Author + information
- Received June 13, 2018
- Revision received July 17, 2018
- Accepted August 13, 2018
- Published online October 15, 2018.
- Benjamin M. Moore, MBBSa,b,
- Robert Anderson, MBBSc,d,
- Ashley M. Nisbet, BSc, MBChB, PhDc,
- Manish Kalla, BSc, MBBS, DPhilc,
- Karin du Plessis, PhDe,f,
- Yves d’Udekem, MD, PhDe,f,g,
- Andrew Bullock, MBBSh,
- Rachael L. Cordina, MBBS, PhDa,b,
- Leeanne Grigg, MBBSc,d,
- David S. Celermajer, MBBS, PhD, DSca,b,
- Jonathan Kalman, MBBS, PhDc,d and
- Mark A. McGuire, MBBS, PhDa,b,∗ ()
- aDepartment of Cardiology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia
- bSydney Medical School, The University of Sydney, Camperdown, New South Wales, Australia
- cDepartment of Cardiology, Royal Melbourne Hospital, Parkville, Victoria, Australia
- dDepartment of Medicine, University of Melbourne, Parkville, Victoria, Australia
- eMurdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, Victoria, Australia
- fDepartment of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
- gDepartment of Cardiac Surgery, The Royal Children’s Hospital, Parkville, Victoria, Australia
- hChildren’s Cardiac Centre, Princess Margaret Hospital for Children, Subiaco, Western Australia, Australia
- ↵∗Address for correspondence:
Prof. Mark McGuire, Department of Cardiology, Royal Prince Alfred Hospital, Missenden Road, Camperdown, New South Wales 2050, Australia.
Objectives This study sought to describe atrial arrhythmia mechanisms, acute outcomes, and long-term arrhythmia burdens following catheter ablation in adult atriopulmonary (AP) Fontan patients.
Background Atrial arrhythmias are a significant cause of morbidity and mortality in the AP Fontan population.
Methods Sixty consecutive atrial arrhythmia ablations were reviewed in 42 AP Fontan patients (31 ± 8 years of age), performed between 1998 and 2017. The number of induced and ablated tachycardias was recorded for each case, as well as the ability to ablate the suspected clinical tachycardia. Longer-term arrhythmia burden was assessed by using a 12-point clinical arrhythmia severity score.
Results Intra-atrial re-entrant tachycardia (IART) was induced in 93% of cases (n = 56), atrioventricular re-entrant tachycardia in 2 (3%) and atrioventricular nodal re-entrant tachycardia in a single case. The mean number of tachycardias induced per case was 2.3. The critical isthmus for IART was mapped to the lateral (n = 10), inferolateral (n = 8), posterior/posterolateral (n = 16), or septal (n = 10) systemic venous atrium, or to the pulmonary venous atrium (n = 4). Ablation of all inducible tachycardias was achieved in 62%, ablation of at least one (but not all) inducible tachycardias in 25%, with failure to ablate any tachycardias in 13%. The suspected clinical arrhythmia was ablated in 50 cases (83%). Catheter ablation resulted in a significant reduction in arrhythmia score at 3 to 6, 12, and 24 months, irrespective of whether all inducible tachycardias were ablated, or the suspected clinical arrhythmia only. Twelve patients (29%) underwent at least one repeat ablation procedure, with a mean time between ablations of 2.7 ± 3.0 years. There were no cases of periprocedural death, stroke or cardiac tamponade.
Conclusions Catheter ablation can be a safe and effective intervention that will significantly reduce arrhythmia burden in the AP Fontan patient.
The atriopulmonary (AP) Fontan operation was developed in 1971, as surgical palliation for single ventricle physiology (1). Over time, chronic pressure and volume loading in the surgically scarred systemic venous atrium (SVA) creates a highly arrhythmogenic substrate (2). Atrial arrhythmias, in the preload dependent Fontan circulation, adversely affect hemodynamics and are associated with substantial morbidity and mortality (3). Subsequent iterations of the Fontan procedure, the lateral tunnel and extracardiac total cavopulmonary circulation (TCPC), have been introduced in an attempt to reduce the incidence of arrhythmias (4).
Antiarrhythmic medication, catheter ablation or conversion surgery (to an extracardiac conduit), are all options for the management of recurrent arrhythmia in AP Fontan patients. Antiarrhythmic medication is often ineffective in controlling arrhythmias (5,6). Evidence for the safety and efficacy of catheter ablation is lacking; previous studies have either examined small cohorts (2,7,8), or mixed cohorts in which atriopulmonary Fontan patients were grouped with other types of congenital heart disease (9–11). Moreover, these studies were performed before recent advances in ablation technology. A previous retrospective study suggested catheter ablation or conversion surgery were approximately equivalent in arrhythmia control (5). However, conversion surgery carries a perioperative mortality risk of 5% to 10% (12,13).
The aim of this study was to evaluate arrhythmia mechanisms, and acute and long-term outcomes of ablation in AP Fontan patients.
We retrospectively reviewed all consecutive ablation procedures in atriopulmonary Fontan patients, performed by two operators experienced in mapping and ablation procedures for complex congenital heart disease (M.M. Royal Prince Alfred Hospital and J.K. Royal Melbourne Hospital), between 1998 and 2017. The indication for ablation was recurrent symptoms despite medical therapy, in all cases. Pre-procedural data on congenital diagnosis, echocardiography, arrhythmia history and medications were collected.
Electrophysiology study and ablation
All procedures were performed under general anesthesia, after informed consent was obtained. Transesophageal echocardiography (TEE) was routine to rule out intracardiac thrombus. 3D electroanatomic mapping was utilized in most cases (CARTO, Biosense Webster, Diamond Bar, California; EnSite NavX, St. Jude Medical, St. Paul, Minnesota; Rhythmia, Boston Scientific, Marlborough, Massachusetts). Scar was traditionally defined as atrial areas with electrograms <0.05 mV and low voltage as <0.5 mV (14). In recent years, the advent of the Rhythmia mapping system allowed the confidence mask for scar to be reduced to just above noise level at 0.02 mV in selected cases in order to identify low amplitude channels (15). Once femoral access was obtained, heparin was infused to obtain an ACT >300 s. In recent years, ablation was performed on uninterrupted warfarin, in some patients. The pulmonary venous atrium (PVA) was accessed in 6 AP Fontan ablations; 1 by baffle puncture, 2 by fenestration, and 3 by retrograde approach. The coronary sinus could not be cannulated in the majority of cases. A His bundle potential could be recorded in only one case.
Mapping was performed using a hybrid approach, which included multipolar wave front mapping (10 pole and/or 20 pole catheters), entrainment mapping and detailed 3D activation mapping. Entrainment was performed when the cycle length (CL) was stable (<20 ms beat to beat variation) and at an entrainment CL ≤20 ms shorter than the tachycardia cycle length. Entrainment was used in order to 1) confirm macro–re-entry; or 2) identify regions either “in” (PPI of ≤20 ms > TCL) or “near” (PPI of 20 to 40 ms > TCL) the re-entrant circuit in order to focus detailed 3D mapping to the region of relevance. When multipolar catheter stability could not be achieved, a temporary screw-in lead was used via a sheath from the femoral venous approach to ensure stability of the reference electrode (Medtronic Inc.) for accuracy of 3D mapping.
Intra-atrial re-entrant tachycardia (IART) was defined as a macro–re-entrant circuit with typical entrainment characteristics (entrainment with endocardial fusion (16) and entrainment at 2 sites ≥2 cm apart demonstrated characteristics of being “in the circuit”). Focal atrial tachycardia (FAT) was defined as a stable atrial arrhythmia originating from a focal area with centrifugal activation. Small circuit re-entry was defined when the entire re-entrant circuit could be recorded on a single localized catheter (e.g., Pentaray or Lasso [Biosense Webster, Irvine, California]). Atrioventricular nodal re-entrant tachycardia (AVNRT) was defined by a regular CL with an atrial-to-ventricular (atrial:ventricular) relationship of 1:1 or 2:1, an atrio-ventricular (AV) response on cessation of ventricular pacing with atrial entrainment, and no atrial reset with ventricular premature beats introduced when His considered refractory. Atrioventricular re-entrant tachycardia (AVRT) was defined by a regular CL with 1:1 atrial relationship, an atrio-ventricular response on cessation of ventricular pacing with atrial entrainment, and atrial reset with (presumed) His-synchronous ventricular premature beats.
Ablation was performed using a bidirectional irrigated catheter. The critical isthmus was targeted when activation and entrainment mapping was possible. For patients with multiple unstable circuits, substrate ablation (joining areas of scar or ablating channels in scar) was performed until the arrhythmia terminated or stabilized. The acute procedural outcome was described as ablation of all inducible tachycardias, ablation of at least one (but not all) inducible tachycardias, or failure to ablate any tachycardias. Furthermore, the success in ablating the suspected clinical arrhythmia (based upon ECG traces prior to ablation) was recorded for each case.
Follow-up and clinical arrhythmia score
A validated multiscale severity score was used to determine clinical severity of arrhythmia immediately prior to ablation and at post ablation follow-up (9). Four subscores were summed to yield a clinical arrhythmia score that ranged from 0 (no arrhythmia activity) to 12 points (severe, incessant and life-threatening arrhythmia activity). Patients were routinely seen by either the proceduralist or the referring congenital clinician at 3 to 6, 12, and 24 months post procedure, for the purpose of assessing arrhythmia scores.
For the purposes of analysis, multiple procedures in the same patient were assumed to be independent. In such cases, only the period after the last ablation procedure was assessed for arrhythmia score. Continuous variables are presented as mean ± SD. Student paired t-tests were used for comparison of arrhythmia scores. Acute ablation outcomes from the first and second decades of procedures (1998 to 2007, 2008 to 2017) were compared using the chi-squared test. A 2-tailed p value of <0.05 was considered statistically significant. Statistical analysis was performed using Statistical Package for Social Services version 22.0 (SPSS, Chicago, Illinois).
The study population consisted of 42 AP Fontan patients, who underwent 60 ablation procedures, at a mean age of 31 ± 8 (range 12 to 51) years of age. Table 1 shows baseline clinical characteristics at time of ablation. The average time from Fontan operation to diagnosis of arrhythmia was 18.2 ± 5.9 (range 9.4 to 30.0) years, with a subsequent average latency from arrhythmia presentation to ablation of 6.3 ± 4.5 years. Mean number of rate or rhythm control medications at time of procedure was 1.3 ± 0.6. Sixteen patients (38%) had been intolerant of at least one medication with 8 documented cases of amiodarone-induced thyroid disease. Warfarin was a pre-existing medication in 52 cases (87%), and dabigatran in a single case. Thrombotic events had previously occurred in 12 cases; 6 right atrial thrombi, 3 pulmonary emboli and 3 systemic arterial events. Right atrial thrombus was identified at the time of ablation in 2 patients; in this situation, the procedure was abandoned and these patients were excluded from the study.
Procedural characteristics and tachycardia mechanisms
Table 2 shows characteristics of the ablation procedure and induced tachycardias. IART alone was induced in 56 cases, AVRT in 2, with IART + AVNRT in a single case. No FATs were identified. In one case the procedure was abandoned because of bleeding at the femoral puncture before ablation was attempted. Detailed activation mapping and entrainment was attempted in all cases, but was not always possible due to rapidly alternating arrhythmias, hemodynamic intolerance or anatomic barriers preventing access to a critical isthmus (for example, a patch over the tricuspid valve). Hemodynamic instability due to induced arrhythmia occurred in 11 cases (18%).
In 45 of 60 procedures (75%) at least 1 critical isthmus for IART could be defined (Figure 1); this isthmus was usually located in the SVA (Figure 2). Common SVA critical isthmuses were located laterally (adjacent to the atriotomy scar), inferolaterally (between the inferior vena cava [IVC] and atriotomy scar), posteriorly (between the IVC and superior vena cava [SVC]), septally (often adjacent to an ASD patch), and adjacent to the AP connection. Two AVRTs were induced, with the accessory pathway localized to mid septal and anterior locations, respectively. Recurrent tachycardia in those patients who required a repeat ablation procedure was more likely to be due to a distinct separate circuit rather than a recurrence of the initially ablated tachycardia (12 and 6 of the repeat ablation cases, respectively).
Ablation of all inducible tachycardias was achieved in 62% of procedures (37 of 60), with ablation of at least 1 (but not all) inducible tachycardias in 25% of procedures (15 of 60). The suspected clinical arrhythmia was ablated in 83% of procedures (50 of 60). In 1 patient with refractory IART, a mechanical systemic AV valve and VVI (ventricular paced, ventricular sensed, inhibits to ventricular sensed event) epicardial pacemaker, AV nodal ablation was attempted unsuccessfully through a retrograde aortic approach before a repeat attempt 2 years later successfully abolished AV nodal conduction. The first attempt was abandoned due to close proximity of the His signal to the mechanical AV valve and concern regarding catheter entrapment. There was a significantly increased probability of successfully ablating at least 1 tachycardia in the second decade of procedures compared to the first (40 of 43 cases [93%] vs. 12 of 17 cases [71%], respectively; p = 0.021).
Complications occurred in 9 of 60 procedures (15%). In 2 cases, temporary pacing was required for bradycardia post procedure (1 transcutaneous for intra-atrial conduction block; 1 temporary atrial pacing wire for AV block with a junctional escape rhythm). Conduction subsequently recovered in both cases. A third patient with symptomatic sinus bradycardia post ablation required early permanent pacing. This patient had pre-existing sinus arrest and a low atrial rhythm prior to the procedure. One patient experienced pericarditis, which resolved with medical therapy. Four femoral vascular complications occurred; 2 false aneurysms requiring operative intervention, 1 arterial hemorrhage treated with coiling, and 1 femoral venous bleed not requiring operative intervention. There were no deaths, strokes, or pericardial effusions.
Figure 3 shows the clinical arrhythmia score calculated immediately prior to ablation and at follow-up (3 to 6, 12, and 24 months). Average follow-up post ablation was 4.6 ± 4.6 years (range 0 to 17 years). The mean score pre-ablation was 7.3 ± 1.6, with significant reductions (on paired Student's t-test) at 3 to 6 months to 2.9 ± 2.2 at 12 months to 2.9 ± 1.8 and at 24 months to 2.8 ± 2.2. Figure 4 displays arrhythmia score at baseline and follow-up divided into 3 groups: ablation of all inducible tachycardias, ablation of at least 1 (but not all) inducible tachycardias, and failure to ablate any tachycardias. A significant reduction in score was seen whether all or only some of the induced tachycardias were ablated. In the group where no tachycardias were ablated, there was a small but significant reduction in score at 3- to 6-month follow-up but no statistically significant differences at 12 months. Arrhythmia score reductions in the first decade were not statistically different from those in the second decade of procedures. A documented episode of recurrent atrial arrhythmia post procedure was seen in 50% of cases (30 of 60). Cardioversion at least 3 months post ablation was performed in 16 cases (27%). The mean number of rate or rhythm control medications post ablation was 1.0 (mean: 1.3 pre-ablation); specifically, 37 of 60 (62%) remained receiving antiarrhythmic therapy at last review (73% receiving antiarrhythmics pre-ablation). Figure 5 shows the Kaplan-Meier curve for freedom from the composite of death, transplantation, or conversion surgery.
Redo ablations, conversion surgery, or deaths
A redo ablation was performed in 29% of patients (12 of 42). Nine patients underwent 2 ablation procedures. In single patients only, 3, 4, and 5 ablations were performed (2 of these patients remain free of arrhythmias at 6 and 24 months post last ablation; the third patient had early recurrence of arrhythmia). The mean time between redo ablations was 2.7 ± 3.0 years. Three patients went on to have AP-to-TCPC conversion surgery during follow-up. One patient underwent an unsuccessful substrate-based ablation procedure and proceeded to surgery 4 months post ablation with good arrhythmia control. The second patient had undergone 2 previous successful ablation procedures and had 6 years of minimal arrhythmia burden before conversion surgery was performed for worsening heart failure. That patient had 5 recurrent episodes of IART requiring cardioversion in the 18 months following conversion. The third patient had undergone successful IART ablation, achieving a reduction in arrhythmia symptom burden. At 4 years post ablation, conversion surgery and Maze procedure were performed for recurrent arrhythmia. A pacemaker was implanted for postoperative bradycardia. At 2 months post surgery, that patient remained clinically well.
There were 4 deaths during follow-up. The first patient had a successful and uncomplicated ablation of multiple IARTs before developing progressive ventricular failure 10 months post procedure. The second patient had an unsuccessful ablation, declined further procedures, and died from heart failure 3.5 years later. The third patient died suddenly 8 years after successful ablation. The fourth patient died from previously undiagnosed metastatic hepatocellular carcinoma several months after undergoing a successful ablation of IART.
This study describes atrial arrhythmia mechanisms, acute outcomes, and longer term arrhythmia burden after catheter ablation in atriopulmonary Fontan patients. The study demonstrates that, in a highly symptomatic Fontan population experiencing recurrent atrial tachycardias, catheter ablation can be a safe and effective palliative procedure. However, it is important to recognize that procedures are often protracted and technically challenging and require specific departmental expertise. The burden of atrial arrhythmias late post AP Fontan operation approaches 60% at 20 years (4,17). These arrhythmias adversely impact hemodynamics, are associated with substantial morbidity, and are often refractory to antiarrhythmic medication (3,5,6).
Most induced arrhythmias were found to be IARTs localized to the systemic venous atrium, in keeping with previous studies (2,7,8). AVRT and AVNRT were uncommon, and no FATs were observed. Nakagawa et al. (18), in detailed mapping of Fontan macro–re-entrant atrial circuits, found critical channels between multiple islands of scar in all cases where ablation was subsequently successful. This “scar” may be due to surgical incision, prosthetic material, progressive atrial fibrosis, or a functional boundary (8,19). Mandapati et al. (20) found that circuits were common around the IVC, with a critical slow zone located in the inferolateral atrium. However, in a larger subsequent series the critical isthmus sites for successful ablation were widely distributed (21). Yap et al. (2) described very low voltage zones (<0.1 mV, likely representing atrial fibrosis) in the lateral and septal SVA walls. In the current large series, we found that the tachycardia critical isthmus could be found anywhere in the Fontan chamber, consistent with a very diffusely abnormal electrophysiologic substrate. Although diffuse, the critical isthmus most commonly was related to the atriotomy scar.
Our study supported the observation that recurrent arrhythmia circuits, in the setting of repeat ablation, commonly occurred at different sites to the initial ablated circuit (7,22). This implicates either a failure to ablate an existing mechanism at the original procedure or development of new arrhythmias due to a progressive atrial myopathy rather than proarrhythmia caused by the prior ablation lesion or ablation failure as the main driver of recurrent arrhythmia.
Efficacy of ablation
Ablation of all inducible arrhythmias was achieved in 62% of cases, with ablation of at least 1 (but not all) inducible tachycardias in a further 25%. The suspected clinical arrhythmia was ablated in 83% of cases. These acute outcomes are similar to those reported in other series of AP Fontan ablations (7,8) or larger ablation cohorts with mixed congenital diagnoses (9–11). Electroanatomic mapping and irrigated ablation were used in most cases and have been shown to improve outcomes (9). Indeed, acute procedural success was more likely in the second decade of our ablations, where technologies such as electroanatomic mapping, irrigation, and contact force and mapping catheters with smaller interelectrode distances were more routinely used.
A multiscale clinical arrhythmia severity score (9) was used as the primary measurement for longer term outcomes post ablation, rather than the classical outcome freedom from arrhythmia. Particularly in the Fontan population, where recurrence rates historically approach 50% (7,8), a global assessment of arrhythmia burden better reflects outcomes post ablation (23) and has been adopted in multiple complex congenital ablation studies (9,10,24,25). In 1 clinical example that illustrates this point, 1 patient required 5 cardioversions pre-ablation over 3 years, with failed amiodarone treatment and intolerance of sotalol. Post ablation this patient had a single sustained episode of IART for 24 h at 4 months, which self-reverted. There were no subsequent arrhythmias over more than 12 months, representing a successful clinical outcome.
Our study found that ablation effectively reduced the clinical burden of arrhythmia at 3 to 6, 12, and 24 months. The mean pre-ablation score of 7.3 was higher than in other published studies, although this is unsurprising given the AP Fontan substrate compared to mixed adult congenital heart disease (9,10) and TCPC (24) ablation cohorts that have previously reported arrhythmia scores. This high score also underscores how highly symptomatic patients were prior to referral for ablation. Despite recurrent arrhythmia episodes in 50%, mean post ablation scores were consistently 2 to 3. Mean arrhythmia score was significantly reduced up to 1 year whether all or only some of the induced tachycardias were ablated. This likely reflects either abolition of the dominant clinical arrhythmia or substrate modification. A similar sustained reduction in arrhythmia score, despite recurrence of arrhythmia, has been recently reported in a TCPC catheter ablation series (24). Our unsuccessful group (no tachycardias ablated) had a small reduction in arrhythmia score post ablation; this may have reflected a degree of substrate modification, or optimization of medical therapy. Although repeat ablations were common, the relatively long average time between procedures of 2.7 years suggests a significant reduction of arrhythmia burden as a result of the primary procedure.
Safety of ablation
Reassuringly, no deaths, strokes, or cardiac tamponade occurred in our ablation series. Notably, 1 patient required permanent pacing post ablation (this patient already had no evidence of sinus node function pre-ablation and was reliant on a low atrial rhythm), and 2 other patients needed temporary pacing for either marked sinus bradycardia or intra-atrial conduction delay. Fontan patients are known to be uniquely susceptible to bradycardia (6). Sinoatrial node dysfunction may result from direct trauma to the sinoatrial nodal region or its artery at time of operation (26). Progressive atrial dilation and fibrosis may further impair sinoatrial nodal function or lead to intra-atrial conduction delay (27). In several cases, ablation was discontinued (prior to ablation of all inducible arrhythmias), due to concern regarding the risk of intra-atrial conduction block. In such cases, pacemaker implantation was electively discussed with the patient.
Hemodynamic instability due to induced arrhythmias (in the context of anesthesia and/or vasodilating medications such as isoprenaline) was common in our series. Furthermore, procedures were generally long and technically challenging. Ablation in AP Fontan patients should be performed at specialist centers by an operator prepared for hemodynamic instability or bradycardia during the case. We recommend that either transcutaneous pacing or a catheter placed retrograde in the systemic circulation (to allow for emergent pacing) be readily available in all cases.
Conversion versus ablation?
This study demonstrates that catheter ablation can be a safe and effective intervention for atrial arrhythmias in the AP Fontan population. The long-term reduction in arrhythmia score was similar to that found in a retrospective review of patients post-conversion surgery for arrhythmia (25). The advantages of catheter ablation include a significantly lower mortality rate (12,13), less pain and discomfort, and likely, a shorter period of interruption of study or work. The 5% to 10% perioperative mortality risk of conversion surgery warrants careful consideration (12,13). Moreover, conversion surgery makes it more difficult to access the atrial mass to ablate arrhythmias that may occur after conversion surgery. On the other hand, delaying conversion surgery may increase the risk of surgery if it is required at a later date for clinical deterioration and may ultimately decrease longevity (13). The decision whether to undertake catheter ablation or conversion surgery in patients with drug refractory arrhythmias and good hemodynamics is complex and depends on factors such as local expertise, patient characteristics, and patient preference.
This was a retrospective study with experienced operators at specialist adult congenital centers; this limits generalizability to nonspecialist centers. However, in keeping with guidelines, these ablation procedures should only be performed in specialist centers, which include physicians experienced in the management of complex congenital heart disease. Holter monitoring was not routinely performed in follow-up, and so recurrent arrhythmia may have been underdetected, although all our patients were clearly symptomatic for their arrhythmia pre-ablation. Comprehensive data for medication changes by individual clinicians post procedure were not available for all patients; it is possible that medication optimization accounted for some of the arrhythmia score reduction. Finally, multiple ablation procedures in the 1 patient might have biased arrhythmia scores following the latter procedures (due to cumulative effect) and therefore overestimate treatment efficacy.
Ablation with contemporary techniques can be a safe and effective palliative treatment approach for the management of atrial arrhythmias in atriopulmonary Fontan patients.
COMPETENCY IN MEDICAL KNOWLEDGE: The management of recurrent atrial arrhythmias in atriopulmonary Fontan patients is challenging. Catheter ablation, when performed at specialist congenital centers, can be a safe and effective intervention to significantly reduce arrhythmia burden.
TRANSLATIONAL OUTLOOK: In the presence of recurrent arrhythmia refractory to medical therapy, atriopulmonary Fontan patients often face a choice between conversion surgery or catheter ablation. Longer term studies should aim to compare mortality, heart failure, and arrhythmia burden between these 2 approaches.
The authors acknowledge support provided by the Australian and New Zealand Fontan Registry and support provided to the Murdoch Children’s Research Institute by the Victorian Government’s Operational Infrastructure Support Program.
Supported by National Health and Medical Research Council (NHMRC) partnership grant 1076849. Profs. d’Udekem and Kalman are clinician practitioner fellows supported by NHMRC grant 1082186. Dr. d’Udekem is a consultant for Merck Sharpe and Dohme and Actelion. Dr. Kalman has received research support from Biosense Webster, Abbott, and Medtronic. Dr. Anderson is supported by postgraduate scholarships co-funded by NHMRC and Royal Australasian College of Physicians NHMRC Woolcock Scholarship. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Edward P. Walsh, MD, served as Guest Editor for this paper.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the author’s institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Abbreviations and Acronyms
- atrioventricular nodal re-entrant tachycardia
- atrioventricular re-entrant tachycardia
- focal atrial tachycardia
- intra-atrial re-entrant tachycardia
- pulmonary venous atrium
- systemic venous atrium
- total cavopulmonary circulation
- transesophageal echocardiography
- Received June 13, 2018.
- Revision received July 17, 2018.
- Accepted August 13, 2018.
- Fontan F.,
- Baudet E.
- Quinton E.,
- Nightingale P.,
- Hudsmith L.,
- et al.
- Egbe A.C.,
- Connolly H.M.,
- Khan A.R.,
- et al.
- Khairy P.,
- Van Hare G.F.,
- Balaji S.,
- et al.
- de Groot N.M.,
- Lukac P.,
- Blom N.A.,
- et al.
- Correa R.,
- Walsh E.P.,
- Alexander M.E.,
- et al.
- Ueda A.,
- Suman-Horduna I.,
- Mantziari L.,
- et al.
- d'Udekem Y.,
- Iyengar A.J.,
- Galati J.C.,
- et al.
- Latcu D.G.,
- Bun S.S.,
- Viera F.,
- et al.
- Barbhaiya C.R.,
- Kumar S.,
- Ng J.,
- et al.
- Nakagawa H.,
- Shah N.,
- Matsudaira K.,
- et al.
- Kalman J.M.,
- VanHare G.F.,
- Olgin J.E.,
- Saxon L.A.,
- Stark S.I.,
- Lesh M.D.
- Correa R.,
- Sherwin E.D.,
- Kovach J.,
- et al.