Pulmonary regurgitation is an important determinant of right ventricular contractile dysfunction in patients with surgically repaired tetralogy of Fallot

Noninvasive Imaging in Adult Congenital Heart Disease

Multimodality cardiovascular imaging plays a central role in caring for patients with congenital heart disease (CHD). CHD clinicians and scientists are interested not only in cardiac morphology but also in the maladaptive ventricular responses and extracellular changes predisposing to adverse outcomes in this population. Expertise in the applications, strengths, and pitfalls of these cardiovascular imaging techniques as they relate to CHD is essential. The purpose of this article is to provide an overview of cardiovascular imaging in CHD. We focus on the role of 3 widely used noninvasive imaging techniques in CHD—echocardiography, cardiac magnetic resonance imaging, and cardiac computed tomography. Consideration is given to the common goals of cardiac imaging in CHD, including assessment of structural and residual heart disease before and after surgery, quantification of ventricular volume and function, stress imaging, shunt quantification, and tissue characterization. Extracardiac imaging is highlighted as an increasingly important aspect of CHD care.

Following up adult patients with tetralogy of fallot: The role of echocardiography

Tetralogy of Fallot (TOF) is one of the most common cyanotic congenital heart diseases. With surgical repair and the advances in postoperative care, contemporary mortality has dramatically improved and an increasing number of patients survive into adulthood, leading to a growing number of adult TOF. However, residual anatomic and hemodynamic abnormalities are encountered in nearly all patients, making follow-up mandatory. Furthermore, mortality starts to increase 25 years after surgery, emphasizing that, in adult TOF, closer monitoring is necessary. We review here the role of echocardiography in the follow-up of the TOF patients, emphasizing the role of multiple echocardiographic techniques. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:79-95, 2017.

Left and right ventricular dyssynchrony and strains from cardiovascular magnetic resonance feature tracking do not predict deterioration of ventricular function in patients with repaired tetralogy of Fallot

BACKGROUND

Patients with repaired tetralogy of Fallot (rTOF) suffer from progressive ventricular dysfunction decades after their surgical repair. We hypothesized that measures of ventricular strain and dyssynchrony would predict deterioration of ventricular function in patients with rTOF.

METHODS

A database search identified all patients at a single institution with rTOF who underwent cardiovascular magnetic resonance (CMR) at least twice, >6 months apart, without intervening surgical or catheter procedures. Seven primary predictors were derived from the first CMR using a custom feature tracking algorithm: left (LV), right (RV) and inter-ventricular dyssynchrony, LV and RV peak global circumferential strains, and LV and RV peak global longitudinal strains. Three outcomes were defined, whose changes were assessed over time: RV end-diastolic volume, and RV and LV ejection fraction. Multivariate linear mixed models were fit to investigate relationships of outcomes to predictors and ten potential baseline confounders.

RESULTS

One hundred fifty-three patients with rTOF (23 ± 14 years, 50 % male) were included. The mean follow-up duration between the first and last CMR was 2.9 ± 1.3 years. After adjustment for confounders, none of the 7 primary predictors were significantly associated with change over time in the 3 outcome variables. Only 1-17 % of the variability in the change over time in the outcome variables was explained by the baseline predictors and potential confounders.

CONCLUSIONS

In patients with repaired tetralogy of Fallot, ventricular dyssynchrony and global strain derived from cine CMR were not significantly related to changes in ventricular size and function over time. The ability to predict deterioration in ventricular function in patients with rTOF using current methods is limited.

Fresh Autologous Pericardium to Reconstruct the Pulmonary Valve at the Annulus When Tetralogy of Fallot Requires a Transannular Patch at Midterm

Tetralogy of Fallot often requires reconstruction of the right ventricular outflow tract with a transannular patch (TAP), but this renders the pulmonary valve incompetent and eventually leads to right ventricular dysfunction. We retrospectively evaluated the efficacy of a reconstructed pulmonary valve and annulus in 70 patients who underwent, from December 2006 through December 2010, complete correction of tetralogy of Fallot. We divided the 70 patients into 2 groups in accordance with whether they required (n=50) or did not require (n=20) a TAP. We used autologous untreated pericardium to fashion the TAP and to create both an annulus of the correct size and a competent pulmonary valve with native leaflets. We evaluated the efficiency of this procedure both functionally and anatomically. The median age of the patients was 11 years (range, 2-38 yr). There were 56 males, with no significant difference in sexual distribution between groups. The clinical follow-up was 88% for 57.5 months, and the echocardiographic follow-up was 80% for 36 months. There was no significant difference in outflow gradient or in the occurrence of pulmonary insufficiency between the TAP group (none, 31; mild, 12; moderate, 6; and severe, 1) and the No-TAP group (none, 16; moderate, 2; and severe, 2) (P=0.59). Nor was there any thickening or calcification in the constructed valves. We conclude that pulmonary valves constructed of untreated autologous pericardium performed as well as native valves after total tetralogy of Fallot correction at midterm.

How best to assess right ventricular function by echocardiography

Right ventricular function is a crucial determinant of long-term outcomes of children with heart disease. Quantification of right ventricular systolic and diastolic performance by echocardiography is of paramount importance, given the prevalence of children with heart disease, particularly those with involvement of the right heart, such as single or systemic right ventricles, tetralogy of Fallot, and pulmonary arterial hypertension. Identification of poor right ventricular performance can provide an opportunity to intervene. In this review, we will go through the different systolic and diastolic indices, as well as their application in practice. Quantification of right ventricular function is possible and should be routinely performed using a combination of different measures, taking into account each disease state. Quantification is extremely useful for individual patient follow-up. Laboratories should continue to strive to optimise reproducibility through quality improvement and quality assurance efforts in addition to investing in technology and training for new, promising techniques, such as three-dimensional echocardiography.

Percutaneous pulmonary and tricuspid valve implantations: An update

The field of percutaneous valvular interventions is one of the most exciting and rapidly developing within interventional cardiology. Percutaneous procedures focusing on aortic and mitral valve replacement or interventional treatment as well as techniques of percutaneous pulmonary valve implantation have already reached worldwide clinical acceptance and routine interventional procedure status. Although techniques of percutaneous pulmonary valve implantation have been described just a decade ago, two stent-mounted complementary devices were successfully introduced and more than 3000 of these procedures have been performed worldwide. In contrast, percutaneous treatment of tricuspid valve dysfunction is still evolving on a much earlier level and has so far not reached routine interventional procedure status. Taking into account that an “interdisciplinary challenging”, heterogeneous population of patients previously treated by corrective, semi-corrective or palliative surgical procedures is growing inexorably, there is a rapidly increasing need of treatment options besides redo-surgery. Therefore, the review intends to reflect on clinical expansion of percutaneous pulmonary and tricuspid valve procedures, to update on current devices, to discuss indications and patient selection criteria, to report on clinical results and finally to consider future directions.

Resting heart rate influences right ventricular volume in repaired tetralogy of Fallot

The aim of this study is to examine the impact of heart rate (HR) on right ventricular end-diastolic volume indexed to body surface area (RVEDVi) in patients with repaired tetralogy of Fallot (TOF). In this cross-sectional study, an institutional database search identified all patients with repaired TOF who underwent cardiac magnetic resonance (CMR) and had a Holter study within 3 months. The association of HR on Holter, HR at the time of CMR, and other clinical and CMR parameters on RVEDVi was explored with univariate and then multivariable models. In the study group (n = 161, median age 23 years), a lower mean Holter HR was associated with a larger RVEDVi (p = 0.004). In a model that also included pulmonary regurgitation fraction, tricuspid regurgitation grade, RV ejection fraction, age at CMR, and gender, mean Holter HR remained associated with RVEDVi (p < 0.0001); for a decrease of 1 bpm, mean RVEDVi increased by 1.09 ml/m(2). When limiting to those with a Holter within 5 days of CMR (n = 70), the impact of mean Holter HR on RVEDVi was stronger (-1.9 ml/m(2)/bpm). HR at time of CMR had a significant but less pronounced relationship to RVEDVi (-0.58 ml/m(2)/bpm, p = 0.002). In conclusion, in repaired TOF patients, a lower HR was significantly associated with a larger RVEDVi. This relationship was stronger with a shorter time interval between the Holter and CMR, and stronger for the mean HR on Holter than for the HR at CMR. Accounting for HR in the interpretation of RVEDVi may impact decisions regarding pulmonary valve replacement and the interpretation of serial CMR data.

Echocardiographic assessment after surgical repair of tetralogy of fallot

Surgical correction of tetralogy of Fallot is still one of the most frequently performed intervention in pediatric cardiac surgery, and in many cases, it is far from being a complete and definitive correction. It is rather an excellent palliation that solves the problem of cyanosis, but predisposes the patients to medical and surgical complications during follow-up. The decision-making process regarding the treatment of late sequel is among the most discussed topics in adult congenital cardiology. In post-operative Fallot patients, echocardiography is used as the first method of diagnostic imaging and currently allows both a qualitative observation of the anatomical alterations and a detailed quantification of right ventricular volumes and function, of the right ventricular outflow tract, and of the pulmonary valve and pulmonary arteries. The literature introduced many quantitative echocardiographic criteria useful for the understanding of the pathophysiological mechanisms involving the right ventricle and those have made much more objective any decision-making processes.

Polytetrafluoroethylene pulmonary valve conduit implantation for chronic pulmonary insufficiency

Pulmonary valve replacement in patients with congenital cardiac disease is now being performed with more liberal indications in light of the data that chronic pulmonary insufficiency is not a benign lesion. The beneficial effects of valve replacement with low operative mortality and morbidity support this approach. Many options exist for a pulmonary valve prosthesis, which underscores the fact that there is no ideal valve available. Our efforts are focussed around a synthetic valve that avoids the bio-degeneration of a bio-prosthesis and avoids the need for life-long coumadin. We developed a bicuspid (bileaflet) polytetrafluoroethylene valve design, which has now gone through three major revisions in >200 patients over 14 years. We began the experience utilising a polytetrafluoroethylene hand-sewn bicuspid valve in the right ventricular outflow tract, initially using 0.6 mm and more recently 0.1 mm polytetrafluoroethylene. The 0.1 mm thickness material functions well as a leaflet, maintaining a relatively thin and flexible nature. It does not calcify or initiate thromboses at least for the first several years. We identified issues with dehiscence of the leaflet from the right ventricular outflow tract muscle, especially in the larger, potentially expansive right ventricular outflow tracts, and this prompted our latest design change to place the valve within a polytetrafluoroethylene tube. This current version of the polytetrafluoroethylene valve conduit has excellent short-to-intermediate-term function. Further follow-up is necessary to determine late durability and life-long valve-related procedural risk for our patients.

Assessment of pulmonary artery pressure and right ventricular function in children with adenotonsillar hypertrophy using different parameters

OBJECTIVE

Our aim was comparison of preoperative and postoperative right ventricular functions of children with adenotonsillar hypertrophy (ATH) who have findings of upper airway obstruction, using new echocardiographic parameters.

METHODS

Forty-one children who have admitted to our hospital with symptoms suggestive of upper airway obstruction, whose history and physical examination findings suggest upper airway obstruction and who have undergone adenoidectomy/adenotonsillectomy and 40 healthy children, all of whom between 2 and 12 years of age, were included in the study. Patient group was evaluated by pulsed wave tissue Doppler echocardiography as well as with conventional echocardiography before the operation and 6 months after the operation.

RESULTS

Of 41 children in study group, 26 (63.4%) had adenotonsillectomy and 15 (36.6%) had adenoidectomy. Tricuspid annular plane systolic excursion (TAPSE) was significantly lower in preoperative group compared to control group (18.46±1.67, 19.77±1.62; p=0.000, respectively). Myocardial performance index (MPI) was significantly higher in preoperative group than postoperative and control group (0.40±0.07, 0.36±0.06, 0.35±0.07; p=0.032, respectively). Tricuspid isovolumic acceleration (TIVA) was significantly lower in preoperative group than preoperative and control group (2.97±0.8, 3.43±0.7, 3.43±0.9; p=0.020, respectively). Disappearance of this difference was found between postoperative and control groups (p=0.984). Pulmonary acceleration time (PAcT) was found to be significantly lower in preoperative group compared to postoperative and control group (109.68±18.03, 118.93±17.46, 120.0±14.07; p=0.010, respectively). Mean pulmonary artery pressure (mPAP) was significantly higher in preoperative group than control group (29.64±8.11, 24.95±6.33; p=0.010, respectively). In postoperative group mPAP was found to be similar to control group (25.48±7.85, 24.95±6.33; p=0.740, respectively).

CONCLUSIONS

TAPSE, PAcT, MPI and TIVA are useful markers for evaluation of preoperative and postoperative ventricular function in children with ATH who have findings of upper airway obstruction. We think that using these practical and easy-to perform parameters may be relevant for evaluation and postoperative follow-up of patients with ATH who have findings of upper airway obstruction. Besides adenotonsillectomy is a beneficial treatment option for these patients.

Usefulness of magnetic resonance imaging to guide referral for pulmonary valve replacement in repaired tetralogy of Fallot

The aim of this study was to determine if adult patients with repaired tetralogy of Fallot are being referred for pulmonary valve replacement (PVR) earlier on the basis of cardiac magnetic resonance imaging (CMR) parameters despite the absence of CMR-based recommendations in the American College of Cardiology and American Heart Association joint guidelines. Variables defined by the guidelines were analyzed in conjunction with CMR-based parameters across 3 groups defined by the release of the guidelines: (1) patients referred before the guidelines, (2) patients referred 0 to 3 years after the guidelines, and (3) patients referred ≥3 years after the guidelines. Seventy-nine patients were identified. No significant trend was observed in guideline-defined variables. Significant trends in indexed right ventricular end-diastolic volume (p = 0.034), indexed right ventricular end-systolic volume (p = 0.001), and the right ventricular ejection fraction (p = 0.005) were observed across groups. By multivariate regression, patients who underwent PVR ≥3 years after the release of the guidelines had a 29 ml/m(2) smaller indexed right ventricular end-diastolic volume (p = 0.01) and a 33 ml/m(2) smaller indexed right ventricular end-systolic volume (p <0.001) compared with patients who underwent PVR before the release of the guidelines. PVR 0 to 3 years after the guidelines was not a significant predictor of either indexed right ventricular end-diastolic volume (p = 0.93) or indexed right ventricular end-systolic volume (p = 0.18). Patients referred for PVR ≥3 years after the guidelines had significantly smaller CMR-based right ventricular volumes without significant trends in guideline-defined variables. Given the increased use of CMR to guide PVR referral, revisiting the guidelines to address appropriate use of CMR derived thresholds is indicated.

Right ventricular function assessment using tissue Doppler imaging and speckle tracking echocardiography

Modern echocardiographic techniques, i.e. tissue Doppler imaging and speckle tracking echocardiography, allow for an assessment of global and regional right ventricular function. The right ventricular myocardial performance index and tricuspid annulus motion are used in the assessment of global right ventricular function, whereas duration of the cardiac cycle phases and myocardial velocities are used in the assessment of regional function. Strain and strain rate allow for an evaluation of both regional and global myocardial function. Literature reports provide data on the usefulness of these methods in patients with pressure and volume overload as well as with direct myocardial damage involving the right ventricle. In pulmonary hypertension, S' wave assessment may be used for therapeutic efficacy evaluation. Longitudinal strain reduction indicates an increased risk of vascular events, while an increased value of myocardial performance index is a predictor for a survival in pulmonary hypertension. A decreased S' wave velocity is associated with limited pulmonary vascular flow in patients with pulmonary embolism. In patients after atrial baffle repair for transposition of the great arteries, decreased longitudinal strain was an independent predictor for heart failure. A statistically significant decrease in both the S' wave as well as acceleration during isovolumic contraction were observed in arrhythmogenic right ventricular cardiomyopathy. S' wave and global right ventricular longitudinal strain values were lower in patients in the acute phase of myocardial infarction involving the right ventricle compared to the corresponding parameters in healthy individuals. In the case of tetralogy of Fallot correction, the evaluation of S' wave velocity may prove useful in identifying patients with reduced cardiac systolic reserve; a good correlation was also found between the global right ventricular longitudinal strain and right ventricular ejection fraction in MRI.

Will catheter interventions replace surgery for valve abnormalities?

PURPOSE OF REVIEW

Catheter-based valve technologies have evolved rapidly over the last decade. Transcatheter aortic valve replacement (TAVR) has become a routine procedure in high-risk adult patients with calcific aortic stenosis. In patients with congenital heart disease (CHD), transcatheter pulmonary valve replacement represents a transformative technology for right ventricular outflow tract dysfunction with the potential to expand to other indications. This review aims to summarize the current state-of-the-art for transcatheter valve replacement (TVR) in CHD; the expanding indications for TVR; and the technological obstacles to optimizing TVR.

RECENT FINDINGS

Multiple case series have demonstrated that TVR with the Melody transcatheter pulmonary valve in properly selected patients is safe, effective, and durable in short-term follow-up. The Sapien transcatheter heart valve represents an alternative device with similar safety and efficacy in limited studies. Innovative use of current valves has demonstrated the flexibility of TVR, while highlighting the need for devices to address the broad range of postoperative anatomies either with a single device or with strategies to prepare the outflow tract for subsequent device deployment.

SUMMARY

The potential of TVR has not been fully realized, but holds promise in treatment of CHD.

Functional assessment for congenital heart disease

Significant improvement in survival of children with congenital cardiac malformations has resulted in an increasing population of adolescent and adult patients with congenital heart disease. Of the long-term cardiac problems, ventricular dysfunction remains an important issue of concern. Despite corrective or palliative repair of congenital heart lesions, the right ventricle, which may be the subpulmonary or systemic ventricular chamber, and the functional single ventricle are particularly vulnerable to functional impairment. Regular assessment of cardiac function constitutes an important aspect in the long-term follow up of patients with congenital heart disease. Echocardiography remains the most useful imaging modality for longitudinal monitoring of cardiac function. Conventional echocardiographic assessment has focused primarily on quantification of changes in ventricular size and blood flow velocities during the cardiac cycles. Advances in echocardiographic technologies including tissue Doppler imaging and speckle tracking echocardiography have enabled direct interrogation of myocardial deformation. In this review, the issues of ventricular dysfunction in congenital heart disease, conventional echocardiographic and novel myocardial deformation imaging techniques, and clinical applications of these techniques in the functional assessment of congenital heart disease are discussed.

Evaluation of right ventricular function in patients with tetralogy of Fallot using the myocardial performance index and isovolumic acceleration: a comparison with cardiac magnetic resonance imaging

BACKGROUND

Assessment of right ventricular function is a key point in the follow-up of operated patients with tetralogy of Fallot. Cardiac magnetic resonance assessment of right ventricular function is considered the gold standard. However, this technique is expensive, has limited availability, and requires significant expertise to acquire and interpret the images. Myocardial performance index and isovolumic acceleration have recently been studied for the assessment of right ventricular function and are shown to be simple yet powerful tools for assessing patients with right ventricular dysfunction of various origins.

METHODS

In this study, the integrity of myocardial performance index and isovolumic acceleration obtained by tissue Doppler imaging echocardiography to quantify right ventricular function was assessed in 31 patients operated for tetralogy of Fallot. Myocardial performance index and isovolumic acceleration measurements were compared with the parameters derived by cardiac magnetic resonance imaging.

RESULTS

In this study, a significant correlation has not been detected between cardiac magnetic resonance-originated right ventricular ejection fraction, pulmonary regurgitation fraction and myocardial performance index, isovolumic acceleration obtained by tissue Doppler imaging echocardiography from the lateral tricuspid annulus of the right ventricle.

CONCLUSION

We have concluded that when evaluated separately, myocardial performance index and isovolumic acceleration obtained from tissue Doppler imaging echocardiography can be used in the long-term follow-up of patients who have been operated for tetralogy of Fallot, but that they do not show correlation with cardiac magnetic resonance-originated right ventricle ejection fraction and pulmonary regurgitation fraction.

Impaired right and left ventricular function in asymptomatic children with repaired tetralogy of Fallot by two-dimensional speckle tracking echocardiography study

BACKGROUND

Early detection of right ventricular (RV) and left ventricular (LV) dysfunction in patients with repaired tetralogy of Fallot (TOF) is essential because dysfunction is correlated with a poor clinical outcome. The aim of this study was to assess RV and LV function in asymptomatic children with repaired TOF by two-dimensional ultrasound speckle tracking echocardiography (STE).

METHODS

Fifty-six asymptomatic children with a preserved biventricular ejection fraction (EF) after repair of TOF and 35 healthy control subjects were studied. RV and LV strain and strain rate were measured by STE. RVEF and pulmonary regurgitation (PR) were assessed using cardiac magnetic resonance imaging.

RESULTS

Compared with the control subjects, RV regional longitudinal strain and strain rate and global longitudinal strain (GLS) and strain rate (GLSR) were impaired in children with repaired TOF. Likewise, LV circumferential and radial strain and strain rate were reduced in patients with TOF. In contrast, longitudinal strain and strain rate did not differ between the groups. RV and LV GLSR were correlated with postoperative follow-up period (r1 = -0.44; r2 = -0.48). RV GLS and GLSR were associated with RVEF (r1 = 0.64; r2 = 0.60) and PR (r1 = -0.48; r2 = -0.49). LV circumferential strain rate was related to PR (r = -0.45).

CONCLUSIONS

STE can identify abnormalities that may represent early impairment of RV and LV systolic function in postoperative TOF patients with a preserved EF. PR is associated with decreased biventricular performance in repaired patients. STE-derived strain and strain rate may be useful indices for detecting the early deterioration of biventricular performance in patients with TOF.

Computer modeling to tailor therapy for congenital heart disease

The inherent structural and physiological complexity of congenital heart disease lends itself strongly to simulation. Complex hemodynamic and structural problems unique to congenital heart disease may be difficult to understand and the response to therapy or intervention uncertain. Methodologies borrowed from engineering, computing and mathematical sciences can be applied to such problems and used to inform clinical decisions. Therapy thus informed by modeling experiments has the potential to contribute significantly to improved clinical outcomes. This field remains in its infancy, and will only become used routinely if validation of current methods is carried out in the clinical setting.

CMR assessment of right ventricular function in patients with combined pulmonary stenosis and insufficiency after correction of tetralogy of Fallot

BACKGROUND

Tetralogy of Fallot (TOF) is one of the most common types of congenital heart disease and requires prompt surgical correction. Post-correction pulmonary insufficiency (PI) often ensues in adulthood. At times, the PI is accompanied by residual pulmonary stenosis (PS). Little is known regarding right ventricular (RV) function in the setting of combined PS and PI.

PURPOSE

To compare cardiac magnetic resonance (CMR) parameters for the assessment of RV function between patients with combined pulmonary stenosis and pulmonary insufficiency (PSPI) and isolated PI following surgical repair of TOF.

MATERIAL AND METHODS

Retrospective review of patients with comparable corrected TOF and similar PI was performed. Seventeen patients (median age, 24 years; range, 10-52 years) had combined PSPI and 30 patients (median age, 30 years; range, 6-70 years) had isolated PI. Cine magnetic resonance (MR) images (Philips Medical Systems, Best, The Netherlands) in the short-axis plane were used to calculate end-systolic, end-diastolic, and stroke volumes (RVESV, RVEDV, RVSV) and to measure RV wall thickness. Velocity-encoded cine MR images were used to measure pulmonary regurgitation fraction (PRF) by calculating the ratio of backward flow and total forward flow, obtained from the main pulmonary flow analysis. Peak pressure gradient across the pulmonary valve was obtained from spectral Doppler echocardiography.

RESULTS

RVEF was 51 ± 8% in the PSPI patients and 39 ± 11%, in the patients with isolated PI (P = 0.001). Additionally, RV wall thickness was 5.2 ± 0.8 mm in the PSPI patients compared to 2.6 ± 0.9 mm in the isolated PI patients (P = 0.001). RVESVi and RVEDVi were significantly lower (P < 0.05) in patients with combined PSPI (60 ± 21 mL/m(2), 121 ± 35 mL/m(2), respectively) compared to the patients with isolated PI (95 ± 48 mL/m(2), 152 ± 61 mL/m(2), respectively).

CONCLUSION

RV function is preserved in patients with PSPI when compared to patients with PI following surgical repair of TOF.

Management of adults with Tetralogy of Fallot

Tetralogy of Fallot is the most common form of cyanotic congenital cardiac disease. Patients with previously repaired tetralogy of Fallot are the most common patients seen in the Program for Adults with Congenital Heart Disease at The Johns Hopkins All Children's Heart Institute. Guidelines for the management of these patients are available from multiple sources including The American College of Cardiology (ACC) and The American Heart Association (AHA), The Canadian Cardiovascular Society, and The European Society of Cardiology (ESC). These guidelines describe multiple components related to the care for these patients including strategies for medical follow-up, the management of arrhythmias and electrophysiological diseases, and the treatment of chronic pulmonary insufficiency and stenosis. Several new strategies are available for replacement of the pulmonary valve including transcatheter replacement of the pulmonary valve and replacement of the pulmonary valve with a self-manufactured bicuspid polytetrafluoroethylene pulmonary valve.

Echocardiographic guidance for diagnostic and therapeutic percutaneous procedures

Echocardiographic guidance has an important role in percutaneous cardiovascular procedures and vascular access. The advantages include real time imaging, portability, and availability, which make it an effective imaging modality. This article will review the role of echocardiographic guidance for diagnostic and therapeutic percutaneous procedures, specifically, transvenous and transarterial access, pericardiocentesis, endomyocardial biopsy, transcatheter pulmonary valve replacement, pulmonary valve repair, transcatheter aortic valve implantation, and percutaneous mitral valve repair. We will address the ways in which echocardiographic guidance provides these procedures with detailed information on anatomy, adjacent structures, and intraprocedural instrument position, thus resulting in improvement in procedural efficacy, safety and patient outcomes.

Right ventricular wall-motion changes after infant open heart surgery--a tissue Doppler study

BACKGROUND

Right ventricular (RV) dysfunction is a well-recognized complication of cardiopulmonary bypass surgery (CPB) in adults. Infants and neonates may also be at high risk for this due to immature myocardium. Conventional assessment of RV function is just qualitative, but novel tissue Doppler echocardiographic (TDI) markers including peak systolic strain rate (SR) and isovolumic contraction acceleration (IVA) permit noninvasive quantitation of RV function. This study assessed myocardial velocities, IVA and SR in infants and neonates undergoing open heart surgery using TDI to study regional myocardial function perioperatively.

METHODS

Transthoracic TDI data were obtained in the OR before and 24 hours post-CPB on 53 consecutive infants (age 0.39 ± 0.23 years). They were followed with TDI through hospital discharge.

RESULTS

Mean CPB time was 87 ± 49 min (cross-clamp 52 ± 26 min). Peak systolic (STDI ) and diastolic myocardial velocities (ETDI , ATDI ), IVA, and peak SR were recorded in RV and LV from standard views for offline analysis. Postoperatively, LV systolic function and diastolic longitudinal function were unchanged or improved from baseline. LV radial velocities were increased postoperatively indicating adequate support. In contrast, RV longitudinal systolic and diastolic function was significantly diminished after CPB. RV changes persisted through hospital discharge.

CONCLUSIONS

In infants and neonates, perioperative measurements of systolic and diastolic tissue Doppler parameters are feasible and revealed significant RV systolic and diastolic dysfunction post-CPB with preserved LV function. As such, TDI provides a sensitive tool to monitor the infant heart after CPB and may potentially be useful to assess different myocardial protection strategies.

Pulmonary arterial wall stiffness and its impact on right ventricular afterload in patients with repaired tetralogy of Fallot

BACKGROUND

Recent histologic studies involving patients with tetralogy of Fallot (TOF) have revealed a reduction in normal elastic fibers in the pulmonary trunk. Such histologic changes may significantly alter the mechanical properties of the arterial wall and may thereby augment the pulsatile afterload on the right ventricle (RV) and propagate RV dilation and dysfunction.

METHODS

We studied 29 patients with repaired TOF (median age, 5.9 years) and 29 age-matched controls. Pulmonary arterial hemodynamics were investigated by measuring the pulmonary input impedance during cardiac catheterization.

RESULTS

Patients with TOF had higher characteristic impedance (p = 0.0002), lower total pulmonary vascular compliance (p < 0.0001), and enhanced wave reflection (p < 0.0001). Consistent with these changes, patients with TOF were subject to higher pulsatile load, measured by fundamental frequency impedance (p < 0.0001), which was significantly related to both reduced RV output and increased RV end-diastolic volume (p = 0.006 and 0.003, respectively). Moreover, pulmonary arterial compliance was strongly related to RV end-diastolic volume (r = -0.69, p = 0.0001). In multivariate analysis, pulmonary arterial compliance was a significant predictor of RV dilation independent of pulmonary regurgitation and pulmonary stenosis (p = 0.03).

CONCLUSIONS

In line with known histologic changes, pulmonary arterial stiffness is increased and is significantly related to reduced RV ejection and RV enlargement in patients with repaired TOF. These results suggest that not only pulmonary valvular function (pulmonary regurgitation/pulmonary stenosis) but also pulmonary vascular pulsatile properties can be an important therapeutic target to improve prognosis in this population.

New technologies for surgery of the congenital cardiac defect

The surgical repair of complex congenital heart defects frequently requires additional tissue in various forms, such as patches, conduits, and valves. These devices often require replacement over a patient's lifetime because of degeneration, calcification, or lack of growth. The main new technologies in congenital cardiac surgery aim at, on the one hand, avoiding such reoperations and, on the other hand, improving long-term outcomes of devices used to repair or replace diseased structural malformations. These technologies are: 1) new patches: CorMatrix® patches made of decellularized porcine small intestinal submucosa extracellular matrix; 2) new devices: the Melody® valve (for percutaneous pulmonary valve implantation) and tissue-engineered valved conduits (either decellularized scaffolds or polymeric scaffolds); and 3) new emerging fields, such as antenatal corrective cardiac surgery or robotically assisted congenital cardiac surgical procedures. These new technologies for structural malformation surgery are still in their infancy but certainly present great promise for the future. But the translation of these emerging technologies to routine health care and public health policy will also largely depend on economic considerations, value judgments, and political factors.

Right ventricle to pulmonary artery conduit reoperations in patients with tetralogy of fallot or pulmonary atresia associated with ventricular septal defect

The short lifespan of right ventricle-to-pulmonary artery (RV-PA) conduits used in repairs of complex congenital heart defects makes future surgical replacement inevitable. Percutaneous pulmonary valve implantation (PPVI) now offers an attractive alternative to surgery in some patients. The objectives of this study were to examine the pattern of conduit reoperations, the factors affecting conduit longevity, and to discuss the role of PPVI in these patients. Forty-nine patients (mean age 27 ± 8 years) with pulmonary atresia or pulmonary stenosis with tetralogy of Fallot who underwent surgery for RV-PA conduits from September 1974 to October 2011 were reviewed. A total of 106 RV-PA conduits were implanted, 57 of which were replacements. Second, third, and fourth conduits were required during the follow-up period in 39, 16, and 2 patients, respectively. Freedom from reoperation at 10 years for the first, second, and third conduits was 50%, 74%, and 86%, respectively. Significant independent predictors of shorter conduit longevity included smaller conduit and conduit type (homograft and other vs Dacron). Furthermore, a significant proportion (32 of 57 [56%]) of conduit replacements took place from ages 9 to 18 years. There were 37 adults whose current existing conduits had not yet failed, with 73% (27 of 37) potentially suitable in the future for PPVI on the basis of conduit size of 16 to 27 mm. In conclusion, multiple RV-PA conduit revisions were required in patients who survived to adulthood, with many replacements taking place during adolescence. Most conduits in this adult cohort met size criteria for PPVI, thereby offering these patients a potential alternative to surgical intervention for conduit failure.

Tetralogy of Fallot with atrioventricular septal defect: surgical strategies for repair and midterm outcome of pulmonary valve-sparing approach

Repair for tetralogy of Fallot (TOF) with complete atrioventricular septal defect (CAVSD) has been reported with good early and intermediate outcomes. Morbidity, however, remains significantly high. To date, repair of CAVSD/TOF using a pulmonary valve-sparing technique (PVS) and freedom from valve reoperation are not well defined. A study was undertaken to investigate outcomes. This study was conducted in as a retrospective investigation. Between January 1988 and December 2008, 13 consecutive patients with CAVSD/TOF were identified, and their records were reviewed retrospectively. Of these 13 patients, 9 had Rastelli type C CAVSD. Trisomy 21 was present in 9 cases (69 %; 7 with type C). Five patients had received a systemic-to-pulmonary shunt (SPS) before complete repair at a mean age 1.7 ± 0.6 months. All the patients survived until complete repair. At complete CAVSD/TOF repair, AVSD was corrected with a two-patch technique in all patients. For eight patients (61.5 %), PVS was used. The remaining five patients had transannular patch (TAP) repair. The mean age at complete repair was 6.3 ± 2.4 months. At complete repair, the mean cardiopulmonary bypass time was 173.5 ± 30.6 min, and the cross-clamp time was 134.7 ± 28.8 min. There was one hospitalization and no late deaths. The median follow-up period was 9.2 years [interquartile range (IQR), 4.7-13.3 years]. The actuarial survival was 90.0 ± 9.5 % at 1 year, 90 ± 9.5 % at 5 years, and 90 ± 9.5 % at 8 years. Of the 12 survivors, 6 had some reintervention during the follow-up period. Within the first 11 years after complete repair, two patients underwent left atrioventricular (AV) valve repair, and one patient had right AV valve repair. Two patients had residual VSD closure. Four patients underwent the first right ventricular outflow tract (RVOT) reintervention for critical insufficiency or stenosis at a mean interval of 6 ± 21) months. One patient had a second RVOT reoperation. Findings showed that CAVSD/TOF with PVS was related to significantly higher freedom from RVOT reintervention (100 % at 1, 5, and 8 years compared with 80 ± 17.9 % at 1 year, 60 ± 21.9 % at 5 years, and 40 ± 21.9 % at 8 years for CAVSD/TOF using TAP; P < 0.05). No patient who underwent PVS had left ventricular outflow tract obstruction requiring reoperation. Overall freedom from any reintervention was 90.9 ± 8.6 % at 1 year, 71.6 ± 14.0 % at 5 years, and 53.7 ± 8.7 % at 8 years in this group of patients. Correction of TOF with CAVSD can be performed at low risk with favorable intermediate-term survival and satisfactory freedom from reoperation. Use of TAP can be avoided in almost two thirds of patients and may influence freedom from early RVOT reintervention.

Physiologic and molecular characterization of a murine model of right ventricular volume overload

Pulmonary insufficiency (PI) is a common long-term sequel after repair of tetralogy of Fallot, causing progressive right ventricular (RV) dilation and failure. We describe the physiologic and molecular characteristics of the first murine model of RV volume overload. PI was created by entrapping the pulmonary valve leaflets with sutures. Imaging, catheterization, and exercise testing were performed at 1, 3, and 6 mo and compared with sham controls. RNA from the RV free wall was hybridized to Agilent whole genome oligonucleotide microarrays. Volume overload resulted in RV enlargement, decreased RV outflow tract shortening fraction at 1 mo followed by normalization at 3 and 6 mo (39 ± 2, 44 ± 2, and 41 ± 2 vs. 46 ± 3% in sham), early reversal of early and late diastolic filling velocities (E/A ratio) followed by pseudonormalization (0.87 ± 0.08, 0.82 ± 0.08, and 0.96 ± 0.08 vs. 1.04 ± 0.03; P < 0.05), elevated end-diastolic pressure (7.6 ± 0.7, 6.9 ± 0.8, and 7 ± 0.5 vs. 2.7 ± 0.2 mmHg; P < 0.05), and decreased exercise duration (26 ± 0.4, 26 ± 1, and 22 ± 1.3 vs. 30 ± 1.1 min; P < 0.05). Subendocardial RV fibrosis was evident by 1 mo. At 1 mo, 372 genes were significantly downregulated. Mitochondrial pathways and G protein-coupled receptor signaling were the most represented categories. At 3 mo, 434 genes were upregulated and 307 downregulated. While many of the same pathways continued to be downregulated, TNF-α, transforming growth factor-β(1) (TGF-β(1)), p53-signaling, and extracellular matrix (ECM) remodeling transitioned from down- to upregulated. We describe a novel murine model of chronic RV volume overload recapitulating aspects of the clinical disease with gene expression changes suggesting early mitochondrial bioenergetic dysfunction, enhanced TGF-β signaling, ECM remodeling, and apoptosis.

Technical modification enabling pulmonary valve-sparing repair of a severely hypoplastic pulmonary annulus in patients with tetralogy of Fallot

OBJECTIVES

Although pulmonary valve-sparing repair is preferable for patients with tetralogy of Fallot, the repair of very small pulmonary valves is challenging. The present study evaluates our modification for preserving severely hypoplastic pulmonary valves in patients with tetralogy of Fallot.

METHODS

Sixty-eight consecutive patients who underwent complete repair of a tetralogy of Fallot between 2005 and 2011 were retrospectively reviewed. Patients with pulmonary atresia, absence of a pulmonary valve, atrioventricular septal defect and/or subarterial ventricular septal defect were excluded. There were 19 (28%) patients with a severely hypoplastic pulmonary annulus determined by preoperative echocardiography (z-score <-4). For these patients, we collected echocardiographic data and information about their postoperative course.

RESULTS

Valve preserving was successful in 11 of 19 (58%) of the z < -4 group, compared with 48 of 49 (98%) of the z > -4 group. In the z < -4 valve-sparing subgroup (n = 11), the preoperative pulmonary valve diameter z-score was -4.9 (range -6.3 to -4.3), and an approach involving ventriculotomy with no transannular patch was employed at a mean age of 6.9 (range 2.2-16.1) months. In this subgroup, residual right ventricular outflow tract velocity was 2.4 ± 0.6 m/s at discharge from the hospital. During a mean follow-up of 2.6 ± 2.4 years, no reintervention was necessary. Late right ventricular outflow tract velocity was 2.2 ± 0.6 m/s, and there was no severe pulmonary regurgitation. The pulmonary valve annulus grew in relation to the patient's body surface area (z = -0.51, range -4.2-0.24) without any aneurysmal changes in the right ventricular outflow tract.

CONCLUSIONS

Although our modification of valve-sparing repair for severely hypoplastic pulmonary valves in patients with tetralogy of Fallot could not be applied in all patients, this strategy enabled acceptable growth of the valve annulus, with only mild stenosis during the early to mid-term follow-up. This modification seems to be an option, even for a very small pulmonary valve.

Improved cardiac MRI volume measurements in patients with tetralogy of Fallot by independent end-systolic and end-diastolic phase selection

Objectives

To investigate to what extent cardiac MRI derived measurements of right ventricular (RV) volumes using the left ventricular (LV) end-systolic and end-diastolic frame misrepresent RV end-systolic and end-diastolic volumes in patients with tetralogy of Fallot (ToF) and a right bundle branch block.

Methods

Sixty-five cardiac MRI scans of patients with ToF and a right bundle branch block, and 50 cardiac MRI scans of control subjects were analyzed. RV volumes and function using the end-systolic and end-diastolic frame of the RV were compared to using the end-systolic and end-diastolic frame of the LV.

Results

Timing of the RV end-systolic frame was delayed compared to the LV end-systolic frame in 94% of patients with ToF and in 50% of control subjects. RV end-systolic volume using the RV end-systolic instead of LV end-systolic frame was smaller in ToF (median −3.3 ml/m², interquartile range −1.9 to −5.6 ml/m²; p<0.001) and close to unchanged in control subjects. Using the RV instead of LV end-systolic and end-diastolic frame hardly affected RV end-diastolic volumes in both groups and ejection fraction in control subjects (54±4%, both methods), while increasing ejection fraction from 45±7% to 48±7% for patients with ToF (p<0.001). QRS duration correlated positively with the changes in the RV end-systolic volume (p<0.001) and RV ejection fraction obtained in ToF patients when using the RV instead of the LV end-systolic and end-diastolic frame (p = 0.004).

Conclusion

For clinical decision making in ToF patients RV volumes derived from cardiac MRI should be measured in the end-systolic frame of the RV instead of the LV.

Numerical study for blood flow in pulmonary arteries after repair of tetralogy of Fallot

Pulmonary regurgitation (PR) is a common phenomenon in pulmonary arteries in patients after repair of tetralogy of Fallot (TOF). The regurgitation fraction of left pulmonary artery (LPA) is usually greater than right pulmonary artery (RPA) according to clinic data. It may be related to blood flow in pulmonary arteries. Therefore, understanding hemodynamics in pulmonary arteries helps to comprehend the reason. The aim of this study is to use 3D reconstructed pulmonary artery models from magnetic resonance imaging (MRI) and to use numerical approaches for simulation of flow variations in pulmonary arteries after repair of TOF. From the numerical results, the blood flow is influenced by the bifurcation angles and geometry of pulmonary artery. The regurgitation happens first in LPA after repair of TOF due to the small angle between LPA and main pulmonary artery (MPA). The recirculation region which obstructs forward blood flow to the left lung is found in LPA during acceleration of systole. We also analyze the pressure distribution; the extreme pressure variations are in dilation area of MPA. Numerical data including regurgitation in MPA, LPA, and RPA are compared with phase contrast MR measured data. Good agreements are found between numerical results and measured data.

Echocardiography and cardiac magnetic resonance-based feature tracking in the assessment of myocardial mechanics in tetralogy of Fallot: an intermodality comparison

We investigated intermodality agreements of strains from two-dimensional echocardiography (2DE) and cardiac magnetic resonance (CMR) feature tracking (FT) in the assessment of right (RV) and left ventricular (LV) mechanics in tetralogy of Fallot (TOF). Patients were prospectively studied with 2DE and CMR performed contiguously. LV and RV strains were computed separately using 2DE and CMR-FT. Segmental and global longitudinal strains (GLS) for the LV and RV were measured from four-chamber views; LV radial (global radial strain [GRS]) and circumferential strains (GCS) measured from short-axis views. Intermodality and interobserver agreements were examined. In 40 patients (20 TOF, mean age 23 years and 20 adult controls), LV, GCS showed narrowest intermodality limits of agreement (mean percentage error 9.5%), followed by GLS (16.4%). RV GLS had mean intermodality difference of 25.7%. GLS and GCS had acceptable interobserver agreement for the LV and RV with both 2DE and CMR-FT, whereas GRS had high interobserver and intermodality variability. In conclusion, myocardial strains for the RV and LV derived using currently available 2DE and CMR-FT software are subject to considerable intermodality variability. For both modalities, LV GCS, LV GLS, and RV GLS are reproducible enough to warrant further investigation of incremental clinical merit.

The Role of Tricuspid Valve Surgery in the Late Management of Tetralogy of Fallot

While surgical repair of tetralogy of Fallot (TOF) is generally associated with good early outcomes, late complications affect long-term survival and may require reoperation. Pulmonary regurgitation (PR) and tricuspid regurgitation (TR) may increase the risk of arrhythmias, reduced cardiac function, and sudden death. Tricuspid valve function can be compromised secondarily in the setting of PR or directly as a result of injury or alteration of the valve related to the original TOF repair. This article reviews the etiologic mechanisms, pathophysiological implications, and surgical interventions for TR. Effective management following TOF repair requires consideration of TR to optimize late outcomes.

Tetralogy of fallot: a surgical perspective

Tetralogy of Fallot (TOF) is an index lesion for all paediatric and congenital heart surgeons. In designing an appropriate operation for children with TOF, the predicted postoperative physiology must be taken into account, both for the short and long term. A favourable balance between pulmonary stenosis (PS) and pulmonary insufficiency (PI) may be critical for preservation of biventricular function. A unified repair strategy to limit both residual PS and PI is presented, along with supportive experimental evidence. A strategy for dealing with coronary anomalies and some comments regarding best timing of operation are also included.