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.

Long-term follow-up shows excellent transmural atrial lead performance in patients with complex congenital heart disease.

BACKGROUND: Many patients with congenital heart disease require permanent pacing for rhythm management but cannot undergo transvenous lead placement. In others, epicardial scarring prohibits adequate sensing and pacing thresholds using epicardial leads. This study describes long-term lead performance using a transmural atrial (epicardial to endocardial) pacing approach in patients with congenital heart disease. METHODS AND RESULTS: For transmural atrial (TMA) lead access, a bipolar, steroid-eluting transvenous lead was placed from the epicardium via purse-string incision or atriotomy and affixed to atrial endocardium. Records were reviewed for patient data and acute and long-term lead performance for TMA leads placed 1998 to 2004. Forty-two of 48 TMA leads remain active at last follow-up. Two leads fractured, 4 were functional at >5-year follow-up but no longer active. Freedom from lead failure 98% (95% confidence interval, 86%-100%) at mean follow-up 7.8 years. TMA leads gave excellent sensing and pacing characteristics at implant and chronically. Median acute and chronic sensing thresholds were 3 and 2.8 mV, respectively; median acute and chronic pacing thresholds at 0.5 ms were 0.9 and 0.7 V, respectively. TMA leads performed similarly in Fontan patients. Overdrive pacing for intra-atrial re-entrant tachycardia was successful in 7 of 8 patients. One patient with high baseline risk died of stroke 7 years after implant. No lead-associated thrombi were observed. CONCLUSIONS: TMA pacing leads had excellent longevity, initial, and chronic functional properties and provide an alternative to epicardial leads in patients with congenital heart disease. Patients who cannot receive transvenous leads, have epicardial scarring or have intra-atrial re-entrant tachycardia could benefit most from routine use of this technique.

Atrial tachycardias in young adults and adolescents with congenital heart disease: conversion using single dose oral sotalol.

UNLABELLED: Atrial tachyarrhythmias are a chronic long-term hazard in patients with congenital heart disease (CHD). These arrhythmias contribute to ventricular dysfunction, heart failure can contribute to sudden death. We performed a prospective study of oral sotalol for the conversion of atrial tachyarrhythmias in adults and adolescents with congenital heart disease and stable hemodynamics. METHODS: Patients were admitted and given oral sotalol in an inpatient, monitored setting. The initial dose was targeted at 2 mg/kg. Antiarrhythmic drugs other than digoxin were stopped. RESULTS: Nineteen patients were enrolled. The average patient age was 20 years (12-39). Four had atrial ectopic tachycardia (AET) and 15 had atrial reentry tachycardia (IART). Nine had Fontan physiology. Permanent pacing therapies had failed to restore sinus or paced rhythm consistently in 6 patients. Overall 16 of 19 atrial tachyarrhythmias (84%) converted with single dose oral sotalol. AET converted to sinus or paced rhythm in 3/4 patients and IART in 13/15 patients. The average times to conversion were 98 and 145 min, respectively. Two patients required pacemakers due to sinus bradycardia. One patient had a lethal thromboembolic event 2 days after conversion. CONCLUSIONS: Oral sotalol offers an effective alternative to direct current cardioversion in adults and adolescents with CHD and hemodynamically stable atrial tachyarrhythmias. Conversion with sotalol at ~2 mg/kg generally occurred within 2 h. Vigilance for thromboembolism must be maintained as well as caution for those with bradycardia without pacemakers in this patient population. There are theoretical and practical advantages of sotalol over cardioversion.

Supraventricular tachycardia in the pediatric primary care setting: Age-related presentation, diagnosis, and management.

As many as 1 in 250 children experience supraventricular tachycardia (SVT), but its presentation is often vague and its symptoms mistakenly attributed to other common pediatric conditions. If SVT is correctly identified in a timely manner, most children will go on to live normal healthy lives. SVT is not covered in depth in most pediatric advanced practice nursing programs, but because of its prevalence, it should be familiar to all pediatric primary care providers. This article reviews common mechanisms of SVT and their age-related presentation, diagnosis, and management. A case study of an 8-year-old boy with SVT is presented.

"Transseptal" technique through atrial baffles for 3-dimensional mapping and ablation of atrial tachycardia in patients with d-transposition of the great arteries.

Access to targets for radiofrequency ablation in patients with congenital heart disease may be limited by anatomy and by surgically placed obstacles. In patients with atrial switch anatomy for d-transposition of the great arteries, the critical isthmus for maintenance of intraatrial macroreentry circuits is found often on the pulmonary venous side of the atrial baffle. A retrograde approach is extremely difficult for these arrhythmias. Use of transseptal techniques for diagnostic catheterization in these patients has been reported. We report the use of a transseptal technique in two cases in conjunction with 3-dimensional electroanatomic mapping for the successful ablation of atrial reentry tachycardias in patients with Mustard and Senning anatomy.

Techniques to avoid atrioventricular block during radiofrequency catheter ablation of septal tachycardia substrates in young patients.

UNLABELLED: Radiofrequency catheter ablation (RFCA) has proven safe for most young patients, but the risk of inadvertent atrioventricular (AV) block remains. The purpose of this report is to describe techniques to avoid inadvertent AV block during effective RFCA in young patients with septal tachycardia substrates. METHODS: The techniques included intubation and apnea during RFCA, coronary sinus pacing during RFCA to observe intact AV conduction during junctional ectopy, localizing the optimal His electrogram prior to RFCA, not ablating during tachycardia and titrating power output with temperature monitoring. RESULTS: In the period January 1995-June 2001, RFCA of 424 tachycardia substrates was performed. A total of 217 consecutive septal tachycardia substrates are included in this report. Apnea eliminated a mean catheter tip displacement of 5.4 +/- 2.5 mm seen during respiration. No patient experienced transient or permanent complete AV block after any of the 217 substrate ablation procedures. All of the patients had normal PR intervals following ablation without development of any degree of AV block in 194 patients at latest follow-up. RFCA success for substrates with septal accessory pathways was 87/96 (91%), permanent junctional reciprocating tachycardia (PJRT) 15/16 (94%), typical atrioventricular node reentry tachycardia (AVNRT) 82/85 (96%), atypical AVNRT 6/7 (86%) and intra-atrial reentry tachycardia (IART) 10/13 (77%). Fluoroscopy time averaged 10.8 minutes. For patients with accessory pathway, 8 (7.9%) developed a recurrence. CONCLUSION: Catheter stability is paramount to safe and effective RFCA in septal locations. Use of these techniques resulted in acceptable success rates and low recurrence rate for RFCA of septal tachycardia substrates while avoiding inadvertent AV block in these young patients.

Pacemaker therapy in isolated congenital complete atrioventricular block.

The aim of this study was to evaluate the effect of pacemaker (PM) therapy in patients with isolated congenital complete atrioventricular block (CCAVB). Patients with CCAVB eventually quality for PM implantation, however, timing remains controversial. Retrospective evaluation of left ventricular end-diastolic diameter (LVEDD), shortening fraction (SF), and cardiothoracic ratio (CTR) in 149 CCAVB patients, before, at, and after PM implantation was carried out. LVEDD shows an average increase of 0.48%/month in non-PM patients, and an average decrease of 0.88%/month in PM patients. SF shows an average increase of 0.10%/month in non-PM, and an average decrease of 0.32%/month in PM patients. CTR shows an average increase of 0.02%/month in non-PM, and an average decrease of 0.19%/month in PM patients. The difference between the non-PM and PM groups is significant (P = 0.05) for all variables. Symptomatic patients show no significant change in LVEDD after PM therapy (from 66.5% before to 68.5% after PM therapy). Asymptomatic patients do show a significant (P < 0.001) decrease in LVEDD after PM therapy (from 78.4% before to 73.3% after PM therapy). CTR does not differ significantly between symptomatic and asymptomatic patients before PM therapy (58% and 57%, respectively). CTR does differ significantly (P < 0.001) between symptomatic and asymptomatic patients after PM therapy (52% and 48%, respectively). Heart size and SF are increased in most patients with isolated CCAVB. PM implantation is associated with a decrease in heart size and normalization of SF in most patients. Indications for PM therapy in children may require reevaluation in asymptomatic patients with increased cardiac size and decreased cardiac function.