Right ventricular overload and induced sustained ventricular tachycardia in operatively "repaired" tetralogy of Fallot

A uniform strategy of primary repair of tetralogy of Fallot: Transventricular approach results in low reoperation rate in the first decade

OBJECTIVES

To review outcomes after a uniform strategy of transventricular repair of tetralogy of Fallot.

METHODS

A total of 244 consecutive patients underwent transventricular primary repair of tetralogy of Fallot from 2004 to 2019. Median age at operation was 71 days; 57 (23%) patients were premature; 57 (23%) patients had low birth weight (<2.5 kg), and 40 (16%) had genetic syndromes. The diameter of pulmonary valve annulus, right pulmonary artery (PA), and left PA were 6.0 ± 1.8 mm (z score, -1.7 ± 1.3), 4.3 ± 1.4 mm (z score, -0.9 ± 1.2) and 4.1 ± 1.5 mm (z score, -0.5 ± 1.3).

RESULTS

Three (1.2%) operative deaths were recorded. Ninety patients (37%) underwent transannular patching. Postoperative echocardiographic peak right ventricular outflow tract gradient decreased from 72 ± 27 mm Hg to 21 ± 16 mm Hg. Median intensive care unit and hospital stay were 3 and 7 days. The survival rate at 10 years was 94.6% ± 1.8%. Reintervention was required 86 times (55 catheter interventions) in 56 patients following tetralogy of Fallot repair. The freedom from all-cause reintervention rate at 10 years was 70.5% ± 3.6%. Cyanotic spells (hazard ratio, 2.14; 95% CI, 1.22-3.90; P < .01) and smaller pulmonary valve annulus z score (hazard ratio, 1.26; 95% CI, 1.01-1.59; P = .04) were associated with increasing risk of all reinterventions. Freedom from redo surgery for right ventricular outflow tract obstruction and right ventricular dilatation at 10 years were, respectively, 85.0% ± 3.1% and 98.7% ± 0.9%. Freedom from valve implantation was 96.7% ± 1.5% at 10 years.

CONCLUSIONS

A uniform strategy of primary repair of tetralogy of Fallot through a transventricular approach resulted in low reoperation rate in the first decade. The need of pulmonary valve implantation was limited to <4% at 10 years.

Right ventricular outflow tract anomalies: Neonatal interventions and outcomes

Right ventricular outflow tract (RVOT) anomalies comprise a wide spectrum of congenital heart disease, typically characterized by obstruction to flow from the right ventricle to pulmonary arteries. This review highlights important considerations surrounding management strategy as well as clinical outcomes for the neonate with RVOT anomaly, including: pulmonary atresia with intact ventricular septum, congenital pulmonary valve stenosis, tetralogy of Fallot, and Ebstein anomaly with anatomic or physiologic RVOT obstruction.

Cardiac MRI-Derived Myocardial Deformation Parameters Correlate with Pulmonary Valve Replacement Indications in Repaired Tetralogy of Fallot

Right ventricular (RV) volumetric cardiac magnetic resonance (CMR) criteria serve as indicators for pulmonary valve replacement (PVR) in repaired tetralogy of Fallot (rTOF). Myocardial deformation and tricuspid valve displacement parameters may be more sensitive measures of RV dysfunction. This study's aim was to describe rTOF RV deformation and tricuspid displacement patterns using novel CMR semi-automated software and determine associations with standard CMR measures. Retrospective study of 78 pediatric rTOF patients was compared to 44 normal controls. Global RV longitudinal and circumferential strain and strain rate (SR) and tricuspid valve (TV) displacement were measured. Correlation analysis between strain, SR, TV displacement, and volumes was performed between and within subgroups. The sensitivity and specificity of strain parameters in predicting CMR criteria for PVR was determined. Deformation variables were reduced in rTOF compared to controls. Decreased RV strain and TV shortening were associated with increased RV volumes and decreased RVEF. Longitudinal and circumferential parameters were predictive of RVESVi (> 80 ml/m2) and RVEF (< 47%), with circumferential strain (> - 15.88%) and SR (> - 0.62) being most sensitive. Longitudinal strain was unchanged between rTOF subgroups, while circumferential strain trended abnormal in those meeting PVR criteria compared to controls. RV deformation and TV displacement are abnormal in rTOF, and RV circumferential strain variation may reflect an adaptive response to chronic volume or pressure load. This coupled with associations of ventricular deformation with traditional PVR indications suggest importance of this analysis in the evolution of rTOF RV assessment.

Relationship between right and left ventricular diastolic dysfunction assessed by 2-dimensional speckle-tracking echocardiography in adults with repaired tetralogy of Fallot

Several studies have reported a correlation between right ventricular (RV) and left ventricular (LV) systolic dysfunction in adults with repaired tetralogy of Fallot (TOF). However, data are lacking regarding the relationship between RV and LV diastolic dysfunction assessed by 2-dimensional speckle-tracking echocardiography. We studied 69 adults with repaired TOF (mean age 34 years, 61% male) who had been regularly followed up and had routinely undergone echocardiography. In addition to conventional echocardiography, global longitudinal strain (GLS) and early diastolic strain rate (SRe) of both ventricles were assessed using 2-dimensional speckle-tracking echocardiography. Results were compared with 30 age- and sex-matched controls. RV and LV GLS were decreased in TOF patients compared with controls (− 18.4 ± 3.3% vs. −23.5 ± 4.2%, p < 0.001 and − 16.0 ± 3.8% vs. −20.0 ± 3.0%, p < 0.001, respectively). RV and LV SRe were also decreased in TOF patients compared with controls (1.22 ± 0.34 sec^− 1 vs. 1.47 ± 0.41 sec^− 1, p = 0.003 and 1.29 ± 0.42 sec^− 1 vs. 1.63 ± 0.42 sec^− 1, p < 0.001, respectively). A correlation between RV and LV SRe was found in TOF patients (r = 0.43, p < 0.001) as well as between RV and LV GLS (r = 0.45, p < 0.001). Two-dimensional speckle-tracking echocardiography reveals subclinical RV and LV diastolic dysfunction in adults with repaired TOF. A correlation is observed between RV and LV diastolic dysfunction as well as between RV and LV systolic dysfunction.

Treatment of severe pulmonary insufficiency with bilateral branch pulmonary artery Melody valve implantation

Branch pulmonary artery valve implantation has been reported in larger patients with dysfunctional right ventricular outflow tracts via routine femoral access. Here, we report treatment of severe pulmonary insufficiency with bilateral branch pulmonary artery Melody valve implantation (Medtronic, Minneapolis, Minnesota). To the best of our knowledge, this is the first report of bilateral valve implantation utilising the hybrid approach in a small-size patient.

Outcomes in Young Adults With Tetralogy of Fallot and Pulmonary Annular Preserving or Transannular Patch Repairs

BACKGROUND

Early surgical tetralogy of Fallot (ToF) repair involved patching across the pulmonic annulus (transannular patch [TAP] repair), which resulted in severe pulmonic regurgitation. Long-term outcome improvements were anticipated with modifications that preserved the pulmonic annulus (annulus-preserving [AP] repair). The objective of the present study was to evaluate the need for late reintervention in adults with AP repair and those with TAP repair.

METHODS

We conducted a retrospective review of adults (born 1981-1996) with childhood intracardiac ToF repairs at a tertiary care center. The primary cardiovascular outcome was need for reintervention after primary intracardiac repair of ToF. Secondary outcomes included a composite of death, heart failure, and ventricular arrhythmias.

RESULTS

Two hundred thirty adults were included: 104 with AP repair and 126 with TAP repair. The median age at last follow up was 25 years (interquartile range [IQR] 20-28) and the median follow-up duration was 7.9 years (IQR 3.5-12). Reintervention of any type was significantly more common in the TAP group during both childhood and adulthood (72.2% TAP vs 20.2% AP, HR 5.5, 95% CI 3.4-9.0; P < 0.001). Pulmonary valve replacement (PVR) was almost 6 times more likely in adults with TAP repair (65.1% TAP vs 16.3% AP, HR 5.7, 95% CI 3.4-9.7; P < 0.001).

CONCLUSIONS

Patients who had AP ToF repair had significantly fewer late reinterventions compared with TAP repair, with the majority of reinterventions due to PVR. More long-term follow-up is required.

Arrhythmogenic Remodeling of the Left Ventricle in a Porcine Model of Repaired Tetralogy of Fallot

Supplemental Digital Content is available in the text.

Background

Ventricular arrhythmias are frequent in patients with repaired tetralogy of Fallot (rTOF), but their origin and underlying mechanisms remain unclear. In this study, the involvement of left ventricular (LV) electrical and structural remodeling was assessed in an animal model mimicking rTOF sequelae.

Methods

Piglets underwent a tetralogy of Fallot repair–like surgery (n=6) or were sham operated (Sham, n=5). Twenty-three weeks post-surgery, cardiac function was assessed in vivo by magnetic resonance imaging. Electrophysiological properties were characterized by optical mapping. LV fibrosis and connexin-43 localization were assessed on histological sections and protein expression assessed by Western Blot.

Results

Right ventricular dysfunction was evident, whereas LV function remained unaltered in rTOF pigs. Optical mapping showed longer action potential duration on the rTOF LV epicardium and endocardium. Epicardial conduction velocity was significantly reduced in the longitudinal direction in rTOF LVs but not in the transverse direction compared with Sham. An elevated collagen content was found in LV basal and apical sections from rTOF pigs. Moreover, a trend for connexin-43 lateralization with no change in protein expression was found in the LV of rTOFs. Finally, rTOF LVs had a lower threshold for arrhythmia induction using incremental pacing protocols.

Conclusions

We found an arrhythmogenic substrate with prolonged heterogeneous action potential duration and reduced conduction velocity in the LV of rTOF pigs. This remodeling precedes LV dysfunction and is likely to contribute to ventricular arrhythmias and sudden cardiac death in patients with rTOF.

Animal Models of Repaired Tetralogy of Fallot: Current Applications and Future Perspectives

Tetralogy of Fallot is the most common cyanotic congenital heart disease. Despite ongoing improvements in the initial surgical repair, there are lingering concerns regarding the long-term outcomes that may be complicated by right ventricular dysfunction, right ventricular dyssynchrony, and sudden cardiac death. The mechanisms leading to these late complications remain incompletely understood. Experimental animal models have been developed as preclinical steps to gain better insight into the pathophysiology of diseases and to develop new therapeutic strategies. This article summarizes the various types of experimental animal models of repaired tetralogy of Fallot published to date in the literature, with the aim of achieving a greater understanding of the deleterious mechanisms that may lead to these known late and sometimes lethal complications. In addition to analysing the type of animals that can be used according to a given study's objectives, needs, and constraints, the present review also evaluates the type of dysfunction that can be reproduced in our model according to the research objectives, as well as the different types of studies in which these models can be used. In view of all that, we propose a decision algorithm to create an animal model of repaired tetralogy of Fallot. This synthesis should furthermore help in the development of future studies and in the design of new experimental models, thus allowing greater insight into this disease, while not forgetting the ultimate goal of broadening future therapeutic measures to reduce the morbidity and mortality of this prevalent congenital heart disease.

One-Year Follow-up After Tetralogy of Fallot Total Repair Preserving Pulmonary Valve and Avoiding Right Ventriculotomy

BACKGROUND

We reviewed our revised surgical strategy for tetralogy of Fallot (TOF) total correction to minimize early exposure to significant pulmonary regurgitation (PR) and to avoid right ventriculotomy (RV-tomy).

METHODS AND RESULTS

Since February 2016, we have tried to preserve, first, pulmonary valve (PV) function to minimize PR by extensive commissurotomy with annulus saving; and second, RV infundibular function by avoiding RV-tomy. With this strategy, we performed total correction for 50 consecutive patients with TOF until May 2018. We reviewed the early outcomes of 27 of 50 patients who received follow-up for ≥3 months. Mean patient age at operation was 10.2±5.0 months, and mean body weight was 8.8±1.2 kg. The preoperative pressure gradient at the RV outflow tract and the PV z-score were improved at most recent echocardiography from 82.0±7.1 to 26.8±6.4 mmHg, and from -2.35±0.49 to -0.55±0.54, respectively, during 11.1±1.6 months of follow-up after operation. One patient required re-intervention for residual pulmonary stenosis. Twenty-two patients had less than moderate PR (none, 1; trivial, 8; mild, 13), and 5 patients had moderate PR. There was no free or severe PR.

CONCLUSIONS

At 1-year follow-up, the patients who underwent total TOF correction with our revised surgical strategy had acceptable results in terms of PV function. The preserved PV had a tendency to grow on short-term follow-up.

Ventricular Arrhythmias in Adult Congenital Heart Disease: Mechanisms, Diagnosis, and Clinical Aspects

The risk of ventricular arrhythmias in the adult congenital heart disease population increases with age. The mechanism, type, and frequency vary depending on the complexity of the defect, whether it has been repaired, and the type and timing of repair. Risk stratification for sudden death in patients with congenital heart disease is often challenging. Current recommendations provide a useful guide for management of these patients and risk stratification continues to evolve. Internal cardiac defibrillator implantation is often challenging due to limited transvenous access, often resulting in the need for epicardial or subcutaneous devices.

The value of right ventricular longitudinal strain in the evaluation of adult patients with repaired tetralogy of Fallot: a new tool for a contemporary challenge

OBJECTIVE

The role of right ventricular longitudinal strain for assessing patients with repaired tetralogy of Fallot is not fully understood. In this study, we aimed to evaluate its relation with other structural and functional parameters in these patients.

METHODS

Patients followed-up in a grown-up CHD unit, assessed by transthoracic echocardiography, cardiac MRI, and treadmill exercise testing, were retrospectively evaluated. Right ventricular size and function and pulmonary regurgitation severity were assessed by echocardiography and MRI. Right ventricular longitudinal strain was evaluated in the four-chamber view using the standard semiautomatic method.

RESULTS

In total, 42 patients were included (61% male, 32±8 years). The mean right ventricular longitudinal strain was -16.2±3.7%, and the right ventricular ejection fraction, measured by MRI, was 42.9±7.2%. Longitudinal strain showed linear correlation with tricuspid annular systolic excursion (r=-0.40) and right ventricular ejection fraction (r=-0.45) (all p<0.05), which in turn showed linear correlation with right ventricular fractional area change (r=0.50), pulmonary regurgitation colour length (r=0.35), right ventricular end-systolic volume (r=-0.60), and left ventricular ejection fraction (r=0.36) (all p<0.05). Longitudinal strain (β=-0.72, 95% confidence interval -1.41, -0.15) and left ventricular ejection fraction (β=0.39, 95% confidence interval 0.11, 0.67) were independently associated with right ventricular ejection fraction. The best threshold of longitudinal strain for predicting a right ventricular ejection fraction of <40% was -17.0%.

CONCLUSIONS

Right ventricular longitudinal strain is a powerful method for evaluating patients with tetralogy of Fallot. It correlated with echocardiographic right ventricular function parameters and was independently associated with right ventricular ejection fraction derived by MRI.

Preprocedural Risk Assessment Prior to PPVI with CMR and Cardiac CT

Percutaneous pulmonary valve intervention (PPVI) is a less invasive and less costly approach to pulmonary valve replacement compared with the surgical alternative. Potential complications of PPVI include coronary compression and pulmonary arterial injury/rupture. The purpose of this study was to characterize the morphological risk factors for PPVI complication with cardiac MRI and cardiac CTA. A retrospective review of 88 PPVI procedures was performed. 44 patients had preprocedural cardiac MRIs or CTAs available for review. Multiple morphological variables on cardiac MRI and CTA were compared with known PPVI outcome and used to investigate associations of variables in determining coronary compression or right ventricular-pulmonary arterial conduit injury. The most significant risk factor for coronary artery compression was the proximity of the coronary arteries to the conduit. In all patients with coronary compression during PPVI, the coronary artery touched the conduit on the preprocedural CTA/MRI, whilst in patients without coronary compression the mean distance between the coronary artery and the conduit was 4.9 mm (range of 0.8-20 mm). Multivariable regression analysis demonstrated that exuberant conduit calcification was the most important variable for determining conduit injury. Position of the coronary artery directly contacting the conduit without any intervening fat may predict coronary artery compression during PPVI. Exuberant conduit calcification increases the risk of PPVI-associated conduit injury. Close attention to these factors is recommended prior to intervention in patients with pulmonary valve dysfunction.

Ventricular Tachycardia in Congenital Pulmonary Stenosis

With modern surgical techniques, there is significantly increased life expectancy for those with congenital heart disease. Although congenital pulmonary valve stenosis is not as complex as tetralogy of Fallot, there are many similarities between the 2 lesions, such that patients with either of these conditions are at risk for ventricular arrhythmias and sudden cardiac death. Those patients who have undergone surgical palliation for congenital pulmonary stenosis are at an increased risk for development of ventricular arrhythmias and may benefit from a more aggressive evaluation for symptoms of palpitations or syncope.

Mid-term outcome of mechanical pulmonary valve prostheses: the importance of anticoagulation

INTRODUCTION

Pulmonary valve replacement (PVR) is being performed more commonly late after the correction of tetralogy of Fallot. Most valves are replaced with an allograft or xenograft, although reoperations are a common theme. Mechanical prostheses have a less favorable reputation due to the necessity of lifelong anticoagulation therapy and higher risk of thrombosis, but they are also less likely to require reoperation. There is a paucity of data on the use of prosthetic valves in the pulmonary position. We report the midterm outcomes of 38 cases of PVR with mechanical prostheses.

METHODS

One hundred twenty two patients who underwent PVR were studied. Thirty-eight patients, mean age 25 ± 8.4 years underwent PVR with mechanical prostheses based on the right ventricular function and the preferences of the patients and physicians. Median age of prosthesis was 1 year (range 3 months to 5 years).

RESULTS

Seven (18%) patients had malfunctioning pulmonary prostheses and two patients underwent redo PVR. Mean International Normalized Ratio (INR) in these seven patients was 2.1±0.8. Fibrinolytic therapy was tried and five of them responded to it well. There was no significant association between the severity of right ventricular dysfunction, patient's age, prostheses valve size and age of the prosthesis in the patients with prosthesis malfunction.

CONCLUSION

PVR with mechanical prostheses can be performed with promising midterm outcomes. Thrombosis on mechanical pulmonary valve prostheses remains a serious complication, but most prosthesis malfunction respond to fibrinolytic therapy, underscoring the need for adequate anticoagulation therapy.

Progress of right ventricular dilatation in adults with repaired tetralogy of Fallot and free pulmonary regurgitation

Background

The time course of progressive dilatation of the right ventricle (RV) in adults with pulmonary regurgitation (PR) late after repair of tetralogy of Fallot (TOF) is poorly characterized.

Methods

We analysed cardiac MRI data (1.5 T) from 14 adult repaired TOF patients (26 ± 11 years of age) with dilated RVs and known significant PR, on 2 separate visits with a between MRI period of 2.1 ± 1.0 years.

Results

Indexed RV end diastolic volume (RVEDVi) increased over 2 years (142 ± 19 to 151 ± 20 mL/m², p = 0.005; change = 8.4 ± 9.3 mL/m², range = − 6 to 26 mL/m²; annual mL/m² increase = 4.3 ± 4.6; annual percentage increase = 3.1 ± 3.3%), whilst RV ejection fraction decreased (53 ± 8 to 49 ± 7 %, p = 0.039). RV muscular corpus (RVMC) EDVi significantly increased (130 ± 19 to 138 ± 20 mL/m², p = 0.014), whereas RV outflow tract (RVOT) EDVi did not (12 ± 7 vs 13 ± 6 mL/m², p = 0.390). No other RV or LV measures significantly changed during the inter-MRI period. The change in RVEDVi correlated significantly with LV end diastolic volume (r = − 0.582, p = 0.029), RVEDVi:LVEDVi (r = 0.6, p = 0.023) and RVMC EDVi (r = 0.9, p < 0.001) but not RVOT EDVi (r = 0.225, p = 0.459).

Conclusions

Adult repaired TOF patients with free PR experienced a mean 3.1%, or 4.3 mL/m², annual increase in RVEDVi, unrelated to the initial RVEDVi or PR fraction. The increase in RVEDVi was due to RVMC rather than RVOT dilatation. This provides a guide to the frequency of MR surveillance and insights into the natural history of progressive RV dilatation in this setting.

Right ventricular outflow tract enlargement prior to pulmonary valve replacement is associated with poorer structural and functional outcomes, in adults with repaired Tetralogy of Fallot

BACKGROUND

Pulmonary valve replacement (PVR) is commonly performed late after Tetralogy of Fallot (TOF) repair. We examined the effects of PVR on cardiac structure, function and exercise capacity in adults with repaired TOF.

METHODS

Eighteen adult patients with repaired TOF and severe pulmonary regurgitation (PR) with right ventricular (RV) dilatation requiring PVR for clinical reasons (age; 25±8 years) were recruited to undergo cardiac MRI (1.5T) and cardiopulmonary exercise testing before and 14±3 months after PVR.

RESULTS

Reduced indexed RV end-diastolic volume (RVEDVi; 186±32mL/m(2) pre-op vs 114±20mL/m(2) post-op, p<0.001) was observed after PVR. "Normalisation" of RVEDVi (≤108mL/m(2)) was achieved in only seven of 18 patients. Pre-PVR RVEDVi correlated with post-operative change in RVEDVi (change=-72.1±20.4mL/m(2), r=-0.815, p<0.001). Exercise capacity remained high-normal post-PVR (% predicted maximal workload: 93±16% vs 91±12%, p=0.5). Regional RV volumes were assessed; RV outflow tract (RVOT) volumes were compared to the RV muscular corpus. Large pre-PVR RVOT volumes correlated negatively with post-surgical RV ejection fraction, peak VO2 and delta VO2 at anaerobic threshold (p<0.05 for all).

CONCLUSIONS

Normalisation of RV volume is unlikely to be achieved above a pre-PVR RVEDVi of 165mL/m(2) or more. In particular, an enlarged RVOT prior to PVR predicts suboptimal structural and functional outcomes.

Survey of reoperation indications in tetralogy of fallot in Japan

BACKGROUND

Although the survival rate for repaired Tetralogy of Fallot (TOF) is dramatically improving, anatomical and functional residua and sequelae followed by arrhythmias and sudden death are still challenging issues to be resolved. Reoperation can reduce the incidence of arrhythmias and sudden death, but there is no consensus on the indications of reoperation for patients with TOF, especially in Japan.

METHODS AND RESULTS

A cross-sectional questionnaire survey of reoperation indications in patients with TOF was performed through a Japanese multicenter study. The questionnaire, which focused on the number of repaired TOF patients aged >15 years old, reoperation indications and management, was sent to the institutions belonging to Japanese Society for Adult Congenital Heart Disease. In total, 41.5% (78/188) of the institutions replied. The total number of repaired TOF patients was 4,010, and sudden cardiac death was observed in 45.236/4,010 (5.9%) experienced reoperation. Pulmonary stenosis (32%) and pulmonary regurgitation (29%) were the most common reasons for reoperation. There were only 2 implantable cardioverter defibrillator or resynchronization therapy defibrillator implantations. The physiological/anatomical indications of reoperation differed among the hospitals.

CONCLUSIONS

Approximately 1.1% of patients suffered sudden death and 6% of repaired TOF patients had reoperation. The indications of reoperation, however, varied among the institutions. Therefore, detailed information for each case of sudden death or reoperation should be collected and analyzed in order to establish guidelines for reoperation.

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.

Percutaneous pulmonary valve replacement after different duration of free pulmonary regurgitation in a porcine model: effects on the right ventricle

BACKGROUND

Free pulmonary regurgitation (PR) after surgical correction of Tetralogy of Fallot (ToF) with transannular patching can lead to irreversible right ventricular (RV) failure. However, the optimal timing of valve replacement is still debated.

METHODS AND RESULTS

Thirty six pigs were included in the study. Twenty one pigs had a bare metal stent placed in the pulmonary annulus inducing free PR and 9 animals served as control. Six animals died prematurely due to procedural complications. The 21 animals were divided into 3 groups with differential duration of PR (1, 2, 3 months, respectively) after which PPVR was performed. After 1 month with competent valve the animals were euthanized. Cardiac magnetic resonance (CMR) and right heart catheterization were performed serially. Free PR led to severe dilation of the RV in all three groups compared to matched controls (p<0.001). Final RV volume after one month with competent pulmonary valve was modeled. Increase in RV volume from baseline to valve replacement (ΔRV) was the only predictor of RV recovery (p<0.001) and increases in ΔRV beyond 120 mL/m2 were predictive of very low probability of recovery. A total of 5 animals did not recover.

CONCLUSIONS

Recovery of right ventricular function after free PR by treatment with PPVR was successful in the majority of animals. Increases in RV volume during PR were the only predictor of non-recovery after PPVR and duration of PR did not in itself predict treatment success.

Electrocardiography recordings in higher intercostal space for children with right ventricular outlet obstruction reconstruction operation

Background and Objectives

We checked traditional and high-level precordial electrocardiogram (ECG) leads in patients who had undergone right ventricular outlet obstruction (RVOT) reconstruction surgery and evaluated the effect of ECG lead position on their QRS duration.

Subjects and Methods

We enrolled 34 patients who had undergone surgery for congenital heart disease with RVOT obstruction and who had received followed up care that included recorded ECG at a pediatric cardiac out-patient clinic. The control group included 29 patients who did not have hemodynamically significant intracardiac abnormality. We recorded traditional standard 12-leads ECG from the 4th intercostals space, and moved the precordial leads to the 3rd and 2nd intercostals spaces, and recorded ECGs repeatedly.

Results

In all groups, there was no significant difference of mean QRS duration and QTc interval between traditional standard 12-leads ECGs and ECGs at higher intercostals spaces. There was no significant difference of ECG parameters between groups. In the control group, the degree of the change between the 4th intercostals space (ICS) QRS and 3rd ICS QRS was significant (p=0.031), and although, it was insignificant, ECGs at the 3rd ICS showed decreased QRS duration in group 1 (V1: 3rd ICS 119.21±21.53 msec vs. 4th ICS 122.80±31.78 msec. V2: 3rd ICS 113.68±19.43 msec vs. 4th ICS 118.24±19.16 msec).

Conclusion

Although the positional change of ECG leads did not result in a significant effect on measuring QRS duration after surgery, ECG leads at the 3rd ICS rather than at the 4th ICS may cause alteration of ECG readings. Therefore, we suggest that ECGs should be recorded in as accurate a position as possible.

Fragmented QRS complexes predict right ventricular dysfunction and outflow tract aneurysms in patients with repaired tetralogy of Fallot

BACKGROUND

Fragmented QRS complexes (fQRS) correlate with myocardial scar, and may predict arrhythmias in patients with repaired tetralogy of Fallot (TOF). We investigated the relationship between fQRS in operated TOF patients with right ventricular (RV) dysfunction and RV outflow tract (RVOT) aneurysm.

METHODS

We studied 56 operated TOF patients with moderate/severe pulmonary regurgitation, referred for cardiac magnetic resonance imaging (MRI) over a 4.5 year period. The presence of fQRS (additional notches in the R/S wave in ≥ 2 contiguous leads on the ECG) was correlated with MRI findings.

RESULTS

fQRS was observed in 44 (78.6%) patients. Patients with fQRS had significantly larger RV end diastolic volume index (RVEDVi; 162 ml vs 141 ml, p=0.028) and RV end systolic volume index (RVESVi; 88 ml vs 70 ml, p=0.031). Increasing number of leads with fragmentation was independently associated with increasingly lower RV ejection fraction (adjusted co-efficient -0.97, 95%CI -1.83 to -0.12, p=0.026), greater pulmonary regurgitation fraction (1.65, 0.28 to 3.01, p=0.019), larger RVEDVi (6.78, 2.00 to 11.56, p=0.006) and RVESVi (5.41, 1.66 to 9.15, p=0.005). Anterior fragmentation correlated most significantly with RV dysfunction (p<0.05). fQRS had no significant association with LV dysfunction. Presence of any fQRS (OR 17.5, 95%CI 2.1-147.8, p=0.009) and inferior fQRS (OR 9.0, 95%CI 2.7-30.1, p<0.001) were found to be significant predictors for RVOT aneurysm.

CONCLUSIONS

The presence of fQRS on the ECG is significantly associated with RV dysfunction and RVOT aneurysms in repaired TOF patients. Increasing burden of fragmentation, especially in the anterior leads, is associated with increasing RV dysfunction.

Relation of left ventricular end diastolic pressure to right ventricular end diastolic volume after operative treatment of tetralogy of fallot

Left ventricular (LV) diastolic dysfunction is associated with poor outcomes after tetralogy of Fallot (TOF) repair, although its cause is not known, and its relation to right ventricular (RV) performance has never been examined. The aim of this study was to test the hypothesis that RV dilation leads to LV diastolic dysfunction after TOF repair. Patients with repaired TOF who underwent cardiac catheterization and cardiac magnetic resonance imaging within 6 months from January 2003 and April 2011 were reviewed to assess the relation of LV end-diastolic pressure (LVEDP) and indexed RV end-diastolic volume (RVEDVi). Thirty-eight patients were included at a median age of 10.1 years (range 0.6 to 54.7). There was a significant linear association between RVEDVi and LVEDP (p = 0.05). RV end-diastolic pressure (p <0.001), right pulmonary artery systolic pressure (p = 0.009), left pulmonary artery systolic pressure (p = 0.02), and total cardiopulmonary support time (p = 0.04) during TOF repair were also significantly associated with LVEDP. Compared to patients with LVEDP <12 mm Hg, those with LVEDP ≥12 mm Hg had significantly higher mean RVEDVi (135.2 ± 47.8 vs 98.6 ± 28 ml/m(2), p = 0.007) and mean RV end-diastolic pressure (11.7 ± 1.6 vs 8.5 ± 2.8 mm Hg, p = 0.0003). In conclusion, after TOF repair, LVEDP is significantly associated with RVEDVi. Furthermore, mean RVEDVi is significantly higher in patients with LVEDP ≥12 mm Hg. These findings support the theory that RV dilation may impair LV diastolic function and that LV parameters may also be important to consider in determining timing of pulmonary valve replacement.

Use of Right Ventricular Remodeling Surgery with a Porcine Pulmonary Prosthesis for Congenital Heart Disease

Background: The reconstruction of the right ventricular outflow tract (RVOT) in congenital heart disease has attracted the interest of cardiac surgeons determined to alleviate the anatomic obstruction and restore RV function.Methods: From June 1991 to September 2008, 203 consecutive patients (mean, 3.0 years; range, 2 months to 35 years) underwent operations. These patients were classified into 5 groups: group 1, tetralogy of Fallot with pulmonary hypoplasia (144 cases, 70.9%); group 2, pulmonary atresia (PA) with ventricular septal defect (VSD) (32 cases, 15.7%); group 3, truncus arteriosus (12 cases, 5.9%); group 4, transposition of the great arteries with left ventricular outflow tract obstructions (8 cases, 3.9%); and group 5, PA with intact ventricular septum (7 cases, 3.4%). Remodeling surgery of the RV consisted of patch closure of the VSD (n = 176), tricuspid valvoplasty repair (n = 25), infundibulum muscle resection, and reconstruction of the RVOT (all patients). The Lecompte procedure was performed in 8 patients in group 4, and the one and a half ventricle technique was performed in 7 patients in group 5.Results: There were 21 hospital deaths (10.3%); 180 patients (88.6%) survived. Patients were followed up from 4 to 206 months (mean, 98.0 months). Sixteen patients (8.8%) underwent reoperation for prosthesis dysfunction, with 2 inhospital deaths (12.5%). The rest of the patients (164, 80.7%) remain free of reoperation.Conclusion: Earlier reconstruction of the pulmonary valve and the RVOT may preserve ventricular performance for a long period. Nevertheless, the porcine pulmonary prosthesis has shown satisfactory results when it has been used for the reconstruction of different types of RV obstructions.

Rate of inducible ventricular arrhythmia in adults with congenital heart disease

Patients with adult congenital heart disease are at increased risk of ventricular arrhythmia (VA) and sudden cardiac death, although no clear predictors have been found. Ventricular programmed stimulation has been shown to predict clinical ventricular tachycardia and sudden death events, but the role of screening electrophysiology studies (S-EPSs) in this population remains poorly defined. Therefore, we sought to determine the prevalence of inducible VA and to evaluate the clinical predictors in a heterogeneous group of patients with adult congenital heart disease (> or =18 years old) undergoing S-EPSs at preoperative or interventional cardiac catheterization. Studies for the primary evaluation of clinical VA were excluded. The demographic, clinical, and diagnostic findings were compared between the patients with positive and negative findings. From 2005 to 2009, 80 patients (mean age 30 +/- 9 years) underwent S-EPSs, and 23 had inducible VA. The diagnoses for those with studies positive for VA included tetralogy of Fallot (n = 12), d-transposition of the great arteries (n = 6), pulmonary stenosis (n = 2), double outlet right ventricle (n = 1), double inlet left ventricle (n = 1), and Ebstein's anomaly (n = 1). Men were significantly more likely to have a S-EPS positive for VA (p = 0.015). Increasing QRS duration, decreasing peak oxygen uptake (percentage of predicted), and ventricular fibrosis with cardiovascular magnetic resonance imaging were significantly associated with studies positive for VA (p <0.05). Combined fibrosis and a peak oxygen uptake <80% of predicted had 100% sensitivity for positive VA findings. In conclusion, almost 30% of those with adult congenital heart disease undergoing S-EPSs had inducible VA. A prolonged QRS duration, diminished exercise capacity, and the presence of ventricular fibrosis were significantly associated with findings positive for VA and might improve patient selection for screening evaluations.

Consequences of a selective approach toward pulmonary valve replacement in adult patients with tetralogy of Fallot and pulmonary regurgitation

OBJECTIVE

The aim of the study was to assess the long-term results of a selective policy toward pulmonary valve replacement in adult patients with repaired tetralogy of Fallot and severe pulmonary regurgitation.

METHODS

Sixty-seven patients with tetralogy of Fallot were followed up from 15 +/- 3 years until 27 +/- 3 years after surgery.

RESULTS

Twenty-two patients had mild-to-moderate pulmonary regurgitation. No significant changes occurred in the follow-up period. Of 45 patients with severe pulmonary regurgitation and severe right ventricular dilatation, 28 (62%) remained free of symptoms and did not undergo pulmonary valve replacement. No changes in right ventricular size or exercise capacity were found. In 3 (11%) of 28 patients, QRS duration increased to more than 180 ms. Seventeen patients had symptoms and underwent pulmonary valve replacement: 9 (54%) of 17 patients improved clinically and echocardiographically, and QRS duration shortened postoperatively. Right ventricular dimensions did not regress despite pulmonary valve replacement in 8 patients.

CONCLUSION

Refraining from pulmonary valve replacement in asymptomatic patients led to no measurable deterioration in 25 (89%) of 28 patients. Referring symptomatic patients for pulmonary valve replacement led to an improvement in 9 (53%) of 17 patients. In 11 (24%) of 45, a selective approach led to questionable or unsatisfactory results.

Catheter Ablation of Ventricular Tachycardia After Repair of Congenital Heart Disease

Background— Catheter ablation of ventricular tachycardia (VT) after repair of congenital heart disease can be difficult because of nonmappable VTs and complex anatomy. Insights into the relation between anatomic isthmuses identified by delineating unexcitable tissue using substrate mapping techniques and critical reentry circuit isthmuses might facilitate ablation.

Methods and Results— Sinus rhythm voltage mapping of the right ventricle was performed in 11 patients with sustained VT after repair of congenital heart disease. Unexcitable tissue from patch material, valve annulus, or dense fibrosis, identified from bipolar voltage (<0.5 mV) and pacing threshold (>10 mA), was defined as an anatomic isthmus boundary bordering 4 isthmuses between (1) the tricuspid annulus and scar/patch in the anterior right ventricular outflow, (2) the pulmonary annulus and right ventricular free wall scar/patch, (3) the pulmonary annulus and septal scar/patch, and (4) the septal scar/patch and tricuspid annulus. The reentry circuit isthmuses of all induced 15 VTs (mean cycle length, 276±78 ms; 73% poorly tolerated), identified by activation, entrainment, and/or pace mapping, were located in an anatomic isthmus (11 of 15 VTs in anatomic isthmus 1). Transecting the anatomic isthmuses by ablation lesions abolished all VTs. During 30.4±29.3 months of follow-up, 91% of patients remained free of VT.

Conclusions— Reentry circuit isthmuses in VT late after repair of congenital heart disease are located within anatomically defined isthmuses bordered by unexcitable tissue. The boundaries can be identified with 3-dimensional substrate mapping and connected by ablation lines during sinus rhythm. These findings should facilitate catheter and surgical ablation of stable and unstable VTs.

Tetralogy of Fallot in teenagers and adults: surgical experience and follow-up

OBJECTIVE

The aim of this study was to review short- and long-term outcomes following total correction in patients with tetralogy of Fallot that presented during adulthood.

METHODS

It was a retrospective analysis of 284 patients (aged 14-50 years, mean 19.4 +/- 2.5 years) with tetralogy of Fallot who underwent total correction at our institution between January 1991 and December 2001. Thirty patients were subjected to postoperative first-pass radionuclide angiocardiography scans. A Hindi version of the standard World Health Organization quality of life proforma was mailed to 120 patients operated on during the first half of the study period.

RESULTS

Altogether, 45 (15.8%) patients had palliative shunts, and 32 (11%) had preoperative coil embolization. The transatrial/transpulmonary artery approach was used in 62 (22%) patients, the transventricular approach in 86 (30%) patients, and a combined approach in 136 (48%) patients. A transannular pericardial patch was used in 200 (70%) patients. A total of 61 (21%) patients had nonfatal complications. There were 28 hospital deaths. Follow-up ranged from 1 month to 10 years (mean 4.6 +/- 2.3 years). There were 7 (2.5%) late deaths and 6 (2.1%) reoperations. Altogether, 94% of patients were in New Yk Heart Association (NYHA) class I. Radionuclide angiocardiography showed normal right ventricular and left ventricular function in 18 (60%) and 22 (73%) patients, respectively. All of the 66 respondents perceived an improved quality of life. The actuarial survival and freedom from reoperation at 10 years were 82.88% +/- 3.80% and 92.82% +/- 3.40%, respectively.

CONCLUSION

Total correction in this subset of patients offers the best option for long-term symptom-free survival.

Cardiac MRI Is an Important Complementary Tool to Doppler Echocardiography in the Management of Patients with Pulmonary Regurgitation

Cardiac MRI (CMR) is a noninvasive diagnostic tool with comprehensive capabilities similar to that of two-dimensional echocardiography with Doppler. In addition to the ability to evaluate the etiology and severity of pulmonary valve regurgitation (PR), CMR is well designed to serially monitor the impact of the PR on the right ventricle (RV). Importantly, RV dilation and dysfunction is a critical determinate to time surgical intervention. CMR gives the silent RV, suffering from PR, a voice.

Outcomes After Late Reoperation in Patients With Repaired Tetralogy of Fallot: The Impact of Arrhythmia and Arrhythmia Surgery

BACKGROUND

We evaluated outcomes in patients requiring late reoperation after tetralogy of Fallot (ToF) repair to identify risk factors for arrhythmia and determine whether arrhythmia surgery decreased the risk of subsequent death or recurrent arrhythmia.

METHODS

Review was performed of all ToF patients from 1969 to 2005 undergoing reoperation late (> 1 year) after repair. Patients with associated lesions, except pulmonary atresia, were included. A total of 249 patients had 278 reoperations. Procedures at initial reoperation included pulmonary valve replacement (PVR) in 217, ablation in 63, and tricuspid valve repair/replacement in 46. Pre-reoperative arrhythmias were present in 75, including supraventricular tachycardia (SVT) in 31, ventricular tachycardia (VT) in 34, and SVT+VT in 10 patients.

RESULTS

Median age at reoperation was 23 years (range, 1 to 63). Ten-year survival after reoperation was 93%, and was independent of arrhythmia status (p = 0.86). Arrhythmia patients were characterized by older age at initial repair and at late reoperation, tricuspid and pulmonary regurgitation, and longer QRS duration (p < 0.001 for all). Risk factors for post-reoperative recurrent arrhythmia were longer QRS duration and not having PVR. Longer QRS duration, with a cut-point of more than 160 msec, was associated with recurrent SVT (p = 0.004). Supraventricular tachycardia ablation improved arrhythmia-free survival (75% versus 33%, p < 0.001) but VT ablation did not (96% versus 95%, p = 0.50). However, recurrent VT occurred in only 3 patients (10%).

CONCLUSIONS

Late mortality in patients undergoing reoperation after ToF repair is not impacted by pre-reoperative arrhythmia. Prolongation of QRS identifies patients at risk for recurrent VT and SVT, but recurrent VT is uncommon. Early PVR, and surgical ablation in patients with SVT, decreases arrhythmic risk.

Cardiac MR Imaging Assessment Following Tetralogy of Fallot Repair

Survivors of tetralogy of Fallot (TOF) repair constitute a large and growing population of patients. Although postsurgical outcome is generally favorable, as these patients move into adulthood, late morbidity is becoming more prevalent and the notion that TOF has been "definitively repaired" is increasingly being challenged. Recent evidence suggests that adverse long-term postsurgical outcome is related to chronic pulmonary regurgitation, right ventricular dilatation, and deteriorating ventricular function. Cardiac magnetic resonance (MR) imaging has been established as an accurate technique for quantifying ventricular size, ejection fraction, and valvular regurgitation. Cardiac MR imaging does not expose the patient to ionizing radiation and is therefore ideal for serial postsurgical follow-up. Familiarity with the anatomic basis of TOF, the surgical approaches to repair, and postrepair sequelae is essential for performing and interpreting cardiac MR imaging examinations. For example, awareness of the complications and sequelae that can occur will assist in determining when to intervene to preserve ventricular function and will improve long-term outcome. Technical facility is necessary to tailor the examination to the individual patient (eg, familiarity with non-breath-hold modifications that allow evaluation of young and less compliant patients). The radiologist can play an essential role in the treatment of patients with repaired TOF by providing noninvasive anatomic and physiologic cardiac MR imaging data. Further technologic advances in cardiac MR imaging are likely to bring about new applications, better normative data, and more examinations that are operator independent.

The roles of chronic pressure and volume overload states in induction of arrhythmias: An animal model of physiologic sequelae after repair of tetralogy of Fallot

OBJECTIVE

Sudden death occurs in as many as 8% of patients after repair of tetralogy of Fallot and has been attributed to arrhythmias. The purpose of this study was to establish an animal model to evaluate the individual contribution of different physiologic sequelae after tetralogy of Fallot repair in the development of late-onset arrhythmias.

METHODS

Forty-nine piglets were divided into 5 groups: (1) pulmonary artery band; (2) pulmonary valvotomy; (3) pulmonary artery band plus pulmonary valvotomy; (4) infundibular scar; and (5) age-matched control animals. Baseline and follow-up electrocardiograms were obtained and recorded, as well as changes in QRS duration. A total of 45 animals underwent hemodynamic evaluation and programmed electrical stimulation at 5.6 months postoperatively.

RESULTS

Sustained ventricular tachyarrhythmias (ventricular tachycardia/ventricular fibrillation) were induced in 31.1%, and atrial arrhythmias were induced in 33.3%. The pulmonary valvotomy group was 30 times more likely to evidence arrhythmias than control animals for sustained ventricular tachycardia/ventricular fibrillation, as well as atrial arrhythmias (P = .01). The pulmonary artery band group was 15 times more likely to evidence atrial arrhythmias than control animals (P = .02). Prolonged QRS duration was predictive of inducibility of both atrial arrhythmias (P < .01) and sustained ventricular tachycardia/ventricular fibrillation (P = .01). Mean right atrial (P = .01) and capillary wedge (P = .01) pressures predicted atrial arrhythmia inducibility. Right ventricular end-diastolic pressure predicted atrial arrhythmia (P= .01) and sustained ventricular tachycardia/ventricular fibrillation inducibility (P = .05). Right ventricular systolic pressure did not predict inducibility of either atrial arrhythmias (P = .10) or sustained ventricular tachycardia/ventricular fibrillation (P = .94).

CONCLUSIONS

Chronic right ventricular volume overload resulted in an increased incidence of inducible ventricular and atrial arrhythmias.

Time Course of Diastolic and Systolic Function Improvement After Pulmonary Valve Replacement in Adult Patients With Tetralogy of Fallot

OBJECTIVES

The aim of this research was to assess right ventricular diastolic and systolic function before and after pulmonary valve replacement (PVR) in adult patients after repair of tetralogy of Fallot.

BACKGROUND

Pulmonary valve replacement (PVR) in adult patients late after repair of tetralogy of Fallot leads to rapid improvement of right ventricular (RV) systolic function.

METHODS

A total of 16 patients and 8 healthy subjects were included. Median age at initial repair was 4.9 (0.9 to 13.1) years, and mean age at PVR was 28.7 (19.5 to 45.6) years. Cardiac magnetic resonance imaging was performed before and 8 and 22 months after PVR. Right ventricular volumes and function as well as RV in- and outflow patterns were assessed.

RESULTS

The volume of the early filling of the RV (Evol) increased from 49.8 +/- 14.7 ml to 53.8 +/- 19.3 ml (not significant) and 62.0 +/- 18.9 ml, respectively (p < 0.05), whereas the volume of the atrial contraction (Avol) remained unchanged. Consequently, the Evol/Avol ratio increased from 1.4 +/- 0.7 before PVR to 1.6 +/- 0.7 at 8 months (not significant) and 2.3 +/- 1.2 at 22 months (p < 0.01). The Evol/Avol ratio was not significantly different from the healthy subjects at 22 months, indicating late recovery of diastolic function. Systolic function improved rapidly after PVR; the indexed RV end-systolic volume decreased from 93.7 +/- 33.0 ml/m2 to 60.9 +/- 18.4 ml/m2 (p < 0.01) and 54.8 +/- 21.0 ml/m2 (p < 0.01).

CONCLUSIONS

In adult patients late after total repair of Fallot, PVR leads to late improvement of diastolic function. We speculate that the rapid volume unloading after PVR increases systolic performance, whereas improvement in diastolic function requires long-term remodeling.

Tetralogy of Fallot: Results of a Pulmonary Valve-Sparing Strategy

BACKGROUND

Our surgical strategy for repair of tetralogy of Fallot has focused on preserving the pulmonary valve. The purpose of this review was to identify pulmonary valve characteristics that mark the limits of this strategy.

METHODS

From 1997 through 2004, 102 consecutive patients underwent repair of tetralogy of Fallot at a median age of 5.9 months. Twenty-five patients had a prior shunt. Eighty-two patients (80%) had pulmonary valve-sparing procedures, predominantly through a transatrial and transpulmonary approach (n = 52). Twenty patients had a transannular patch (20%). Intraoperative measurements included the pulmonary valve annulus size and the postoperative pressure ratio between the right and left ventricles.

RESULTS

Eighty of 85 (94%) patients with z-score greater than -4 had a pulmonary valve-sparing procedure compared with 2 of 17 patients (12%) with pulmonary valve annulus z-scores less than -4 (p < 0.0001). All patients with a tricuspid pulmonary valve (n = 26) had a pulmonary valve-sparing procedure compared with 56 of 76 (74%) patients with a bicuspid pulmonary valve (p = 0.0016). Five patients with initial pulmonary valve-sparing operations required reoperation for residual stenoses; 4 pulmonary valve-sparing right ventricular outflow tract resections and 1 transannular patch. The only death occurred after reoperation elsewhere. Three of 9 patients (33%) who had a postoperative pressure ratio between the right and left ventricles greater than 0.7 after their initial pulmonary valve-sparing procedure required reoperation compared with 2 of 73 with postoperative pressure ratio between the right and left ventricles less than 0.7 (3%; p = 0.008). Fifteen of 25 patients (60%) with prior shunts had pulmonary valve-sparing procedures.

CONCLUSIONS

A pulmonary valve-sparing approach to the repair of tetralogy of Fallot was applied successfully in 80% of patients. Significant markers for success were a measured pulmonary annulus z-score of -4 or larger, a tricuspid pulmonary valve, and a postoperative pressure ratio between the right and left ventricles less than 0.7.

Angiocardiographic Pressure Volume Loops in the Analysis of Right Ventricular Function after Repair of Tetralogy of Fallot

OBJECTIVE

The objective of the study was to estimate the capacity of pressure volume (PV) loop analysis to assess right ventricular (RV) function after Fallot (TOF) repair.

PATIENTS

Fifty six patients were examined after TOF repair. PV loops were constructed from RV angiocardiography and simultaneous pressure measurement. Patients were divided in three groups according to RV size and pressure (Group I: normal RV size and pressure; group II: enlarged RV, near normal pressure; group III: normal RV size, elevated pressure).

MAIN OUTCOME MEASURES

Systolic stroke work corrected for body surface area (W/BSA) and for RV enddiastolic volume (W/EDV), peak RV filling (PFR) and emptying rates (PER) corrected for RV stroke volume, cycle efficiency (CE), RV ejection fraction (RVEF).

RESULTS

W/BSA was significantly higher in group II than in group I (0.19 +/- 0.05 vs. 0.11 +/- 0.04 J/m(2), p < 0.001) and was similar between groups II and III (0.19 +/- 0.05 vs. 0.17 +/- 0.05 J/m(2) ; NS). W/EDV was similar in groups I and II (12.4 +/- 5.4 vs. 12.4 +/- 2.9 mmHg; NS). CE was smallest in group II. The difference was significant between groups II and III (0.62 +/- 0.08 vs. 0.73 +/- 0.09; p < 0.05). RVEF was negatively correlated to RV end systolic volume (RVESV) in the patients of groups I and II (r = -0.32, p < 0.05). A similar correlation was found between PFR and RVESV (r = -0.28, p < 0.05).

CONCLUSIONS

Analysis of a single PV loop allows quantification of RV load after TOF repair. W/BSA is increased to the same extent under volume and pressure load. The lack of decrease in W/EDV in patients with enlarged RV indicates that RV is capable to perform adequate work in a wide range. RVESV is a useful measure for estimating RV function after TOF repair depicting parameters of systolic and diastolic RV function.

Long-Term Outcome After Total Correction of Tetralogy of Fallot in Adolescent and Adult Age

Although most patients with tetralogy of Fallot (TOF) undergo radical repair during infancy and childhood, patients remaining undiagnosed and untreated until adulthood can still be treated. These patients have either a previous palliative or natural collateral circulation to the lung or a mild form of right ventricular outflow tract (RVOT) obstruction. The aim of this study is to analyze the perioperative and long-term results of radical corrective procedures in patients who reached adult ages. Two hundred and seven patients with TOF underwent complete correction between 1985-and 2002, 64 (30.9%) of whom were aged 14 years or more. The mean age at corrective repair for this group was 20.6 +/- 7.5 years (range 14 to 49 years). Only two patients had previous modified Blalock-Taussig shunts. In 44 patients (68.7%) besides infundibular resection, a transannular gluteraldehyde-treated pericardial patch was used to reconstruct right ventricular outflow tract (RVOT). Only infundibular patching was used in 15 patients (23.4%) and infundibular muscular resection with primary closure of right ventricle was performed in five patients (7.8%). Hospital mortality was 3.1% with two patients. Four patients (6.2%) underwent reoperation because of recurrent ventricular septal defect (VSD) with/without residual obstruction or pulmonary regurgitation. All survivors were in NYHA class I (42) or II (17). Late mortality was recorded in two patients and 16-year actuarial survival was 89.2%+/- 4.9%. The significant negative predictors of late survival determined by univariate analysis were reoperation <0.018) and associated cardiac anomalies <0.011). Multivariate analysis showed that there was no negative predictor of late-term mortality. Corrective procedures in adult patients with TOF can be performed successfully compared to patients who underwent operation during infancy and childhood.

Pulmonary insufficiency: preparing the patient with ventricular dysfunction for surgery

Insufficiency of any of the four cardiac valves is a common cause of heart failure in children. Progression of ventricular dysfunction can be predictable, but requires thorough understanding of valvar disease. In valvar regurgitation, the heart has to cope with an increased volume of blood. The pathophysiological sequence is similar for both the right and the left heart. There is initially an increase in end-diastolic volume, followed by an increase in end-systolic volume, and at the end, a decrease in the shortening and ejection fractions. Different compensatory mechanisms and pathophysiologic adaptations develop to maintain the stroke volume for each type of valvar insufficiency, but heart failure eventually ensues. When symptoms of heart failure develop, irreversible ventricular dysfunction is often established, and outcome after surgery may ultimately be compromised. Discerning the optimal time for intervention, before irreversible ventricular dysfunction develops, is a key point in the management of regurgitant valvar heart disease.

Pulmonary regurgitation: not a benign lesion

Pulmonary regurgitation (PR) is a common complication after surgical or percutaneous relief of pulmonary stenosis and following repair of tetralogy of Fallot. Significant PR is usually well tolerated in childhood. However, in the long term, chronic PR has a detrimental effect on right ventricular (RV) function and exercise capacity and leads to an increased risk of arrhythmia and sudden cardiac death (SCD). Recent advances in non-invasive imaging and, in particular, wider availability of cardiovascular magnetic resonance (CMR), have improved the assessment of PR and RV function in these patients. This in turn has facilitated decision making on the optimal timing for elective pulmonary valve replacement (PVR), which should be performed before irreversible RV dysfunction ensues.

Timing and type of surgery for severe pulmonary regurgitation after repair of tetralogy of Fallot

Repaired tetralogy of Fallot (rTOF) has an excellent long-term prognosis; however, survival is somewhat less than normal. Of all the residual lesions and sequellae after rTOF, pulmonary regurgitation (PR) is the most important, correlating with right ventricular (RV) size, exercise intolerance and serious ventricular arrhythmias. Pulmonary valve replacement (PVR) has beneficial effects on RV size and function, provided it is performed early, before irreversible RV dysfunction ensues. Moreover, PVR is associated with an improvement in patients' symptoms and exercise tolerance and combined with arrhythmia surgery (cryoablation) it leads to a dramatic decrease in the incidence of fatal ventricular arrhythmias. Associated lesions, especially branch pulmonary artery stenosis, which aggravates PR, and tricuspid regurgitation, which further impacts on RV size and function, need addressing. Large right ventricular outflow (RVOT) akinetic and aneurysmal regions are frequent and further compromise RV function; therefore, resection during PVR should be attempted. Despite excellent mid-term results, homografts and xenografts, usually used for RVOT reconstruction, suffer late dysfunction and failure, committing patients and surgeons to further operations. Therefore, the decision to operate should be based on the balance between progressive RV dilatation, exercise intolerance, symptoms, arrhythmias and the fact that further reoperations will be needed. Research on the ideal valve for RVOT reconstruction is ongoing. Prospective follow-up of patients with rTOF with exercise testing and assessment of RV size and function, preferably with magnetic resonance, will define better the natural history of the disease and will probably provide firm guidelines for PVR timing especially in asymptomatic patients.

Right Ventricular Function after Pulmonary Valve Replacement in Patients with Tetralogy of Fallot

PURPOSE

To assess the time course of right ventricular (RV) function improvement after pulmonary valve replacement (PVR) in patients 25.2 years +/- 7.0 after repair of tetralogy of Fallot.

MATERIALS AND METHODS

The medical ethics committee approved this study, and informed consent was obtained. Cardiac magnetic resonance (MR) imaging was performed before, 7 months after, and 19 months after PVR in 25 consecutive patients with tetralogy of Fallot with a 1.5-T MR imager. RV function was assessed with gradient-echo sequences in the short-axis plane. Pulmonary flow was assessed with a velocity-encoded phase-contrast sequence. Paired t test was used to evaluate follow-up data. Independent samples t test was used to assess differences based on the presence of recurrent pulmonary regurgitation (PR).

RESULTS

Mean indexed RV end-diastolic volume decreased from 166.9 mL/m(2) +/- 41.3 before PVR to 113.5 mL/m(2)+/- 35.7 (P < .001) at 7-month follow-up and 111.7 mL/m(2)+/- 41.1 (P = .46) at 19-month follow-up. The RV ejection fraction was corrected for PR and improved from 25.0% +/- 7.7 before surgery to 44.1% +/- 11.9 (P < .001) and 45.2% +/- 11.1 (P = .39), at 7- and 19-month follow-up, respectively. Recurrent PR after PVR was found in 11 patients; 14 patients did not have recurrent PR. Total reduction of indexed RV end-diastolic volume at 19 months follow-up was more prominent in patients who did not have recurrent PR than in patients who did have recurrent PR (P < .05). Furthermore, improvement of RV ejection fraction corrected for regurgitation was more marked in patients who did not have recurrent PR than in patients who did have recurrent PR (P < .05).

CONCLUSION

In patients with tetralogy of Fallot, RV function improves rapidly after PVR and is sustained at 19-month follow-up in most patients; however, recurrence of PR after PVR appears to reduce recovery of RV systolic function.