Relationship between type of outflow tract repair and postoperative right ventricular diastolic physiology in tetralogy of Fallot. Implications for long-term outcome

Tetralogy of Fallot Across the Lifespan: A Focus on the Right Ventricle

Tetralogy of Fallot is a cyanotic congenital heart disease, for which various surgical techniques allow patients to survive to adulthood. Currently, the natural history of corrected tetralogy of Fallot is underlined by progressive right ventricular (RV) failure due to pulmonic regurgitation and other residual lesions. The underlying cellular mechanisms that lead to RV failure from chronic volume overload are characterized by microvascular and mitochondrial dysfunction through various regulatory molecules. On a clinical level, these cardiac alterations are commonly manifested as exercise intolerance. The degree of exercise intolerance can be objectified and aid in prognostication through cardiopulmonary exercise testing. The timing for reintervention on residual lesions contributing to RV volume overload remains controversial; however, interval assessment of cardiac function and volumes by echocardiography and magnetic resonance imaging may be helpful. In patients who develop clinically important RV failure, clinicians should aim to maintain a euvolemic state through the use of diuretics while paying particular attention to preload and kidney function. In patients who develop signs of cardiogenic shock from right heart failure, stabilization through the use of inotropes and pressor is indicated. In special circumstances, the use of mechanical support may be appropriate. However, cardiologists should pay particular attention to residual lesions that may impact the efficacy of the selected device.

Use of Cardiovascular Magnetic Resonance for Risk Stratification in Repaired Tetralogy of Fallot

The risk of premature death in adult patients with repaired tetralogy of Fallot is real and not inconsiderable. From the third decade of life, the incidence of malignant ventricular arrhythmia (VA) is known to exponentially rise. Progressive adverse mechanoelectrical modelling because of years of volume and/or pressure overload from residual pulmonary valve dysfunction and ventricular scar creates the perfect catalyst for VA. Although potentially lifesaving, implantable cardiac defibrillators are associated with substantial psychological and physical morbidity. Better selection of patients most at risk of VA, so that implantable cardiac defibrillators are not inflicted on patients who will never need them, is therefore crucial and has inspired research on this topic for several decades. Cardiovascular magnetic resonance (CMR) enables noninvasive, radiation-free clinical assessment of anatomy and function, making it ideal for the lifelong surveillance of patients with congenital heart disease. Gold standard measurements of ventricular volumes and systolic function can be derived from CMR. Tissue characterization using CMR can identify a VA substrate and provides insight into myocardial disease. We detail risk factors for VA identified using currently available CMR techniques. We also discuss emerging and advanced CMR techniques that have not all yet translated into routine clinical practice. We review how CMR-defined predictors of VA in repaired tetralogy of Fallot can be incorporated into risk scores with other clinical factors to improve the accuracy of risk prediction and to allow for pragmatic clinical application. Finally, we discuss what the future may hold.

End-diastolic forward flow in repaired tetralogy of Fallot: Mid-term outcomes from a single center

Background

Pulmonary arterial end-diastolic forward flow (EDFF) following repaired tetralogy of Fallot (rTOF) is recognized as right ventricular (RV) restrictive physiology, which is closely related to poor prognosis. This study sought to review mid-term experience and investigate the risk factors of EDFF in the rTOF patients.

Methods

From September 2016 to January 2019, 100 patients (age < 18 years old) who underwent complete tetralogy of Fallot (TOF) repair were enrolled and were divided into EDFF group (n = 52) and non-EDFF group (n = 48) based on the presence of postoperative EDFF. Elastic net analysis was performed for variable selection. Univariate and multivariate logistic analyses were used to analyze the correlation between risk factors and EDFF.

Results

End-diastolic forward flow group had lower systolic blood pressure (P = 0.037), diastolic blood pressure (P = 0.027), and higher vasoactive-inotrope score within 24 h after surgery (P = 0.022) than non-EDFF group. Transannular patch (TAP) was an independent predictor of postoperative EDFF [P = 0.029, OR: 2.585 (1.102∼6.061)]. Patients were followed up for a median of 2.6 years [interquartile range (IQR) 1.6] after the first TOF repair. During follow-up, the prevalence of the EDFF was lower in those with pulmonary valve (PV) reconstructions than that in those undergoing patch enlargement without PV reconstructions in the primary TOF repair (P < 0.001).

Conclusion

End-diastolic forward flow was associated with TAP. Patients with EDFF might have a transient hemodynamic instability in the early postoperative period. PV reconstructions in the TOF repair might reduce the incidence of EDFF in the mid-term follow-up.

Right atrial function early after tetralogy of Fallot repair

Diastolic dysfunction after repair for Tetralogy of Fallot (TOF) is associated with adverse long-term outcomes. Right atrial (RA) mechanics as a proxy of right ventricular (RV) diastolic function in the early post-operative period after surgical repair for TOF has not been reported. We sought to evaluate RA and RV strain prior to hospital discharge after TOF repair and to identify important patient factors associated with strain using a machine learning method. Single center retrospective cohort study of TOF patients undergoing surgical repair, with analysis of RA and RV strain from pre-and post-operative echocardiograms. RA function was assessed by the peak RA strain, systolic RA strain rate, early diastolic RA strain rate and RA emptying fraction. RV systolic function was measured by global longitudinal strain. Pre- and post-operative values were compared using Wilcoxon rank sum test. Gradient boosted machine (GBM) models were used to identify the most important predictors of post-operative strain. In total, 153 patients were enrolled, median age at TOF repair 3.5 months (25th-75th percentile: 2.2- 5.2), mostly male (67%), and White (64.1%). From pre-to post-operative period, there was significant worsening in all RA parameters and in RV strain. GBM models identified patient, anatomic, and surgical factors that were strong predictors of post-operative RA and RV strain. These factors included pulmonary valve and branch pulmonary artery Z scores, birth weight, gestational age and age at surgery, pre-operative RV fractional area change and oxygen saturation, type of outflow tract repair, duration of cardiopulmonary bypass, and early post-operative partial arterial pressure of oxygen. There is significant worsening in RA and RV strain early after TOF repair, indicating early alteration in diastolic and systolic function after surgery. Several patient and operative factors influence post-operative RV function. Most of the factors described are not readily modifiable, however they may inform pre-operative risk-stratification. The clinical application of RA strain and the prognostic implication of these early changes merit further study.

End-Diastolic Forward Flow and Restrictive Physiology in Repaired Tetralogy of Fallot: A Systematic Review and Meta-Analysis

Background

Pulmonary arterial end‐diastolic forward flow (EDFF) following repaired tetralogy of Fallot has been thought to represent right ventricular (RV) restrictive physiology, but is not fully understood. This systematic review and meta‐analysis sought to clarify its physiological and clinical correlates, and to define a framework for understanding EDFF and RV restrictive physiology.

Methods and Results

PubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for observational studies published before March 2021. Random‐effects meta‐analysis was performed to identify factors associated with EDFF. Forty‐two individual studies published between 1995 and 2021, including a total of 2651 participants (1132 with EDFF; 1519 with no EDFF), met eligibility criteria. The pooled estimated prevalence of EDFF among patients with repaired tetralogy of Fallot was 46.5% (95% CI, 41.6%–51.3%). Among patients with EDFF, the use of a transannular patch was significantly more common, and their stay in the intensive care unit was longer. EDFF was associated with greater RV indexed volumes and mass, as well as smaller E‐wave velocity at the tricuspid valve. Finally, pulmonary regurgitation fraction was greater in patients with EDFF, and moderate to severe pulmonary regurgitation was more common in this population.

Conclusions

EDFF is associated with dilated, hypertrophied RVs and longstanding pulmonary regurgitation. Although several studies have defined RV restrictive physiology as the presence of EDFF, our study found no clear indicators of poor RV compliance in patients with EDFF, suggesting that EDFF may have multiple causes and might not be the precise equivalent of RV restrictive physiology.

Tetralogy of Fallot: stent palliation or neonatal repair?

Surgical repair of Tetralogy of Fallot has excellent outcomes, with over 90% of patients alive at 30 years. The ideal time for surgical repair is between 3 and 11 months of age. However, the symptomatic neonate with Tetralogy of Fallot may require earlier intervention: either a palliative intervention (right ventricular outflow tract stent, ductal stent, balloon pulmonary valvuloplasty, or Blalock-Taussig shunt) followed by a surgical repair later on, or a complete surgical repair in the neonatal period. Indications for palliation include prematurity, complex anatomy, small pulmonary artery size, and comorbidities. Given that outcomes after right ventricular outflow tract stent palliation are particularly promising - there is low mortality and morbidity, and consistently increased oxygen saturations and increased pulmonary artery z-scores - it is now considered the first-line palliative option. Disadvantages of right ventricular outflow tract stenting include increased cardiopulmonary bypass time at later repair and the stent preventing pulmonary valve preservation. However, neonatal surgical repair is associated with increased short-term complications and hospital length of stay compared to staged repair. Both staged repair and primary repair appear to have similar long-term mortality and morbidity, but more evidence is needed assessing long-term outcomes for right ventricular outflow tract stent palliation patients.

Evolution of echocardiography in adult congenital heart disease: from pulsed-wave Doppler to fusion imaging

The number of patients with adult congenital heart disease (ACHD) has been dramatically increasing and adults with congenital heart disease now outnumber children with congenital heart disease. However, patients with ACHD are still at increased risk of morbidity and mortality due to residua and sequelae. Although echocardiography is an indispensable imaging modality in the comprehensive assessment of ACHD, accurate echocardiographic assessment of ACHD is challenging especially for physicians or sonographers who are not familiar with ACHD because of its complex morphology, physiology, and hemodynamics. A recently developed fusion imaging technology can provide synchronized display of real-time echocardiographic images and multiplanar reconstruction images of computed tomography or magnetic resonance imaging corresponding to the image plane of real-time echocardiography. We have reported the clinical utility of this fusion imaging technology for the precise evaluation of complex ACHD. On the other hand, conventional echocardiographic technology also plays an important role in assessing unique ACHD pathophysiology. For example, restrictive right ventricular physiology is a common finding after tetralogy of Fallot or pulmonary stenosis repair and can be evaluated by conventional pulsed-wave Doppler. In this review, we discuss the clinical usefulness of modern and conventional echocardiographic technologies for the evaluation of ACHD by presenting a case series.

Diagnosis and Management of Lymphatic Disorders in Congenital Heart Disease

Purpose of Review

Lymphatic disorders have received an increasing amount of attention over the last decade. Sparked primarily by improved imaging modalities and the dawn of lymphatic interventions, understanding, diagnostics, and treatment of lymphatic complications have undergone considerable improvements. Thus, the current review aims to summarize understanding, diagnostics, and treatment of lymphatic complications in individuals with congenital heart disease.

Recent Findings

The altered hemodynamics of individuals with congenital heart disease has been found to profoundly affect morphology and function of the lymphatic system, rendering this population especially prone to the development of lymphatic complications such as chylous and serous effusions, protein-losing enteropathy and plastic bronchitis.

Summary

Although improved, a full understanding of the pathophysiology and targeted treatment for lymphatic complications is still wanting. Future research into pharmacological improvement of lymphatic function and continued implementation of lymphatic imaging and interventions may improve knowledge, treatment options, and outcome for affected individuals.

Derivation and Validation of a Nomogram to Predict In-Hospital Complications in Children with Tetralogy of Fallot Repaired at an Older Age

Background

We aimed to develop and validate a prediction model for in‐hospital complications in children with tetralogy of Fallot repaired at an older age.

Methods and Results

A total of 513 pediatric patients from the Tianjin data set formed a derivation cohort, and 158 pediatric patients from the Hefei and Xiamen data sets formed validation cohorts. We applied least absolute shrinkage and selection operator analysis for variable selection and logistic regression coefficients for risk scoring. We classified patients into different risk categorizations by threshold analysis and investigated the association with in‐hospital complications using logistic regression. In‐hospital complications were defined as death, need for extensive pharmacologic support (vasoactive‐inotrope score of ≥20), and need for mechanical circulatory support. We developed a nomogram based on risk classifier and independent baseline variables using a multivariable logistic model. Based on risk scores weighted by 11 preoperative and 4 intraoperative selected variables, we classified patients as low, intermediate, and high risk in the derivation cohort. With reference to the low‐risk group, the intermediate‐ and high‐risk groups conferred significantly higher in‐hospital complication risks (adjusted odds ratio: 2.721 [95% CI, 1.267–5.841], P=0.0102; 9.297 [95% CI, 4.601–18.786], P<0.0001). A nomogram integrating the ARIAR‐Risk classifier (absolute and relative low risk, intermediate risk, and aggressive and refractory high risk) with age and mean blood pressure showed good discrimination and goodness‐of‐fit for derivation (area under the receiver operating characteristic curve: 0.785 [95% CI, 0.731–0.839]; Hosmer‐Lemeshow test, P=0.544) and external validation (area under the receiver operating characteristic curve: 0.759 [95% CI, 0.636–0.881]; Hosmer‐Lemeshow test, P=0.508).

Conclusions

A risk‐classifier–oriented nomogram is a reliable prediction model for in‐hospital complications in children with tetralogy of Fallot repaired at an older age, and strengthens risk/benefit–based decision‐making.

Usefulness of Pulmonary Arterial End-Diastolic Forward Flow Late After Tetralogy of Fallot Repair to Predict a "Restrictive" Right Ventricle

The functional significance of pulmonary arterial end-diastolic forward flow (EDFF) in patients with repaired tetralogy of Fallot (rTOF) is not fully understood, with conflicting reports regarding its associations with pulmonary regurgitation (PR), right ventricular (RV) size and function, and so-called restrictive RV physiology. To examine these associations, we retrospectively analyzed 399 patients with rTOF who had contemporaneous echocardiography (Echo) and cardiovascular magnetic resonance (CMR) studies. The median age at TOF repair was 0.7 years (0.21, 2.66), age at CMR was 19.8 years (13.0, 29.4), and interval between Echo and CMR was 48 days (0, 182). Doppler identified EDFF in 122 (31%) patients and CMR in 113 patients (28%). Compared with those without EDFF, patients with EDFF were younger, had greater PR, and higher RV end-diastolic volume, stroke volume, and ejection fraction. Markers of RV restriction such as right atrial size did not differ between groups. On multivariable regression, EDFF was associated with higher RV stroke volume and lower left ventricular end-diastolic volume. The association between Echo and CMR measurements of EDFF was modest (area under the receiver operating characteristic curve = 0.684, r = 0.374, p < 0.001). In conclusion, EDFF was common in this large cohort of patients with rTOF, but its presence and extent varied between Echo and CMR. EDFF was associated with greater PR and larger RV size, but not with markers of poor RV compliance such as right atrial enlargement. Mechanisms beyond RV noncompliance may contribute to the presence of EDFF.

Changes in contractile protein expression are linked to ventricular stiffness in infants with pulmonary hypertension or right ventricular hypertrophy due to congenital heart disease

Background

The right ventricle (RV) is not designed to sustain high pressure leading to failure. There are no current medications to help RV contraction, so further information is required on adaption of the RV to such hypertension.

Methods

The Right Ventricle in Children (RVENCH) study assessed infants with congenital heart disease undergoing cardiac surgery with hypertensive RV. Clinical and echocardiographic data were recorded, and samples of RV were taken from matched infants, analysed for proteomics and compared between pathologies and with clinical and echocardiographic outcome data.

Results

Those with tetralogy of Fallot (TOF) were significantly more cyanosed than those with ventricular septal defect (median oxygen saturation 83% vs 98%, P=0.0038), had significantly stiffer RV (tricuspid E wave/A wave ratio 1.95 vs 0.84, P=0.009) and had most had restrictive physiology. Gene ontology in TOF, with enrichment analysis, demonstrated significant increase in proteins of contractile mechanisms and those of calmodulin, actin binding and others associated with contractility than inventricular septal defect. Structural proteins were also found to be higher in association with sarcomeric function: Z-disc, M-Band and thin-filament proteins. Remaining proteins associated with actin binding, calcium signalling and myocyte cytoskeletal development. Phosphopeptide enrichment led to higher levels of calcium signalling proteins in TOF.

Conclusion

This is the first demonstration that those with an RV, which is stiff and hypertensive in TOF, have a range of altered proteins, often in calcium signalling pathways. Information about these alterations might guide treatment options both in terms of individualised therapy or inotropic support for the Right ventricle when hypertensive due to pulmoanry hypertension or congenital heart disease.

Tetralogy of Fallot and Its Variants

OBJECTIVES

The objectives of this review are to discuss the anatomy, pathophysiology, surgical repair, and perioperative management strategies for tetralogy of Fallot and its variants.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSIONS

Significant refinements have been made in the repair strategy for tetralogy of Fallot, based on improved understanding of postrepair physiology. Important considerations for timing and technique of surgery and perioperative management have been presented, and continued evolution is expected. Expanded use of the pulmonary valve reconstruction technique outlined herein, whatever the age of repair, may improve long-term outcome.

Restrictive right ventricular performance assessed by cardiac magnetic resonance after balloon valvuloplasty of critical pulmonary valve stenosis

BACKGROUND

Little data are published about right ventricular diastolic performance in patients with critical pulmonary valve stenosis after balloon pulmonary valvuloplasty thus far.

METHODS

A total of 44 patients with isolated critical pulmonary valve stenosis who had undergone balloon valvuloplasty with haemodynamic recordings were enrolled to the study; 33 patients who came for follow-up underwent further imaging by echocardiography after 6 months and their right ventricular functional parameters were compared with 33 control patients of the same age and sex. Out of 33 patients, 21 underwent cardiac MRI with late gadolinium enhancement to assess the presence of right ventricular fibrosis.

RESULTS

The right ventricular systolic pressure (p<0.0001) and right ventricular outflow tract gradient (p<0.0001) decreased acutely (p<0.0001) after balloon valvuloplasty. During follow-up, M-mode left ventricular end diastolic dimension (p<0.001) and end systolic dimension increased (p<0.001), whereas right ventricular end diastolic dimension decreased (p<0.001). Compared with controls, patients (n=33) had significantly reduced tricuspid annular Ea and higher E/Ea (p<0.001). Right ventricular systolic dysfunction was also suggested by reduced tricuspid annular systolic velocity (p<0.001). Late gadolinium enhancement was demonstrated in 13 out of 21 patients with restrictive physiology, which involves the anterior right ventricular outflow tract, anterior wall, and inferior wall. The right ventricular late gadolinium enhancement score correlated positively with age (r=0.7, p<0.001) and right ventricular mass index (r=0.52, p<0.001).

CONCLUSION

The persistence of right ventricular diastolic dysfunction after relief of chronic pressure overload of critical pulmonary valve stenosis suggests that a factor - other than increase in afterload - is involved in this physiology. Fibrosis is the most likely factor responsible for persistence of restrictive physiology as documented by late gadolinium enhancement.

Delayed enhancement imaging in a contemporary patient cohort following correction of tetralogy of Fallot

OBJECTIVE

To test the hypothesis that myocardial scars after repair of tetralogy of Fallot are related to impaired cardiac function and adverse clinical outcome.

METHODS

A total of 53 patients were retrospectively analysed after repair of tetralogy of Fallot. The median patient age was 20 years (range 2-48). Cardiac MRI with a 1.5 T magnet included cine sequences to obtain volumes and function, phase-sensitive inversion recovery delayed enhancement imaging to detect myocardial scars, and flow measurements to determine pulmonary regurgitation fraction. In addition, clinical parameters were obtained.

RESULTS

An overall 83% of patients were in NYHA class I. All patients with the exception of 2 (96%) had pulmonary insufficiency. Mean ejection fraction and end-diastolic volume index were 46% and 128 ml/m2 for the right ventricle and 54% and 82 ml/m² for the left ventricle, respectively. Excluding enhancement of the septal insertion and prosthetic patches, delayed enhancement was seen in 11/53 cases (21%). Delayed enhancement of the right ventricle was detected in 6/53 patients (11%) and of the left ventricle in 5/53 patients (9%). The patient group with delayed enhancement was significantly older (p=0.003), had later repair (p=0.007), and higher left ventricular myocardial mass index (p=0.009) compared with the group without delayed enhancement.

CONCLUSIONS

This study reveals that scarring is common in patients after surgical repair of tetralogy of Fallot and is associated with older age and late repair. However, there was no difference in right ventricular function, NYHA class, or occurrence of clinically relevant arrhythmias between patients with and those without myocardial scars.

Right Ventricular Mass is Associated with Exercise Capacity in Adults with Repaired Tetralogy of Fallot

The relationship between exercise capacity and right ventricular (RV) structure and function in adult repaired tetralogy of Fallot (TOF) is poorly understood. We therefore aimed to examine the relationships between cardiac MRI and cardiopulmonary exercise test variables in adult repaired TOF patients. In particular, we sought to determine the role of RV mass in determining exercise capacity. Eighty-two adult repaired TOF patients (age at evaluation 26 ± 10 years; mean age at repair 2.5 ± 2.8 years; 23.3 ± 7.9 years since repair; 53 males) (including nine patients with tetralogy-type pulmonary atresia with ventricular septal defect) were prospectively recruited to undergo cardiac MRI and cardiopulmonary exercise testing. As expected, these repaired TOF patients had RV dilatation (indexed RV end-diastolic volume: 153 ± 43.9 mL/m(2)), moderate-severe pulmonary regurgitation (pulmonary regurgitant fraction: 33 ± 14 %) and preserved left (LV ejection fraction: 59 ± 8 %) and RV systolic function (RV ejection fraction: 51 ± 7 %). Exercise capacity was near-normal (peak work: 88 ± 17 % predicted; peak oxygen consumption: 84 ± 17 % predicted). Peak work exhibited a significant positive correlation with RV mass in univariate analysis (r = 0.45, p < 0.001) and (independent of other cardiac MRI variables) in multivariate analyses. For each 10 g higher RV mass, peak work was 8 W higher. Peak work exhibits a significant positive correlation with RV mass, independent of other cardiac MRI variables. RV mass measured on cardiac MRI may provide a novel marker of clinical progress in adult patients with repaired TOF.

Distinctive Hemodynamics in the Immediate Postoperative Period of Patients with a Longer Cardiac Intensive Care Stay Post-Tetralogy of Fallot Repair

OBJECTIVE

After complete surgical repair the majority of tetralogy of Fallot (ToF), patients stay ≤2 days in the Cardiac Intensive Care Unit (CICU) while some may stay longer. We undertook this study to investigate the factors associated with shorter vs. longer length of stay in the CICU to help manage resources effectively.

DESIGN

Patients who underwent ToF repair at Aga Khan University, Pakistan, between July 2006 and December 2011 were studied in a case-control design. Clinical parameters were compared between short stay group (SSG) (≤2 days) and long stay group (LSG) (>2 days). Odds ratios were calculated, and regression was performed.

RESULTS

Ninety-eight patients (LSG 65, SSG 33) were included. Patients with lower preoperative saturation were 2.67 times more likely to be in the LSG group (P = .02). At 4 hours postoperatively, patients with a higher inotropic score (odds ratio [OR] = 3.03, confidence interval [CI] = 1.19-7.7, P = .02), higher central venous pressure (OR = 3.04, CI = 1.27-7.32, P = .013), and significant tachycardia at 4 hours (OR = 3.5, CI = 1.19-10.3. P = .02) were at risk for having a prolonged CICU stay. On multivariate analysis, significant postoperative tachycardia at 4 hours (z-score ≥3) was highly specific (sensitivity = 38.5%, specificity = 84.9%) for predicting the chances of being in the LSG. Other predictors included preop O(2) saturation ≤82.5% (sensitivity = 61.1%, specificity = 63.0%) and CVP ≥10 mm Hg at 4 hours (sensitivity = 55.4%, specificity = 71.9%).

CONCLUSION

Patients who end up staying longer in the CICU have features that are distinctive in the immediate postoperative period, and this can help clinicians in identifying patients who may need more support.

Pulmonary Valve Replacement With a Bovine Pericardial Valve

Objectives:

From a population of 90 patients after pulmonary valve replacement with a biological valve (Carpentier-Edwards Perimount valve), 56 of 80 available patients were examined five years after surgery.

Background:

Pulmonary valve replacement is needed in many patients with congenital heart disease. Homografts have limited availability and predictable degeneration, and mechanical valves require anticoagulation. No superiority of one kind of pulmonary valve replacement has been shown. Biological valves that are readily available are being used and evaluated in increasing numbers.

Methods:

In this cross-sectional study, five years following surgery, data were gathered from hospital charts, echocardiography, stress echocardiography, magnetic resonance imaging, and exercise testing.

Results:

In 90 patients, there were three new valve replacements, one early cardiac death, and four late noncardiac deaths. Echocardiographic assessment of the study group showed pulmonary Doppler velocities (m/s) before, after operation, and at five-year follow-up of 2.8 ± 1.1, 1.6 ± 0.4, and 2.3 ± 0.7, respectively. The assessed insufficiencies (0-3) at the same times were 2.3 ± 1.0, 0.3 ± 0.4, and 1.1 ± 0.8. Maximal oxygen uptake increased from 65.6% ± 10.1% to 77.1% ± 18.2% of predicted and QRS width increased by 7 ± 23ms. Valve degeneration could be associated with young age but not with diagnosis or valve size.

Conclusion:

In our study, the biological valve in the pulmonary position showed excellent mid-term results with few reoperations, low gradients, and mild to moderate insufficiency. Oversizing, in contrast to young age, was not a risk factor for valve degeneration. In younger patients, this allows later percutaneous replacement, reducing the need for further surgery. However, longer follow-up is needed.

Arrhythmias in adult congenital heart disease

Recent advances in pediatric cardiology and cardiac surgery have allowed a rapidly expanding population of patients with congenital heart disease to thrive well into their adult years. Often after prolonged uneventful clinical courses as children and adolescents, arrhythmias may surface later in life. These arrhythmias are a major source of morbidity. In addition, sudden death is the leading cause of mortality in adult patients with congenital heart disease. This review highlights the various types of brady- and tachyarrhythmias encountered in the more common forms of adult congenital heart disease and explores prognostic implications and therapeutic options.

Restrictive right ventricular physiology after tetralogy of Fallot repair is associated with fibrosis of the right ventricular outflow tract visualized on cardiac magnetic resonance imaging

AIMS

To determine whether the restrictive physiology seen in Tetralogy of Fallot (TOF) patients can be explained by fibrosis of the right ventricular (RV) outflow tract. The aetiology for restrictive RV physiology after TOF repair is not known.

METHODS AND RESULTS

TOF patients (n = 31, 13 girls, 10.2 years ± 2.8) were included 9.2 ± 2.9 years after total correction and examined with cardiac magnetic resonance (CMR) and Doppler echocardiography. Cine, flow, and late gadolinium contrast enhanced (LGE) CMR imaging were performed to quantify RV volumes, pulmonary flow and regurgitation (PR), and fibrosis. Healthy children (n = 12) were investigated with CMR of the pulmonary flow. Forward flow during atrial contraction above mean + 2 SD of healthy subjects was set as a marker of restrictive physiology. Four patients were excluded due to suboptimal LGE-CMR. Fisher's exact test was used to determine the association between restrictive physiology and fibrosis. Sixteen patients showed fibrosis in the right ventricular outflow tract (RVOT) on LGE-CMR and 14 of them showed restrictive physiology on CMR. Of the 11 patients without fibrosis in the RVOT, 1 showed restrictive physiology. The odds ratio for RVOT fibrosis in patients with restrictive RV physiology was 70.0 (CI: 5.6-882.7, P < 0.001). The transannular patch repair did not differ between the groups (P = 0.37). The degree of RVOT fibrosis correlated positively with PR (r(2) = 0.38, P < 0.001) and RV volumes (r(2) = 0.51 for end-diastolic volume and r(2) = 0.47 for end-systolic volume, P < 0.001).

CONCLUSION

There is a strong association between the restrictive RV physiology detected on CMR and fibrosis of the RVOT in children after TOF repair.

Assessment of a right-ventricular infundibulum-sparing approach in transatrial-transpulmonary repair of tetralogy of Fallot

OBJECTIVE

The study aimed to evaluate the outcome of transatrial-transpulmonary repair of tetralogy of Fallot in relation to a right-ventricular outflow tract (RVOT)-sparing surgery.

METHODS

Based on the surgical management of right-ventricular outflow tract obstruction (RVOTO) at repair of tetralogy of Fallot, 140 children were retrospectively divided into three groups: (1) pulmonary valve (PV)-sparing, (2) infundibulum-sparing and (3) extended trans-annular patch (TAP). Clinical and echocardiographic outcome was assessed with regards to three equally divided study time eras between January 1994 and June 2010.

RESULTS

Over a 15-year study period, median age decreased from 11 (2-101) to 5 (1-11) months (p<0.001), whereas type of RVOT repair changed significantly between the first and the last era (group 1: 18-40%, group 2: 25-40% vs group 3: 57-20% (p=0.002)). Mortality was 0%. Complications were mainly related to clinical restrictive RV physiology (27%) and arrhythmia (10%). This cardiac morbidity remained constant over the eras and was associated with younger age (p=0.04), increased postoperative right ventricle/left ventricle (RV/LV) pressure ratio (p=0.01) and type of RVOT repair at the cost of TAP (p=0.03). Median follow-up of 8 years (1-16 years) showed an overall freedom from RVOT re-operation of 84% and 73%, respectively at 5 and 10 years. Most re-operations were for residual/recurrent RVOTO (12%) occurring more frequently in the latter era: 16% versus 7% in era 1 (p=0.08). Late echocardiographic evaluation revealed a strong correlation between severity of pulmonary regurgitation and increased RV/LV size ratio, which was mainly determined by increased TAP length (p<0.001) and duration of follow-up (p=0.06).

CONCLUSION

In a 15-year's experience with transatrial-transpulmonary correction of tetralogy of Fallot, a valve- and infundibulum-sparing approach has been advanced by lowering the age for elective repair. This change has been performed without compromising immediate clinical outcome, despite an increased early re-operation rate for residual obstruction. However, longer follow-up will disclose whether this approach is protective against progressive and late RV dysfunction.

Abnormal right atrial and right ventricular diastolic function relate to impaired clinical condition in patients operated for tetralogy of Fallot

BACKGROUND

Atrial enlargement may reflect ventricular diastolic dysfunction. Although patients with tetralogy of Fallot (TOF) have been studied extensively, little is known about atrial size and function. We assessed bi-atrial size and function in patients after TOF repair, and related them to biventricular systolic and diastolic function, and clinical parameters.

METHODS

51 Patients (21 ± 8 years) and 30 healthy controls (31 ± 7 years) were included and underwent magnetic resonance imaging to assess bi-atrial and biventricular size, systolic and diastolic function. Patients also underwent exercise testing, and N-terminal prohormone brain natriuretic peptide (NT-proBNP) assessment.

RESULTS

In patients, right atrial (RA) minimal volume (34 ± 8 ml/m(2) vs. 28 ± 8 ml/m(2), p=0.001) and late emptying fraction were increased; RA early emptying fraction was decreased. Patients had longer right ventricular (RV) deceleration time (0.24 ± 0.10 vs. 0.13 ± 0.04, p<0.001), reflecting impaired RV relaxation, and larger RV volumes. Patients with end-diastolic forward flow (EDFF) had larger RA and RV size, abnormal RA emptying, higher NT-proBNP levels, higher VE/VCO2 slope (ventilatory response to carbon dioxide production), and the most abnormal LV diastolic function (impaired compliance). Patients with abnormal RA emptying (reservoir function <30% and pump function >24%) had higher NT-proBNP levels and worse exercise capacity. RA minimal volume was associated with RV end-diastolic volume (r=0.35, p=0.013).

CONCLUSIONS

In TOF patients with moderate RV dilatation, abnormal bi-atrial function and biventricular diastolic dysfunction are common. Abnormal RA emptying was associated with signs of impaired clinical condition, as was the presence of EDFF. These parameters, together with RA enlargement, could serve as useful markers for clinically relevant RV diastolic dysfunction.

Outcomes of prenatally diagnosed tetralogy of Fallot: Implications for valve-sparing repair versus transannular patch

OBJECTIVES

To assess outcomes of prenatally diagnosed tetralogy of Fallot and determine factors associated with the choice to undergo a valvesparing repair versus transannular patch, and the use of prostaglandins at birth.

METHODS

All cases at The Hospital for Sick Children (Toronto, Ontario) with a fetal diagnosis of tetralogy of Fallot from 1998 to 2006, were reviewed for demographic and fetal echocardiographic data to determine factors associated with the valve-sparing repair and need for perinatal support.

RESULTS

Sixty-four fetuses met inclusion criteria (median gestational age 22 weeks) with 47 live births. Twenty-six underwent valve-sparing repair (median age 5.7 months) and 14 underwent transannular patch repair (median age 4.5 months). There were seven deaths before surgery and one post-transannular patch repair. One patient required a transannular patch repair after the initial valve-sparing repair. Twelve of 29 (41%) patients received prostaglandins at birth. Type of surgical repair, use of prostaglandins and postnatal death were among the outcomes investigated. The mean pulmonary valve (PV) z-score was -3.0+/-2.0 and the mean PV/aortic valve (AoV) ratio was 0.65+/-0.10. Lower PV z-score (P=0.04), smaller PV/AoV ratio (P=0.04) and the presence of nonantegrade arterial duct flow (P=0.02) were associated with prostaglandin use. A higher PV/AoV ratio was associated with valvesparing repair (P=0.04). Fetal z-scores of the PV, AoV and right pulmonary artery at 29 to 32 weeks gestational age correlated with respective postnatal z-scores (P=0.01).

CONCLUSION

Fetal echocardiographic variables were associated with the use of prostaglandins and valve-sparing repair in fetuses with tetralogy of Fallot, and at 29 weeks, correlated with postnatal valve diameters.

Tetralogy of Fallot

Tetralogy of Fallot is the most common form of cyanotic congenital heart disease, and one of the first to be successfully repaired by congenital heart surgeons. Since the first procedures in the 1950s, advances in the diagnosis, perioperative and surgical treatment, and postoperative care have been such that almost all those born with tetralogy of Fallot can now expect to survive to adulthood. The startling improvement in outcomes for babies born with congenital heart disease in general-and for those with tetralogy of Fallot in particular-is one of the success stories of modern medicine. Indeed, in many countries adults with tetralogy of Fallot outnumber children. Consequently, new issues have emerged, ranging from hitherto unpredicted medical complications to issues with training for caregivers and resource allocation for this population of survivors. Therefore, evolution of treatment, recognition of late complications, research on disease mechanisms and therapies-with feedback to changes in care of affected children born nowadays-are templates on which the timely discussion of organisation of care of those affected by congenital heart diseases from the fetus to the elderly can be based. Here, we focus on new developments in the understanding of the causes, diagnosis, early treatment, and late outcomes of tetralogy of Fallot, emphasising the continuum of multidisciplinary care that is necessary for best possible lifelong treatment of the 1% of the population born with congenital heart diseases.

Assessment of left ventricular dyssynchrony and function using real-time 3-dimensional echocardiography in patients with congenital right heart disease

BACKGROUND

Patients after repair of congenital right heart disease (CRHD) may exhibit left ventricular (LV) dyssynchrony (LVD). However, the diagnosis of LVD is difficult and its reliability limited because current methods do not assess LVD of the whole LV simultaneously. The aim of the study was to assess LVD according to a novel global systolic dyssynchrony index (SDI) derived from real-time 3-dimensional echocardiography in patients after repaired CRHD.

METHODS

Two-dimensional echocardiography and real-time 3-dimensional echocardiography were performed in 30 patients after CRHD repair and in 30 matched healthy controls. Real-time 3-dimensional echocardiography data sets provided time-volume curves, and 2 global SDIs were derived from the dispersion of time to reach minimal systolic volume according to a 16- or 17-LV segment model.

RESULTS

Both SDIs were significantly elevated in the patient as compared with the control group (P < .001). A cutoff value for both SDIs was calculated and LVD defined as one of the SDIs exceeding cutoff. Left ventricular dyssynchrony was present in 5 (100%) of 5 patients with a LV ejection fraction (EF) <50% and 13 (52%) of 25 patients with preserved LVEF, thus being diagnosed in a total of 18 (60%) of 30 patients. Moreover, patients with LVD showed a significantly higher degree of pulmonary regurgitation (P = .01) with elevated right ventricular volumes and altered septal motion. Stepwise multivariate analysis identified LVEF (P = .005) and the degree of pulmonary regurgitation (P = .02) as independent predictors of LVD.

CONCLUSIONS

Left ventricular dyssynchrony can be detected in about 60% of patients after CRHD repair and is mainly due to significant pulmonary regurgitation resulting in an altered septal motion and systolic LV function.

Tetralogy of Fallot repair: the Right Ventricle Infundibulum Sparing (RVIS) strategy

Despite the excellent operative survival for tetralogy of Fallot (TOF) repair, well-documented long-term complications and reduced life expectancy remain challenges for these patients and their clinicians. In an attempt to change the natural history of repaired TOF, we at Texas Children's Hospital (Houston, TX) have developed a management strategy not focused on age, but rather focused on preserving the right ventricular (RV) infundibulum. The RV infundibulum sparing (RVIS) repair of TOF consists of a transatrial and transpulmonary approach to close the ventricular septal defect and resect RV infundibular muscle coupled with a mini (< 5 mm) transannular patch or no ventricular incision. This strategy is applied with the ambition of decreasing the well-documented, long-term complications of TOF repair with large right ventriculotomies such as RV dilation, arrhythmias, need for pulmonary valve replacement, and RV failure. The RVIS strategy is an attempt based on our current knowledge and experience to optimize the time of repair so that we can not only maximize the early operative results but the long-term effects of this approach as these children mature into adolescents and adults. We have uniformly applied the RVIS strategy since 1995, which includes over 320 isolated TOF patients. We are currently reviewing this cohort in hopes that it will strengthen our beliefs and known results as well as give us more insight into whether the RVIS strategy can change the natural history of repaired TOF.

The current strategy of repair of tetralogy of Fallot in children and adults

OBJECTIVES

The strategies of repair of tetralogy of Fallot change with the age of patients. In children older than 4 years and adults, the optimal strategy may be to use different method of reconstruction of the right ventricular outflow tract from those followed in younger children, so as to avoid, or reduce, the pulmonary insufficiency that is increasingly known to compromise right ventricular function.

METHODS

From April, 2001, through May, 2008, we undertook complete repair in 312 patients, 180 male and 132 female, with a mean age of 11.3 years +/-0.4 years, and a range from 4 to 48 years, with typical clinical and morphological features of tetralogy of Fallot, including 42 patients with the ventriculo-arterial connection of double outlet right ventricle. The operation was performed under moderate hypothermia using blood cardioplegia. The ventricular septal defect was closed with a Dacron patch. When it was considered necessary to resect the musculature within the right ventricular outflow tract, or perform pulmonary valvotomy, we sought to preserve the function of the pulmonary valve by protecting as far as possible the native leaflets, or creating a folded monocusp of autologous pericardium.

RESULTS

The repair was achieved completely through right atrium in 192, through the right ventricular outflow tract in 83, and through the right atrium, the outflow tract, and the pulmonary trunk in 36 patients. A transjunctional patch was inserted in 169 patients, non-valved in all but 9. There were no differences regarding the periods of aortic cross-clamping or cardiopulmonary bypass. Of the patients, 5 died (1.6%), with no influence noted for the transjunctional patch. Of those having a non-valved patch inserted, three-tenths had pulmonary regurgitation of various degree, while those having a valved patch had minimal pulmonary insufficiency and good right ventricular function postoperatively, this being maintained after follow-up of 8 to 24-months.

CONCLUSIONS

Based on our experience, we suggest that the current strategy of repair of tetralogy of Fallot in older children and adults should be based on minimizing the insertion of transjunctional patches, this being indicated only in those with very small ventriculo-pulmonary junctions. If such a patch is necessary, then steps should be taken to preserve the function of the pulmonary valve.

Right ventricular restrictive physiology in repaired tetralogy of Fallot is associated with smaller respiratory variability

BACKGROUND

Long-term outcomes of patients with repaired tetralogy of Fallot (TOF) are known to be related with right ventricular (RV) volume overload, severity of pulmonary insufficiency (PI) and the type of outflow repair. Right ventricular restrictive physiology (RVRP) has also been reported to interfere with several factors influencing the late result in repaired TOF patients. However, the mechanism and physiology of this unique myocardial property in the chronically overloaded right ventricle are not yet clearly understood.

METHODS

We investigated 43 patients after repair of TOF to assess the relationships among biventricular diastolic function, volume characteristics, and influence of respiratory effort. The patients were classified into 3 groups; 15 patients with RVRP and significant PI (RP group, 35%), 19 without RVRP in the presence of significant PI (NR+PI group, 44%), and 9 without RP or significant PI (NR-PI group, 21%). Doppler spectrals obtained by echocardiography from systemic and pulmonary veins, main pulmonary artery (MPA), and both ventricular inlets, and biventricular diastolic function were compared according to the respiratory cycle.

RESULTS

The RP group revealed higher pulmonary venous systolic/diastolic flow ratio (S/D ratio) and the NR+PI group showed larger velocity-time integral (VTI) ratio of total regurgitant/antegrade flow at the MPA and more respiratory variability in the systemic vein.

CONCLUSION

RP is associated with less volume overload of the RV and smaller respiratory variability is also associated with the restrictive RV. The diastolic function and volume status of the RV may influence the diastolic properties of the left heart.