Hemodynamics in Adults with Systemic Right Ventricles: Differences Between Congenitally Corrected and Complete Transposition of the Great Arteries.

Despite their anatomical differences, congenitally corrected (ccTGA) and complete transposition of the great arteries (d-TGA) post-atrial switch are frequently studied together and managed similarly from a medical standpoint due to the shared systemic right ventricle (sRV). The aim was to assess differences in their underlying hemodynamics. The study is a retrospective review of 138 adults with ccTGA or d-TGA post-atrial switch undergoing cardiac catheterization at Mayo Clinic, MN between 2000 and 2021. ccTGA was categorized into isolated or complex ccTGA depending on concomitant ventricular septal defect and/or left ventricular outflow obstruction. There were 53 patients with d-TGA (91% post-Mustard procedure), 51 with complex and 34 with isolated ccTGA. Isolated ccTGA patients were older (51.8 ± 13.1 years) than those with d-TGA (37.5 ± 8.3 years) or complex ccTGA (40.8 ± 13.4 years). There were no differences in sRV or left ventricular size and function across groups. The ccTGA group more commonly had ≥ moderate tricuspid regurgitation than those with d-TGA; ≥ moderate mitral and ≥ moderate pulmonary regurgitation were most prevalent in complex ccTGA. There were no differences in sRV end-diastolic pressure (sRVEDP) or PAWP between groups. However, the ratio of PAWP:sRVEDP was higher in those with d-TGA compared to those with ccTGA. Cardiac index was higher in the d-TGA group than both groups of ccTGA patients with the latter showing higher indices of ventricular afterload. In conclusion, despite sharing a sRV, adults with d-TGA and ccTGA have substantial differences in hemodynamics and structural/valvular abnormalities. Further investigation regarding disease-specific responses to heart failure therapy in those with d-TGA and ccTGA is warranted.

Modified Senning procedure in a patient with dextrocardia with left atrial isomerism and anomalous systemic venous drainage: a rare case report.

The atrial switch procedure by Senning or Mustard technique primarily aims in correcting parallel systemic and pulmonary circulations at atrial level. This procedure may be used in late presenting D-transposition of great arteries with a deconditioned left ventricle, congenitally corrected transposition of great arteries and isolated ventricular inversion. We describe the case of a child with dextrocardia, left atrial isomerism with complex pulmonary and systemic venous drainage resulting in mixing at atrial level. She was successfully operated by modified Senning procedure performed through the left-sided atrium.

Long-Term Influence of Atrial Switch Operation on Hemodynamics After the Rastelli Procedure.

The study aimed to investigate the long-term influence of atrial switch on post-Rastelli hemodynamic condition. Of 112 patients with transposition of the great arteries (TGA) or TGA-type double outlet right ventricle, ventricular septal defect (VSD), and pulmonary stenosis (PS) who underwent intra-cardiac repair between 1979 and 2018, 50 patients with levo-TGA underwent atrial switch and Rastelli as an anatomic repair and 62 patients with dextro-TGA underwent Rastelli. Postoperative outcomes were retrospectively compared. The median follow-up durations were 20.1 years (interquartile range: 4.3, 32.4) in the Rastelli group and 15.3 years (7.1, 23.0) in the atrial switch plus Rastelli group (p = 0.19). Sex, age, and weight at operation were similar in both groups. Overall survival rates at 30 years were 69.8% in the Rastelli group and 80.1% in the atrial switch plus Rastelli group (p = 0.18). The atrial switch plus Rastelli group required more frequent catheter interventions (p < 0.001), mainly for caval obstruction (n = 8) and atrial arrhythmia (n = 6). Medication was more frequent in the atrial switch plus Rastelli group (p = 0.009). Exercise capacity was similarly reduced in two groups. Protein-losing enteropathy (PLE) occurred in three long-term survivors in the atrial switch plus Rastelli group (p = 0.07). Concomitantly performed atrial switch operation did not affect long-term survival and exercise capacity after Rastelli procedure. However, the occurrence of PLE, a frequent need for medication, and catheter interventions after atrial switch plus Rastelli may result from atrial switch under the post-Rastelli condition.

Repeat radiofrequency catheter ablation of atrial tachycardias in patients with congenital heart disease.

INTRODUCTION: Atrial tachycardias (AT) in patients with congenital heart disease (CHD) are significantly contributing to morbidity and mortality. Aim of this study was to evaluate the long-term course of CHD patients requiring repeat ablation procedures (RAP) of AT. PATIENTS AND METHODS: All 144 patients with CHD who had undergone ablation of AT at our center between January 2003 and October 2018 were enrolled. Patients were classified according to the complexity of CHD: complex CHD (cCHD), moderate CHD (mCHD), and simple CHD (sCHD). RESULTS: A total of 101 RAP were performed in 64 patients. One RAP was performed in n = 40, two in n = 13, three in n = 10, and five in n = 1. Acute success rate was 82% (83/101) and was not associated with the complexity of CHD (p = 1.0). Number of procedures was lower in patients with sCHD than in patients with mCHD and cCHD (sCHD 1.3 ± 0.6, mCHD 1.8 ± 1.0, and cCHD 1.8 ± 1.1, p = .04). RAP were most frequent in patients after Fontan palliation or Atrial switch procedure (2.0 ± 1.1 [n = 41] vs. 1.6 ± 0.9 all others, p = .016) and in patients with multiple unstable AT's (2.5 ± 1.1 [n = 11] vs. 1.7 ± 1.0, p = .008). Major complications occurred in 4/101 procedures. Complete follow-up was available in 125 patients. Since last RAP 73% of the patients were in sinus/atrial rhythm and 34/125 patients (27%) with AT recurrence did not require re-ablation with mean follow-up of 52 ± 40 months. CONCLUSIONS: Recurrences after ablation of AT in CHD patients were frequent. After RAP promising long-term results could be achieved. Data encourage repetitive ablation procedures in this patient population.

Management of pregnancy and delivery in women with transposition of the great arteries after atrial switch operation: A 16-year single-center experience.

AIM: This study aimed to summarize cases of successful pregnancy and delivery in patients with transposition of the great arteries (TGA) after atrial switch operation (ASO), to provide management, clinical experience, and maternal and fetal outcomes. METHODS: During a 16-year period (2004-2019), we experienced 30 pregnancies in 15 patients after ASO at our institution. We retrospectively reviewed the medical records of the patients. RESULTS: In 30 pregnancies, there were 21 (70%) live births, five (17%) miscarriages, and four (13%) artificial abortions. There were no maternal or neonatal deaths. Cardiac complications occurred in nine (43%) patients: deterioration of right ventricular (RV) function in one, symptomatic heart failure (HF) in three, supraventricular tachyarrhythmia requiring electrical cardioversion in two, sick sinus syndrome that required pacemaker implantation in two, and hemoptysis in one. Obstetric complications occurred in five (24%). Neonatal complications were premature births (delivery at <37 weeks of gestation) in 15 (71%), and birthweight <2500 g in 18 (86%). The mode of delivery consisted of vaginal delivery (VD) in five (24%), and cesarean section (CS) in 16 (76%). CONCLUSION: A high incidence of preterm CS and cardiac complications including deterioration of RV function was observed in patients who had undergone ASO for TGA.

Oxygen Uptake Efficiency Slope Predicts Adverse Outcome Following Atrial Switch Procedure.

Prior to the 1990s, d-TGA was palliated with the atrial switch procedure resulting in a systemic right ventricle associated with significant long-term morbidity and mortality. Determining the optimal timing of heart transplantation (HT) in these patients has been difficult. While cardiopulmonary exercise testing (CPET) is commonly used to try and risk stratify these patients, traditional exercise parameters have lacked the sensitivity and specificity to assess long-term risk. We sought to assess changes in exercise parameters over time in order to determine if any CPET parameter or combination of parameters could reliably identify risk for adverse outcome in this patient group. A retrospective review of serial CPET for 40 patients over 17 years was completed. Patients with adverse event within 6 months prior to CPET were noted. CPET parameters were compared and linear mixed model regression with repeated measures was performed on serial tests for longitudinal assessment. The linear mixed model regression identified OUES indexed to BSA to be the most sensitive parameter in identifying patients at risk of adverse event and became a stronger predictor of adverse event when combined with peak heart rate. CPET is useful in identifying patients with atrial switch at increased risk of adverse outcome. Indexed OUES and peak heart rate are better prognostic indicators than VO2 and VE/VCO2.

Edge to edge repair using a MitraClip for severe tricuspid valve regurgitation after a Mustard operation.

A 48-year-old who underwent a Mustard operation in 1972 followed by a second cardiac intervention in 1996 for pulmonary venous baffle enlargement and residual baffle leak closure, complicated by recurrent atrial flutter, was admitted to our institution for severe systemic atrio-ventricular valve regurgitation (SAVVR) associated with severely impaired systemic right ventricular (RV) function. After careful preoperative anatomic assessment including three-dimensional transesophageal echocardiography (3DTEE) to define the clipping strategy and computed tomography to optimize the transvenous baffle puncture site, the intervention was performed under general anesthesia, fluoroscopic, and 3DTEE guidance. One XTR MitraClip was successfully implanted, achieving a significant reduction in regurgitation and immediate clinical improvement. The transbaffle puncture was closed using an 8 mm atrial septal defect (ASD) device without residual shunt or obstruction of the venous baffle. Post-operative clinical evaluation showed immediate improvement in the NYHA functional class (from III to II), but the patient presented with recurrent flutter at 1 week after the procedure, which was successfully treated by catheter ablation with another transbaffle approach next to the ASD device. Clinical improvement was maintained at 1- and 6-month follow-up with significant reduction in SAVVR, reduced systemic RV volumes and improved RV ejection fraction. This case demonstrates the feasibility of percutaneous treatment of systemic SAVV in patients with systemic RV after atrial redirection.

Transbaffle/transconduit puncture using a simple CARTO-guided approach without echocardiography in patients with congenital heart disease.

INTRODUCTION: Catheter ablation (CA) of atrial tachyarrhythmias (ATs) in patients with complex congenital heart disease (CHD) often requires technically challenging transbaffle or transconduit puncture. The aim was to assess the feasibility and safety of transbaffle/transconduit puncture based on computed tomography (CT) three-dimensional (3D) reconstruction merged with electro-anatomical mapping (EAM) without per-procedure echocardiographic guidance. METHODS AND RESULTS: We included 18 consecutive CHD patients in two centers who had atrial-switch or Fontan surgery and underwent CA of AT by an antegrade approach requiring intracardiac puncture. Twelve patients with atrial-switch surgery and six patients with extracardiac Fontan surgery were referred for CA of AT. Cardiac CT with 3D reconstruction was performed before the procedure. The 3D volume of the systemic venous atrium or extracardiac conduit acquired by EAM was merged with the corresponding CT 3D reconstruction. The ablation catheter was positioned at the optimal puncture site. Under fluoroscopic guidance, the needle was positioned next to the ablation and the puncture was performed. Balloon expansion of the puncture site was performed in every case of transconduit puncture and in two (17%) cases of transbaffle puncture. Overall, 17 intra-atrial reentrant tachycarrythmias and 9 focal ATs were successfully ablated, with no acute complications. The median time to access the pulmonary atrium was 78.5 minutes (range, 55-185) and total median fluoroscopy time was 23 minutes (range, 7-53). CONCLUSIONS: Transbaffle and transconduit punctures can be performed safely in CHD patients by using a simple technique relying on CT 3D reconstruction and EAM.

Extract-stent-replace for treatment of upper baffle stenosis with pacing leads after atrial switch procedures for transposition of the great arteries: An approach to avoid "jailing" the lead.

INTRODUCTION: Venous stenosis is a late complication of the atrial switch (Mustard/Senning) procedure seen in patients with transposition of the great arteries ( d-TGA). Many atrial switch patients require cardiac implantable electronic devices (CIEDs) which further increases the incidence of venous stenosis. Stenosis of the superior limb of the systemic venous pathway (SLSVP) in the presence of CIED leads presents a management challenge. We propose a method for navigating SLSVP stenosis in atrial switch patients with CIEDs. METHODS: The pulse generator and leads were removed using standard extraction techniques. Axillary access was retained via existing leads or new access was obtained. The interventional cardiology team, via groin access, performed stent-angioplasty of the stenotic SLSVP. After stent deployment, the axillary access wire was snared from below, guided through the stent, and pulled into a long groin sheath. A sheath was then advanced over the axillary wire and into the groin sheath creating a path for passage of leads through the stent. New leads were advanced through the axillary sheath into the heart. Leads were secured using standard techniques. RESULTS: All patients had a history of d-TGA and prior atrial switch procedures. In each case, there was stenosis of the SLSVP in the setting of a CIED lead. There were no immediate complications and there was no restenosis on follow-up. CONCLUSION: Post-atrial switch patients with CIEDs can develop stenosis of the SLSVP. A collaboration between electrophysiology and interventional cardiology can allow for device extraction, stent-angioplasty, and lead reimplantation to avoid "jailing" the leads.

Global longitudinal strain correlates to systemic right ventricular function.

BACKGROUND: The aim of this retrospective study was to evaluate the relationship between right ventricular function derived from cardiac magnetic resonance imaging (CMR), echocardiography and exercise stress test performance, NT-proBNP (N-terminal proB-type natriuretic peptide) level and NYHA class in patients with a systemic right ventricle. METHODS: All patients with congenitally corrected transposition of the great arteries (ccTGA), or transposition of the great arteries after Mustard or Senning procedures, (TGA) followed at our centre who had undergone CMR, echocardiography, an exercise stress test and blood sampling, were included in the study. RESULTS: We examined 11 patients (six after the Senning procedure, one after the Mustard procedure, and four ccTGA) who have a median age of 32 years (22-67 years). A significant correlation was observed between the systemic ventricular function, expressed as the CMR-derived right ventricular ejection fraction and the right ventricular global longitudinal strain (r= -0.627; p=0.039). CONCLUSION: We have demonstrated that in patients with ccTGA or TGA right ventricular global longitudinal strain may be useful in the evaluation of the systemic right ventricular function.

A unique indication for the senning procedure: Atrioventricular discordance with ventriculoarterial concordance.

OBJECTIVE: We describe experience treating a patient with atrioventricular (AV) discordance with ventriculoarterial (VA) concordance, ventricular septal defect (VSD), and situs inversus. This is a rare congenital lesion in which closing the VSD would septate D-transposition physiology and performing an arterial switch and VSD closure would produce congenitally corrected transposition of the great arteries physiology. As such, it is the only lesion for which an isolated atrial switch (and VSD closure) remains the preferred correction. CASE: A term baby girl born with AV discordance/VA concordance, a large VSD, and situs inversus totalis was palliated with atrial septostomy on day of life 3 to allow for optimal mixing and pulmonary artery banding during the 6th week of life to control symptoms of pulmonary overcirculation and protect the pulmonary vasculature. At 8 months of age, she underwent complete repair with a Senning atrial switch procedure, VSD closure, and pulmonary artery debanding with pulmonary arterioplasty. RESULTS: The patient underwent corrective surgery with patch closure of the VSD, and the Senning atrial switch procedure resulting in a total anatomic correction. The patient was discharged on postoperative day 6 and is clinically doing well 12 months later. Follow-up transthoracic echocardiogram shows no pulmonary venous baffle obstruction, mild systemic venous baffle obstruction, and moderate pulmonary stenosis/pulmonary insufficiency. CONCLUSION: The isolated atrial switch is rarely employed as its outcomes are inferior to the arterial switch operation in the setting of the dextro-transposition of the great arteries. However, it remains the procedure of choice for AV discordance with VA concordance as it leads to physiologically corrected biventricular circulation.

Modification of the Senning procedure in the double-switch operation: The triangular double-door technique.

We developed a modified Senning procedure in the double-switch operation for the patients with congenitally corrected transposition of the great arteries (ccTGA). In our technique, the right atrial (RA) free wall is not used as a baffle for draining systemic venous blood to the left atrium. Instead, a patch material is used for the baffling. A wide communication between the pulmonary venous chamber and RA is created by making the triangular double door with the RA-free wall, and the window is closed with in situ pericardial flap. We have successfully adopted this technique in our recent two consecutive ccTGA patients.

Transcatheter baffle leak closure via an amplatzer septal occluder in a senning-operated child.

Senning operation is a surgical treatment for transposition of great arteries that can be complicated by post-procedural atrial or caval baffle leaks. We present a 6-year-old boy with a history of Senning repair for transposition of great arteries, who developed a pulmonary venous baffle leak. Percutaneous baffle leak closure was successfully performed using an Amplatzer septal occluder.

Systemic Right Ventricle in Adults With Congenital Heart Disease: Anatomic and Phenotypic Spectrum and Current Approach to Management.

The systemic right ventricle (SRV) is commonly encountered in congenital heart disease representing a distinctly different model in terms of its anatomic spectrum, adaptation, clinical phenotype, and variable, but overall guarded prognosis. The most common clinical scenarios where an SRV is encountered are complete transposition of the great arteries with previous atrial switch repair, congenitally corrected transposition of the great arteries, double inlet right ventricle mostly with previous Fontan palliation, and hypoplastic left heart syndrome palliated with the Norwood-Fontan protocol. The reasons for the guarded prognosis of the SRV in comparison with the systemic left ventricle are multifactorial, including distinct fibromuscular architecture, shape and function, coronary artery supply mismatch, intrinsic abnormalities of the tricuspid valve, intrinsic or acquired conduction abnormalities, and varied SRV adaptation to pressure or volume overload. Management of the SRV remains an ongoing challenge because SRV dysfunction has implications on short- and long-term outcomes for all patients irrespective of underlying cardiac morphology. SRV dysfunction can be subclinical, underscoring the need for tertiary follow-up and timely management of target hemodynamic lesions. Catheter interventions and surgery have an established role in selected patients. Cardiac resynchronization therapy is increasingly used, whereas pharmacological therapy is largely empirical. Mechanical assist device and heart transplantation remain options in end-stage heart failure when other management strategies have been exhausted. The present report focuses on the SRV with its pathological subtypes, pathophysiology, clinical features, current management strategies, and long-term sequelae. Although our article touches on issues applicable to neonates and children, its main focus is on adults with SRV.

Natural history of a systemic right ventricle.

The natural history of a systemic right ventricle after an atrial switch procedure has yet to be fully characterised. We describe the case of the longest surviving patient at our institution who underwent a Mustard Baffle correction for dextro-transposition of great arteries in childhood. Over following decades he was reviewed regularly with deteriorating systemic right ventricle function. At around 50 years of age he developed worsening heart failure on maximal medical therapy. He was subsequently assessed for cardiac transplantation which he underwent successfully at the age of 55 years.

Corrected Transposition: Anatomic Repair Using the Hemi-Mustard Atrial Baffle and Bidirectional Superior Cavopulmonary Connection.

Anatomic repair for congenitally corrected transposition requires thoughtful surgical planning at both initial (neonatal or late) presentation, and during definitive repair. An algorithmic approach to the overall management of this lesion, with its many associated intracardiac anomalies, is presented. Modified atrial switch with bidirectional superior cavopulmonary connection is commonly utilized and demonstrates favorable results through a 20-year experience. Herein, technical considerations learned during the implementation of this strategy are described and emphasize the concept, in selected cases, of native pulmonary root preservation by translocation as an adjunct that is uniquely suited by adopting this approach.

Differential Myocardial Mechanics in Volume and Pressure Loaded Right Ventricles Demonstrated by Cardiac Magnetic Resonance.

In patients with D-looped transposition of the great arteries (D-TGA) status post atrial switch operation, the systemic right ventricle (RV) shifts to predominantly circumferential (CS) rather than longitudinal strain (LS), which may represent adaptation or dysfunction. We aimed to evaluate myocardial mechanics in pressure loaded, volume-loaded, and normal RVs by cardiac magnetic resonance (CMR). Patients with D-TGA post atrial switch operation with CMR from 2008 to 2015 were matched 1:1 for age and RV ejection fraction (EF) with repaired tetralogy of Fallot (TOF) patients (volume-loaded RVs), and 1:1 for age with control patients. RV free wall LS and CS were measured using feature tracking software (TomTec, Unterscleissheim, Germany). A total of 32 D-TGA (median age 32 years, 56% male), 32 TOF, and 32 control patients were included. D-TGA patients had less dilatation than TOF patients (125 ± 35 ml/m2 vs. 149 ± 44 ml/m2, p = 0.02) and lower RVEF than controls (42.9 ± 7.7% vs. 56.3 ± 5.6%, p < 0.0001). RV LS was similar in D-TGA and TOF ( - 13.2 ± 4.5% vs. - 14.5 ± 5.9%, p = 0.32), both decreased compared to controls. However, CS in D-TGA was higher than controls ( - 14.1 ± 4.1% vs. - 11.4 ± 4.4%, p = 0.01), with a higher CS:LS ratio (1.2 ± 0.7 vs. 0.6 ± 0.3, p < 0.0001), while CS in TOF and controls did not differ. RVEF in D-TGA correlated closely with CS (r = - 0.85, p < 0.0001) but not LS (r = 0.10, p = 0.58). I n conclusion, CMR can differentiate strain patterns in pressure- and volume-loaded RVs, with decreased LS in both conditions, while systemic RVs compensate with supra-normal CS. CS may be a more clinically relevant measure of RV function in this population.

Long-Term Follow-up of Adults Following the Atrial Switch Operation for Transposition of the Great Arteries - A Contemporary Cohort.

BACKGROUND: The atrial switch operation for transposition of the Great Arteries (TGA) (Mustard or Senning Procedure) provides excellent short-term survival. Significant long-term concerns exist for these patients, however, including the ability of the right ventricle to maintain systemic perfusion and the risk of arrhythmia. We seek to describe long-term mortality and morbidity of this group of adult patients. METHODS: Consecutive patients who had undergone an atrial switch procedure, who were aged over 16 years and who were followed up at our tertiary level adult congenital heart disease (ACHD) service in Sydney, Australia since 2000 were included. We documented mortality using a National Death Index and analysed the prospectively defined composite endpoint of "Serious Adverse Events" including death, heart failure hospitalisation and/or documented ventricular arrhythmia. RESULTS: There were 83 patients included; mean age at most recent follow-up was 35 ± 5 years. Overall survival was 82% at 35 years and 22% of patients experienced a serious adverse event. Atrial and ventricular arrhythmias occurred in 45% and 7% of patients respectively. Eighteen (22%) patients required a pacemaker and six (7%) required implantable cardiac defibrillator (ICD) implantation. Significant right ventricular dysfunction was present in 26% of patients on their most recent visit and this, or requirement for permanent pacing, was associated with an increased risk of serious adverse events (OR 10.22, p<0.001), (OR 4.998, p=0.04) respectively. CONCLUSIONS: Significant mortality and morbidity accrues by mid-adult life after an atrial procedure for TGA. Right ventricular dysfunction and permanent pacing are associated with serious adverse events.

Incorrect ventricular lead placement into the systemic right ventricle of a patient with D-transposition of the great vessels after Mustard procedure.

Incorrect pacemaker lead placement into the systemic ventricle is a complication that has rarely been described in patients with D-transposition status after atrial baffle palliation. We present a case of ventricular lead misplacement in the systemic right ventricle of a patient with D-transposition of the great arteries after Mustard procedure. This case demonstrates the challenges with proper imaging of lead placement in patients with atrial baffles and long-term management of a lead in the systemic ventricle.

Transbaffle catheter ablation of atrial re-entrant tachycardia within the pulmonary venous atrium in adult patients with congenital heart disease.

AIMS: Catheter ablation of atrial re-entrant tachycardia in patients after atrial switch procedure for transposition of the great arteries or with a Fontan circulation is technically challenging if the critical part of the re-entry circuit is located within the pulmonary venous atrium (PVA). We report our experience in transbaffle access (TBA) to the PVA for ablation of atrial re-entrant tachycardia focusing on technical details. METHODS AND RESULTS: In eight patients, six after Mustard procedure and two with a Fontan circulation, endocardial mapping of atrial re-entrant tachycardia revealed the critical part of the re-entry circuit within the PVA. A total of 10 ablation procedures were performed. Detailed angiographic assessment of the anatomy of the systemic and pulmonary venous atria was performed prior to baffle puncture. Transbaffle access was successfully established with a standard transseptal needle in 9 of 10 procedures. No major complications occurred. At the end of the procedure and the removal of the transseptal sheath, there was no residual shunt in any patient. CONCLUSION: Transbaffle access to the PVA for ablation of atrial re-entrant tachycardia is feasible, less invasive than alternative approaches and can be safely applied in patients after Mustard procedure or with a Fontan circulation. However, the rigidity of prosthetic material may preclude baffle puncture at least in a subset of those patients.