survey do not follow the current AHA guidelines on ABX prophylaxis and administer post-OP ABX. Most pediatric EP physicians believe that the increased risk of infection in children merits additional ABX.

Bridge to success: A better method of cryoablation for atrioventricular nodal reentrant tachycardia in children.

BACKGROUND: Cryoablation for atrioventricular nodal reentrant tachycardia (AVNRT) is associated with higher recurrence rates than radiofrequency ablation (RFA). Junctional tachycardia marks procedural success with RFA, but no such indicator exists for cryoablation. OBJECTIVE: The purpose of this study as to determine the impact of voltage mapping plus longer ablation lesions on midterm success of cryoablation for children with AVNRT. METHODS: We performed a single-center retrospective analysis of pediatric patients with AVNRT who underwent cryoablation from 2011 to 2015. Patients ablated using a standard electroanatomic approach (control) were compared with patients ablated using voltage mapping (voltage group). In the voltage group, EnSite NavX navigation and visualization technology (St Jude Medical, St Paul, MN) was used to develop a "bridge" of lower voltage gradients (0.3-0.8 mV) of the posteroseptal right atrium to guide cryoablation. Kaplan-Meier analysis was used to determine freedom from recurrence of supraventricular tachycardia. RESULTS: In all, 122 patients were included (71 voltage, 51 control). There was no difference between groups regarding age, sex, or catheter-tip size. Short-term success was similar in both groups (98.5% voltage vs 92% control; P = .159), but recurrence rates were lower in the voltage group (0% vs 11%, P = .006). Follow-up time was shorter in the voltage group (15 ± 7 months vs 22 ± 17 months, P < .05). The 1-year freedom from recurrence was lower in the voltage group (100% vs 91.5%, P <.05). Ablation times were longer in the voltage group (43.7 ± 20.9 minutes vs 34.3 ± 20.5 minutes, P = .01), but overall procedure times were shorter in the voltage group (157 ± 40 minutes vs 198 ± 133 minutes; P = .018). No significant complication was seen in either group. CONCLUSION: Voltage gradient mapping and longer lesion time can decrease recurrence rates in pediatric patients with AVNRT.

Ventricular pacing in single ventricles-A bad combination.

BACKGROUND: Chronic ventricular pacing (VP) is associated with systolic dysfunction in a subset of pediatric patients with heart block and structurally normal hearts. The effect of chronic VP in congenital heart disease is less well understood, specifically in the single-ventricle (SV) population. OBJECTIVE: To determine the longitudinal effect of VP in SV patients. METHODS: SV patients with heart block and dual-chamber pacemakers requiring >50% VP were compared with nonpaced (controls) SV patients matched for age, sex, and SV morphology. Patients were excluded if a prepacing echocardiogram was not available. Echocardiogram and clinical parameters were compared at baseline (prepacing) and at last follow-up in the paced group, and in controls when they were at ages similar to those of their paced-group matches. RESULTS: Twenty-two paced and 53 control patients from 2 institutions were followed for similar durations (6.6±5 years vs 7.6±7.6 years; P = .59). There was no difference between groups regarding baseline ventricular function or the presence of moderate-to-severe atrioventricular valvar regurgitation (AVVR). Paced patients were more likely to develop moderate-to-severe systolic dysfunction (68% vs 15%; P < .01) and AVVR (55% vs 8%; P < .001) and require heart failure medications (65% vs 21%; P < .001). Chronic VP was also associated with a higher risk of transplantation or death (odds ratio, 4.9; 95% confidence interval, 1.05-22.7; P = .04). CONCLUSIONS: SV patients requiring chronic VP are at higher risk of developing moderate-to-severe ventricular dysfunction and AVVR with an increased risk of death or transplantation compared with controls. New strategies to either limit VP or improve synchronization in this vulnerable population is imperative.

Is There a Difference in Tachycardia Cycle Length during SVT in Children with AVRT and AVNRT?

BACKGROUND: There are limited adult data suggesting the tachycardia cycle length (TCL) of atrioventricular reentry tachycardia (AVRT) is shorter than atrioventricular nodal reentry tachycardia (AVNRT), though little data exist in children. We sought to determine if there is a difference in TCL between AVRT and AVNRT in children. METHODS: A single-center retrospective review of children with supraventricular tachycardia (SVT) from 2000 to 2015 was performed. INCLUSION CRITERIA: Age ≤ 18 years, invasive electrophysiology study (EPS) confirming AVRT or AVNRT. EXCLUSION CRITERIA: Atypical AVNRT, congenital heart disease, antiarrhythmic medication use at time of EPS. Data were compared between patients with AVRT and AVNRT via t-test, χ2 test, and linear regression. RESULTS: A total of 835 patients were included (12 ± 4 years, 52 ± 31 kg, TCL 321 ± 55 ms), 539 (65%) with AVRT (270 Wolff-Parkinson-White, 269 concealed pathways) and 296 (35%) with AVNRT. Patients with AVRT were younger (11.7 ± 4.1 years vs 13.0 ± 3.6 years, P < 0.001) and smaller (49 ± 22 kg vs 57 ± 43 kg, P < 0.001). In the baseline state, the TCL was shorter in AVRT than AVRNT (329 ± 51 ms vs 340 ± 60 ms, P = 0.04). In patients requiring isoproterenol to induce SVT, there was no difference in TCL (290 ± 49 ms vs 297 ± 49 ms, P = 0.26). When controlling for age, there was no difference in TCL between AVRT and AVNRT at baseline or on isoproterenol. The regression equation for TCL in the baseline state was TCL = 290 + 4 (age), indicating the TCL will increase by 4 ms above a baseline of 290 ms for each year of life. CONCLUSIONS: When controlling for age, there is no difference in the TCL between AVRT and AVNRT in children. Age, not tachycardia mechanism, is the most significant factor in predicting TCL.

Erratum to: Safety and feasibility of oral immunotherapy to multiple allergens for food allergy.

[This corrects the article DOI: 10.1186/1710-1492-10-1.].

50 is the new 70: Short ventriculoatrial times are common in children with atrioventricular reciprocating tachycardia.

BACKGROUND: One of the basic electrophysiological principles of atrioventricular reciprocating tachycardia (AVRT) is that ventriculoatrial (VA) times during tachycardia are >70 ms. We hypothesized, however, that children may commonly have VA times <70 ms in AVRT. OBJECTIVE: This study sought to determine the incidence and characteristics associated with short-VA AVRT in children. METHODS: A retrospective single-center review of children with AVRT from 2000 to 2014 was performed. All patients ≤18 years of age with AVRT at electrophysiology study were included. Patients with persistent junctional reciprocating tachycardia, atrioventricular nodal reentry tachycardia, and tachycardia not unequivocally proven to be AVRT were excluded. VA time was defined as the time between earliest ventricular activation and earliest atrial activation in any lead and was confirmed by 2 electrophysiologists. Patients with VA times <70 ms (SHORT-VA) and those with standard VA times ≥70 ms (STD-VA) were compared. Logistic regression analysis identified characteristics of SHORT-VA patients. RESULTS: A total of 495 patients with AVRT were included (mean age 11.7 ± 4.1 years). There were 265 patients (54%) with concealed accessory pathways (APs) and 230 (46%) with Wolff-Parkinson-White syndrome. AP location was left-sided in 301 patients (61%) and right-sided in 194 (39%). The mean VA time in AVRT was 100 ± 33 ms. A total of 63 patients (13%) had VA times <70 ms (SHORT-VA). The shortest VA time during AVRT was 50 ms. There was no difference in age, AV nodal block cycle, or body surface area between SHORT-VA and STD-VA patients, but SHORT-VA patients had lower weight (43 ± 17 vs 51 ± 23 kg, P = .02), lower AV nodal effective refractory period (AVNERP; 269 ± 50 vs 245 ± 52 ms, P < .01), and more left-sided APs (50 [79%] vs 251 [58%]; P < .01]. On multivariate logistic regression, factors associated with SHORT-VA included left-sided AP (odds ratio [OR] 5.79, confidence interval [95% CI] 2.21-15.1, P < .01), shorter AVNERP (OR 0.99, CI 0.98-0.99, P < .01), and lower weight (OR 0.97, CI 0.95-0.99, P < .01). CONCLUSIONS: Children with AVRT can frequently have VA times <70 ms, with 50 ms being the shortest VA time. This finding debunks the classic electrophysiology principle that VA times in AVRT must be >70 ms. SHORT-VA AVRT was more common in children with left-sided APs.

Phase 1 results of safety and tolerability in a rush oral immunotherapy protocol to multiple foods using Omalizumab.

BACKGROUND: Up to 30% of patients with food allergies have clinical reactivity to more than one food allergen. Although there is currently no cure, oral immunotherapy (OIT) is under investigation. Pilot data have shown that omalizumab may hasten the ability to tolerate over 4 g of food allergen protein. OBJECTIVE: To evaluate the safety and dose tolerability of a Phase 1 Single Site OIT protocol using omalizumab to allow for a faster and safe desensitization to multiple foods simultaneously. METHODS: Participants with multiple food allergies received OIT for up to 5 allergens simultaneously with omalizumab (rush mOIT). Omalizumab was administered for 8 weeks prior to and 8 weeks following the initiation of a rush mOIT schedule. Home reactions were recorded with diaries. RESULTS: Twenty-five (25) participants were enrolled in the protocol (median age 7 years). For each included food, participants had failed an initial double-blind placebo-controlled food challenge at a protein dose of 100 mg or less. After pre-treatment with omalizumab, 19 participants tolerated all 6 steps of the initial escalation day (up to 1250 mg of combined food proteins), requiring minimal or no rescue therapy. The remaining 6 were started on their highest tolerated dose as their initial daily home doses. Participants reported 401 reactions per 7,530 home doses (5.3%) with a median of 3.2 reactions per 100 doses. Ninety-four percent (94%) of reactions were mild. There was one severe reaction. Participants reached their maintenance dose of 4,000 mg protein per allergen at a median of 18 weeks. CONCLUSION: These phase 1 data demonstrate that rush OIT to multiple foods with 16 weeks of treatment with omalizumab could allow for a fast desensitization in subjects with multiple food allergies. Phase 2 randomized controlled trials are needed to better define safety and efficacy parameters of multi OIT experimental treatments with and without omalizumab.