Electrophysiological findings in adolescents with atrial fibrillation who have structurally normal hearts

The higher recurrence rate after catheter ablation in younger patients with atrial fibrillation suggesting different pathophysiology

BACKGROUND

Young atrial fibrillation (AF) patients have been underrepresented in studies of radiofrequency catheter ablation (RFCA) and the outcome of RFCA has not been widely addressed. We investigated age-related differences in clinical features, the recurrence of atrial tachyarrhythmia, and its predictors of patients who underwent RFCA for AF.

METHODS

This is a multicenter prospective study of 2799 patients who underwent RFCA for AF in 2017-2020. The patients were divided into two groups - group A (age < 60 years, n = 1269) and group B (age ≥ 60 years, n = 1530) - and a recurrence of any atrial tachyarrhythmia 1 year after RFCA following a 90-day blanking period was compared.

RESULTS

The mean age was 51.6 ± 6.7 and 66.8 ± 5.2 years for groups A and B, respectively. Higher body mass index, smaller left atrium, and more prevalent cardiomyopathy and obstructive sleep apnea were observed in group A. Overall, 1-year atrial tachyarrhythmia-free survival was 85.6% and lower in young patients (83.1% in group A vs. 87.7% in group B, log-rank p < 0.01): adjusted hazard ratio (aHR) of recurrence (95% confidence interval (CI)), 1.45 (1.13-1.86) for group A compared to group B (p < 0.01). The association between younger age and higher recurrence was continuously observed in patients under 60 years. Any non-PV ablation was associated with a lower recurrence of atrial tachyarrhythmia in group B (aHR 0.68 (0.47-0.96), p < 0.05), but not in group A.

CONCLUSIONS

AF patients younger than 60 years had a higher 1-year AF recurrence after RFCA. Young AF patients might have distinctive pathophysiology of AF requiring more integrated management.

Adolescent Persistent Atrial Fibrillation Concomitant with Pectus Excavatum

A 19-year-old man with pectus excavatum developed symptomatic persistent atrial fibrillation (AF). He had no remarkable medical history or comorbidities and had not exercised intensely during childhood. Electrical cardioversion and pre-treatment with amiodarone for two months failed to maintain sinus rhythm. Computed tomography before ablation revealed compression of the right and left atria between the sternal bone and vertebral bodies. Voltage mapping revealed that the right and left atrial voltages were preserved within the normal limit. However, radiofrequency catheter ablation successfully eliminated recurrent persistent AF. No recurrence was observed during eight months of follow-up.

Review of atrial fibrillation for the general paediatrician

Paediatric atrial fibrillation (AF) is an infrequent entity in the absence of congenital heart disease as children are unlikely to have the structural and functional changes in their myocardium to sustain the arrhythmia. Any child presenting with this arrhythmia needs to be carefully evaluated for concealed cardiac pathology such as cardiomyopathy or inherited arrhythmia syndromes. AF leading to a haemodynamically unstable patient is rare and should prompt synchronised cardioversion, while stable patients can be discussed with a paediatric cardiologist. Tachycardia-induced cardiomyopathy and thromboembolism are possible complications of sustained AF and anticoagulation is usually indicated to prevent the latter. Risk of AF increases with age and body mass index. Obesity and athletics are known risk factors and recurrence can be seen even in the absence of any identifiable underlying pathology.

Management and outcomes of atrial fibrillation in 241 healthy children and young adults: Revisiting "lone" atrial fibrillation-A multi-institutional PACES collaborative study

BACKGROUND

Atrial fibrillation (AF) in healthy children and young adults is rare. Risk of recurrence and treatment efficacy are not well defined.

OBJECTIVE

The purpose of this study was to assess recurrence patterns and treatment efficacy in AF.

METHODS

A retrospective multicenter cohort study including 13 congenital heart centers was facilitated by the Pediatric & Congenital Electrophysiology Society (PACES). Patients ≤21 years of age with documented AF from January 2004 to December 2018 were included. Demographics, family and clinical history, medications, electrophysiological study parameters, and outcomes related to the treatment of AF were recorded and analyzed. Patients with contributory diseases were excluded.

RESULTS

In 241 subjects (83% male; mean age at onset 16 years), AF recurred in 94 patients (39%) during 2.1 ± 2.6 years of follow-up. In multivariable analysis, predictors of AF recurrence were family history in a first-degree relative <50 years of age (odds ratio [OR] 1.9; P = .047) and longer PR interval in sinus rhythm (OR 1.1 per 10 ms; P = .037). AF recurrence was similar whether patients began no treatment (39/125 [31%]), began daily antiarrhythmic therapy (24/63 [38%]), or had an ablation at any time (14/53 [26%]; P = .39). Ablating non-AF substrate with supraventricular tachycardia improved freedom from AF recurrence (P = .013).

CONCLUSION

Recurrence of AF in the pediatric population is common, and the incidence of recurrence was not impacted by "no treatment," "medication only," or "ablation" treatment strategy. Ablation of pathways and other reentrant targets was the only intervention that decreased AF recurrence in children and young adults.

[Catheter treat-ment of patients with atrial fibrillation and myocardial inflammation]

The review presents current data on atrial fibrillation, therapeutic approaches, and possibilities of interventional treatment and addresses inflammatory heart damage and its interrelation with arrhythmia.The review presents current data on atrial fibrillation, therapeutic approaches, and possibilities of interventional treatment and addresses inflammatory heart damage and its interrelation with arrhythmia.

Usefulness of High-Dose Oral Flecainide for Termination of Recent-Onset Atrial Fibrillation in Children

A high dose of oral flecainide has been used for acute termination of atrial fibrillation (AF) and atrial flutter or intra-atrial re-entry tachycardia (AFL-IART) in adults. The use of flecainide for these conditions in children has not been well described. We describe our institutional experience on acute termination of AF or AFL-IART in children with a single high dose of oral flecainide in a hospital setting. All patients who received a single high dose of oral flecainide from 2009 to 2016 who were <21 years of age were included. Patients were treated only if AF or AFL-IART was less than 24 hours of duration. The dose was 300 mg for patients >70 kg, 200 mg for patients 40 to 70 kg, and 5 mg/kg for patients <40 kg. Charts were reviewed to determine demographic information, flecainide dose, termination of arrhythmia, and time to termination. There were 22 patients identified. The median age was 16 years (range 4.6 to 20.3) with a median weight of 75 kg (range 19 to 112). There were 13 patients with AF (11 with a normal heart, 85%) and 9 patients with AFL-IART (1 with a normal heart, 11%) (p <0.05). The median dose of flecainide given was 3.6 mg/kg (range 2.7 to 6.1) or 136 mg/m² (range 90 to 171). AF in all patients (13/13, 100%) and AFL-IART in 5 of 9 patients (55%) terminated acutely (p <0.05). All patients with normal heart (12/12, 100%) and 6 of the 10 patients (60%) with heart disease have their arrhythmia terminated acutely (p <0.05). The only patients whose tachycardia did not terminate were 4 patients with IART and heart disease. The arrhythmia terminated in a median time of 60 minutes (range 30 to 120). There were no adverse events or proarrhythmia encountered. In conclusion, a single high dose of oral flecainide successfully terminated AF of less than 24 hours' duration in all pediatric patients without side effects. This approach is less effective for AFL-IART in patients with heart disease.

Relation of Left Atrial Size to Atrial Fibrillation in Patients Aged ≤22 Years

Left atrial (LA) dilation has been shown to be associated with atrial fibrillation (AF) in the adult population, with some studies indicating that larger LAs are more prone to AF recurrence. The relation of LA size to AF in the pediatric and young adult population has not been investigated. In this study, all pediatric patients (aged ≤22 years) who presented to Boston Children's Hospital from January 2002 to December 2012 with AF were reviewed. Patients with significant congenital heart disease, cardiomyopathies, proven channelopathies, previous cardiac surgery, end-stage renal disease, or severe lung disease/cystic fibrosis were excluded. LA measurements were taken using the echocardiogram performed at the initial presentation. In total, 48 patients with AF were identified. The median age at presentation was 17.1 years (range 3.7 to 22.9 years); 38 patients (79%) were men. Eleven patients (23%) had at least 1 recurrence of their AF. There was no difference in body mass index, prevalence of systemic hypertension, alcohol, stimulant, or illicit drug use between those who had an isolated episode of AF and those who had a recurrence. There was no significant difference in LA dimension Z-scores between groups, with only 2 patients (1 isolated AF, 1 recurrent AF) having Z-scores >2. In conclusion, AF in the young without underlying heart disease is not associated with LA dilation.

Electrophysiology testing and catheter ablation are helpful when evaluating asymptomatic patients with Wolff-Parkinson-White pattern: the con perspective

The association between asymptomatic Wolff-Parkinson-White (WPW) syndrome and sudden cardiac death (SCD) has been well documented. The inherent properties of the accessory pathway determine the risk of SCD in WPW, and catheter ablation essentially eliminates this risk. An approach to WPW syndrome is needed that incorporates the patient's individualized considerations into the decision making. Patients must understand that there is a trade-off of a small immediate risk of an invasive approach for elimination of a small lifetime risk of the natural history of asymptomatic WPW. Clinicians can minimize the invasive risk by only performing ablation for patients with at-risk pathways.

Triggers and anatomical substrates in the genesis and perpetuation of atrial fibrillation

The definition of atrial fibrillation (AF) as a functional electrical disorder does not reflect the significant underlying structural abnormalities. Atrial and Pulmonary Vein (PV) muscle sleeve microstructural remodeling is present, and establishes a vulnerable substrate for AF maintenance. In spite of an incomplete understanding of the anatomo-functional basis for AF, current evidence demonstrates that this arrhythmia usually requires a trigger for initiation and a vulnerable electrophysiological and/or anatomical substrate for maintenance. It is still unclear whether the trigger mechanisms include focal enhanced automaticity, triggered activity and/or micro re-entry from myocardial tissue. Initiation of AF can be favored by both parasympathetic and sympathetic stimulation, which also seem to play a role in maintaining AF. Finally, evolving clinical evidence demonstrates that inflammation is associated with new-onset and recurrent AF through a mechanism that possibly involves cellular degeneration, apoptosis, and subsequent atrial fibrosis.

Lone atrial fibrillation in the young - perhaps not so "lone"?

OBJECTIVE

To determine if pediatric patients with a history of lone atrial fibrillation (AF) have other forms of supraventricular tachycardia (SVT) that may potentially trigger AF.

STUDY DESIGN

A multicenter review of patients with lone AF who underwent electrophysiology (EP) study from 2006-2011 was performed.

INCLUSION CRITERIA

age ≤21 years, normal ventricular function, structurally normal heart, history of AF, and EP study and/or ablation performed.

EXCLUSION CRITERIA

congenital heart disease or cardiomyopathy. Patient demographics, findings at EP study and follow-up data were recorded.

RESULTS

Eighteen patients met inclusion criteria. The mean age was 17.9 ± 2.2 years, weight was 82 ± 21 kg, body mass index was 27 ± 6, and 15 (83%) were males. Eleven (61%) were overweight or obese. Seven (39%) had inducible SVT during EP study: 5 atrioventricular nodal re-entry tachycardia (71%) and 2 concealed accessory pathways with inducible atrioventricular re-entry tachycardia (29%). All 7 patients with inducible SVT underwent radiofrequency ablation. There were no complications during EP study and/or ablation for all 18 patients. The mean follow-up was 1.7 ± 1.5 years and there were no recurrences in the 7 patients who underwent ablation. There were 2 recurrences of AF in patients with no other form of SVT during EP study.

CONCLUSIONS

Inducible SVT was found in 39% of pediatric patients undergoing EP study for lone AF. EP study should be considered for pediatric patients presenting with lone AF.

Atrial fibrillation in healthy adolescents after highly caffeinated beverage consumption: two case reports

INTRODUCTION

Energy drinks and highly caffeinated drinks comprise some of the fastest growing products of the beverage industry, often targeting teenagers and young adults. Cardiac arrhythmias in children related to high caffeine consumption have not been well described in the literature. This case series describes the possible association between the consumption of highly caffeinated drinks and the subsequent development of atrial fibrillation in the adolescent population.

CASE PRESENTATIONS

We report the cases of two Caucasian adolescent boys of 14 and 16 years of age at the time of presentation, each without a significant cardiac history, who presented with palpitations or vague chest discomfort or both after a recent history of excessive caffeine consumption. Both were found to have atrial fibrillation on electrocardiogram; one patient required digoxin to restore a normal sinus rhythm, and the other self-converted after intravenous fluid administration.

CONCLUSION

With the increasing popularity of energy drinks in the pediatric and adolescent population, physicians should be aware of the arrhythmogenic potential associated with highly caffeinated beverage consumption. It is important for pediatricians to understand the lack of regulation in the caffeine content and other ingredients of these high-energy beverages and their complications so that parents and children can be educated about the risk of cardiac arrhythmias with excessive energy drink consumption.

Simulating pulmonary vein activity leading to atrial fibrillation using a rule-based approach on realistic anatomical data

Atrial fibrillation (AF) is the most common cardiac arrhythmia leading to a high rate of stroke. The underlying mechanisms of initiation and maintenance of AF are not fully understood. Several findings suggest a multitude of factors to leave the atria vulnerable to AF. In this work, a rule-based approach is taken to simulate the initiation of AF in a computer model for the purpose of generating a model with which the influence of anatomical structures, electrophysiological properties of the atria and arrhythmogenic activity can be evaluated. Pulmonary vein firing has been simulated leading to AF in 65.7 % of all simulations. The excitation pattern generated resemble chaotic excitation behavior, which is characteristic for AF as well as stable reentrant circuits responsible for atrial flutter. The findings compare well with literature. In future, the presented computer model of AF can be used in therapy planning such as ablation therapy or overdrive pacing.

Randomized Comparison Between Open Irrigation Technology and Intracardiac-Echo-Guided Energy Delivery for Pulmonary Vein Antrum Isolation: Procedural Parameters, Outcomes, and the Effect on Esophageal Injury

INTRODUCTION

We performed a prospective study to compare efficacy and safety of both open irrigation tip (OIT) technology with intracardiac echo (ICE)-guided energy delivery in patients presenting for PVAI.

METHODS AND RESULTS

Fifty-three patients presenting for PVAI were randomized to ablation using an OIT catheter (Group 1, 26 patients; temperature and power were set at 50 degrees and 50 W, respectively, with a saline pump flow rate of 30 mL/min) or radiofrequency (RF) energy delivery under ICE guidance (Group 2, 27 patients; energy was titrated based on microbubbles formation). The mean procedure time and fluoroscopy exposure were lower in Group 1 (164 +/- 42 min and 7,560 +/- 2,298 microGray m2 vs 204 +/- 47 min and 12,240 +/- 4,356 microGray m2; P = 0.005 and 0.008, respectively). Moreover, the durations of RF lesions applied per PV antrum was lower in Group 1 compared with Group 2 (5.1 +/- 2.2 min vs 9.2 +/- 3.2 min, P = 0.03, respectively). Within 24 hours after PVAI in 35.7% (all erythema) of Group 1 and 57.1% (21.4% erythema and 35.7% necrosis) of Group 2, patients' esophageal wall changes were documented. After 14 +/- 2 months of follow up, recurrences were documented in 19.2% of Group 1 and 22.2% of Group 2 patients.

CONCLUSION

Although both OIT and ICE-guided energy delivery possess a similar effect in treating AF, OIT seems to be superior in terms of achieving isolation and shortening fluoroscopy exposure. Moreover, a lower incidence of esophageal wall injury was observed utilizing OIT for PVAI.

Multiple wavelets, rotors, and snakes in atrial fibrillation--a computer simulation study

BACKGROUND

Multiple wavelets and rotors are accused of maintaining atrial fibrillation (AF). However, snake-like excitation patterns have recently been observed in AF. So far, computer models have investigated AF in a simplified anatomical model. In this work, pulmonary vein firing is simulated to investigate the initiation and maintenance of AF in a realistic anatomical model.

METHODS AND RESULTS

Thirty-five ectopic foci situated around all pulmonary veins were simulated by a unidirectional conduction block. The excitation propagation was simulated by an adaptive cellular automaton on a realistic 3-dimensional atrial anatomy. Atrial fibrillation was initiated in 65.7% of the simulations. Stable excitation patterns were broken up in anatomically heterogeneous regions, creating a streak-like excitation pattern similar to snakes. Multiple wavelets and rotors could be observed in anatomically smooth areas at the atria's roofs.

CONCLUSIONS

The influence of macroscopic anatomical structures on the course of AF seems to play an important role in the excitation propagation in AF. The computer simulations indicate that multiple mechanisms contribute to the maintenance of AF.

[Progress in pediatric cardiology and congenital heart defects]

We present a review of progress reported in the fields of pediatric cardiology and congenital heart disease between July 2004 and July 2005. The review covers diagnosis, medical treatment, interventional cardiology, and surgery. Among advances in diagnosis, we highlight new diagnostic imaging methods such as three-dimensional echocardiography, magnetic resonance imaging, CT angiography, and tissue Doppler imaging. In the area of fetal cardiology, we focus on advances in fetal interventions, such as percutaneous aortic valvuloplasty, percutaneous pulmonary valvuloplasty, and intact or restrictive atrial balloon septostomy. In interventional cardiology, we highlight advances in the application of percutaneous techniques to adult congenital heart disease to help solve problems resulting from previous surgery, and we review new devices for enabling the percutaneous closure of muscular and membranous ventricular septal defects. In cardiac surgery, a number of developments in valved conduits and in aortic translocation in patients with complex transposition of the great arteries are of particular interest.