Congenitally corrected transposition of the great arteries (ccTGA) is a rare cardiac anomaly. The management strategy historically consisted of physiologic repair, leaving the morphologic right ventricle to support the systemic circulation. More recently, anatomic repair has been implemented to bring the left ventricle into the systemic circulation. Uncertainty persists about which repair strategy has the best outcome.

This meta-analysis aimed to summarize the long-term mortality risks following anatomic and physiologic repair of ccTGA.

PubMed, Embase, and the Cochrane Database were searched. Data were extracted using prespecified data forms. The primary outcome was the composite risk of all-cause mortality or heart transplantation during hospitalization and at 1, 5, and 10 years of follow-up. Secondary outcomes included reintervention risk.

Forty-seven studies totaling 2,844 patients were included. The incidence risk of mortality at 10 years was 11.7% (95% CI: 8.5%-15.3%) and 17.4% (95% CI: 12.4%-23.0%) in the anatomic and physiologic repair groups, respectively. The incidence risk of reintervention at 10 years was 24.5% (95% CI: 19.2%-30.1%) and 30.3% (95% CI: 23.5%-37.6%), respectively. The primary outcome was significantly lower at 10 years in anatomically repaired patients who had surgery at <5 years of age and who had preoperative pulmonary artery banding (Pheterogeneity < 0.01).

Anatomic repair of ccTGA patients results in higher overall and reintervention-free survival compared to physiologic repair. Specifically, patients who had anatomic repair at <5 years of age or who had preoperative pulmonary artery banding have better survival.

Patients with congenitally corrected transposition of the great arteries may require left ventricular training before the double switch operation. We evaluated the effects of combined pressure and volume loading.

We performed a retrospective study of patients with congenitally corrected transposition of the great arteries who underwent left ventricular training between 2012 and 2022.

Fifteen patients underwent left ventricular training at a median age of 1.5 years (interquartile range [IQR], 0.7-5.6). Their median left ventricular mass index was 21 g/m2 (IQR, 18.9-36.6), left ventricular end-diastolic volume index was 65.1 mL/m2 (IQR, 40.6-84.6), and systolic left ventricular/right ventricular pressure ratio was 0.35 (IQR, 0.31-0.5). In addition to pulmonary artery banding, atrial septectomy was performed in 12 patients (80%). Two patients already had a relevant shunt. One patient required systemic ventricular assist device implantation and heart transplantation. After a median of 1.9 years (IQR, 0.8-4.4), left ventricular mass index had increased to 38.5 g/m2 (IQR, 25-49, P = .002), left ventricular end-diastolic volume index to 71.4 mL/m2 (IQR, 50.1-94.4, P = .13), and systolic left ventricular/right ventricular pressure ratio to 0.94 (IQR, 0.84-1.1, P = .002). Older patients demonstrated a lower increase in left ventricular pressure. Six patients (6/14, 43%) have met eligibility criteria for the double switch operation (5 performed). Their age at the time of pulmonary artery banding was 1.7 years (IQR, 0.5-3.7), and the time between pulmonary artery banding and double switch operation was 3.1 years (IQR, 1.5-5.2). One patient required double switch operation takedown due to left ventricular failure. Two older patients were considered nonresponders to left ventricular training.

Combined pressure and volume loading resulted in a significant increase in left ventricular mass index and left ventricular pressure. Among older patients, there were nonresponders who remained not suitable for the double switch operation.

Background: Congenitally corrected transposition of the great arteries (cc-TGA) is a defect characterized by arterio-ventricular and atrioventricular disconcordance. Most patients have co-existing cardiac abnormalities that warrant further treatment. Some patients do not require surgical intervention, but most undergo physiological repair or anatomical surgery, which enables them to reach adulthood. Aims: We aimed to evaluate mortality risk factors in patients with cc-TGA. Results: We searched the PubMed database and included 10 retrospective cohort studies with at least a 5-year follow-up time with an end-point of cardiovascular death a minimum of 30 days after surgery. We enrolled 532 patients, and 83 met the end-point of cardiovascular death or equivalent event. As a risk factor for long-term mortality, we identified New York Heart Association (NYHA) class ≥III/heart failure hospitalization (OR = 10.53; 95% CI, 3.17-34.98) and systemic ventricle dysfunction (SVD; OR = 4.95; 95% CI, 2.55-9.64). We did not show history of supraventricular arrhythmia (OR = 2.78; 95% CI, 0.94-8.24), systemic valve regurgitation ≥moderate (SVR; OR = 4.02; 95% Cl, 0.84-19.18), and pacemaker implantation (OR = 1.48; 95% Cl, 0.12-18.82) to affect the long-term survival. In operated patients only, SVD (OR = 4.69; 95% CI, 2.06-10.71) and SVR (OR = 3.85; 95% CI, 1.5-9.85) showed a statistically significant impact on survival. Conclusions: The risk factors for long-term mortality for the entire cc-TGA population are NYHA class ≥III/heart failure hospitalization and systemic ventricle dysfunction. In operated patients, systemic ventricle dysfunction and at least moderate systemic valve regurgitation were found to affect survival.

Patients with a transposition of the great arteries (TGA) and a systemic right ventricle are at risk of heart failure (HF) development, arrhythmia and early mortality. Prognostic evaluations in clinical studies are hampered by small sample sizes and single-centred approaches. We aimed to investigate yearly rate of outcome and factors affecting it.

A systematic literature search of four electronic databases (PubMed, EMBASE, Web of Science and Scopus) was conducted from inception to June 2022. Studies reporting the association of a systemic right ventricle with mortality with a minimal follow-up of 2 years during adulthood were selected. Incidence of HF hospitalization and/or arrhythmia were captured as additional endpoints. For each outcome, a summary effect estimate was calculated.

From a total of 3891 identified records, 56 studies met the selection criteria. These studies described the follow-up (on average 7.27 years) of 5358 systemic right ventricle patients. The mortality incidence was 1.3 (1-1.7) per 100 patients/year. The incidence of HF hospitalization was 2.6 (1.9-3.7) per 100 patients/year. Predictors of poor outcome were a lower left ventricular (LV) and right ventricular ejection fraction (RVEF) (standardized mean differences (SMD) of -0.43 (-0.77 to -0.09) and - 0.85 (-1.35 to -0.35), respectively), higher plasma concentrations of NT-proBNP (SMD of 1.24 (0.49-1.99)), and NYHA class ≥2 (risk ratio of 2.17 (1.40-3.35)).

TGA patients with a systemic right ventricle have increased incidence of mortality and HF hospitalization. A lower LVEF and RVEF, higher levels of NT-proBNP and NYHA class ≥2 are associated with poor outcome.

The purpose of this study is to compare the long-term outcomes of 2 different tricuspid surgeries including valvuloplasty and replacement for significant tricuspid regurgitation in patients with systemic right ventricle.

This is a retrospective study of 34 patients with dextro-transposition of the great arteries or levo-transposition of the great arteries with biventricular circulation and systemic right ventricle undergoing tricuspid valve surgery between April 1979 and April 2022. Patients were divided into 2 groups based on the procedure: tricuspid valvuloplasty (n = 11) and tricuspid valve replacement (n = 23). These groups were compared in terms of survival, tricuspid valve dysfunction, and tricuspid valve-related reoperation.

There was no significant difference between the groups in operative age, body weight, the proportion of dextro-transposition of the great arteries, Ebstein-like tricuspid dysplasia, and preoperative right ventricular volume/function. During the median follow-up of 9.7 years, there was 1 early death (tricuspid valvuloplasty group) and 4 late deaths (3 in tricuspid valvuloplasty group and 1 in tricuspid valve replacement group). There were 7 tricuspid valve dysfunctions, including 6 significant tricuspid regurgitations in the tricuspid valvuloplasty group and 1 prosthetic valve dysfunction in the tricuspid valve replacement group, and 4 tricuspid valve-related reoperations (3 in the tricuspid valvuloplasty group and 1 in the tricuspid valve replacement group) were performed. There were significant differences between the groups in survival (tricuspid valvuloplasty vs tricuspid valve replacement: 72.7 vs 94.7% at 10 years after surgery, P = .0328) and cumulative incidence of tricuspid valve dysfunction at 10 years after tricuspid surgery (tricuspid valvuloplasty vs tricuspid valve replacement: 27.3% vs 0%, P = .0121).

Tricuspid valve replacement provided better long-term survival and tricuspid function in patients with systemic right ventricle compared with tricuspid valvuloplasty.

Congenitally corrected transposition of the great arteries (ccTGAs) represents a complex form of congenital heart disease that is associated with several cardiac complications. Herein is a case series of three children with ccTGA and ventricular assist device (VAD) inserted for systemic right ventricle failure at a single institution. All patients remained hemodynamically stable postimplant and were successfully discharged from the intensive care unit to undergo postoperative rehabilitation. All three patients received an orthotopic heart transplant with uneventful posttransplant courses. This case series provides insight into the medical management and technical feasibility of VAD support in children with ccTGA with end-stage heart failure.

Congenitally corrected transposition of great arteries is a rare anomaly which are responsible for 0.5% of all CHDs and can be associated with other congenital cardiac abnormalities. Association of congenitally corrected transposition of great arteries and isolated atrial septal defect is a very rare condition, and management of this association is challenging. In this paper, we describe three patients with congenitally corrected transposition of great arteries and isolated atrial septal defect who were admitted to our clinic and all of them underwent percutaneous closure of defect. From 2017 to 2020, we visited three patients with congenitally corrected transposition of great arteries and isolated atrial septal defect. Our patients' ages ranged from 28 to 38 years. All of them underwent percutaneous atrial septal defect device closure without any complications. Patients were discharged from hospital in good condition with a daily dose of Aspirin 80 mg and Plavix 75 mg. For all of them, follow-up echocardiography was performed the day after the procedure at 1, 3, and 6 months later and showed the function of the right-sided left ventricle improvement and the severity of the mitral regurgitation was reduced. Furthermore, clinical evaluation also indicated functional class improvement. Although the cases of percutaneous transcatheter closure are few and cannot be regarded as strong evidence to recommend this procedure, the outcomes are promising and can demonstrate that this approach is practical.

Congenitally corrected transposition of the great arteries is a complex pathology characterised by atrioventricular and ventriculo-arterial discordance. Optimal surgical approaches are still a matter of debate.

To evaluate the outcomes of different surgical treatments in a single centre.

Between 1998 and 2020, 89 patients were studied. The cohort was divided into three groups: physiologic, anatomic, and univentricular repair.

Physiologic correction (56.18%) was associated with significant tricuspid valve regurgitation progress (42%) and complete AV block (30%) compared to anatomic repair. Right ventricular systolic dysfunction was developed in 14%. Instead, anatomic correction (30.34%) (double switch 59% and Rastelli type 40.7%) presented moderate to severe aortic regurgitation (4%) and left ventricular systolic dysfunction (11%). Complete AV block was developed in 14.8%. Rate of reintervention was 34% for physiologic and 26% for anatomic. Univentricular palliation (13.8%) presented no complications or late mortality during the follow-up. The overall survival at 5 and 10 years, respectively, was 80% (95% CI 69, 87) and 75% (95% CI 62, 84). There was no statistically significant difference in mortality between the groups (p log-rank = 0.5752).

Management of congenitally corrected transposition of the great arteries remains a challenge. In this cohort, outcomes after physiologic repair were satisfactory in spite of the progression of tricuspid regurgitation and the high incidence of AV block. Anatomic repair improved tricuspid regurgitation but increased the risk of aortic regurgitation and left ventricular systolic dysfunction. The Fontan group showed the lowest incidence of complications.

Surgical treatment for congenitally corrected transposition of the great arteries is widely debated, with both physiologic repair and anatomic repair holding advantages and disadvantages. This meta-analysis, which includes 44 total studies consisting of 1857 patients, compares mortality at different time points (operative, in-hospital, and post-discharge), reoperation rates, and postoperative ventricular dysfunction between these two categories of procedures. Although anatomic and physiologic repair had similar operative and in-hospital mortality, anatomic repair patients had significantly less post-discharge mortality (6.1% vs 9.7%; P = .006), lower reoperation rates (17.9% vs 20.6%; P < .001), and less postoperative ventricular dysfunction (16% vs 43%; P < .001). When anatomic repair patients were subdivided into those who had atrial and arterial switch versus those who had atrial switch with Rastelli, the double switch group had significantly lower in-hospital mortality (4.3% vs 7.6%; P = .026) and reoperation rates (15.6% vs 25.9%; P < .001). The results of this meta-analysis suggest a protective benefit of favoring anatomic repair over physiologic repair.

Treatment of congenitally corrected transposition of great arteries (cc-TGA) with anatomic repair strategy has been considered superior due to restoration of the morphologic left ventricle in the systemic circulation. However, data on long term outcomes are limited to single center reports and include small sample sizes.

To perform a systematic review and meta-analysis for observational studies reporting outcomes on anatomic repair for cc-TGA.

MEDLINE and Scopus databases were queried using predefined criteria for reports published till December 31, 2017. Studies reporting anatomic repair of minimum 5 cc-TGA patients with at least a 2 year follow up were included. Meta-analysis was performed using Comprehensive meta-analysis v3.0 software.

Eight hundred and ninety-five patients underwent anatomic repair with a pooled follow-up of 5457.2 patient-years (PY). Pooled estimate for operative mortality was 8.3% [95% confidence interval (CI): 6.0%-11.4%]. 0.2% (CI: 0.1%-0.4%) patients required mechanical circulatory support postoperatively and 1.7% (CI: 1.1%-2.4%) developed post-operative atrioventricular block requiring a pacemaker. Patients surviving initial surgery had a transplant free survival of 92.5% (CI: 89.5%-95.4%) per 100 PY and a low rate of need for pacemaker (0.3/100 PY; CI: 0.1-0.4). 84.7% patients (CI: 79.6%-89.9%) were found to be in New York Heart Association (NYHA) functional class I or II after 100 PY follow up. Total re-intervention rate was 5.3 per 100 PY (CI: 3.8-6.8).

Operative mortality with anatomic repair strategy for cc-TGA is high. Despite that, transplant free survival after anatomic repair for cc-TGA patients is highly favorable. Majority of patients maintain NYHA I/II functional class. However, monitoring for burden of re-interventions specific for operation type is very essential.

Associated cardiovascular malformations in congenitally corrected transposition of the great arteries (CCTGA) should not be missed when a patient requires surgical correction. We present a case of an adult CCTGA patient who required redo surgery for recurrent tricuspid (left atrioventricular) valve regurgitation and previously unidentified partial anomalous pulmonary venous return.

Localization of the components of the cardiac conduction system (CCS) is essential for many therapeutic procedures in cardiac surgery and interventional cardiology. While histological studies provided fundamental insights into CCS localization, this information is incomplete and difficult to translate to aid in intraprocedural localization. To advance our understanding of CCS localization, we set out to establish a framework for quantifying nodal region morphology. Using this framework, we quantitatively analyzed the sinoatrial node (SAN) and atrioventricular node (AVN) in ovine with postmenstrual age ranging from 4.4 to 58.3 months. In particular, we studied the SAN and AVN in relation to the epicardial and endocardial surfaces, respectively. Using anatomical landmarks, we excised the nodes and adjacent tissues, sectioned those at a thickness of 4 μm at 100 μm intervals, and applied Masson's trichrome stain to the sections. These sections were then imaged, segmented to identify nodal tissue, and analyzed to quantify nodal depth and superficial tissue composition. The minimal SAN depth ranged between 20 and 926 μm. AVN minimal depth ranged between 59 and 1192 μm in the AVN extension region, 49 and 980 μm for the compact node, and 148 and 888 μm for the transition to His Bundle region. Using a logarithmic regression model, we found that minimal depth increased logarithmically with age for the AVN (R2 = 0.818, P = 0.002). Also, the myocardial overlay of the AVN was heterogeneous within different regions and decreased with increasing age. Age associated alterations of SAN minimal depth were insignificant. Our study presents examples of characteristic tissue patterns superficial to the AVN and within the SAN. We suggest that the presented framework provides quantitative information for CCS localization. Our studies indicate that procedural methods and localization approaches in regions near the AVN should account for the age of patients in cardiac surgery and interventional cardiology.

Congenitally corrected transposition of the great arteries (ccTGA) is a lesion that rarely occurs in isolation. The presenting physiology of ccTGA is predominantly secondary to the concurrent cardiac lesions; however, as the child ages, unrepaired ccTGA results in progressive failure of the morphologic right ventricle under the strain of maintaining a systemic pressure. Repair of ccTGA was initially focused on rectification of the underlying physiologic aberrations, but in recent years, the focus of repair has shifted toward anatomic correction to avoid failure of the morphologic right ventricle. This anatomic repair is commonly associated with improved long-term mortality at the cost of increased short-term mortality. Key preoperative considerations such as morphologic left ventricular pressure, tricuspid valve competency, and out flow tract obstructions can assist in determining the optimal repair for individual patients. An alternative, single ventricle, pathway has been proposed for any patient without optimal preoperative anatomy to improve long-term survival. Adjunctive repair options including pulmonary artery banding and one-and-a-half ventricle repairs have also been proposed to augment the survival curves.

Despite great advances in caring for patients with congenitally corrected transposition of the great arteries (ccTGA), a high proportion of these patients go on to develop heart failure and death in early adulthood. Adults with congenital heart disease (ACHD) only comprise a small number of patients receiving ventricular assist devices (VAD), but ccTGA accounted for 36% of ACHD patients in the INTERMACS database. Review of the literature describing ccTGA patients receiving VAD therapy shows promising results. With newer devices and the assistance of advanced imaging, mechanical circulatory support is becoming a desirable option for this population of patients and has the potential to provide significant long-term support, relieving them of heart failure symptoms and delaying and perhaps in the future avoiding, the need for cardiac transplantation.

Congenitally corrected transposition of the great arteries (ccTGA) can occur in isolation, or in combination with other structural cardiac anomalies, most commonly ventricular septal defect, pulmonary stenosis and tricuspid valve disease. Clinical recognition can be challenging, so echocardiography is often the means by which definitive diagnosis is made. The tricuspid valve and right ventricle are on the systemic arterial side of the ccTGA circulation, and are therefore subject to progressive functional deterioration. The natural history of ccTGA is also greatly influenced by the nature and severity of accompanying lesions, some of which require surgical repair. Some management strategies leave the right ventricle as the systemic arterial pump, but carry the risk of worsening heart failure. More complex 'double switch' repairs establish the left ventricle as the systemic pump, and include an atrial baffle to redirect venous return in combination with either arterial switch or Rastelli operation (if a suitable ventricular septal defect permits). Occasionally, the anatomic peculiarities of ccTGA do not allow straightforward biventricular repair, and Fontan palliation is a reasonable option. Regardless of the approach selected, late cardiovascular complications are relatively common, so ongoing outpatient surveillance should be established in an age-appropriate facility with expertise in congenital heart disease care.

Adults with congenital heart disease (ACHD) undergoing systemic atrioventricular valve (SAVV) surgery are a complex, understudied population. We assessed midterm outcomes and prognostic factors in ACHD undergoing SAVV surgery.

We performed retrospective evaluation of ACHD undergoing SAVV surgery from January 2005 to February 2016: 14 (33%) patients with congenital mitral valve stenosis/regurgitation, 15 (35%) with atrioventricular septal defect (AVSD), and 14 (33%) with congenitally corrected transposition of the great arteries (ccTGA) with systemic tricuspid valve regurgitation. Adverse events were defined as mortality, reoperation on SAVV, and late more-than-moderate (> moderate) SAVV regurgitation. Statistical analysis was performed using Fisher's exact test and one-way analysis of variance as well as univariate and multivariate risk factor analysis.

Fifteen (35%) patients had preoperative systemic ventricular dysfunction, including 13 patients with ccTGA (93%, P < .001). Twenty-three (54%) patients underwent valve repair, 20 (47%) patients underwent replacement, and 20 (47%) patients underwent an associated procedure. Replacement was higher in patients with ccTGA (86%) than the other groups ( P < 0.01). Thirty-seven patients (91% of survivors) were free of significant SAVV regurgitation at last follow-up, with patients with AVSD having greater regurgitation grades compared to the other groups ( P < 0.01). In-hospital mortality, late mortality, late > moderate SAVV regurgitation, and SAVV reoperation rates were 5% (n = 2), 2% (n = 1), 9% (n = 3), and 7% (n = 3), respectively. On multivariate analysis, predischarge SAVV regurgitation grade was the only significant predictor of adverse events (odds ratio = 8.2, 95% confidence interval: 1.1-63.8, P = .045).

Overall outcomes in this challenging population are good. The single factor associated with adverse events was predischarge SAVV regurgitation grade.

In patients with congenitally corrected transposition of the great arteries (ccTGA) or after atrial (Mustard or Senning) correction for transposition of the great arteries (acTGA), the right ventricle (RV) supports the systemic circulation. The tricuspid valve (TV) (systemic atrioventricular valve) is prone to regurgitation in these patients and this is associated with impending RV failure and decreased survival. This study evaluates mid-term functional improvements, echocardiographic findings and survival after TV surgery in this patient group.

From July 1999 to November 2014, 26 patients (mean age 37.1 ± 12.3 years, 14 females) with ccTGA (n = 15) or acTGA (n = 11) had TV surgery. All patients had RV dysfunction and more-than-moderate TV regurgitation (TR); 14 underwent TV replacement (TVR) and 12 had valvuloplasty (TVP). Main outcomes were New York Heart Association (NYHA) functional class, TR and RV dysfunction at 1 year postoperatively and at latest follow-up. Complications and freedom from the composite end-point of death or recurrent TR were analysed.

The median follow-up time was 5.9 years (range, 0-16.1 years). Mean NYHA functional class significantly improved to 1.7 [95% confidence interval (CI): 1.3-2.1] at 1 year (P= 0.004) and was 2.1 (95% CI: 1.7-2.6) at latest follow-up (P= 0.14). TV competence significantly improved to a mean TR grade of 1.1 (95% CI: 0.5-1.7) at latest follow-up (P< 0.001). The mean grade for RV function at latest follow-up was 2.7 (95% CI: 2.3-3.0). Most encountered postoperative complications were arrhythmias and temporary haemodynamic instability due to low cardiac output. Early mortality was 11.5% (n = 3); late mortality was 15.4% (n = 4). Estimated freedom from the composite end-point of death or recurrent TR was 76.9% (95% CI: 55.7-88.9%) at 1 year and 64.8% (95% CI: 43.2-79.9%) at 5 years. In TVP patients, TV function at 1 year and at latest follow-up was significantly worse than in TVR patients (P< 0.001 and P= 0.003, respectively). Also, TVP patients had a significantly lower composite end-point survival curve compared with TVR patients (P= 0.018).

In this patient group, TV surgery showed stabilization of RV function and improvement of NYHA functional class for at least several years. In this series, TVR appears superior to TVP with respect to occurrence of recurrent TR. Early and late mortality after TV surgery is substantial, and we believe that patients with significant TR should be referred earlier for surgery for better outcome.

The short-term outcome of physiologic repair for congenitally corrected transposition of the great arteries (ccTGA) is generally considered favorable; however, the long-term outcome is the greatest problem, especially with regard to right ventricular (RV) function and tricuspid regurgitation (TR). Although tricuspid valve replacement (TVR) appears to be a realistic choice for treating severe TR, determining the timing of TVR may be difficult.

We carried out a retrospective analysis of the long-term outcomes of physiologic repair for ccTGA focusing on patients with TVR. The study involved 23 patients after physiologic repair 10 or more years prior. There were 9 TVR cases in 5 pediatric patients (before age 18) and 4 adult patients.

There were two late deaths; however, there was no case related with cardiac events. Overall survival at 10 and 20 years were 95.5 and 90.2 %, respectively, and 7 of 8 patients after TVR were NYHA class I or II. No patient has presented postoperative complications in the form of bleeding or embolism after TVR with mechanical valve.

An analysis of the results of physiologic repair for ccTGA showed that the long-term outcome was overall favorable. To maintain RV function, early TVR may be a reasonable option, even in the management of patients during childhood.

Adult congenital heart disease (ACHD) clinicians are hampered by the paucity of data to inform clinical decision-making. The objective of this study was to identify priorities for clinical research in ACHD.

A list of 45 research questions was developed by the Alliance for Adult Research in Congenital Cardiology (AARCC), compiled into a survey, and administered to ACHD providers. Patient input was sought via the Adult Congenital Heart Association at community meetings and online forums. The 25 top questions were sent to ACHD providers worldwide via an online survey. Each question was ranked based on perceived priority and weighted based on time spent in ACHD care. The top 10 topics identified are presented and discussed.

The final online survey yielded 139 responses. Top priority questions related to tetralogy of Fallot (timing of pulmonary valve replacement and criteria for primary prevention ICDs), patients with systemic right ventricles (determining the optimal echocardiographic techniques for measuring right ventricular function, and indications for tricuspid valve replacement and primary prevention ICDs), and single ventricle/Fontan patients (role of pulmonary vasodilators, optimal anticoagulation, medical therapy for preservation of ventricular function, treatment for protein losing enteropathy). In addition, establishing criteria to refer ACHD patients for cardiac transplantation was deemed a priority.

The ACHD field is in need of prospective research to address fundamental clinical questions. It is hoped that this methodical consultation process will inform researchers and funding organizations about clinical research topics deemed to be of high priority.

Risks associated with pediatric reconstructive heart surgery include injury of the sinoatrial node (SAN) and atrioventricular node (AVN), requiring cardiac rhythm management using implantable pacemakers. These injuries are the result of difficulties in identifying nodal tissues intraoperatively. Here we describe an approach based on confocal microscopy and extracellular fluorophores to quantify tissue microstructure and identify nodal tissue.

Using conventional 3-dimensional confocal microscopy we investigated the microstructural arrangement of SAN, AVN, and atrial working myocardium (AWM) in fixed rat heart. AWM exhibited a regular striated arrangement of the extracellular space. In contrast, SAN and AVN had an irregular, reticulated arrangement. AWM, SAN, and AVN tissues were beneath a thin surface layer of tissue that did not obstruct confocal microscopic imaging. Subsequently, we imaged tissues in living rat hearts with real-time fiber-optics confocal microscopy. Fiber-optics confocal microscopy images resembled images acquired with conventional confocal microscopy. We investigated spatial regularity of tissue microstructure from Fourier analysis and second-order image moments. Fourier analysis of fiber-optics confocal microscopy images showed that the spatial regularity of AWM was greater than that of nodal tissues (37.5 ± 5.0% versus 24.3 ± 3.9% for SAN and 23.8 ± 3.7% for AVN; P<0.05). Similar differences of spatial regularities were revealed from second-order image moments (50.0 ± 7.3% for AWM versus 29.3 ± 6.7% for SAN and 27.3 ± 5.5% for AVN; P<0.05).

The study demonstrates feasibility of identifying nodal tissue in living heart using extracellular fluorophores and fiber-optics confocal microscopy. Application of the approach in pediatric reconstructive heart surgery may reduce risks of injuring nodal tissues.

Congenital division of the left atrium (cor triatriatum) and congenitally corrected transposition of the great arteries are both rare congenital cardiac malformations; their coexistence is exceedingly rare with only two previous reports identified in the literature. This combination of lesions is characterized by a pressure-loaded morphologically left ventricle and a propensity for pulmonary edema dependent on the degree of pulmonary venous obstruction caused by the dividing left atrial shelf. The probable impact of this on the natural history and surgical decision making is discussed.