PACES/HRS expert consensus statement on the management of the asymptomatic young patient with a Wolff-Parkinson-White (WPW, ventricular preexcitation) electrocardiographic pattern: developed in partnership between the Pediatric and Congenital Electrophysiology Society (PACES) and the Heart Rhythm Society (HRS). Endorsed by the governing bodies of PACES, HRS, the American College of Cardiology Foundation (ACCF), the American Heart Association (AHA), the American Academy of Pediatrics (AAP), and the Canadian Heart Rhythm Society (CHRS)

Serial Exercise Testing in Children With Known or Suspected Congenital and Acquired Heart Disease: A Narrative Review and Survey of Current Practice

BACKGROUND

Exercise parameters can be altered in children with congenital heart disease or acquired heart disease compared with children with normal hearts. Exercise testing has proven a useful tool to predict patient outcomes and even the need for reintervention in several cardiovascular disease processes. There are established guidelines for serial exercise stress testing in adults with congenital heart disease, but corollary guidelines do not exist for the pediatric population.

METHODS AND RESULTS

A narrative literature review was completed. Evidence was ranked by a 4-point scale as outlined by the American College of Sports Medicine evidence categories. A survey was sent to experts in pediatric exercise physiology across the country regarding their current testing practices for 26 unique congenital heart disease or known or suspected acquired heart disease lesions. Survey questions were related to the frequency of testing, the age at which exercise testing is started, and if the frequency of testing is altered by a patient presenting with symptoms. Our literature search yielded 122 relevant studies pertaining to exercise stress testing in pediatric heart disease. We received 59 responses to our survey from 33 unique institutions in the United States and Canada.

CONCLUSIONS

Twenty-one summaries were provided regarding exercise stress testing in pediatric patients with heart disease. Multicentered or national stress testing registries may allow for adequate sample sizes of rare pediatric diseases to allow for development of improved guidelines regarding the type and timing of stress testing.

Spontaneous Resolution of Ventricular Pre-Excitation During Childhood: A Retrospective Study

Background/Objectives: Ventricular pre-excitation (VP) increases the risk of sudden cardiac death among children. While transcatheter ablation could potentially be therapeutic, it is not without risk, especially in smaller children. Accessory pathways (APs) may spontaneously lose anterograde conduction properties over time, making invasive treatment unnecessary. We aim to investigate the probability of spontaneous loss of VP during childhood, as well as the potential factors that may be associated with VP resolution. Methods: We conducted a retrospective study of patients with VP diagnosed before 12 years of age and referred to two Northern Italian tertiary care hospitals between 1993 and 2021. Patients with complex congenital heart disease were excluded. Our primary objective was to determine the likelihood of spontaneous resolution of VP. Results: Overall, 153 patients were included, with a median age at first diagnosis of 4.9 years (25th-75th percentile: 75 days-8.4 years) and a median follow-up of 4.9 years (25th-75th percentile: 1.8-8 years). Through left truncated Kaplan-Meier analysis, we estimated that anterograde conduction would persist in 53% and 33.8% of patients at the age of 1 and 16 years, respectively. Our findings revealed that the absence of symptoms and intermittent VP were associated with a higher likelihood of VP resolution. It is noteworthy that no major arrhythmic events were reported. Conclusions: Our study strongly supports the implementation of a conservative strategy in younger children with VP. Our findings indicate that a significant proportion of pediatric patients may experience spontaneous resolution of VP in the early years of their lives, making any invasive treatment unnecessary.

Catheter Ablation of Septal Accessory Pathways in Children: A 12-Year Experience at a Tertiary Care Center

Background: Septal accessory pathways (APs) are challenging ablation targets. This study aims to contribute to the pediatric literature by presenting our long-term experience of septal AP ablations with limited fluoroscopy. Methods: This is a retrospective study of all patients who underwent septal AP ablations from July 2012 to July 2023 at a single center. Results: We identified 298 septal AP connections in 291 (11.8 ± 4.9 years) patients. Seventy-nine (27%) cases were diagnosed with supraventricular tachycardia, and 212 (73%) cases were diagnosed with Wolff-Parkinson-White (WPW). The AP locations were posteroseptal (n = 159; 54%), anteroseptal (n = 86; 30%), and midseptal (n = 46; 16%). Of those diagnosed with WPW, 61 (28%) had high-risk AP, and 90 (40%) were adenosine-responsive. Cryoablation was used in 190 (66%), radiofrequency ablation (RFA) was used in 36 (12.5%), and both were used in 62 (21.5%) patients. The overall acute success rate of initial procedures was 89.6% (the acute success rate of cryoablation = 86.6%, and of RFA = 94.1%). No statistically significant difference was observed between cryoablation and RFA (p = 0.617). During a mean follow-up of 88.5 ± 33.0 months, the overall recurrence rate was 11.3% (cryoablation vs. RFA; p = 0.834), with the highest at the right-posteroseptal location. An irrigated-tip RFA was preferred during redo procedures in 20 (45%) cases. The long-term success rate was 99% when the repeat procedures were considered. No complications were observed. Conclusions: Due to the higher recurrence rates in septal AP ablations compared to other locations, repeated procedures might be needed to achieve definitive long-term success. This study indicates that similar acute and long-term success rates can be achieved with cryoablation compared to RFA, with the significant benefit of increased safety.

A rare genetic variant in PRDM16 is associated with Wolff-Parkinson-White syndrome with complex accessory pathway characteristics and left ventricular non-compaction cardiomyopathy

Not only has Wolff-Parkinson-White syndrome been associated with congenital cardiac abnormalities and cardiomyopathies, but familial clustering of Wolff-Parkinson-White syndrome has also been reported. Despite these well-known associations, direct genetic aetiology is rarely implicated in patients with Wolff-Parkinson-White syndrome. We report a 17-year-old girl with Wolff-Parkinson-White syndrome and left ventricular non-compaction cardiomyopathy due to a rare genetic variant in PR-domain containing protein 16. The report is supplemented by a comprehensive review of literature on association between PRDM16, left ventricular non-compaction and Wolff-Parkinson-White syndrome.

Impact of growth on electrophysiological properties of ventricular pre-excitation in paediatric athletes

AIM

Risk stratification is recommended for patients with ventricular pre-excitation, particularly when sports eligibility is required. Few studies have examined the changes in the electrophysiological properties of the accessory pathway during growth. This study investigates the evolution of electrophysiological properties of the ventricular pre-excitation in young athletes referred for sports eligibility.

METHODS

Between January 2011 and July 2022, 44 paediatric patients (32 males; mean age, 10 ± 2.42) with ventricular pre-excitation underwent an electrophysiological study, both at rest and during adrenergic stress at two different times (T0 and T1) within a minimal interval of 2 years. Transcatheter ablation was not performed between the two electrophysiological studies. Electrophysiological data were collected and compared.

RESULTS

Electrophysiological study under basal conditions showed a significant decrease in the anterograde accessory pathway effective refractory period and 1:1 conduction over the accessory pathway from T0 to T1. The shortest pre-excited R-R interval during atrial fibrillation did not significantly change at the basal condition; however, it decreased during the stress test. Furthermore, six patients (13.6%) changed the risk profile of their accessory pathway: two "high-risk" patients at T0 became "low-risk" and four "low-risk" patients became "high-risk" at T1. Atrioventricular re-entry tachycardia inducibility did not differ significantly between the two electrophysiological studies.

CONCLUSIONS

This study highlights the importance of repeating electrophysiological study (transesophageal or intracardiac) in paediatric athletes with ventricular pre-excitation because significant and clinically relevant changes in the conduction and refractoriness of accessory pathway can occur. This could influence risk stratification for sports eligibility and the correct indication and timing for accessory pathway ablation.

Different patterns of pre-excitation in a large Italian cohort of asymptomatic non-competitive athletes evaluated by telecardiology screening: Prevalence and ECG features

Background

Telecardiology has proven to be a useful and cost-effective tool for ECG screening in several contexts, allowing the evaluation of large cohorts of subjects in a short time, even for non-competitive athletes (NCA).

Aim of the study

To evaluate and detail the prevalence of the Wolff-Parkinson-White (WPW) syndrome in a large Italian cohort of young NCA.

Methods

In a 4-year period 216,424 consecutive NCA (118,851 males; 55%) underwent preparticipation ECG screening through a Telecardiology System. ECGs were recorded and sent by a network of 'spoke' centers located all over Italy; a 'hub' center, located in Genoa, received and reported back on ECGs, digitally stored and analyzed. Only asymptomatic NCA were included in the study.

Results

Out of 216,424 NCA 88 (mean age: 14 ± 8) presented a WPW pre-excitation at ECG analysis (55 males, 62.5 %); the prevalence of WPW pre-excitation in this population was 4.1 per 10,000 NCA. No significant sex-related differences were found. The highest incidence (29 WPW patterns) was observed in the 10-15 year group with an equal sex ratio (M/F:16/13).Intermittent pre-excitation was found in 8 NCAs. The most frequent accessory pathway locations were right antero-septal (25.0%), mid-septal (21.6%) and postero-septal (13.6%).

Conclusions

In a large population of young NCA the prevalence of ECG pre-excitation at telemedicine remote screening was 4.1 per 10,000; intermittent pre-excitation was found in 9% of NCA with ECG pre-excitation.

Risk Stratification in Pediatric Wolff-Parkinson-White: Practice Variation Among Pediatric Cardiologists and Electrophysiologists

BACKGROUND

Published guidelines provide recommendations for risk stratification in pediatric Wolff-Parkinson-White (WPW). There are no data on provider concordance with these guidelines. We hypothesized that significant practice variation exists between pediatric cardiologists (PC) and electrophysiologists (EP).

METHOD

The records of all patients, age 8 to 21 years, with a new ECG diagnosis of WPW between 1/1/2013 and 12/31/2018, from a single center, were retrospectively reviewed. Subjects were categorized on the basis of symptoms and resting ECG findings as one of the following: asymptomatic intermittent WPW, asymptomatic persistent WPW, or symptomatic WPW. The performance and results of diagnostic testing, including Holter monitor, event monitor, exercise stress test (EST), and electrophysiology study (EPS), were recorded. The primary outcome was concordance with published guidelines. A secondary outcome was documentation of a discussion of sudden cardiac death (SCD) risk.

RESULTS

615 patient encounters were analyzed in 231 patients with newly diagnosed WPW pattern on ECG (56% male; mean age at diagnosis 13.9 ± 2.5 years). EP were observed to have a significantly higher rate of guideline concordance than PC (95% vs. 71%, p < 0.001). There was significant practice variation between PC and EP in the documentation of a discussion of SCD risk: 96% in EP vs. 39% in PC (p < 0.001).

CONCLUSION

Significant practice variation exists in the non-invasive and invasive risk stratification of pediatric WPW, with lower concordance to published guidelines amongst PC, when compared to EP. This report highlights the need to promote awareness of current WPW guidelines in the pediatric cardiology community at large.

What an anesthesiologist should know about pediatric arrhythmias

Identifying and treating pediatric arrhythmias is essential for pediatric anesthesiologists. Pediatric patients can present with narrow or wide complex tachycardias, though the former is more common. Patients with inherited channelopathies or cardiomyopathies are at increased risk. Since most pediatric patients present for anesthesia without a baseline electrocardiogram, the first identification of an arrhythmia may occur under general anesthesia. Supraventricular tachycardia, the most common pediatric tachyarrhythmia, represents a broad category of predominately narrow complex tachycardias. Stimulating events including intubation, vascular guidewire manipulation, and surgical stimulation can trigger episodes. Valsalva maneuvers are unreliable as treatment, making adenosine or other intravenous antiarrhythmics the preferred acute therapy. Reentrant tachycardias are the most common supraventricular tachycardia in pediatric patients, including atrioventricular reciprocating tachycardia (due to a distinct accessory pathway) and atrioventricular nodal reentrant tachycardia (due to an accessory pathway within the atrioventricular node). Patients with ventricular preexcitation, often referred to as Wolff-Parkinson-White syndrome, have a wide QRS with short PR interval, indicating antegrade conduction through the accessory pathway. These patients are at risk for sudden death if atrial fibrillation degenerates into ventricular fibrillation over a high-risk accessory pathway. Automatic tachycardias, such as atrial tachycardia and junctional ectopic tachycardia, are causes of supraventricular tachycardia in pediatric patients, the latter most typically noted after cardiac surgery. Patients with inherited arrhythmia syndromes, such as congenital long QT syndrome, are at risk of developing ventricular arrhythmias such as polymorphic ventricular tachycardia (Torsades de Pointes) which can be exacerbated by QT prolonging medications. Patients with catecholaminergic polymorphic ventricular tachycardia are at particular risk for developing bidirectional ventricular tachycardia or ventricular fibrillation during exogenous or endogenous catecholamine surges. Non-selective beta blockers are first line for most forms of long QT syndrome as well as catecholaminergic polymorphic ventricular tachycardia. Anesthesiologists should review the impact of medications on the QT interval and transmural dispersion of repolarization, to limit increasing the risk of Torsades de Pointes in patients with long QT syndrome. This review explores the key anesthetic considerations for these arrhythmias.

Electrophysiologic Considerations in Adult Patients with Ebstein's Anomaly

Ebstein's anomaly (EA) is a rare cyanotic form of congenital heart disease (CHD) characterized by apical displacement of the tricuspid valve, with resultant hemodynamic and electrical manifestations. The severity of symptoms is determined by the degree of apical displacement and deformity and incompetence of the tricuspid valve. As a result, patients with EA can be severely symptomatic during infancy and childhood or can be incidentally discovered in the sixth or seventh decade of life. Hallmarks of Ebstein's anomaly include progressive cyanosis, right-sided heart failure, and tachyarrhythmias, among which tachyarrhythmias (most commonly atrial, but also ventricular) are the most common presenting symptoms in Ebstein's anomaly patients during adulthood. This review aims to provide insight into the genetic and electrophysiological (EP) basis underlying the tachyarrhythmias encountered when managing patients with EA.

Catheter ablation in a monochorionic diamniotic twin pregnancy: A case report and literature review

RATIONALE

Preexcitation syndrome is an uncommon congenital cardiac disorder that impairs the normal cardiac conduction system. Radiofrequency ablation is one of the most effective treatments for this condition. Nevertheless, radiofrequency ablation is rare in women with preexcitation syndrome during pregnancy.

PATIENT CONCERNS

A 33-year-old woman with monochorionic diamniotic twin pregnancy complicated by sinus arrhythmia with ventricular preexcitation at 14 weeks and 5 days of gestation, with paroxysmal palpitations and shortness of breath at 16 weeks with paroxysmal supraventricular tachycardia with preexcitation syndrome and a heart rate ranging from 180 to 225 beats per minute.

DIAGNOSES

The pregnant occurred sudden palpitations and shortness of breath in the shower. Electrocardiography revealed paroxysmal supraventricular tachycardia, and electrophysiological study revealed preexcitation syndrome (dominant accessory route of the left free wall) with atrioventricular reentrant tachycardia.

INTERVENTIONS

Radiofrequency catheter ablation was performed at 20 weeks.

OUTCOMES

Symptoms of preexcitation syndrome resolved after the radiofrequency catheter ablation, and 2 healthy infants were delivered at 36 weeks and 2 days of gestation by cesarean section.

LESSONS

Preexcitation syndrome may result in life-threatening arrhythmias such as supraventricular tachycardia during pregnancy and delivery. It might be efficiently controlled through optimal treatment by a multidisciplinary team, which would effectively minimize arrhythmia risk events during pregnancy and improve maternal-fetal outcomes. Based on the patient's individual situation, radiofrequency ablation may be a procedure in pregnant women with preexcitation syndrome.

Electrocardiographic Clues for Early Diagnosis of Ventricular Pre-Excitation and Non-Invasive Risk Stratification in Athletes: A Practical Guide for Sports Cardiologists

Ventricular pre-excitation (VP) is a cardiac disorder characterized by the presence of an accessory pathway (AP) that bypasses the atrioventricular node (AVN), which, although often asymptomatic, exposes individuals to an increased risk of re-entrant supraventricular tachycardias and sudden cardiac death (SCD) due to rapid atrial fibrillation (AF) conduction. This condition is particularly significant in sports cardiology, where preparticipation ECG screening is routinely performed on athletes. Professional athletes, given their elevated risk of developing malignant arrhythmias, require careful assessment. Early identification of VP and proper risk stratification are crucial for determining the most appropriate management strategy and ensuring the safety of these individuals during competitive sports. Non-invasive tools, such as resting electrocardiograms (ECGs), ambulatory ECG monitoring, and exercise stress tests, are commonly employed, although their interpretation can sometimes be challenging. This review aims to provide practical tips and electrocardiographic clues for detecting VP beyond the classical triad (short PR interval, delta wave, and prolonged QRS interval) and offers guidance on non-invasive risk stratification. Although the diagnostic gold standard remains invasive electrophysiological study, appropriate interpretation of the ECG can help limit unnecessary referrals for young, often asymptomatic, athletes.

2024 HRS expert consensus statement on arrhythmias in the athlete: Evaluation, treatment, and return to play

Youth and adult participation in sports continues to increase, and athletes may be diagnosed with potentially arrhythmogenic cardiac conditions. This international multidisciplinary document is intended to guide electrophysiologists, sports cardiologists, and associated health care team members in the diagnosis, treatment, and management of arrhythmic conditions in the athlete with the goal of facilitating return to sport and avoiding the harm caused by restriction. Expert, disease-specific risk assessment in the context of athlete symptoms and diagnoses is emphasized throughout the document. After appropriate risk assessment, management of arrhythmias geared toward return to play when possible is addressed. Other topics include shared decision-making and emergency action planning. The goal of this document is to provide evidence-based recommendations impacting all areas in the care of athletes with arrhythmic conditions. Areas in need of further study are also discussed.

CT-scan-guided-irrigated trans-catheter ablation of epicardial accessory pathways in the coronary sinus: safety and feasibility in pediatric patients

BACKGROUND

The most common site of epicardial APs is posterior-septal, and ablation from the coronary sinus (CS) or its main tributaries is needed. However, particularly in children, it can carry a considerable risk of complications, such as coronary artery (CA) injury, CS damage, and perforation. This study aims to assess the efficacy and safety of computed tomography (CT)-scan-guided-irrigated trans-catheter (TC) ablation of epicardial APs through the CS in children.

METHODS

Twenty-four children (19 males; mean age 13.8 ± 2.6) with posterior-septal and left posterior epicardial APs who underwent an endocavitary electrophysiological study (EPS) and TC ablation from the CS were enrolled in this study. All patients underwent a CT scan to visualize the CS and its branches and their proximity to the CAs before the ablation. Clinical, electrophysiological and follow-up data were collected.

RESULTS

Acute success rate was 87.5% (21 out of 24 procedures). No complications occurred. In 16 (66.7%) patients, the ablation site was detected at the proximal CS, in two (8.3%) patients in the mid-proximal CS and in six (25%) in the middle cardiac vein (MCV). Ablation was achieved using an irrigated radiofrequency (RF) catheter in all patients and without the use of fluoroscopy in 20 patients (83.3%). Over a median follow-up of 15.1 months (IQR 2.5-32.3), no recurrences or complications occurred.

CONCLUSION

Epicardial posterior-septal and left posterior APs, in the area of CS or MCV, can be definitively eliminated in most children using CT-scan-guided electro-anatomical mapping and transvenous irrigated RF ablation.

Diagnostic cost-effectiveness of a two-stage cardiovascular evaluation program in young-adolescent athletes. Role of echocardiography

BACKGROUND

Sports medical examinations are a tool to detect potentially life-threatening situations during physical activity, but their usefulness and protocols in young athletes remain controversial. The aim was to describe the diagnostic performance of a 2-step ECG and echocardiogram screening model in a large sample of healthy young-adolescent athletes (aged 11-16 years), evaluating its cost-effectiveness for cardiovascular disease (CVD) detection.

METHODS

Cross-sectional study of 2617 individuals (81 % male, mean age 15 years), over 20 federated sports (La Rioja-Spain). A cardiological examination included family and personal history, physical examination, ECG, and transthoracic echocardiogram. The previous ECG, conducted at 11-13 years old, was reviewed in 1589 individuals (60 %). ECGs were interpreted according to 2017 international criteria. The prevalence of structural cardiac disease (CD) was investigated, and the diagnostic performance of both tests and the cost of screening was evaluated.

RESULTS

CVD was diagnosed in 63 athletes (2.4 %) and 16 (0.6 %) with pathology related to sudden cardiac death (SCD). In 3 cases (0.11 %), cessation of sporting activity was indicated, and in 2 cases (0.07 %) treatment for congenital CD was indicated. ECG alterations were infrequent (2.5 %). Eighty percent of the structural CD diagnosed by echocardiogram had a normal ECG. The cost per CVD detected was €3,080, and for CVD associated with SCD, it was €12,323.

CONCLUSIONS

Our study shows the diagnostic cost-effectiveness of a two-step cardiac screening protocol, including ECG, and highlights the role of echocardiography in young adolescent athletes, which could be implemented at a low and reasonable cost.

Pregnancy outcomes in patients complicated with pre-excitation syndrome

INTRODUCTION

Pregnant women with pre-excitation syndrome are more likely to develop supraventricular tachycardia (SVT) during pregnancy and delivery, leading to an increased risk of adverse events.

METHOD

This was a retrospective study of 309 pregnancies in 280 women (29 women had two pregnancies in this series) with pre-excitation syndrome who delivered at West China Second University Hospital from June 2011 to October 2021. All the 309 pregnant women with pre-excitation syndrome were divided into SVT and non-SVT groups to analyze the cardiac and obstetric complications.

RESULTS

Among the included pregnant women in the past 10 years, the prevalence of pre-excitation syndrome was 0.24% (309/127725). There were 309 cases with pre-excitation syndrome in all hospitalized pregnant women. Among them, 62 (20.1%, 62/309) had a history of SVT. In the 62 cases with SVT during pregnancy, 22 (35.5%) cases had a history of SVT. Gestational diabetes mellitus was associated with SVT during pregnancy. The cesarean section rate was 88.7% in the SVT group, which was significantly higher than that in the non-SVT group (64.8%) (P < 0.001). Cases with SVT during pregnancy had more cardiac and obstetric complications. Four fetal deaths were recorded in the SVT group. Additionally, 29 women experienced two pregnancies during the study period, among whom, five received radiofrequency ablation after the first delivery and obtained better outcomes in the second pregnancy.

CONCLUSION

The adverse outcomes such as cardiac complications, maternal and fetal complications (PROM, prematurity, SGA, fetal distress, etc.) in pregnant women with pre-excitation syndrome were closely related to SVT, with possible risk factors including history of SVT before pregnancy, cardiac function, heart organic abnormalities, and gestational diabetes mellitus.

New Guidelines of Pediatric Cardiac Implantable Electronic Devices: What Is Changing in Clinical Practice?

Guidelines are important tools to guide the diagnosis and treatment of patients to improve the decision-making process of health professionals. They are periodically updated according to new evidence. Four new Guidelines in 2021, 2022 and 2023 referred to pediatric pacing and defibrillation. There are some relevant changes in permanent pacing. In patients with atrioventricular block, the heart rate limit in which pacemaker implantation is recommended was decreased to reduce too-early device implantation. However, it was underlined that the heart rate criterion is not absolute, as signs or symptoms of hemodynamically not tolerated bradycardia may even occur at higher rates. In sinus node dysfunction, symptomatic bradycardia is the most relevant recommendation for pacing. Physiological pacing is increasingly used and recommended when the amount of ventricular pacing is presumed to be high. New recommendations suggest that loop recorders may guide the management of inherited arrhythmia syndromes and may be useful for severe but not frequent palpitations. Regarding defibrillator implantation, the main changes are in primary prevention recommendations. In hypertrophic cardiomyopathy, pediatric risk calculators have been included in the Guidelines. In dilated cardiomyopathy, due to the rarity of sudden cardiac death in pediatric age, low ejection fraction criteria were demoted to class II. In long QT syndrome, new criteria included severely prolonged QTc with different limits according to genotype, and some specific mutations. In arrhythmogenic cardiomyopathy, hemodynamically tolerated ventricular tachycardia and arrhythmic syncope were downgraded to class II recommendation. In conclusion, these new Guidelines aim to assess all aspects of cardiac implantable electronic devices and improve treatment strategies.

Intermittent Wolff-Parkinson-White Syndrome Mimicking a Ventricular Tachycardia

This case report describes a patient in their 50s with a history of pneumoconiosis and chronic obstructive pulmonary disease who presented to the emergency department with sudden onset shortness of breath.

Wolf-Parkinson-White Syndrome: Diagnosis, Risk Assessment, and Therapy-An Update

Wolf-Parkinson-White (WPW) syndrome is a disorder characterized by the presence of at least one accessory pathway (AP) that can predispose people to atrial/ventricular tachyarrhythmias and even sudden cardiac death. It is the second most common cause of paroxysmal supraventricular tachycardia in most parts of the world, affecting about 0.1-0.3% of the general population. Most patients with WPW syndrome have normal anatomy, but it may be associated with concomitant congenital heart disease or systemic diseases. Although many individuals are asymptomatic, during supraventricular arrhythmia episodes, they may experience severe symptoms, including syncope or even sudden cardiac death (mainly due to pre-excited atrial fibrillation over rapidly conducting AP). In addition to arrhythmia-related symptoms, for some specific locations of the APs with overt anterograde conduction, there might be a reduction in exercise capacity mediated by a reduction in LV systolic performance due to anomalous LV depolarization. Although it is typically diagnosed through electrocardiography (ECG), additional tests are necessary for risk assessment. Management of WPW syndrome may be quite challenging and can vary from only acknowledging the presence of the accessory pathway to pharmacological treatment or radiofrequency ablation. Early diagnosis, risk assessment, and appropriate treatment are critical steps in the management of WPW syndrome, aiming to improve the quality of life and reduce the risk of life-threatening arrhythmias.

Coronary sinus ablations in pediatric patients with supraventricular arrhythmias

BACKGROUND

Intracoronary sinus ablations have been performed for various arrhythmical substrates. The aim of this study is to report our experience on pediatric patients of the safety and efficacy of ablations in the coronary sinus.

METHODS

This is a retrospective study of all patients who underwent ablations in the coronary sinus from October 2013 to October 2021 at a single center. Clinical presentation, type of arrhythmia causing tachycardia, ablation procedure, and outcome were recorded.

RESULTS

A total of 27 patients were included in the study. Nineteen (69%) of those followed up received a diagnosis of Wolff-Parkinson-White syndrome (WPW), 4 (15%) were cases of supraventricular tachycardia with concealed accessory pathway (AP), 2 (8%) were cases of focal atrial tachycardia, and 2 (8%) were cases of permanent junctional reciprocating tachycardia. Negative delta wave was noteworthy especially in lead II in 11/19 (58%) cases and coronary sinus diverticulum was detected in the WPW cases. Of those with manifest AP (19 cases), 15 (79%) had a high-risk AP and the AP in all WPW cases was adenosine unresponsive. Radiofrequency (RF) catheter ablation was performed in 25/27 (93%) cases during the procedure, and 16/25 (64%) of these were irrigated RF catheters. No complications were observed in the follow-up, including coronary artery injury.

CONCLUSIONS

Catheter ablation of supraventricular tachyarrhythmias can be accomplished effectively and potentially safely within the coronary sinus. Coronary sinus diverticula should be suspected in patients with manifest posteroseptal APs who have a previous failed ablation and typical electrocardiographic signs.

Sudden Onset of Broad Complex Tachycardia in a Fit Young Man: A Case Report

Wolff-Parkinson-White (WPW) syndrome is a clinical pre-excitation syndrome often strongly associated with tachyarrhythmias that are predominantly atrioventricular re-entrant tachycardia (AVRT). It is generally considered to be a relatively benign arrhythmogenic condition associated with a slightly higher risk of sudden cardiac death (SCD) in comparison to the general population. Epidemiological data suggests that 0.1%-0.3% of the general population have electrocardiographic (ECG) findings suggesting that during sinus rhythm, in addition to atrioventricular (AV) conduction over the AV node-His bundle pathway, there is an additional atrioventricular conduction across an accessory pathway. Whilst in most cases, such phenomenon is associated with WPW syndrome, other similar conditions, including Lown-Ganong-Levine (LGL) syndrome and Mahaim-type pre-excitation, have also been documented. Our patient is a young man in his late twenties admitted with broad complex tachycardia at 252 beats per minute associated with diaphoresis and pre-syncope. In our case report, we describe how we managed this emergency, eventually unveiling the underlying aetiology as well as a stepwise approach to dealing with adult broad-complex tachycardia.

Electrocardiographic findings in pediatric versus young-adolescent athletes: A comparative analysis using general international criteria

BACKGROUND

The inclusion of electrocardiogram (ECG) in medical examinations for sports practice serves as a valuable tool for identifying potential life-threatening conditions during physical exercise. However, its applicability in young individuals remains a subject of controversy, primarily due to relatively high rates of false positives and the associated costs of further investigations. Furthermore, the validation of International Criteria for athletes below 12 years of age in optimizing pre-participation screening for young athletes is yet to be established. In light of these considerations, this study aims to describe the prevalence of ECG findings in a sample of children and young-adolescent athletes aged 11-16 years, employing refined Seattle interpretation criteria. Additionally, we seek to compare these findings based on age group and sex.

METHODS

This was a retrospective and observational study of 3747 athletes 11-16 year-olds. Evaluation included interviewer-administered questionnaires for relevant history, physical examination and resting 12 - lead ECG for each participant. The primary outcome measure was abnormal ECG findings according to the International Recommendations for Electrocardiographic Interpretation in Athletes.

RESULTS

Among the evaluated population of pediatric and young adolescent athletes (77.5% boys; >99% Caucasian), the vast majority exhibited normal electrocardiogram (ECG) results, with adaptive findings related to sports participation being more frequent among young adolescents and males. The presence of significant ECG abnormalities in young-adolescent athletes was uncommon (2.05%; 1.92% children and 2.32% young-adolescent) and required additional examinations. 0.27% of the total population were diagnosed with a previously unknown cardiac pathology only through the ECG.

CONCLUSIONS

This study provides valuable insights into the prevalence of normal, borderline, and abnormal electrocardiogram (ECG) findings in a large population of pediatric and young-adolescent athletes. These findings serve as guidance in detecting potentially serious cardiac alterations within this specific group, considering variations based on age and sex. The study confirms that ECG screening is a useful tool for identifying cardiac abnormalities in pediatric and young-adolescent athletes, even though the prevalence of significant findings in this population is relatively low. Furthermore, our findings support the utilization of the refined Seattle criteria as a sensitive and specific technique for screening pediatric and young-adolescent athletes, further enhancing the accuracy of ECG-based evaluations.

Intermittent ventricular pre-excitation in symptomatic adults: Always a marker of low risk?

BACKGROUND

Intermittent ventricular pre-excitation was considered a low-risk marker for sudden death. However, to date, some studies do not exclude the existence of accessory pathways (APs) with high-risk intermittent antegrade conductive properties. According to current European Guidelines, high-risk features of APs are antegrade pathway conduction ≤250 ms in baseline or during the adrenergic stimulus, inducibility of atrioventricular reciprocating tachycardias (AVRT), inducibility of pre-excited atrial fibrillation (AF), and presence of multiple APs. For all of these transcatheter ablation is recommended. The aim of our study was to evaluate the existence of differences in risk characteristics between patients with intermittent pre-excitation (IPX) and those with persistent pre-excitation (PPX), from a sample of adults with ventricular pre-excitation and symptoms like palpitations.

METHODS

293 adults [IPX: 51 (17.4%); PPX: 242 (82.6%)] underwent electrophysiological study and then catheter ablation of their APs if arrhythmia inducibility (AVRT/AF) was noted, or, conversely, if it was appreciated a fast AP antegrade conduction, in baseline or during intravenous isoproterenol infusion, or if multiple APs were detected.

RESULTS

There were no statistically significant differences in demographic characteristics (age and gender), AVRT/AF inducibility, antegrade conductive properties, the prevalence of multiple APs, and APs locations between IPX and PPX patients.

CONCLUSIONS

In our study, patients with IPX did not show significant differences in clinical and electrophysiological features versus PPX patients.

Diagnosis and treatment of fetal and pediatric age patients (0-12 years) with Wolff-Parkinson-White syndrome and atrioventricular accessory pathways

Overt or concealed accessory pathways are the anatomic substrates of ventricular preexcitation (VP), Wolff-Parkinson-White syndrome (WPW) and paroxysmal supraventricular tachycardia (PSVT). These arrhythmias are commonly observed in pediatric age. PSVT may occur at any age, from fetus to adulthood, and its symptoms range from none to syncope or heart failure. VP too can range from no symptoms to sudden cardiac death. Therefore, these arrhythmias frequently need risk stratification, electrophysiologic study, drug or ablation treatment. In this review of the literature, recommendations are given for diagnosis and treatment of fetal and pediatric age (≤12 years) WPW, VP, PSVT, and criteria for sport participation.

The Wolff-Parkinson-White pattern in neonates: results from a large population-based cohort study

AIMS

Wolff-Parkinson-White (WPW) syndrome is a conduction disorder characterized by an accessory electrical pathway between the atria and ventricles, which may predispose to supraventricular tachycardia (SVT) and sudden cardiac death. It can be seen as an isolated finding or associated with structural heart disease. Our aims were to determine the prevalence of a WPW pattern in a large and unselected cohort of neonates and to describe the electro- and echocardiographic characteristics as well as the natural history during early childhood.

METHODS AND RESULTS

Electrocardiograms and echocardiograms of neonates (aged 0-30 days) from a large, prospective, population-based cohort study were included. Neonates with a WPW pattern were identified and matched 1:4 to controls. Localization of the accessory pathway was assessed by different algorithms. Among 17 489 neonates, we identified 17 (76% boys) with a WPW pattern consistent with a prevalence of 0.1%. One neonate had moderate mitral regurgitation while other echocardiographic parameters were similar between cases and controls (all P > 0.05). The accessory pathways were primarily predicted to be left-sided. At follow-up (available in 14/17 children; mean age 3.2 years) the pre-excitation pattern persisted in only four of the children and none of the children had experienced any episodes of SVT.

CONCLUSION

The prevalence of a WPW pattern in our cohort of unselected neonates was 0.1%. The WPW pattern was more frequent in boys and generally not associated with structural heart disease, and the accessory pathways were primarily left-sided. At follow-up, the WPW pattern had disappeared in most of the children suggesting either an intermittent nature or that normalization occurs.

CLINICAL TRIAL REGISTRATION

Copenhagen Baby Heart, NCT02753348.

Asymptomatic Wolff-Parkinson-White Syndrome: An Ounce of Prevention Is Worth the Risk of Cure

PURPOSE OF REVIEW

With increased electrocardiogram screening, asymptomatic preexcitation has become more prevalent. Historically, the asymptomatic-symptomatic dichotomy has directed management. This approach warrants scrutiny, as asymptomatic Wolff-Parkinson-White (WPW) syndrome is not without risk. Children may be unreliable symptom reporters, have atypical arrhythmia symptoms, yet have years to become symptomatic.

RECENT FINDINGS

In a large WPW study, symptomatic patients were more likely to undergo ablation than asymptomatic patients, yet, except for symptoms, there were no differences in clinical or electrophysiology study (EPS) characteristics. Present data confirm real risk in asymptomatic WPW-sudden death can be the first symptom. Although malignant arrhythmias correlate better with EPS risk stratification than with symptoms, EPS data are imperfect predictors. Unlike adults with WPW, children have yet to prove survivorship. Asymptomatic children must be treated differently than adults. Sudden death risk is low but front-loaded in the young. An aggressive approach to asymptomatic WPW is warranted in this era of highly successful, low-risk catheter ablations.

["Asymptomatic WPW" : Is treatment necessary?]

The term "asymptomatic WPW" (Wolff-Parkinson-White) is often used as a synonym for ventricular pre-excitation of the WPW type due to an accessory pathway characterized by a short PR interval and a delta wave on the electrocardiogram (ECG) without the clinical occurrence of paroxysmal tachycardia. Asymptomatic WPW is often diagnosed in young and otherwise healthy people. There is a small associated risk of sudden cardiac death due to rapid antegrade conduction over the accessory pathway during atrial fibrillation. This paper highlights aspects of noninvasive and invasive risk stratification, therapy by catheter ablation, and the ongoing risk-benefit discussion in asymptomatic WPW.

The success rate of radiofrequency catheter ablation in Wolff-Parkinson-White-Syndrome patients: A systematic review and meta-analysis

INTRODUCTION

radiofrequency catheter ablation (RFA) is the first-line therapy for symptomatic Wolff Parkinson White (WPW) patients according to the American Heart Association. We conducted this study to assess the success rate, recurrence rate, and rate of complications associated with the utilization of radiofrequency catheter ablation for managing patients with WPW.

METHOD

We searched PubMed, Cochrane library, Web of Science and Scopus databases using all identified keywords and index terms through 4 January 2022. We included all studies conducted on WPW patients who were treated with ablation. We conducted the analysis using Open Meta Analyst and MedCalc version 19.1.

RESULTS

Among 2268 unique articles identified, only 11 articles met our inclusion criteria. The pooled effect estimates showed high success rate (94.1%[95%CI:92.3-95.9], p < 0.001)), low recurrence rate (6.2% [95%CI:4.5-7.8, p < 0.001]) and low rate of complications (1%[95%CI:0.4-1.5, p < 0.001]).

CONCLUSION

RFA showed a high success rate, low recurrence rate and low rate of complications in WPW patients.

Association of Weight With Ablation Outcomes in Pediatric Wolff-Parkinson-White: Analysis of the NCDR IMPACT Registry

BACKGROUND

Guidelines for electrophysiology study (EPS) and catheter ablation in Wolff-Parkinson-White (WPW) are age based, but size may be a more relevant factor in determination of outcomes.

OBJECTIVES

The goal of this study was to evaluate the association of patient weight with outcomes of catheter ablation for pediatric WPW.

METHODS

A multicenter retrospective cohort study was performed on children aged 1 to 21 years with WPW and first-time EPS from April 2016 to December 2019 recorded in the IMPACT (Improving Pediatric and Adult Congenital Treatment) registry, excluding those with congenital heart disease, cardiomyopathy, and >1 ablation target. A weight threshold of 30 kg was selected, representing 1 SD below the cohort mean. The primary outcome was major adverse events (MAEs); additional outcomes included deferred ablation, use of cryoablation, and ablation success.

RESULTS

A total of 4,456 subjects from 84 centers were evaluated, with 14% weighing <30 kg. Subjects weighing <30 kg were more likely to have preprocedural supraventricular tachycardia (45% vs 29%; P < 0.001) and less likely to have right septal accessory pathways (25% vs 33%; P < 0.001). MAEs were rare, although with higher incidence in the <30 kg cohort (0.3% vs 0.05%; P = 0.04). No difference was seen in likelihood of deferred ablation (9% vs 12%; P = 0.07) or use of cryoablation (11% vs 11%; P = 0.70). Success was higher in the <30 kg cohort: 95% vs 92% (P = 0.009). This effect persisted after adjusting for covariates (odds ratio: 1.6; 95% CI: 1.01-2.70; P = 0.046).

CONCLUSIONS

Weight <30 kg was associated with a small but elevated risk of MAEs. Rates of deferred ablation and cryoablation were similar. Adjusting for factors (including accessory pathway type and location), weight <30 kg remained an independent predictor of acute success.

Iatrogenic ventricular fibrillation in Wolff-Parkinson-White syndrome

Wolff-Parkinson-White (WPW) syndrome is the most common manifestation of ventricular pre-excitation syndrome and is mostly found in individuals with no structural heart disease. Although the risk of malignant arrhythmias is low, sudden cardiac death (SCD) as the first clinical manifestation of WPW syndrome is well documented, and atrial fibrillation (AF) with a rapid ventricular response is the main mechanism involved. Unfortunately, the signs of pre-excitation and arrhythmias are sometimes under-diagnosed and under-treated. We describe the case of a 31-year-old man who was admitted with an irregular wide complex tachycardia consistent with pre-excited AF, which was not promptly diagnosed, and who developed ventricular fibrillation (VF) after administration of atrioventricular (AV) nodal blockers, as a primary manifestation of WPW syndrome. Blocking the AV node in patients with pre-excited AF may increase the ventricular rate and potentially result in hemodynamic instability. Among patients with WPW syndrome who survive an episode of SCD, catheter ablation of the accessory pathway is the treatment of choice.

Asymptomatic latent Wolff-Parkinson-White syndrome detected during school heart screening: a case Report

In latent Wolff-Parkinson-White syndrome, ventricular pre-excitation is inapparent during sinus rhythm but carries the same possibility of sudden cardiac death and palpitations as overt Wolff-Parkinson-White syndrome. It is difficult to diagnose latent Wolff-Parkinson-White syndrome when a patient does not have syncope or palpitations. We report the case of an asymptomatic patient with latent Wolff-Parkinson-White syndrome detected on school heart screening using subtle electrocardiography findings.

Fasciculoventricular pathways-A rare and innocent variant: A Retrospective study focusing on clinical and electrophysiologic characteristics

BACKGROUND

Fasciculoventricular pathways (FVPs) are variants of pre-excitation syndrome which were investigated insufficiently because of its rarity.

OBJECTIVE

This report aimed to represent one of the largest series of FVP, focusing on its clinical and electrophysiological properties.

METHODS

We analyzed retrospectively 26 consecutive patients who underwent electrophysiological study (EPS) for FVP between January 1998 and June 2020.

RESULTS

Among 1437 patients with accessory pathways, 26 had FVP (1.80%). All the 26 patients (100%) were males, with a mean age of 22.15 ± 3.50 years (range, 20-34 years). In the baseline electrocardiograms of the patients with FVP, pre-excitation and transitional zone were seen in leads V₂ -V₄ . During EPS procedures, normal AH interval and shortened HV interval were detected. All the patients had AH prolongation after atrial pacing due to atrioventricular (AV) nodal delay without change in pre-excitation degree. Five of the FVP patients (19.2%) had extra accessory pathways, all of which were ablated successfully while the FVPs were followed clinically.

CONCLUSION

Fasciculoventricular pathways are uncommon variants of pre-excitation syndrome; therefore, they should be diagnosed correctly and followed up noninvasively to avoid damages.

Recommendations for participation in leisure-time physical activity and competitive sports in patients with arrhythmias and potentially arrhythmogenic conditions: Part 1: Supraventricular arrhythmias. A position statement of the Section of Sports Cardiology and Exercise from the European Association of Preventive Cardiology (EAPC) and the European Heart Rhythm Association (EHRA), both associations of the European Society of Cardiology

Symptoms attributable to arrhythmias are frequently encountered in clinical practice. Cardiologists and sport physicians are required to identify high-risk individuals harbouring such conditions and provide appropriate advice regarding participation in regular exercise programmes and competitive sport. The three aspects that need to be considered are: (a) the risk of life-threatening arrhythmias by participating in sports; (b) control of symptoms due to arrhythmias that are not life-threatening but may hamper performance and/or reduce the quality of life; and (c) the impact of sports on the natural progression of the underlying arrhythmogenic condition. In many cases, there is no unequivocal answer to each aspect and therefore an open discussion with the athlete is necessary, in order to reach a balanced decision. In 2006 the Sports Cardiology and Exercise Section of the European Association of Preventive Cardiology published recommendations for participation in leisure-time physical activity and competitive sport in individuals with arrhythmias and potentially arrhythmogenic conditions. More than a decade on, these recommendations are partly obsolete given the evolving knowledge of the diagnosis, management and treatment of these conditions. The present document presents a combined effort by the Sports Cardiology and Exercise Section of the European Association of Preventive Cardiology and the European Heart Rhythm Association to offer a comprehensive overview of the most updated recommendations for practising cardiologists and sport physicians managing athletes with supraventricular arrhythmias, and provides pragmatic advice for safe participation in recreational physical activities, as well as competitive sport at amateur and professional level. A companion text on recommendations in athletes with ventricular arrhythmias, inherited arrhythmogenic conditions, pacemakers and implantable defibrillators is published as Part 2 in Europace.

Incidence of life-threatening events in children with Wolff-Parkinson-White syndrome: Analysis of a large claims database

BACKGROUND

Previous estimates of life-threatening event (LTE) risk in Wolff-Parkinson-White (WPW) syndrome are limited by selection bias inherent to tertiary referral-based cohorts.

OBJECTIVE

This analysis sought to measure LTE incidence in children with WPW syndrome in a large contemporary representative population.

METHODS

A retrospective cohort study was conducted using claims data from the IBM MarketScan Research Databases, evaluating patients with WPW syndrome (age 1-18 years) from any encounter between January 1, 2013, and December 31, 2018. Subjects with congenital heart disease and cardiomyopathy were excluded. The primary outcome was diagnosis of ventricular fibrillation (VF); a composite outcome, LTE, was defined as occurrence of VF and/or cardiac arrest. VF and LTE rates were compared to matched representative controls without WPW syndrome (3:1 ratio).

RESULTS

The prevalence of WPW syndrome was 0.03% (8733/26,684,581) over a median follow-up of 1.6 years (interquartile range 0.7-2.9 years). Excluding congenital heart disease/cardiomyopathy, 6946 subjects were analyzed. LTE occurred in 49 subjects, including VF in 20. The incidence of VF was 0.8 events per 1000 person-years, and the incidence of LTE was 1.9 events per 1000 person-years. There were no occurrences of VF in controls; the rate of LTE was 70 times higher in patients with WPW syndrome (0.7%; 95% confidence interval 0.5%-0.9%) than in controls (0.01%; 95% confidence interval 0%-0.02%).

CONCLUSION

The use of a large claims data set allowed for an evaluation of VF and LTE risk in an unselected pediatric population with WPW syndrome. The observed range of 0.8-1.9 events per 1000 person-years is consistent with prior reports from selected populations. A comparison of event rates to matched controls confirms and quantifies the significant elevation in VF and LTE risk in pediatric WPW syndrome.

Endocavitary electrophysiological study by percutaneous antecubital vein and without X-ray for risk stratification of asymptomatic ventricular pre-excitation in young athletes

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Evaluation of AP is usually performed by transesophageal and intracardiac studies.

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In young athletes with AVP, our standard of care is to perform ESnoXR.

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ESnoXR may considered a less invasive alternative for risk stratification of AP.

Athletes with asymptomatic ventricular pre-excitation (VP) should undergo electrophysiological study for risk stratification. We aimed to evaluate the feasibility, efficacy, safety and tolerability of an electrophysiological study using a percutaneous antecubital vein access and without the use of X-ray (ESnoXr). Methods: We collected data from all young athletes < 18 year-old with AVP, who underwent ESnoXr from January 2000 to September 2020 for evaluation of accessory pathway refractoriness and arrhythmia inducibility using an antecubital percutaneous venous access. Endocavitary signals were used to advance the catheter in the right atrium and ventricle. Results: We included 63 consecutive young athletes (mean age 14.6 ± 1.9 years, 46% male). Feasibility of the ESnoXr technique was 87% while in 13% fluoroscopy and/or a femoral approach were needed. Specifically, fluoroscopy was used in 7 cases to position the catheter inside the heart cavities with an average exposure of 43 ± 38 s while in 2 femoral venous access was needed. The mean procedural time was 35 ± 11 min. The exam was diagnostic in all patients, there were no procedural complications and tolerability was excellent. 53% of the patients had an accessory pathway with high refractoriness and no inducible atrio-ventricular reentry tachycardia: this subgroup was considered eligible to competitive sports and no event was observed during long-term follow-up (13.6 ± 5.2 years) without drug use. The others underwent catheter ablation. Conclusion. ESnoXr has been shown to be a feasible, effective, safe and well-tolerated procedure for the assessment of arrhythmic risk in a population of young athletes with asymptomatic VP.

Characteristics of antegrade-only accessory pathways in children and adolescents

There is minimal data regarding antegrade-only accessory pathways in young patients. Given evolving recommendations and treatments, retrospective analysis of the clinical and electrophysiologic properties of antegrade-only pathways in patients <21 years old was performed, with subsequent comparison of electrophysiology properties to age-matched controls with bidirectional pathways. Of 522 consecutive young patients with ventricular pre-excitation referred for electrophysiology study, 33 (6.3%) had antegrade-only accessory pathways. Indications included palpitations (47%), chest pain (25%), and syncope (22%). The shortest value for either the accessory pathway effective refractory period or the pre-excited R-R interval was taken for each patient, with the median of the antegrade-only group significantly greater than shortest values for the bidirectional group (310 [280-360] ms versus 270 [240-302] ms, p < 0.001). However, the prevalence of pathways with high-risk properties (effective refractory period or shortest pre-excited R-R interval <250 ms) was similar in both study patients and controls (13% versus 21%) (p = 0.55). Sixteen patients had a single antegrade-only accessory pathway and no inducible arrhythmia. Six patients had Mahaim fibres, all right anterolateral with inducible antidromic reciprocating tachycardia. However, 11 patients with antegrade-only accessory pathways and 3 with Mahaim fibres had inducible tachycardia due to a second substrate recognised at electrophysiology study. These included concealed accessory pathways (7), bidirectional accessory pathways (5), and atrioventricular node re-entry (2). Antegrade-only accessory pathways require comprehensive electrophysiology evaluation as confounding factors such as high-risk conduction properties or inducible Supraventricular Tachycardia (SVT) due to a second substrate of tachycardia are often present.

Sudden Death in the Young: Information for the Primary Care Provider

There are multiple conditions that can make children prone to having a sudden cardiac arrest (SCA) or sudden cardiac death (SCD). Efforts have been made by multiple organizations to screen children for cardiac conditions, but the emphasis has been on screening before athletic competition. This article is an update of the previous American Academy of Pediatrics policy statement of 2012 that addresses prevention of SCA and SCD. This update includes a comprehensive review of conditions that should prompt more attention and cardiology evaluation. The role of the primary care provider is of paramount importance in the evaluation of children, particularly as they enter middle school or junior high. There is discussion about whether screening should find any cardiac condition or just those that are associated with SCA and SCD. This update reviews the 4 main screening questions that are recommended, not just for athletes, but for all children. There is also discussion about how to handle post-SCA and SCD situations as well as discussion about genetic testing. It is the goal of this policy statement update to provide the primary care provider more assistance in how to screen for life-threatening conditions, regardless of athletic status.

High accessory pathway conductivity blocks antegrade conduction in Wolff-Parkinson-White syndrome: A simulation study

BACKGROUND

Wolff-Parkinson-White (WPW) syndrome is characterized by an anomalous accessory pathway (AP) that connects the atrium and ventricles, which can cause abnormal myocardial excitation and cardiac arrhythmias. The morphological and electrophysiological details of the AP remain unclear. The size and conductivity of the AP may affect conduction and WPW syndrome symptoms.

METHODS

To clarify this issue, we performed computer simulations of antegrade AP conduction using a simplified wall model. We focused on the bundle size of the AP and myocardial electrical conductivity during antegrade conduction (from the atrium to the ventricle).

RESULTS

We found that a thick AP and high ventricular conductivity promoted antegrade conduction, whereas a thin AP is unable to deliver the transmembrane current required for electric conduction. High ventricular conductivity amplifies transmembrane current. These findings suggest the involvement of a source-sink mechanism. Furthermore, we found that high AP conductivity blocked antegrade conduction. As AP conductivity increased, sustained outward transmembrane currents were observed. This finding suggests the involvement of an electrotonic effect.

CONCLUSIONS

The findings of our theoretical simulation suggest that AP size, ventricular conductivity, and AP conductivity affect antegrade conduction through different mechanisms. Our findings provide new insights into the morphological and electrophysiological details of the AP.

Into a Fluoroless Future: an Appraisal of Fluoroscopy-Free Techniques in Clinical Cardiac Electrophysiology

Purpose of Review

There are risks to both patients and electrophysiology providers from radiation exposure from fluoroscopic imaging, and there is increased interest in fluoroscopic reduction. We review the imaging tools, their applications, and current uses to eliminate fluoroscopy.

Recent Findings

Multiple recent studies provide supporting evidence for the transition to fluoroscopy-free techniques for both ablations and device implantation. The most frequently used alternative imaging approaches include intracardiac echocardiography, cardiac MRI guidance, and 3D electroanatomic mapping systems. Electroanatomic mapping and intracardiac echocardiography originally used to augment fluoroscopy imaging are now replacing the older imaging technique. The data supports that the future of electrophysiology can be fluoroscopy-free or very low fluoroscopy for the vast majority of cases.

Summary

As provider and institution experience grows with these techniques, many EP labs may choose to completely forego the use of fluoroscopy. Trainees will benefit from early experience with these techniques.