Impact of Atrial Pacing in Fontan Patients with Junctional Rhythm: A Prospective Echocardiographic Study

Sinus node dysfunction (SND) with junctional rhythm (JR) is common after the Fontan operation. Atrial pacing (AP) restores atrioventricular (AV) synchrony, but the placement of a pacemaker carries significant morbidity. To study the impact of AP on echocardiographic parameters of function in Fontan patients with SND and JR. Nine Fontan patients with AP for SND and JR were prospectively studied with echocardiography in the following conditions-baseline paced rhythm, underlying JR and, if possible, slow-paced rhythm below their baseline paced rate (~ 10 bpm faster than their JR rate). Cardiac index was significantly lower in JR (3 ± 1.1 L/min/m2) vs AP (4.2 ± 1.4 L/min/m2; p = 0.002). Diastolic function also significantly worsened with increased ratio of early diastolic systemic AV valve inflow velocity to early diastolic systemic AV valve annulus velocity (E/e' ratio) by tissue Doppler imaging (TDI) in JR (11.6 ± 4.6) vs AP (8.8 ± 2.2, p = 0.016). Pulmonary venous flow reversal was present in 7/9 patients in JR vs 0/9 in AP (p = 0.016). There were no significant differences in these echocardiographic measurements between the paced and slow-paced conditions. When compared to AP, JR was associated with a significant reduction in cardiac output and diastolic function, and an increased prevalence of pulmonary vein flow reversal. There were no differences between paced and slow-paced conditions, suggesting that AV synchrony rather than heart rate was primarily contributing to cardiac output. Further studies are needed to understand the chronic impact of JR on Fontan outcomes.

Combined Atrial Volume is Associated with Significant Atrial Arrhythmias in Total Cavopulmonary Connection Fontan Patients

Atrial arrhythmias are a common late manifestation after Fontan palliation and are known to contribute to significant morbidity and mortality. Atrial volume by cardiac magnetic resonance imaging has been increasingly used in patients with congenital heart disease with no reports in those with Fontan palliation. In acquired heart disease, left atrial volume has been shown to be a strong predictor of outcomes of sustained atrial arrhythmias, including recurrence of atrial fibrillation. We hypothesized that combined atrial volume (CAV) in patients with total cavopulmonary connection (TCPC) Fontan palliation may be associated with increased risk of significant atrial arrhythmias (SAA). This is a single center retrospective case-control study. Cases were defined as patients with TCPC Fontan palliation ≥ 18 years of age, with SAA requiring intervention. Only those with advanced imaging for 3D rendering between 2013 and 2022 were included. CAV was analyzed from a 3-dimensional (3D) data set, including both the left and right atria, excluding the Fontan baffle. Seventeen TCPC Fontan case patients and 17 control patients were included. There was no difference in age between the two groups. There was no difference between gender, type of Fontan palliation, atrio-ventricular valve regurgitation, or combined ventricular function between the two groups. CAV was higher in SAA group compared to controls, and all control patients had indexed CAV ≤ 80 mL/kg. This is the first data suggesting CAV is associated with SAA in TCPC Fontan patients. Indexed CAV ≥ 80 mL/kg may be a valuable marker for SAA risk.

Late development of intra-atrial reentrant tachycardia in lateral tunnel Fontan patients and the preventive role of prophylactic cryoablation

OBJECTIVE

Intra-atrial reentrant tachycardia is an important late-onset complication in patients undergoing the Fontan procedure. However, the protective effects of prophylactic cryoablation against late-onset intra-atrial reentrant tachycardia are unclear. This study investigated the late development of intra-atrial reentrant tachycardia in patients undergoing the lateral tunnel Fontan procedure and the role of prophylactic cryoablation.

METHODS

This was a single-center retrospective cohort study of patients who underwent the lateral tunnel Fontan procedure between 1988 and 2003. Univariate and multivariable competing risks regression models were used to determine the associations of prophylactic cryoablation and covariates with the outcomes of interest: late-onset intra-atrial reentrant tachycardia, all-cause mortality, and cardiovascular mortality.

RESULTS

In total, 130 patients who underwent the lateral tunnel Fontan procedure, 30 of whom had undergone prophylactic cryoablation, were included in this study and followed up for a median of 23.6 years (interquartile range, 17.7-26.5). Intra-atrial reentrant tachycardia was identified in 14 patients (10.8%), none of whom underwent prophylactic cryoablation. The median Fontan-to-intra-atrial reentrant tachycardia time was 17.2 years (interquartile range, 11.1-23.1). Prophylactic cryoablation was protective against late-onset intra-atrial reentrant tachycardia (P < .0001) and cardiovascular mortality (P < .0001) in the type 3 test.

CONCLUSIONS

None of the patients who underwent prophylactic cryoablation developed late-onset intra-atrial reentrant tachycardia during a median follow-up time of 22.9 years. Our study demonstrated that prophylactic cryoablation was effective in preventing late-onset intra-atrial reentrant tachycardia and cardiovascular mortality in patients undergoing the lateral tunnel Fontan.

EASL-ERN position paper on liver involvement in patients with Fontan-type circulation

Fontan-type surgery is the final step in the sequential palliative surgical treatment of infants born with a univentricular heart. The resulting long-term haemodynamic changes promote liver damage, leading to Fontan-associated liver disease (FALD), in virtually all patients with Fontan circulation. Owing to the lack of a uniform definition of FALD and the competitive risk of other complications developed by Fontan patients, the impact of FALD on the prognosis of these patients is currently debatable. However, based on the increasing number of adult Fontan patients and recent research interest, the European Association for The Study of the Liver and the European Reference Network on Rare Liver Diseases thought a position paper timely. The aims of the current paper are: (1) to provide a clear definition and description of FALD, including clinical, analytical, radiological, haemodynamic, and histological features; (2) to facilitate guidance for staging the liver disease; and (3) to provide evidence- and experience-based recommendations for the management of different clinical scenarios.

Atrial Arrhythmias in Adults with Fontan Palliation

Single ventricle physiology is a rare form of congenital heart disease and was, historically, a uniformly lethal condition. However, the atriopulmonary Fontan operation, and its successive iterations, the lateral tunnel and extracardiac conduit Fontan, became the fundamental approach to treating single ventricle heart disease. Over time, dysrhythmias are some of the most common complications with Fontan physiology, compounding morbidity and mortality. Atrial arrhythmias are prevalent in the Fontan population and occur in about 15-60% of patients with Fontan palliation, increasingly with age. Diagnosing atrial arrhythmias in patients with Fontan palliation may be challenging because of low voltage amplitudes arising from myopathic atrial tissue making it difficult to clearly assess atrial depolarization on surface electrocardiograms (ECG), vague symptoms not suggestive of tachyarrhythmia, or atrial arrhythmia with ventricular rates below 100 beats per minute. Intra-atrial reentrant tachycardia (IART) is the most common type of supraventricular tachycardia in adults with Fontan palliation. Acute management of atrial arrhythmias in patients with Fontan palliation involves prompt assessment of a patient's hemodynamic stability, anticoagulation and thrombosis risk, systemic ventricular function, and risk of sedation or anesthesia if needed. Long-term management of atrial arrhythmias is often multifactorial and may include long-term anti-arrhythmic therapy, permanent pacing, and ablation. The best approach for the management of atrial arrhythmias in adults with Fontan palliation is patient-specific and involves collaboration between congenital electrophysiologists, adult congenital cardiologists, and the patient.

Subcutaneous defibrillator use with unipolar pacemakers: Cautiously possible

Implantation of subcutaneous implantable cardioverter-defibrillator in a patient with existing unipolar pacemaker is against manufacturer recommendations. We report the case of a successful subcutaneous implantable cardioverter-defibrillator implantation in a patient with Fontan circulation and concomitant active unipolar pacing and present a summary of recommendations when considering subcutaneous implantable cardioverter-defibrillator implantation with unipolar pacing. Recommendations included: pre-procedure screening, rescreening during implantation and ventricular fibrillation induction, pacemaker programming, and post-procedure investigations.

The Secrets of the Frogs Heart

The heart of the African clawed frog has a double-inlet and single-outlet ventricle supporting systemic and pulmonary circulations via a truncus, and a lifespan of 25-30 years. We sought to understand the unique cardiac anatomic and physiologic characteristics, with balanced circulation and low metabolic rate, by comparing the basic anatomy structures with focused echocardiography and cardiac magnetic resonance imaging. Twenty-four adult female African clawed frogs were randomly subjected to anatomic dissection (n = 4), echocardiography (n = 10), and cardiac magnetic resonance (n = 10). All anatomical features were confirmed and compared with echocardiography and cardiac magnetic resonance imaging. The main characteristics of the cardiovascular circulation in frogs are the following: Intact interatrial septum, with two separate atrio-ventricular valves, preventing atrial mixing of oxygenated and desaturated blood. Single spongiform ventricular cavity, non-conducive for homogeneous mixing. Single outlet with a valve-like mobile spiral structure, actively streaming into systemic and pulmonary arteries. Intact interatrial septum, spongiform ventricle, and valve-like spiral in the conus arteriosus are likely responsible for balanced systemic and pulmonary circulation in frogs, in spite of double-inlet and single-outlet ventricle.

Cardiac Implantable Electronic Devices in the Fontan Patient

As a result of remarkable progress in operative techniques and cardiology care during childhood, Fontan patients continue to age and require team-based multidisciplinary expertise to manage complications encountered in adulthood. They face particular challenges in terms of altered hemodynamic stressors, cardiac and hepatic failure, and arrhythmias. Arrhythmias in Fontan patients are highly prevalent and associated with underlying anatomy, surgical technique, and postoperative sequelae. Diagnostic tools, treatments, and device strategies for arrhythmias in Fontan patients should be adapted to the specific anatomy, type of surgical repair, and clinical status. Great strides in our understanding of arrhythmia mechanisms, options and techniques to obtain access to relevant cardiac structures, and application of both old and new technologies have contributed to improving cardiac implantable electronic device (CIED) therapies for this unique population. In this state-of-the-art review, we discuss the various arrhythmias encountered in Fontan patients, their diagnosis, and options for treatment and prevention, with a focus on CIEDs. Throughout, access challenges particular to the Fontan circulation are considered. Recently developed technologies, such as the sub-cutaneous implantable cardioverter defibrillator carry the potential to be transformative but require awareness of Fontan-specific issues. Moreover, new leadless pacing technology represents a promising strategy that may soon become applicable to Fontan patients with sinus node dysfunction. CIEDs are essential tools in managing Fontan patients but the complex clinical scenarios that arise in this patient population are among the most challenging for the congenital electrophysiologist.

QRS fragmentation and prolongation as predictors of exercise capacity in patients after Fontan palliation

INTRODUCTION

Patients with Fontan anatomy are at increased risk for exercise intolerance and early morbidity and mortality. QRS complex fragmentation (fQRS) and prolongation have been studied in multiple heart diseases, but their clinical importance is unknown in the Fontan population.

METHODS

A retrospective cross-sectional study was performed. ECGs were evaluated for QRS prolongation (>98 %ile for age) and fQRS [ ≥3 R-waves/ notches in the R/S complex (more than 2 in RBBB) in ≥2 contiguous leads]. The primary outcome measures was CPET performance.

RESULTS

Ninety patients (median age 18 years, 57% male, 59% RV dominant) were included; 13% had fQRS and 31% had prolonged QRS. Demographically, patients with fQRS or prolonged QRS were like those without. Peak VO2 (64% vs 63%, p 0.45), VE/VCO2 slope (85% vs 88%, p = 0.74), and O2 pulse (149% vs 129%, p = 0.83) were similar in the fQRS group versus those without. Upon multi-variable regression, body mass index (β = -0.38, p < 0.01) and QRS duration (β = -0.29, p < 0.01) were independently associated with % predicted VO2; fQRS was not. Lower cardiac index (2.2 vs 2.8 L/min/m2, p = 0.03) and higher ventricular end-diastolic pressure (13 vs 10 mmHg, p = 0.02) was seen with fQRS.

CONCLUSIONS

QRS fragmentation is present in patients with Fontan physiology. fQRS showed no association with CPET performance but was related to invasive hemodynamic markers of ventricular performance. QRS duration may be a better predictor of exercise function following Fontan. This article is protected by copyright. All rights reserved.

Adolescents and adults with Fontan circulation: insights from the PREpArE-Fontan registry

The Patient Registry for Adolescents and Adults with Stable Fontan Circulation aims to describe a contemporary cohort of Fontan patients who could be eligible for a clinical trial investigating macitentan, an endothelin receptor antagonist. This international, non-interventional, multicentre, cross-sectional, observational registry enrolled patients with "stable" Fontan circulation ≥10 years following extra-cardiac conduit or lateral tunnel procedure. Main exclusion criteria were NYHA functional class IV, reoperation of Fontan circulation, or signs of disease worsening. Patient characteristics at enrolment are described; available data were collected during a single registration visit. Of the 266 screened patients, 254 were included in this analysis. At enrolment, median (interquartile range) age was 24 (20;30) years, 37%/63% of patients were from the USA/Europe, 54% were male, 54%/47% had undergone extra-cardiac conduit/lateral tunnel procedures, and 95% were in NYHA functional class I or II. History of arrhythmia was more common in older patients and patients with lateral tunnel; overall prevalence was 19%. Most laboratory values were within the normal range but mean creatinine clearance was abnormally low (87.7 ml/min). Angiotensin-converting enzyme inhibitors were used by 48% of patients and their use was associated with creatinine clearance <90 ml/min (p = 0.007), as was Fontan completion at an older age (p = 0.007). 53.4% of patients had clinical characteristics that could potentially meet an endothelin receptor antagonist trial's eligibility criteria. The PREpArE-Fontan registry describes a cohort of patients who could potentially participate in an endothelin receptor antagonist trial and identified early subtle signs of Fontan failure, even in "stable" patients.

Prevalence of Arrhythmia in Adults after Fontan Operation

Structural, hemodynamic, and morphological cardiac changes following Fontan operation (FO) can contribute to the development of arrhythmias and conduction disorders. Sinus node dysfunction, junction rhythms, tachyarrhythmias, and ventricular arrhythmias (VAs) are some of the commonly reported arrhythmias. Only a few studies have analyzed this condition in adults after FO. This study aimed to determine the type and prevalence of arrhythmias and conduction disorders among patients who underwent FO and were under the medical surveillance of the John Paul II Hospital in Krakow. Data for the study were obtained from 50 FO patients (mean age 24 ± 5.7 years; 28 men (56%)). The median follow-up time was 4 (2–9) years. Each patient received a physical examination, an echocardiographic assessment, and a 24 h electrocardiogram assessment. Bradyarrhythmia was diagnosed in 22 patients (44%), supraventricular tachyarrhythmias in 14 patients (28%), and VAs in 6 patients (12%). Six patients required pacemaker implantation, and three required radiofrequency catheter ablation (6%). Arrythmias is a widespread clinical problem in adults after FO. It can lead to serious haemodynamic impairment, and therefore requires early diagnosis and effective treatment with the use of modern approaches, including electrotherapy methods.

A Multimodal Score Accurately Classifies Fontan Failure and Late Mortality in Adult Fontan Patients

Objectives

Despite the outstanding success of the Fontan operation, it is a palliative procedure and a substantial number of patients experience late failure of the Fontan circulation. Clinical presentation and hemodynamic phenotypes of Fontan failure are considerably variable. While various parameters have been identified as risk factors for late Fontan failure, a feasible score to classify Fontan failure and possibly allow timely risk stratification is lacking. Here, we explored the possibility of developing a score based on hemodynamic, clinical and laboratory parameters to classify Fontan failure and mortality.

Methods

We performed a retrospective study in our cohort of adult Fontan patients from two institutions [n = 198, median follow-up after Fontan 20.3 (IQR 15.6–24.3) years], identifying those patients with clinical Fontan failure (n = 52, 26.3%). Various hemodynamic, echocardiographic, laboratory and clinical data were recorded and differences between patients with and without Fontan failure were analyzed. We composed a Fontan Failure Score containing 15 parameters associated with Fontan failure and/or mortality and assessed its accuracy to discriminate between patients with and without late Fontan failure as well as late mortality and survival.

Results

Late failure occurred at a median of 18.2 (IQR 9.1–21.1) years after Fontan completion. Mortality associated with Fontan failure was substantial (25/52, 48.1%) with freedom of death/transplantation/take-down of 64% at 5 years and 36% at 10 years after onset of Fontan failure, respectively. Patients with Fontan failure had a significantly higher median Fontan Failure Score compared to non-failing Fontan patients [8 points (IQR 5–10) vs. 2 points (IQR 1-5), p < 0.001]. The score accurately classifies Fontan failure as well as mortality as assessed with receiver operating characteristic analysis. Area under the curve of the Fontan Failure Score was 0.963 (95% CI 0.921; 0.985, p < 0.001) to discriminate failure and 0.916 (95% CI 0.873; 0.959, p < 0.001) to classify mortality.

Conclusion

We have developed an uncomplex yet remarkably accurate score to classify Fontan failure and late mortality in adult Fontan patients. Prospective validation and most likely refinement and calibration of the score in larger and preferably multi-institutional cohorts is required to assess its potential to predict the risk of Fontan failure and late mortality.

Hemodynamic Impact of Atrial Pacing in Patients with Fontan Physiology and Junctional Rhythm: A Cardiac Catheterization Study

Sinus node dysfunction is a common problem and adversely impacts patients who have undergone the Fontan operation. In Fontan patients with an adequate junctional escape rhythm, the benefit of atrial pacing to restore atrioventricular synchrony remains unclear. Data were collected retrospectively on all Fontan patients with junctional rhythm who underwent atrial pacing during cardiac catheterization. Hemodynamics were obtained at baseline and after atrial pacing for 5-10 min. Seven patients, mean age 10 years (3-21) were studied. The type of Fontan was extracardiac in 6 and lateral tunnel in one. Patients were paced at 10 bpm faster than their junctional rate. With pacing, there was a significant decrease in left atrial pressure from (mean ± SEM) 8.8 ± 2.6 to 5.5 ± 2.9 mmHg (p = 0.02), a significant increase in cardiac index from 2.7 ± 0.8 to 3.5 ± 1 L/min/m² (p = 0.01) and pulmonary blood flow from 2.1 ± 0.6 to 2.7 ± 0.7 L/min/m² (p = 0.001), and no significant change in pulmonary artery pressure, from 13.4 ± 2.8 to 12.4 mmHg ± 3.6 (p = 0.06) or pulmonary vascular resistance from 2.1 ± 0.86 to 3.25 ± 1.9 WU × M2 (p = 0.1). In Fontan patients with junctional rhythm, atrial pacing decreased the left atrial pressure, increased cardiac output and did not significantly change the pulmonary artery pressure. Our study supports further investigation into the utility of prophylactic atrial pacemaker implantation in Fontan patients with significant durations of JR on ambulatory monitoring.

Catheter ablation of atrial arrhythmias in patients post-Fontan

Atrial arrhythmias are highly prevalent in the aging Fontan population and contribute importantly to morbidity and mortality. Although the most common arrhythmia is scar-based intra-atrial re-entrant tachycardia, various other arrhythmias may occur including focal atrial tachycardia, atrioventricular node-dependent tachycardias, and atrial fibrillation. The type and prevalence of atrial arrhythmia is determined, in part, by the underlying congenital defect and variant of Fontan surgery. While the cumulative incidence of atrial tachyarrhythmias has decreased substantially from the atriopulmonary anastomosis to the more recent total cavopulmonary connection Fontan, the burden of atrial arrhythmias remains substantial. Management is often multi-faceted and can include anticoagulation, anti-arrhythmic drug therapy, pacing, and cardioversion. Catheter ablation plays a key role in arrhythmia control. Risks and benefits must be carefully weighed. Among the important considerations are the clinical burden of arrhythmia, ventricular function, hemodynamic stability in tachycardia, suspected arrhythmia mechanisms, risks associated with anaesthesia, venous access, approaches to reaching the pulmonary venous atrium, and accompanying co-morbidities. Careful review of surgical notes, electrocardiographic tracings, and advanced imaging is paramount, with particular attention to anatomic abnormalities such as venous obstructions and displaced conduction systems. Despite numerous challenges, ablation of atrial arrhythmias is effective in improving clinical status. Nevertheless, onset of new arrhythmias is common during long-term follow-up. Advanced technologies such as high-density mapping catheters and remote magnetic guided ablation carry the potential to further improve outcomes. Fontan patients with atrial arrhythmias should be referred to centers with dedicated expertise in congenital heart disease including catheter ablation, anaesthesia support, and advanced imaging.

Case report of the broad spectrum of late complications in an adult patient with univentricular physiology palliated by the Fontan circulation

Background

At the most severe end of the spectrum of congenital heart disease are patients with an univentricular physiology. They comprise a heterogeneous group of congenital heart malformations that have the common characteristic that the cardiac morphology is not equipped for sustaining a biventricular circulation.

Case summary

Here, we present a case of an adult patient after Fontan palliation, illustrative of the complex clinical course and the broad spectrum of complications that can be encountered during follow-up, highlighting the need for a multidisciplinary approach in the clinical care for these patients.

Discussion

During the surgical Fontan procedure, the inferior vena cava is connected to the pulmonary circulation, after prior connection of the superior vena cava to the pulmonary arterial circulation. The resulting cavopulmonary connection, thus lacking a subpulmonic ventricle, provides non-pulsatile passive flow of oxygen-poor blood from the systemic venous circulation into the lungs, and the functional monoventricle pumps the oxygen-rich pulmonary venous return blood into the aorta. With an operative mortality of <5% and current 30-year survival rates up to 85%, the adult population of patients with a Fontan circulation is growing. This increase in survival is, however, inevitably accompanied by long-term complications affecting multiple organ systems, resulting in decline in cardiovascular performance.

Conclusion

For optimal treatment, the evaluation in a multidisciplinary team is mandatory, using the specific expertise of the team members to timely detect and address late complications and to support quality of life.

Management of circulatory failure after Fontan surgery

With improvement in survival after Fontan surgery resulting in an increasing number of older survivors, there are more patients with a Fontan circulation experiencing circulatory failure each year. Fontan circulatory failure may have a number of underlying etiologies. Once Fontan failure manifests, prognosis is poor, with patient freedom from death or transplant at 10 years of only about 40%. Medical treatments used include traditional heart failure medications such as renin-angiotensin-aldosterone system blockers and beta-blockers, diuretics for symptomatic management, antiarrhythmics for rhythm control, and phosphodiesterase-5 inhibitors to decrease PVR and improve preload. These oral medical therapies are typically not very effective and have little data demonstrating benefit; if there are no surgical or catheter-based interventions to improve the Fontan circulation, patients with severe symptoms often require inotropic medications or mechanical circulatory support. Mechanical circulatory support benefits patients with ventricular dysfunction but may not be as useful in patients with other forms of Fontan failure. Transplant remains the definitive treatment for circulatory failure after Fontan, but patients with a Fontan circulation face many challenges both before and after transplant. There remains significant room and urgent need for improvement in the management and outcomes of patients with circulatory failure after Fontan surgery.

Current Treatment Options for the Failing Fontan Circulation

The Fontan operation was introduced in 1968. For congenital malformations, where biventricular repair is unsuitable, the Fontan procedure has provided a long-term palliation strategy with improved outcomes compared to the initially developed procedures. Despite these improvements, several complications merely due to a failing Fontan circulation, including myocardial dysfunction, arrhythmias, increased pulmonary vascular resistance, protein-losing enteropathy, hepatic dysfunction, plastic bronchitis, and thrombo-embolism, may occur, thereby limiting the life-expectancy in this patient cohort. This review provides an overview of the most common complications of Fontan circulation and the currently available treatment options.

Autologous Umbilical Cord Blood-Derived Mononuclear Cell Therapy Promotes Cardiac Proliferation and Adaptation in a Porcine Model of Right Ventricle Pressure Overload

Congenital heart diseases, including single ventricle circulations, are clinically challenging due to chronic pressure overload and the inability of the myocardium to compensate for lifelong physiological demands. To determine the clinical relevance of autologous umbilical cord blood-derived mononuclear cells (UCB-MNCs) as a therapy to augment cardiac adaptation following surgical management of congenital heart disease, a validated model system of right ventricular pressure overload due to pulmonary artery banding (PAB) in juvenile pigs has been employed. PAB in a juvenile porcine model and intramyocardial delivery of UCB-MNCs was evaluated in three distinct 12-week studies utilizing serial cardiac imaging and end-of-study pathology evaluations. PAB reproducibly induced pressure overload leading to chronic right ventricular remodeling including significant myocardial fibrosis and elevation of heart failure biomarkers. High-dose UCB-MNCs (3 million/kg) delivered into the right ventricular myocardium did not cause any detectable safety issues in the context of arrhythmias or abnormal cardiac physiology. In addition, this high-dose treatment compared with placebo controls demonstrated that UCB-MNCs promoted a significant increase in Ki-67-positive cardiomyocytes coupled with an increase in the number of CD31+ endothelium. Furthermore, the incorporation of BrdU-labeled cells within the myocardium confirmed the biological potency of the high-dose UCB-MNC treatment. Finally, the cell-based treatment augmented the physiological adaptation compared with controls with a trend toward increased right ventricular mass within the 12 weeks of the follow-up period. Despite these adaptations, functional changes as measured by echocardiography and magnetic resonance imaging did not demonstrate differences between cohorts in this surgical model system. Therefore, this randomized, double-blinded, placebo-controlled pre-clinical trial establishes the safety of UCB-MNCs delivered via intramyocardial injections in a dysfunctional right ventricle and validates the induction of cardiac proliferation and angiogenesis as transient paracrine mechanisms that may be important to optimize long-term outcomes for surgically repaired congenital heart diseases.

Long-term management of Fontan patients: The importance of a multidisciplinary approach

The Fontan operation is a palliative procedure that leads to increased survival of patients with a functional single ventricle (SV). Starting from 1967 when the first operation was performed by Francis Fontan, more and more patients have reached adulthood. Furthermore, it is expected that in the next 20 years, the population with Fontan circulation will reach 150,000 subjects. The absence of right ventricular propulsion and the inability to improve cardiac output because of the low cardiac reserve are the main issues with the Fontan circulation; however, potential complications may also involve multiple organ systems, such as the liver, lungs, brain, bones, and the lymphatic system. As these patients were initially managed mainly by pediatric cardiologists, it was important to assure the appropriate transition to adult care with the involvement of a multidisciplinary team, including adult congenital cardiologists and multiple subspecialists, many of whom are neither yet familiar with the pathophysiology nor the end-organ consequences of the Fontan circulation. Therefore, the aim of our work was to collect all the best available evidence on Fontan's complications management to provide "simple and immediate" information sources for practitioners looking for state of the art evidence to guide their decision-making and work practices. Moreover, we suggest a model of follow-up of patients with Fontan based on a patient-centered multidisciplinary approach.

Failures of the Fontan System in Univentricular Hearts and Mortality Risk in Heart Transplantation: A Systematic Review and Meta-Analysis

The Fontan procedure (FP) is the standard surgical treatment for Univentricular heart diseases. Over time, the Fontan system fails, leading to pathologies such as protein-losing enteropathy (PLE), plastic bronchitis (PB), and heart failure (HF). FP should be considered as a transitional step to the final treatment: heart transplantation (HT). This systematic review and meta-analysis aims to establish the risk of death following HT according to the presence of FP complications. There was a total of 691 transplanted patients in the 18 articles, immediate survival 88% (n = 448), survival from 1 to 5 years of 78% (n = 427) and survival from 5.1 to 10 years of 69% (n = 208), >10 years 61% (n = 109). The relative risk (RR) was 1.12 for PLE (95% confidence interval [CI] = 0.89-1.40, p = 0.34), 1.03 for HF (0.7-1.51, p = 0.88), 0.70 for Arrhythmias (0.39-1.24, p = 0.22), 0.46 for PB (0.08-2.72, p = 0.39), and 5.81 for CKD (1.70-19.88, p = 0.005). In patients with two or more failures, the RR was 1.94 (0.99-3.81, p = 0.05). After FP, the risk of death after HT is associated with CKD and with the presence of two or more failures.

Device-detected non-sustained ventricular tachycardia in adult congenital heart disease without tetralogy of fallot

OBJECTIVES

To evaluate any association between non-sustained ventricular tachycardia (NSVT) detected by intra-cardiac device and clinical outcomes in repaired adult congenital heart disease (ACHD) without tetralogy of Fallot (TOF).

BACKGROUND

NSVT portends a higher risk of serious ventricular tachyarrhythmia in TOF. However its clinical significance when incidentally detected by implantable cardiac device is not well elucidated in non-TOF ACHD cohort.

METHODS

We performed a single center, retrospective, longitudinal follow-up study in repaired ACHD (≥ 18 years) patients without TOF who hosted a pacemaker or automatic implantable cardiac defibrillator (AICD). The cohort was divided based on presence/absence of device detected NSVT. The primary end-point was a composite of sustained ventricular tachycardia (VT), ventricular fibrillation (VF), or sudden cardiac death (SCD).

RESULTS

158 patients [male 56.3%, median (IQR) age of 35 (28-43) years at last follow-up] with longitudinal post-implant follow-up duration of 8 (5-12) years were included. NSVT was detected in 52 (33%) patients. The primary composite end-point was more frequent in NSVT group [11.5% vs. 2.8%; p = 0.04]. Patients with NSVT were i) older at the time of initial implant (age 25 vs. 18 years, p = 0.011) and more frequently demonstrated ii) systemic ventricular dysfunction (44% vs. 26%; p = 0.015), as well as iii) history of ventriculotomy (38% vs. 21%;p = 0.017).

CONCLUSIONS

In our repaired ACHD cohort, we noted a significant association between device-detected-NSVT and the primary composite end-point of sustained VT/VF or SCD. Systemic ventricular dysfunction and history of ventriculotomy were more frequent in the NSVT group and likely constituted the clinical milieu. This article is protected by copyright. All rights reserved.

Utility of Surveillance Ambulatory Rhythm Monitoring in the Pediatric Fontan Population

Our institution established a Fontan surveillance plan, which included ambulatory rhythm monitoring (ARM) at 6, 10, 13, 16 and 19 years old, for early detection of Fontan-associated complications. We conducted a retrospective chart review of Fontan patients followed at our institution 2014-2018 to determine the utility of surveillance ARMs. 139 ARMs from 83 patients were included. ARMs with supraventricular tachycardia, sinus node dysfunction, accelerated junctional rhythm, > 1st degree atrioventricular block, and complex ventricular ectopy were classified as positive for arrhythmia. Arrhythmias were occult if detected on surveillance ARM. The ARM indication was surveillance in 78 (56%) and clinically indicated in 61 (44%). 52 (37%) ARMs in 27 (33%) patients had an arrhythmia. There was no difference in the age of patients with and without arrhythmias [median 10.9 (6.5, 17.1 years) vs. 8.8 (7, 13.6 years), p = 0.5]. Clinically indicated ARMs more frequently demonstrated arrhythmias than surveillance ARMs (52% vs. 26%, p < 0.01). Compared to patients without arrhythmias, those with arrhythmias were more likely to be female (48% vs. 23%, p = 0.02), have a single right ventricle (46% vs. 19%, p < 0.01) and longer QRS duration on ECG [100 (91, 116 ms) vs. 94 (84, 104 ms), p = 0.046]. Patients with occult arrhythmias were less likely to have moderate to severe atrioventricular valvar regurgitation (0% vs. 46%; p = 0.04) or ventricular dysfunction (0% vs. 46%; p = 0.04) than those with clinical arrhythmia(s). Arrhythmia findings resulted in change in management for 16/52 (31%) ARMs. The findings suggest the frequent presence of arrhythmias on periodic ARMs in patients following the Fontan procedure regardless of symptomatic status.

Reaching consensus for unified medical language in Fontan care

Aims

The Fontan operation has resulted in improved survival in patients with single‐ventricle congenital heart disease. As a result, there is a growing population of teenagers and adults with a Fontan circulation. Many co‐morbidities have been increasingly recognized in this population due to the unique features of the Fontan circulation. Standardization of how Fontan co‐morbid conditions are defined will help facilitate understanding, consistency and interpretability of research and clinical experience. Unifying common language usage in Fontan is a critical precursor step for data comparison of research findings and clinical outcomes and ultimately accelerating improvements in management for this growing group of patients. This manuscript aimed to create unified definitions for morbidities seen after the Fontan palliation.

Methods

In association of many congenital heart disease organizations, this work used Delphi methodology to reach a broad consensus among recognized experts regarding commonly used terms in Fontan care and research. Each definition underwent at least three rounds of revisions to reach a final definition through surveys sent to experts in the field of single‐ventricle care.

Results

The process of reaching a consensus on multiple morbidities associated with the Fontan procedure is summarized in this manuscript. The different versions that preceded reaching the consensus are also presented in the Supporting Information. Table 1 represents the final definitions according to the consensus.

Conclusions

We propose the use of these definitions for clinical care, future research studies, registry development and clinical trials.

Perioperative and long-term management of Fontan patients

A Fontan circulation requires a series of three-staged operations aimed to palliate patients with single-ventricle CHD. Currently, the most frequent technique is the extracardiac total cavopulmonary connection, an external conduit connecting the IVC and right pulmonary artery, bypassing the right side of the heart. Fontan candidates must meet strict criteria; they are assessed utilising both cardiac catheterisation and cardiac magnetic resonance. Postoperatively, treatment protocols prioritise antibiotic prophylaxis, diuretics, angiotensin-converting enzyme inhibitors, anticoagulation, and oxygen therapy with fluid restriction and a low-fat diet. These measures aim to reduce length of stay in the ICU and hospital by preventing acute complications such as infection, venous thromboembolism, low cardiac output, pleural effusion, and acute kidney injury. Late complications of a Fontan procedure include circulation failure, protein-losing enteropathy, plastic bronchitis, and Fontan-associated liver disease. The definitive management is cardiac transplantation, with promising innovations in selective embolisation of lymphatic vessels and Fontan-specific ventricular assist devices. Further research assessing current protocols in the perioperative management of Fontan patients would be beneficial for standardising current practice and improving outcomes.

Perioperative Management of the Fontan Patient for Cardiac and Noncardiac Surgery

The Fontan circulation is the single-ventricle approach to surgical palliation of complex congenital heart disease wherein biventricular separation and function cannot be safely achieved. Incremental improvements in this surgical technique, along with improvements in the long-term medical management of these patients, have led to greater survival of these patients and a remarkably steady increase in the number of adults living with this unusual circulation and physiology. This has implications for healthcare providers who now have a greater chance of encountering Fontan patients during the course of their practice. This has particularly important implications for anesthesiologists because the effects of their interventions on the finely balanced Fontan circulation may be profound. The American Heart Association and American College of Cardiology recommend that, when possible, elective surgery should be performed in an adult congenital heart disease center, although this may not be feasible in the provision of true emergency care. This review article summarizes the pathophysiology pertinent to the provision of anesthesia in this complex patient group and describes important modifications to anesthetic technique and perioperative management.

Transvenous shock-only implantable cardioverter defibrillator after an atrio-pulmonary Fontan surgery

A 42‐year‐old woman with tricuspid atresia who underwent a Fontan surgery (atrio‐pulmonary connection) was admitted to our hospital due to symptomatic ventricular tachycardia (VT). A defibrillation lead was implanted in a distal site of a coronary vein since there was no usual entry to the ventricle. Ventricular pacing was impossible due to the high threshold, however, good sensing was obtained. Three years later, she felt palpitations and a subsequent shock therapy while climbing stairs. The cardioverter data showed that an appropriate cardioversion therapy successfully converted VT to normal rhythm.

Ablation for idiopathic left ventricular tachycardia in a patient with double outlet right ventricle who underwent Fontan operation: a case report

Background

The incidence of ventricular tachycardia (VT) in patients following Fontan operation is reported as 3.5%. Furthermore, in patients with repaired double outlet right ventricle (DORV), scar-related VT and outflow tract VT have been reported; however, Purkinje-related VT has not previously been reported. In this report, we present the case of idiopathic left VT (ILVT) in a patient with DORV who underwent Fontan operation.

Case summary

A 31-year-old man was diagnosed as having DORV with complete atrioventricular defect at birth. When he was 17 years old, he underwent surgical repair, including extracardiac Fontan operation and common atrioventricular valve replacement. Five years later, VT was detected. Since some medications were ineffective in suppressing VT, he was referred to our hospital for definitive treatment. Ventricular tachycardia was induced by atrial and ventricular programmed electrical stimulations. The mechanism of the VT was determined to be re-entry. The earliest activation site was located at the mid-inferior septum of the hypoplastic left ventricle, in which Purkinje potentials were observed before the local ventricular electrogram. Radiofrequency catheter ablation (RFCA) was performed at this site to eliminate VT.

Discussion

Most VTs originate from surgical scars in patients with congenital heart disease. Catheter ablation was feasible in scar-related VT. To the best of our knowledge, this is the first report of ILVT treated successfully with RFCA in a DORV patient who had undergone Fontan operation.

The Adult Patient with a Fontan

The authors summarize the most important anatomic and physiologic substrates of Fontan circulation. Common anatomic substrates include hypoplastic left heart syndrome, tricuspid atresia, double inlet left ventricle, and unbalanced atrioventricular septal defects. After the Fontan operation exercise capacity is limited and the key hemodynamic drivers is limited preload due to a relatively fixed pulmonary vascular resistance. The authors provide contemporary data on survival, morbidity, and need for reintervention. Operative morality is now expected to be less than 1% and 30 year survival approximately 89%. The authors delineate potential therapeutic approaches for the potential late complications.

Sudden death in patients with Ebstein anomaly

Aims

Ventricular dysfunction or structural alteration of either ventricle is a well-established risk factor for sudden death (SD). Ebstein anomaly (EA) can present with both right and left heart abnormalities; however, predictors of SD have not been described. We therefore sought to characterize the incidence and risk factors of SD among a large cohort of patients with EA.

Methods and results

All EA patients who underwent evaluation at a high-volume institution over a 4-decade period were retrospectively reviewed. Clinical variables, cardiovascular surgical procedure(s), and cause of death were recorded. Sudden death incidence from birth and following tricuspid valve (TV) surgery were estimated using the Kaplan-Meier method. Cox regression analysis was used to identify clinical and surgical predictors of SD. The cohort comprised of 968 patients [mean age 25.3 years, 41.5% male; 79.8% severe EA, 18.6% accessory pathway, 0.74% implantable cardioverter-defibrillator (ICD) placement]. The 10-, 50-, and 70-year cumulative incidences of SD from birth were 0.8%, 8.3%, and 14.6%, respectively. Prior ventricular tachycardia [hazard ratio (HR) 6.37, P < 0.001)], heart failure (HR 5.64, P < 0.001), TV surgery (HR 5.94, P < 0.001), syncope (HR 2.03, P = 0.019), pulmonic stenosis (HR 3.42, P = 0.001), and haemoglobin > 15 g/dL (HR 2.05, P = 0.026) were multivariable predictors of SD. In a similar subgroup analysis of patients who underwent TV surgery, all of the above factors except syncope were significantly associated with post-operative SD on multivariable analysis.

Conclusion

Patients with EA are at significant risk for SD. Key clinical SD predictors identified can aid in risk stratification and potentially guide primary prevention ICD implantation.

Autologous Right Auricular Versus PTFE Cavopulmonary Lateral Tunnel: Influence of Surgical Technique on Arrhythmias

BACKGROUND

To compare the incidence of arrhythmias and the overall survival at long-term follow-up of the right auricular baffle technique (RA) versus Gore-Tex^® (GT) baffle as intra-atrial cavopulmonary lateral tunnel, as well as the Nakata index and tunnel dimensions on cardiac magnetic resonance.

METHODS

Data were retrospectively collected. Serial 24-hour Holter recordings and cardiac magnetic resonance findings of the two groups were compared.

RESULTS

There was no significant difference in the estimated freedom from arrhythmias (87% at 10 years and 78% at 15 years vs 80% at 10 years and 70% at 15 years in RA and GT, respectively; P = .44) nor cumulative survival (86% at 10 years and 84% at 15 years vs 97% at 10 years and 81% at 15 years in RA and GT, respectively; P = .8). Also, no difference between the groups was observed in the Nakata index. The tunnel dimensions on cardiac magnetic resonance were significantly wider in the RA group. In reference to other potential risk indicators, using Cox proportional hazard regression analysis, only age (5 years or older at the time of total cavopulmonary connection) was associated with an increased risk for both arrhythmia and mortality.

CONCLUSIONS

This study demonstrated that there was no difference in freedom from arrhythmias, Nakata index, or survival between the two groups. This study confirmed the growth potential of the right auricular tunnel. However, the growth of the tunnel did not influence the incidence of arrhythmias.

Evaluation and Management of the Child and Adult With Fontan Circulation: A Scientific Statement From the American Heart Association

It has been 50 years since Francis Fontan pioneered the operation that today bears his name. Initially designed for patients with tricuspid atresia, this procedure is now offered for a vast array of congenital cardiac lesions when a circulation with 2 ventricles cannot be achieved. As a result of technical advances and improvements in patient selection and perioperative management, survival has steadily increased, and it is estimated that patients operated on today may hope for a 30-year survival of >80%. Up to 70 000 patients may be alive worldwide today with Fontan circulation, and this population is expected to double in the next 20 years. In the absence of a subpulmonary ventricle, Fontan circulation is characterized by chronically elevated systemic venous pressures and decreased cardiac output. The addition of this acquired abnormal circulation to innate abnormalities associated with single-ventricle congenital heart disease exposes these patients to a variety of complications. Circulatory failure, ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, protein-losing enteropathy, and plastic bronchitis are potential complications of the Fontan circulation. Abnormalities in body composition, bone structure, and growth have been detected. Liver fibrosis and renal dysfunction are common and may progress over time. Cognitive, neuropsychological, and behavioral deficits are highly prevalent. As a testimony to the success of the current strategy of care, the proportion of adults with Fontan circulation is increasing. Healthcare providers are ill-prepared to tackle these challenges, as well as specific needs such as contraception and pregnancy in female patients. The role of therapies such as cardiovascular drugs to prevent and treat complications, heart transplantation, and mechanical circulatory support remains undetermined. There is a clear need for consensus on how best to follow up patients with Fontan circulation and to treat their complications. This American Heart Association statement summarizes the current state of knowledge on the Fontan circulation and its consequences. A proposed surveillance testing toolkit provides recommendations for a range of acceptable approaches to follow-up care for the patient with Fontan circulation. Gaps in knowledge and areas for future focus of investigation are highlighted, with the objective of laying the groundwork for creating a normal quality and duration of life for these unique individuals.

Diagnostic and Therapeutic Approach to Arrhythmias in Adult Congenital Heart Disease

PURPOSE OF REVIEW

Adult survivors of congenital heart disease (CHD) are at increased risk of arrhythmia. The goal of this review is to outline diagnostic and therapeutic approaches to arrhythmia in adult CHD patients.

RECENT FINDINGS

Macro-reentrant atrial tachyarrhythmia is the most common arrhythmia encountered in adults with CHD. Approximately 25% of hospitalizations associated with arrhythmia. The risk of ventricular arrhythmia is estimated as high as 25-100 times that for the general population and increased after two decades. Routine ambulatory monitoring is important for arrhythmia risk assessment in adults with CHD. There are limitations, potential adverse effects, and risk of recurrence with antiarrhythmic drugs, catheter ablation, and surgical approaches. Adults with CHD suffer various forms of arrhythmia, are at increased risk of sudden death, and require special consideration for medical and interventional therapy.

Clinical Outcomes in Adolescents and Adults After the Fontan Procedure

BACKGROUND

Long-term outcomes of Fontan patients who survive to age ≥16 years have not been well characterized. The Australian and New Zealand Fontan Registry (ANZFR) provides a unique opportunity to understand survival and complication rates in Fontan patients who transition to adult congenital heart disease centers.

OBJECTIVES

This study sought to describe the survival and complications of adult patients who have had a Fontan procedure.

METHODS

The study analyzed outcomes in patients ≥16 years of age who were prospectively enrolled in the ANZFR.

RESULTS

Data from all 683 adult survivors from the ANZFR were analyzed. Mortality status was confirmed from the National Death Index. There were 201 atriopulmonary (AP) connections and 482 total cavopulmonary connections (249 lateral tunnels and 233 extracardiac conduits). For these subjects, the survival rate at age 30 years was 90% (95% CI: 87% to 93%), and it was 80% (95% CI: 75% to 87%) at 40 years of age. Survival at age 30 years was significantly worse for the patients with AP connections (p = 0.03). At latest follow-up, only 53% of patients were in New York Heart Association functional class I. After the age of 16 years, 136 (20%) had experienced at least 1 new arrhythmia, 42 (6%) required a permanent pacemaker, 45 (7%) had a thromboembolic event, and 135 (21%) required a surgical reintervention. Only 41% (95% CI: 33% to 51%) of Fontan patients were free of serious adverse events at 40 years of age.

CONCLUSIONS

This comprehensively followed cohort showed that a variety of morbid complications is common in Fontan adults, and that there is a substantial incidence of premature death, particularly in patients with AP connections.

Physiological Fontan Procedure

Objective: The conventional Fontan circulation deviates the superior vena cava (SVC = 1/3 of the systemic venous return) toward the right lung (3/5 of total lung volume) and the inferior vena cava (IVC = 2/3 of the systemic venous return) toward the left lung (2/5 of total lung volume). A "physiological" Fontan deviating the SVC toward the left lung and the IVC toward the right lung was compared with the conventional setting by computational fluid dynamics, studying whether this setting achieves a more favorable hemodynamics than the conventional Fontan circulation. Materials and Methods: An in-silico 3D parametric model of the Fontan procedure was developed using idealized vascular geometries with invariant sizes of SVC, IVC, right pulmonary artery (RPA), and left pulmonary artery (LPA), steady inflow velocities at IVC and SVC, and constant equal outflow pressures at RPA and LPA. These parameters were set to perform finite-volume incompressible steady flow simulations, assuming a single-phase, Newtonian, isothermal, laminar blood flow. Numerically converged finite-volume mass and momentum flow balances determined the inlet pressures and the outflow rates. Numerical closed-path integration of energy fluxes across domain boundaries determined the flow energy loss rate through the Fontan circulation. The comparison evaluated: (1) mean IVC pressure; (2) energy loss rate; (3) kinetic energy maximum value throughout the domain volume. Results: The comparison of the physiological vs. conventional Fontan provided these results: (1) mean IVC pressure 13.9 vs. 14.1 mmHg (= 0.2 mmHg reduction); (2) energy loss rate 5.55 vs. 6.61 mW (= 16% reduction); (3) maximum kinetic energy 283 vs. 396 J/m3 (= 29% reduction). Conclusions: A more physiological flow distribution is accompanied by a reduction of mean IVC pressure and by substantial reductions of energy loss rate and of peak kinetic energy. The potential clinical impact of these hemodynamic changes in reducing the incidence and severity of the adverse long-term effects of the Fontan circulation, in particular liver failure and protein-losing enteropathy, still remains to be assessed and will be the subject of future work.

Prediction of heart failure and death in an adult population of Fontan patients

BACKGROUND

Late Fontan survivors are at high risk to experience heart failure and death. Therefore, the current study sought to investigate the role of non-invasive diagnostics as prognostic markers for failure of the systemic ventricle following Fontan procedure.

METHODS

This monocentric, longitudinal observational study included 60 patients with a median age of 24.5 (19-29) years, who were subjected to cardiac magnetic resonance imaging, echocardiography, cardiopulmonary exercise testing, and blood analysis. The primary endpoint of this study was decompensated heart failure with symptoms at rest, peripheral and/or pulmonary edema, and/or death.

RESULTS

During a follow-up of 24 months, 5 patients died and 5 patients suffered from decompensated heart failure. Clinical (NYHA class, initial surgery), functional (VO2 peak, ejection fraction, cardiac index), circulating biomarkers (N-terminal pro brain natriuretic peptide), and imaging parameters (end diastolic volume index, end systolic volume index, mass-index, contractility, afterload) were significantly related to the primary endpoint. Multi-variate regression analysis identified afterload as assessed by cardiac magnetic resonance imaging as an independent predictor of the primary endpoint (hazard ratio 1.98, 95% confidence interval 1.19-3.29, p = 0.009).

CONCLUSION

We identified distinct parameters of cardiopulmonary exercise testing, cardiac magnetic resonance imaging, and blood testing as markers for future decompensated heart failure and death in patients with Fontan circulation. Importantly, our data also identify increased afterload as an independent predictor for increased morbidity and mortality. This parameter is easy to assess by non-invasive cardiac magnetic resonance imaging. Its modulation may represent a potential therapeutic approach target in these high-risk patients.

Pacemakers are associated with a higher risk of late death and transplantation in the Fontan population

BACKGROUND

The need for permanent pacing has been identified as a predictor of poor outcomes in the late survivors of Fontan surgery. However, it is not clear if the need for a pacemaker is a surrogate marker of a declining Fontan state, or if pacing is deleterious to the Fontan circulation.

OBJECTIVES

We sought to compare the long-term outcomes of propensity-matched Fontan patients with and without a permanent pacemaker.

METHODS

Patients who have survived Fontan completion with a documented history of cardiac arrhythmia were identified from the Australia and New Zealand Fontan Registry. Pacemaker insertion details, cardiac function and electrophysiological data were obtained for the patients with a permanent pacemaker. Survival analysis was performed with propensity score matching to compare late survival and outcomes in patients with versus without a pacemaker.

RESULTS

There was a total of 310 patients with a history of cardiac arrhythmia, of which 126 (41%) had a permanent pacemaker. After propensity-score matching, 99 pairs were generated (n = 198). Patients with a permanent pacemaker had a higher risk of death (HR 3.32 95% CI 1.60-6.90, p = 0.001) and death or transplantation (HR 3.55 95% CI 1.87-6.73, p < 0.001). Patients who were only paced atrially were not at a significantly increased risk of death or transplantation. However, patients who were ventricular paced >50% of the time were much more likely to encounter late death or transplantation (HR 3.82 95% CI 1.64-8.95, p = 0.002).

CONCLUSIONS

Having a permanent pacemaker and needing ventricular pacing is likely associated with an increased risk of death and transplantation in patients with a Fontan circulation.