Atrial Fibrillation in Congenital Heart Disease

Ischemic Stroke in Adults With Congenital Heart Disease: Cumulative Incidence and Associated Factors

BACKGROUND

When more patients with congenital heart disease reach adult age, increased incidence of long-term complications, including ischemic stroke, are expected. The aim of this study was to analyze cumulative incidence of ischemic stroke, associated factors, and case fatality in adult congenital heart disease.

METHODS AND RESULTS

The study is based on Swedish national registers on congenital heart disease and stroke. Patients with congenital heart disease were followed between 2001 and 2018 for first-ever ischemic stroke events (ischemic stroke due to patent foramen ovale excluded). Factors possibly associated with ischemic stroke were analyzed using Cox regression models. Out of 8914 adult patients with congenital heart disease, 108 suffered ischemic stroke over a mean period of 7.6±4.7 years. The mean age at ischemic stroke was 53.8 years, and the cumulative incidence was 0.15% at 1 year, 0.5% at 5 years, and 1.5% at 10 years. In multivariable analysis, age (hazard ratio [HR], 1.04 [95% CI, 1.03-1.06]), diabetes (HR, 2.9 [95% CI, 1.3-6.4]), ejection fraction <50% (HR, 1.9 [95% CI, 1.1-3.4]), atrial septal defect (HR, 3.0 [95% CI, 1.03-8.5]), and aortic valve lesions (HR, 4.8 [95% CI, 1.6-14.1]) were associated with increased risk. Among those with ischemic stroke, approximately half were on antithrombotic treatment (anticoagulants or antiplatelets) before admission. Case fatality was 6.5%.

CONCLUSIONS

The cumulative incidence of ischemic stroke was 1.5% after 10 years. In adult congenital heart disease, the type of heart lesion, diabetes, ejection fraction <50%, and age were important factors associated with ischemic stroke. Despite a relatively young age, mortality is a significant threat. At time of the ischemic stroke event, approximately half of the patients were on antithrombotic treatment.

Prevalence, Management, and Outcomes of Atrial Fibrillation in Paediatric Patients: Insights from a Tertiary Cardiology Centre

Background and Objectives: Atrial fibrillation (AF) is increasingly recognised in paediatric patients, presenting unique challenges in management due to its association with various underlying heart conditions. This study aimed to evaluate the prevalence, management strategies, and outcomes of AF in this population. Materials and Methods: A retrospective analysis was conducted at a tertiary paediatric cardiology centre, including patients aged ≤18 years diagnosed with AF between January 2015 and December 2023. The study focused on demographic details, clinical presentations, treatments, and outcomes. Descriptive statistics were employed to assess treatment efficacy, recurrence rates, and complications. Results: The study included 36 paediatric patients (median age: 15 years, IQR: 13-17; 58% male). Of these, 52.8% had acquired heart disease, 16.7% had congenital heart anomalies, and 16.7% presented with lone AF. The initial management strategies involved electrical cardioversion in 53.3% of patients and pharmacological conversion with amiodarone in 46.7%. Rhythm control therapy was administered to over 80% of the cohort, and 63.9% were placed on oral anticoagulation, predominantly for rheumatic and congenital heart diseases. The overall success rate of rhythm control was 96.2%, with an AF recurrence rate of 3.8%. Ischemic stroke was the most common complication, occurring in three patients, all with underlying rheumatic heart disease. Conclusions: AF in paediatric patients is predominantly associated with rheumatic and congenital heart diseases, though a significant proportion of patients present with lone AF. Despite effective rhythm control in most cases, neurological complications, particularly ischemic strokes in patients with underlying heart disease, remain a critical concern. These findings underscore the need for more comprehensive studies to better understand the aetiology, risk factors, and optimal management strategies for paediatric AF.

Transient titin-dependent ventricular defects during development lead to adult atrial arrhythmia and impaired contractility

Developmental causes of the most common arrhythmia, atrial fibrillation (AF), are poorly defined, with compensation potentially masking arrhythmic risk. Here, we delete 9 amino acids (Δ9) within a conserved domain of the giant protein titin's A-band in zebrafish and human-induced pluripotent stem cell-derived atrial cardiomyocytes (hiPSC-aCMs). We find that ttna Δ9/Δ9 zebrafish embryos' cardiac morphology is perturbed and accompanied by reduced functional output, but ventricular function recovers within days. Despite normal ventricular function, ttna Δ9/Δ9 adults exhibit AF and atrial myopathy, which are recapitulated in TTN Δ9/Δ9-hiPSC-aCMs. Additionally, action potential is shortened and slow delayed rectifier potassium current (I Ks) is increased due to aberrant atrial natriuretic peptide (ANP) levels. Strikingly, suppression of I Ks in both models prevents AF and improves atrial contractility. Thus, a small internal deletion in titin causes developmental abnormalities that increase the risk of AF via ion channel remodeling, with implications for patients who harbor disease-causing variants in sarcomeric proteins.

Mid-term outcomes after catheter ablation in patients with congenital heart disease

INTRODUCTION

Cardiac arrhythmias are a major concern in patients with CHD. The purpose of this study was to evaluate the long-term outcomes in patients with CHD submitted to catheter ablation.

MATERIALS AND METHODS

Observational retrospective study of patients with CHD referred for catheter ablation from January 2016 to December 2021 in a tertiary referral centre. Acute procedural endpoints and long-term outcomes were assessed.

RESULTS

A total of 44 ablation procedures were performed in 36 CHD patients (55% male, mean age 43 ±3 years). Fifty-four arrhythmias were ablated: 23 cavotricuspid isthmus atrial flutters, 10 atrial re-entrant tachycardias, eight focal atrial tachycardias, eight atrial fibrillations, three atrioventricular re-entrant tachycardias, and two ventricular tachycardias. During a median follow-up time of 37 months (interquartile range 12-51), freedom from arrhythmia recurrence was achieved in 93%, with 1.2 procedures per patient (18% with anti-arrhythmic drugs). There were no adverse events related to catheter ablation. No predictors of recurrence were identified.

CONCLUSION

In patients with CHD, catheter ablation presents a high mid-term efficacy while maintaining a safe profile.

Atrial Fibrillation Ablation in Congenital Heart Disease: Therapeutic Challenges and Future Perspectives

The increasing prevalence of atrial fibrillation (AF) in adults with congenital heart disease raises significant questions regarding its management. The unique underlying anatomic and physiological background further adds to the difficulty in eliminating the AF burden in these patients. Herein, we provide an overview of the current knowledge on the pathophysiology and risk factors for AF in adult congenital heart disease, with a special focus on the existing challenges in AF ablation. Emerging imaging modalities and ablation techniques might have a role to play. Evidence regarding the safety and efficacy of AF ablation in adult congenital heart disease is summarized, especially for patients with an atrial septal defect, Ebstein anomaly of the tricuspid valve, tetralogy of Fallot, and Fontan circulation. Finally, any remaining gaps in knowledge and potential areas of future research are highlighted.

Prognostic implications of atrial fibrillation in adults with Ebstein anomaly

OBJECTIVE

Supraventricular arrhythmias are common in adults with Ebstein anomaly (EA). However, there are limited data about prognostic implications of atrial fibrillation (AF) in this population. Accordingly, our aim was to assess the clinical profile and burden of AF in adults with EA, and the relationship between AF and outcomes.

METHODS AND RESULTS

Six hundred eighty-two consecutive adults with a median age of 36 (24-49) years from Mayo Clinic, Minnesota, USA, between 2003 and 2020 were included. Sustained episodes of AF, clinical, echocardiographic, rhythm and surgical data were collected. Prevalence of AF at baseline was 18% (126 patients); the first episode occurred at a mean age of 43±17 years. Patients with AF were older, were more likely men, and had hypertension, renal dysfunction, cardiac devices, and more advanced right-sided and left-sided remodelling. During a median follow-up of 156 (81-240) months, 62 patients (11%) developed incident AF. At the last encounter, prevalence of AF was 28% (188 patients); of those, 63 (34%) had recurrent AF. Hospitalisation for heart failure (HF) occurred in 51 patients (7%). AF (HR 2.32, 95% CI 1.18 to 4.47; p=0.01) was independently associated with hospitalisation for HF. All-cause death occurred in 53 patients (8%); it was more frequent in those with AF in the univariable analysis, although it did not remain significant in the multivariable analysis.

CONCLUSIONS

AF in EA develops at relatively young ages with one-third of the cohort exhibiting a recurrent pattern. Patients with AF had a higher prevalence of comorbidities and worse right-sided and left-sided cardiac remodelling. AF was independently associated with HF hospitalisation.

Prevalence and Treatment Outcomes of Arrhythmias in Patients with Single Ventricle Physiology over the Age of 40 Years

Background: Arrhythmias are a well known complication in patients with single ventricle physiology (SVP). However, there is still a lack of data regarding arrhythmias in older patients. The aim of this study was to analyze arrhythmia type and frequency, treatment and recurrence rates in patients with SVP over the age of 40 years. Methods: Data was obtained retrospectively from clinical records. All patients > 40 years with SVP with arrhythmias between 2005 and 2018 were included in the study. Treatment was classified as medical, interventional (electrophysiological studies (EPS) in combination with catheter ablation) or direct current cardioversion (DCCV). Results: Altogether, 29 patients (11 female; mean 47.5 ± 4.6 years) with 85 arrhythmia episodes were identified. The median follow-up time was 6.3 years. Cavo-tricuspid (CTI) and non-CTI related intra-atrial reentrant tachycardia (IART) and atrial fibrillation (AF) were most common (48.2% and 37.6%, respectively). In total, 18 EPS/ablations were performed in 9 patients and 52 DCCVs in 20 patients. Acute success was 98% for DCCV and 72.2% for EPS/ablation. Recurrence rate was high (70% for DCCV and 55% for EPS). AT recurrences occurred after a median of 8 and 2.5 months, respectively. On multivariate analyses, age was the only risk factor for arrhythmia recurrence (HR 0.58, 95% C.I. 0.43−0.78, p < 0.0001). Pacemaker implantation was necessary in seven patients (AV block n = 4, sinus node dysfunction n = 3) and one patient received an ICD for secondary prophylaxis. Sudden death occurred in three patients. Conclusions: The most common arrhythmias in patients with SVP > 40 years are IART and AF. Arrhythmia recurrence following EPS or DCCV is frequent. Older age is an independent risk factor for arrhythmia recurrence.

Risk Factors for Atrial Arrhythmias in Adults With Ebstein Anomaly

Background

Atrial arrhythmias (AA) are common in Ebstein anomaly (EA), but risk factors associated with AA are not well understood.

Objectives

The purpose of this study was to determine the prevalence and risk factors for AA at baseline, incidence, and risk factors for AA during follow-up.

Methods

Adults with EA receiving care at Mayo Clinic, MN, between 2003 and 2020 were included. AA was defined as atrial fibrillation (AF) or atrial flutter/tachycardia (AFL). Clinical, echocardiographic, rhythm, surgical data were collected.

Results

Of 682 patients (aged 36 [24-49] years), 235 (34%) had AA at baseline (126 [18%] AF and 144 [21%] AFL), and the risk factors for AA were age, left and right atrial volume indexes, and reservoir strain. Among 447 patients without AA, 10-year cumulative incidence of AF and AFL was 16% and 22%, respectively. The risk factors for incident AF were older age and right atrial reservoir strain. The risk factors for incident AFL were atrial septal defect, left atrial volume index, and male sex. Among patients with baseline AA, 129 (40%) had recurrent episodes (AF 63 [20%], AFL 78 [24%]). The 5-year recurrence rate of AA was 34%, without significant difference for AF vs AFL (46% vs 27%, P = 0.081). Older age and right atrial reservoir strain were associated with recurrent AF.

Conclusions

Patients with EA are at risk for incident and recurrent AA. AF was almost as common as AFL despite relatively young ages. Echocardiographic indexes of atrial function can identify at-risk patients, hence be used to improve risk stratification and guide therapy.

Partial Anomalous Pulmonary Venous Connection with Intact Atrial Septum: Early and Mid-Term Outcomes

BACKGROUND

Partial anomalous pulmonary venous return (PAPVR) with intact atrial septum warrants greater understanding and evaluation in the literature.

METHODS

From January 1993 to December 2018, 293 patients with PAPVR underwent surgical repair. Of these, 45 patients (15.3%) had an intact atrial septum. The median (1^st quartile, 3^rd quartile) age was 36 (24-48) years. Direct reimplantation, intra cardiac baffling, and caval division (Warden) technique was used in 17 (38%), 15 (33%), and 13 (29%) patients, respectively. Descriptive statistics were used to assess the data and Kaplan Meier analysis was used to assess survival.

RESULTS

Anomalous veins were right-sided in 27 patients (60%), left-sided in 16 patients (36%) and bilateral in 2 patients (4%). The insertion sites were the superior vena cava (SVC) 23 (51%), innominate vein 12 (27%), inferior vena cava (IVC) 6 (13%), coronary sinus 2 (4%), right atrium 1 (2%) and unknown in 1 (2%). Scimitar syndrome was noted in 8 patients (18%). There was no postoperative mortality or residual defects. Post-operative echocardiography excluded any obstruction of pulmonary or systemic veins. Post-operative complications included atrial fibrillation in 9 patients (20%) and pneumothorax requiring chest tube in 5 patients (11%). Survival at 1, 5, and 10 years was 100%, 95%, and 95%. Two patients underwent pulmonary vein dilatation one at 3 years the other at 7 years.

CONCLUSIONS

Surgical repair of PAPVC with intact atrial septum can be performed with excellent early and mid-term outcomes. The overall incidence of mid-term systemic or pulmonary vein stenosis is low.

In-vivo Sino-Atrial Node Mapping in Children and Adults With Congenital Heart Disease

BACKGROUND

Sinus node dysfunction (SND) and atrial tachyarrhythmias frequently co-exist in the aging patient with congenital heart disease (CHD), even after surgical correction early in life. We examined differences in electrophysiological properties of the sino-atrial node (SAN) area between pediatric and adult patients with CHD.

METHODS

Epicardial mapping of the SAN was performed during sinus rhythm in 12 pediatric (0.6 [0.4-2.4] years) and 15 adult (47 [40-55] years) patients. Unipolar potentials were classified as single-, short or long double- and fractionated potentials. Unipolar voltage, relative R-to-S-amplitude ratio and duration of all potentials was calculated. Conduction velocity (CV) and the amount of conduction block (CB) was calculated.

RESULTS

SAN activity in pediatric patients was solely observed near the junction of the superior caval vein and the right atrium, while in adults SAN activity was observed even up to the middle part of the right atrium. Compared to pediatric patients, the SAN region of adults was characterized by lower CV, lower voltages, more CB and a higher degree of fractionation. At the earliest site of activation, single potentials from pediatrics consisted of broad monophasic S-waves with high amplitudes, while adults had smaller rS-potentials with longer duration which were more often fractionated.

CONCLUSIONS

Compared to pediatric patients, adults with uncorrected CHD have more inhomogeneous conduction and variations in preferential SAN exit site, which are presumable caused by aging related remodeling. Long-term follow-up of these patients is essential to demonstrate whether these changes are related to development of SND and also atrial tachyarrhythmias early in life.