Repaired Tetralogy Of Fallot Patients Research Articles

PO-04-158 INTRACARDIAC ECHOCARDIOGRAPHY GUIDES ANATOMICAL ISTHMUS ABLATION IN PATIENTS WITH VENTRICULAR TACHYCARDIA AND REPAIRED TETRALOGY OF FALLOT

Successful catheter ablation of monomorphic ventricular tachycardia (VT) in patients with repaired Tetralogy of Fallot (TOF) can be achieved by targeting one or more of four common anatomical isthmuses. However, variability in the size and location of surgical patches means careful mapping is required to design ablation lines to block the critical isthmus. Intracardiac echocardiography (ICE) may assist ablation by accurate identification of individual TOF anatomy. To determine whether the routine use of ICE aids linear ablation of VT isthmuses in patients with repaired TOF. Retrospective study of repaired TOF patients undergoing VT ablation at our centre from January 2017 to November 2022. Cases were divided into those which used ICE to assist anatomical mapping versus those which used voltage mapping to identify patches and valve annuli. Once anatomy was defined, we started with a VT stimulation study where haemodynamically stable VTs were mapped. Non-inducible or unstable VTs underwent substrate mapping in sinus rhythm. All cases underwent ablation and had no inducible monomorphic VT as the endpoint. Data are presented as median and [interquartile range]. Twenty-six patients were identified, of which 15 were guided by ICE. The baseline demographic data is presented in the table and a representative figure shows the use of ICE to identify surgical patches. The use of ICE allowed linear ablation of the critical anatomical isthmus in 12/15 patients (80%) compared to 4/11 (36%) without ICE (p=0.023). The remaining patients without linear ablation underwent substrate-based ablation only to sites of local abnormal ventricular activity. There was no significant difference in overall procedure time (ICE: 165 [60] minutes versus no ICE: 145 [50] minutes; p=0.24), nor in fluoroscopy time (ICE: 25 [17] minutes versus no ICE: 31 [16] minutes; p=0.9). Over time, the introduction of ICE was associated with improved workflow. When comparing the first and last five cases using ICE, both median procedure times (from 196 to 160 minutes) and fluoroscopy times (from 35 to 20 minutes) were shorter. Intracardiac echocardiography improves targeted linear ablation of the critical anatomical isthmus for VT in patients with repaired TOF. ICE provides real-time individualised identification of surgical patches and valve anatomy to guide optimal linear lesion sets across isthmuses, with routine use over time showing a trend towards shorter procedural and fluoroscopy times.Tabled 1Baseline demographicsICE (n=15)No ICE (n=11)Age (years)53 [26]41 [23]Male10 (67%)7 (64%)Number of sternotomies2 [1]3 [2]History of syncope5 (33%)1 (9%)QRS width (milliseconds)176 [59]172 [54]Left ventricular ejection fraction (%)50 [25]54 [9]Right ventricular ejection fraction (%)29 [8]27 [7]Implantable cardiac defibrillator7 (47%)5 (45%)History of sustained VT12 (80%)8 (73%)VT ablation15 (100%)11 (100%)Inducible VT at electrophysiology study11 (73%)6 (55%)Linear anatomical isthmus ablation12 (80%)4 (36%)Procedure time (minutes)165 [60]145 [50]Fluoroscopy time (minutes)25 [17]31 [16] Open table in a new tab

Intracardiac Flow Analysis of the Right Ventricle in Pediatric Patients With Repaired Tetralogy of Fallot Using a Novel Color Doppler Velocity Reconstruction

Repaired tetralogy of Fallot (RTOF) patients will develop right ventricular (RV) dysfunction from chronic pulmonary regurgitation (PR). Cardiac magnetic resonance sequences such as four-dimensional flow can demonstrate altered vorticity and flow energy loss (FEL); however, they are not as available as conventional echocardiography (echo). The study determined whether a novel, vendor-independent Doppler velocity reconstruction (DoVeR) could measure RV intracardiac flow in conventional echo of RTOF patients. The primary hypothesis was that DoVeR could detect increased vorticity and diastolic FEL in RTOF patients. Repaired tetralogy of Fallot patients with echo were retrospectively paired with age-/size-matched controls. Doppler velocity reconstruction employed the stream function-vorticity equation to approximate intracardiac flow fields from color Doppler. A velocity field of the right ventricle was reconstructed from the apical 4-chamber view. Vortex strength (VS, area integral of vorticity) and FEL were derived from DoVeR. Cardiac magnetic resonance and exercise stress parameters (performed within 1year of echo) were collected for analysis. Twenty RTOF patients and age-matched controls were included in the study. Mean regurgitant fraction was 40.5%±7.6%, and indexed RV end-diastolic volume was 158±36mL/m2. Repaired tetralogy of Fallot patients had higher total, mean diastolic, and peak diastolic VS (P=.0013, P=.0012, P=.0032, respectively) and higher total, mean diastolic, and peak diastolic body surface area-indexed FEL (P=.0016, P=.0022, P<.001, respectively). Peak diastolic indexed FEL and peak diastolic VS had weak-to-moderate negative correlation with RV ejection fraction (r=-0.52 [P=.019] and r=-0.49 [P=.030], respectively) and left ventricular ejection fraction (r=-0.47 [P=.034] and r=-0.64 [P=.002], respectively). Mean diastolic indexed FEL and VS had moderate-to-strong negative correlation with percent predicted maximal oxygen consumption (r=-0.69 [P=.012] and r=-0.75 [P=.006], respectively). DoVeR can detect alterations to intracardiac flow in RTOF patients from conventional color Doppler imaging. Echo-based measures of diastolic VS and FEL correlated with ventricular function. DoVeR has the potential to provide serial evaluation of abnormal flow dynamics in RTOF patients.

Abstract 12962: Circulating Biomarkers Are Associated With Left and Right Ventricular Strain Measured by Cardiac Magnetic Resonance Imaging in Repaired Tetralogy of Fallot Patients

Introduction: Circulating biomarkers thought to represent myocardial fibrosis and stretch are understudied in repaired tetralogy of Fallot (TOF) patients. We aim to identify associations between biomarkers and right ventricular (RV) and left ventricular (LV) function measured as strain by cardiac magnetic resonance (CMR) in repaired TOF patients. Methods: N-terminal-pro hormone BNP (NTproBNP), galectin-3 (Gal-3) and matrix metalloproteinase 1 (MMP1) were measured in serum obtained from TOF patients at the time of standard of care CMR. High and low biomarker groups were created using the median value. CMR strain analysis was performed using cvi42 (Circle Cardiovascular Imaging). CMR parameters were compared by biomarker group using two sample Student’s t tests (given normal distribution), and Pearson correlation coefficients were obtained. Results: Twenty patients were analyzed (45% male). Median age at TOF repair and CMR was 4.1 months (interquartile range [IQR] 1.6, 6.8) and 11.5 years (IQR 10, 15.5), respectively. Patients with higher Gal-3 had worse LV global longitudinal strain (Table) . Those with higher NTproBNP had worse RV global longitudinal and circumferential strain, and those with greater MMP1 values had worse LV global circumferential strain. Gal-3 was moderately inversely correlated with pulmonary regurgitant fraction and RV end-systolic volume (Table) . NTproBNP values were moderately directly correlated with RV mass. MMP1 values were moderately directly correlated with RV end-systolic volume and inversely correlated with RV ejection fraction. Conclusions: The three biomarkers investigated have associations with right and left ventricular strain. Gal-3 and MMP1 are potential biomarkers of LV function, while NTproBNP is a potential biomarker of RV function. Further, Gal-3 may inform more favorable RV remodeling. Future studies will determine if circulating biomarkers will identify early ventricular dysfunction after TOF repair.

Abnormal Diastolic Hemodynamic Forces: A Link Between Right Ventricular Wall Motion, Intracardiac Flow, and Pulmonary Regurgitation in Repaired Tetralogy of Fallot.

Background and ObjectiveThe effect of chronic pulmonary regurgitation (PR) on right ventricular (RV) dysfunction in repaired Tetralogy of Fallot (RTOF) patients is well recognized by cardiac magnetic resonance (CMR). However, the link between RV wall motion, intracardiac flow and PR has not been established. Hemodynamic force (HDF) represents the global force exchanged between intracardiac blood volume and endocardium, measurable by 4D flow or by a novel mathematical model of wall motion. In our study, we used this novel methodology to derive HDF in a cohort of RTOF patients, exclusively using routine CMR imaging.MethodsRTOF patients and controls with CMR imaging were retrospectively included. Three-dimensional (3D) models of RV were segmented, including RV outflow tract (RVOT). Feature-tracking software (QStrain 2.0, Medis Medical Imaging Systems, Leiden, Netherlands) captured endocardial contours from long/short-axis cine and used to reconstruct RV wall motion. A global HDF vector was computed from the moving surface, then decomposed into amplitude/impulse of three directional components based on reference (Apical-to-Basal, Septal-to-Free Wall and Diaphragm-to-RVOT direction). HDF were compared and correlated against CMR and exercise stress test parameters. A subset of RTOF patients had 4D flow that was used to derive vorticity (for correlation) and HDF (for comparison against cine method).Results68 RTOF patients and 20 controls were included. RTOF patients had increased diastolic HDF amplitude in all three directions (p<0.05). PR% correlated with Diaphragm-RVOT HDF amplitude/impulse (r = 0.578, p<0.0001, r = 0.508, p < 0.0001, respectively). RV ejection fraction modestly correlated with global HDF amplitude (r = 0.2916, p = 0.031). VO2–max correlated with Septal-to-Free Wall HDF impulse (r = 0.536, p = 0.007). Diaphragm-to-RVOT HDF correlated with RVOT vorticity (r = 0.4997, p = 0.001). There was no significant measurement bias between Cine-derived HDF and 4D flow-derived HDF by Bland-Altman analysis.ConclusionRTOF patients have abnormal diastolic HDF that is correlated to PR, RV function, exercise capacity and vorticity. HDF can be derived from conventional cine, and is a potential link between RV wall motion and intracardiac flow from PR in RTOF patients.

Tricuspid Valve Repair at Pulmonary Valve Replacement in Repaired Tetralogy of Fallot.

Pulmonary valve replacement (PVR) is often performed in patients with repaired tetralogy of Fallot (TOF). Concomitant tricuspid valvuloplasty (TVP) in those with tricuspid regurgitation (TR) at the time of PVR is still controversial. We retrospectively reviewed clinical records of patients who underwent PVR between 2001 and 2012. We analyzed the impact of concomitant TVP on the tricuspid valve function and right ventricle function and size in mid-term. 119 patients with mild to moderate TR at the time of PVR were enrolled. 33 patients underwent concomitant TVP (TVP group) and 86 patients underwent PVR alone (no-TVP group). There was a significant reduction of TR (p < 0.001) and right ventricular end-diastolic volume index (RVEDVi) (p < 0.001). However, in patients who showed prosthetic pulmonary valve (PV) failure at the last follow-up, there was no significant decrease in TR regardless of concomitant TVP. In the patients with preserved prosthetic PV function, TR was significantly improved (p < 0.001 in both groups). The multivariable analysis showed that significant risk factors for recurrence of significant TR were preoperative moderate TR and prosthetic PV failure. After PVR in repaired TOF patients, there was an improvement in the degree of TR and the RVEDVi. Concomitant TVP at the time of PVR may not be able to prevent the recurrence of TR when prosthetic PV failure occurs; however, it may effectively preserve tricuspid valve function until that time.

Health-related quality of life in adults with tetralogy of Fallot repair: a systematic review and meta-analysis.

With the advancement in diagnostics and clinical management, patients with Tetralogy of Fallot (ToF) are surviving till adulthood. Hence, assessing the impact of ToF repair on health-related quality of life (HRQOL) of these patients is becoming increasingly important. The objective of this paper is to conduct a systematic review and meta-analysis of the HRQOL in patients who have undergone ToF repair. A systematic search was conducted using PubMed, CINAHL, Medline and Web of Science databases. Studies that compared the HRQOL of adult patients (mean age ≥ 18years) who had previously undergone ToF repair with healthy controls were included. Analysis was done via Revman V5.3 using a random effects model. The 16 studies (15 using SF-36) included in the meta-analysis, comprised 1818 patients and 50,265 healthy controls. There was a higher proportion of males (59%). The mean ages at surgery and at HRQOL assessment were 5.37years and 30.3years, respectively. We found that repaired ToF patients had a statistically significantly lower score in the physical component summary (SMD = -0.92 CI = -1.54, -0.30) and physical functioning (SMD = -0.27 CI = -0.50, -0.03) compared to healthy controls. However, these patients had statistically significantly higher scores in the bodily pain domain (SMD = 0.35 CI = 0.12, 0.58) and social functioning (SMD = 0.23 CI = 0.01, 0.46), while there was no significant difference in other domains. Overall, physical domain of HRQOL was statistically significantly lower in repaired ToF patients compared to healthy controls. However, repaired ToF patients scored significantly higher on bodily pain and Social Functioning. There was additionally no difference in the HRQOL between the two groups in other domains of HRQOL.

Cardiopulmonary exercise testing in repaired tetralogy of Fallot: a valuable tool for pulmonary regurgitation severity assessment

Abstract Funding Acknowledgements Type of funding sources: None. Introduction and purpose The optimal timing for pulmonary valve replacement (PVR) in asymptomatic patients with repaired tetralogy of Fallot (TOF) and pulmonary regurgitation (PR) remains uncertain but is often guided by imaging characterization of the right ventricle. As cardiopulmonary exercise testing (CPET) performance is an accessible prognostic indicator, we assessed which CPET parameters best correlate with pulmonary regurgitation severity to potentially improve identification of high-risk patients. Methods A retrospective chart review was done from 2009 to 2018 on adult patients with repaired TOF who underwent maximal effort cardiopulmonary exercise testing with cycle ergometry and with concurrent pulmonary function testing. Demographics, standard measures of CPET interpretation, and major cardiovascular outcomes were collected. Results Cardiopulmonary exercise testing was performed in 54 adult repaired TOF patients (59% male), with a mean follow-up of 60 ± 33 months. The mean age was 34 ± 9 years. 30 patients (56%) had severe pulmonary regurgitation and 26 patients (48%) were submitted to PVR, with a 0% mortality rate. PVR was performed a mean 28 ± 7 years after TOF repair surgery. There was moderate to severe right ventricular dysfunction in 11 patients (20%). 12 patients (22%) had a hospitalization for heart failure. Arrhythmic events occurred in 9 patients (17%), mainly atrial fibrillation or atrial flutter (67%). 2 patients (4%) received an implantable cardioverter-defibrillator for secondary prevention of sudden cardiac death. Peak VO2 consumption (pVO2) showed no statistically significant correlation with severity of pulmonary regurgitation (HR 0.26, 95% CI 0.879-1.036, p= 0.262) or PVR (HR 0.92, 95% CI 0.829-1.028, p = 0.914), while percent of predicted pVO2 significantly correlated with severity of pulmonary regurgitation (HR 0.95, 95% CI 0.918-0.993, p = 0.020) and PVR (HR 0.94, 95% CI 0.886-0.992, p = 0.025). VE/VCO2 slope was not a significant predictor of severity of pulmonary regurgitation (HR 1.03, 95% CI 0.929-1.130, p = 0.622) or PVR (HR 1.04, 95% CI 0.952-1.128, p = 0.414) or) and neither cardiorespiratory optimal point (HR 0.94, 95% CI 0.786-1.120, p = 0.480) nor maximum end-tidal carbon dioxide pressure (PETCO2) (HR 0.93, 95% CI 0.846-1.037, p = 0.213) correlated with severity of pulmonary regurgitation or PVR. Conclusion Percent of predicted peak VO2 had the highest predictive power of all CPET parameters analysed in adult repaired TOF patients. Preoperative CPET could be an accessible way to identify high-risk patients earlier for PVR and should therefore be included in the routine assessment of these patients.

Late gadolinium enhancement in patients with Tetralogy of Fallot: A systematic review

PurposeThe aim of this study is to review the literature concerning myocardial late gadolinium enhancement (LGE) with cardiac magnetic resonance in patients with Tetralogy of Fallot (ToF), with regards to its prevalence, characteristics and clinical relevance. MethodsWe performed a systematic search, aiming to retrieve original articles that evaluated LGE in ToF, running a search string on MEDLINE and EMBASE in November 2019 and November 2020. Papers were then selected by two independent, blinded readers based on title and abstract, and then on full-text reading, and articles which did not include LGE evaluation were excluded. From each included paper two readers extracted descriptive data concerning technical parameters of LGE acquisition, LGE description and clinical significance. Results18 articles were eventually included in our review. The included studies observed that a higher amount of right ventricular LGE relates with higher right ventricular volumes, lower ejection fraction and a higher pulmonary regurgitant fraction, thus acting as a marker of progressive impairment of myocardial function. Moreover, LGE in ToF patients correlated with the onset of arrhythmias, and with serum biomarkers indicative of myocardial stress and fibrosis. ConclusionsLGE could be used in the follow-up repaired ToF patients as its appraisal can provide information concerning cardiac dysfunction. Moreover, it may be ideal to aim towards a common framework for standardizing assessment and quantification of LGE in ToF patients.

Assessment of flow pattern of right ventricle outflow and pulmonary arteries in surgically corrected tetralogy of Fallot patients by four-dimensional cardiac magnetic resonance flow

BackgroundThe most common post-surgical complication of tetralogy of Fallot (TOF) is pulmonary regurgitation (PR) which can lead to right ventricle (RV) dysfunction/failure. Cardiac magnetic resonance (CMR) is the imaging modality of choice to follow-up a repaired TOF. However, the conventional two-dimensional phase-contrast (2D-PC) flow usually underestimates PR as well as the pulmonary peak systolic velocity (PSV). Recently, four-dimensional (4D) CMR flow is introduced for more accurate quantitative flow assessment. This work aimed to compare between 4D-CMR and 2D-PC flow across the main (MPA), right (RPA), and left (LPA) pulmonary arteries (PAs) in surgically corrected TOF patients.ResultsThis study was conducted on 20 repaired TOF patients (range 3–9 years, 50% males). All patients had CMR exam on 1.5T scanner. 4D-CMR and 2D-PC flows were obtained at the proximal segments of the MPA, RPA, and LPA. The stroke volume index (SVI), regurgitation fraction (RF), and PSV measured by 4D-CMR were compared to 2D-PC flow. The SVI across the PAs was nearly similar between both methods (P = 0.179 for MPA, 0.218 for RPA, and 0.091 for LPA). However, the RF was significantly higher by 4D-CMR in comparison to 2D-PC flow (P = 0.027 for MPA, 0.039 for RPA, and 0.046 for LPA). The PSV as well was significantly higher by 4D-CMR flow (P = 0.003 for MPA, < 0.001 for RPA, and 0.002 for LPA). The Bland-Altman plots showed a good agreement between 4D-CMR and 2D-PC flow for the SVI, RF, and PSV across the pulmonary arteries.ConclusionA good agreement existed between the two studied methods regarding pulmonary flow measurements. Because of its major advantage of performing a comprehensive flow assessment in a shorter time, 4D-CMR flow plays an important role in the assessment of patients with complex CHD especially in the pediatric group.

Biventricular Shape Modes Associated with Clinical History and Pulmonary Regurgitation in Repaired Tetralogy of Fallot

Surgical repair of tetralogy of Fallot (ToF) often involves damage to the right ventricular (RV) outflow tract typically resulting in pulmonary valve impairment and subsequent pulmonary regurgitation. Residual pulmonary regurgitation leads to progressive RV remodeling in the form of RV dilation and apical bulging, and plays an important role in long‐term outcomes. Patients with severe pulmonary regurgitation and RV decompensation undergo pulmonary valve replacement (PVR) to reduce the risk of arrhythmia, heart failure, and sudden death. However, the clinical decision on whether and when to perform PVR remains unclear. We sought to quantify biventricular shape modes associated with clinical history and pulmonary regurgitation prior to valve replacement using a biventricular geometric atlas constructed using principle component analysis. In this cross‐sectional retrospective study, biventricular shape models were customized using cardiovascular magnetic resonance images from 97 repaired ToF patients. Patients were divided into two groups: those that subsequently had PVR and those that did not. Regression and clustering techniques were used to quantify shape variations associated with type of surgical repair, time following surgical repair, time leading up to valve replacement, and pulmonary regurgitant volumes. Principal components of biventricular shape variation were associated with RV dilation and apical bulging, overall size and sphericity, and valve plane orientation. Biventricular shape modes were quantified using statistical shape modeling techniques and are correlated with clinical history and pulmonary regurgitation.Support or Funding InformationFunding was provided by the National Institutes of Health 1R01HL121754. SG acknowledges National Institutes of Health NHLBI 1T32HL105373. CM acknowledges New Zealand Heart Foundation Grant 1695. AY acknowledges Health Research Council Grant 17/234.

Echocardiographic surveillance in children after tetralogy of Fallot repair: Adherence to guidelines?

BackgroundLongitudinal clinical surveillance by transthoracic echocardiography (TTE) is an established practice in children with repaired tetralogy of Fallot (TOF). Non-Invasive Imaging Guidelines recommends a list of reporting elements that should be addressed during routine TTE in this population. In this study, we assessed the adherence to these recommendations. MethodsThis was a multi-center (n = 8) retrospective review of TTE reports in children ≤11 years of age who have had complete TOF repair. We included 10 patients from each participating center (n = 80) and scored 2 outpatient follow-up TTE reports on each patient. The adherence rate was based on completeness of TTE reporting elements derived from the guidelines. ResultsWe reviewed 160 TTE reports on 80 patients. Median age was 4.4 months (IQR 1.5-6.6) and 3.6 years (IQR 1.3-6.4) at the time of complete surgical repair and first TTE report, respectively. The median adherence rate to recommended reporting elements was 61% (IQR 53–70). Of the 160 reports, 9 (7%) were ≥80% adherent and 40 (25%) were ≥70% adherent. Quantitative measurements of right ventricular outflow tract (RVOT), right ventricular (RV) size and function, and branch pulmonary arteries were least likely to be reported. ConclusionsOverall adherence to the most recent published imaging guidelines for surveillance of children with repaired TOF patients was suboptimal, especially for reporting of RVOT, RV size and function, and branch pulmonary arteries. Further studies are needed to explore the barriers to adherence to guidelines and most importantly, whether adherence is associated with clinical outcomes.

Mitral annulus is enlarged and functionally impaired in adult patients with repaired tetralogy of Fallot as assessed by three-dimensional speckle-tracking echocardiography-results from the CSONGRAD Registry and MAGYAR-Path Study.

Fibrous mitral annulus (MA) is an important part of the mitral valve having a role in forwarding blood from the left atrium (LA) to the left ventricle (LV). MA can be assessed by three-dimensional speckle-tracking echocardiography (3DSTE) respecting the cardiac cycle. The present study was designed to test whether repaired Tetralogy of Fallot (TOF) is associated with morphological and functional alterations of the MA. The role of the type of treatment (early total reconstruction vs. early palliation, late correction) was also assessed. The study population consisted of 29 consecutive adults repaired TOF patients (mean age: 35.4±15.5 years, 18 men), from which 13 patients underwent early total reconstruction (etrTOF), while 16 patients were firstly palliated and later corrected (pcTOF). Their data were compared to that of 76 age- and gender-matched healthy controls (mean age: 35.9±7.6 years, 33 men). All repaired TOF patients and controls were assessed by two-dimensional (2D) Doppler echocardiography and 3DSTE. Dilated end-systolic and end-diastolic MA diameter, area and perimeter and reduced MA fractional area change and MA fractional shortening could be demonstrated in repaired TOF patients as compared to controls. Increased body surface area-indexed end-diastolic and end-systolic MA diameter and perimeter could be demonstrated in pcTOF patients as compared to that of etrTOF cases. MA enlargement and functional impairment could be detected in adult patients with repaired TOF regardless of the type of correction. However, pcTOF patients have worse results.

Diffuse myocardial fibrosis in adolescents operated with arterial switch for transposition of the great arteries - A CMR study

Diffuse myocardial fibrosis in adolescents operated with arterial switch for transposition of the great arteries - A CMR study

Relation between fragmented QRS complex to the right ventricular volumes and fraction of pulmonary regurgitation in patients with repaired tetralogy of Fallot

Patients with repaired tetralogy of Fallot (TOF) have not uncommonly fragmented QRS complexes (fQRS) on surface electrocardiogram. We suggested that the right heart hemodynamics might be correlated with both the number of leads showing fQRS (fQRS extent) and the QRS duration. A retrospective analysis of the magnetic resonance imaging (MRI) derived data of 30 patients following total correction of TOF was performed. The number of leads showing fragmentation (fQRS extent) as well as the QRS duration were assessed and tested for correlation with the right ventricular volumes and severity of pulmonary regurgitation (PR) as detected by MRI. Twenty-one patients had fQRS in at least 2 consecutive leads. fQRS correlated with larger right ventricular volumes and lower ejection fraction. fQRS in 5 leads was an accurate parameter in identifying an indexed right ventricular end diastolic volume >150 ml/m2 with a sensitivity of 87.5% and a specificity of 85.7%. Moreover, it was the most accurate parameter in detecting a PR fraction > 45%. To conclude, assessment of fQRS extent and duration is a simple, available, and an accurate parameter in identifying patients with significant right ventricular hemodynamic changes in repaired TOF patients.

Impact of surgical pulmonary valve replacement on ventricular strain and synchrony in patients with repaired tetralogy of Fallot: a cardiovascular magnetic resonance feature tracking study

BackgroundIn patients with repaired tetralogy of Fallot (TOF), a better understanding of the impact of surgical pulmonary valve replacement (PVR) on ventricular mechanics may lead to improved indications and outcomes. Therefore, we used cardiovascular magnetic resonance (CMR) feature tracking analysis to quantify ventricular strain and synchrony in repaired TOF patients before and after PVR.MethodsThirty-six repaired TOF patients (median age 22.4 years) prospectively underwent CMR a mean of 4.5 ± 3.8 months before PVR surgery and 7.3 ± 2.1 months after PVR surgery. Feature tracking analysis on cine steady-state free precession images was used to measure right ventricular (RV) and left ventricular (LV) circumferential strain from short-axis views at basal, mid-ventricular, and apical levels; and longitudinal strain from 4-chamber views. Intraventricular synchrony was quantified using the maximum difference in time-to-peak strain, the standard deviation of the time-to-peak, and cross correlation delay (CCD) metrics; interventricular synchrony was assessed using the CCD metric.ResultsFollowing PVR, RV end-diastolic volume, end-systolic volume, and ejection fraction declined, and LV end-diastolic volume and end-systolic volume both increased with no significant change in the LV ejection fraction. LV global basal and apical circumferential strains, and basal synchrony improved. RV global circumferential and longitudinal strains were unchanged, and there was a varied impact on synchrony across the locations. Interventricular synchrony worsened at the midventricular level but was unchanged at the base and apex, and on 4-chamber views.ConclusionsSurgical PVR in repaired TOF patients led to improved LV global strain and no change in RV global strain. LV and RV synchrony parameters improved or were unchanged, and interventricular synchrony worsened at the midventricular level.

Development of quality metrics for ambulatory care in pediatric patients with tetralogy of Fallot.

The objective of this study was to develop quality metrics (QMs) relating to the ambulatory care of children after complete repair of tetralogy of Fallot (TOF). A workgroup team (WT) of pediatric cardiologists with expertise in all aspects of ambulatory cardiac management was formed at the request of the American College of Cardiology (ACC) and the Adult Congenital and Pediatric Cardiology Council (ACPC), to review published guidelines and consensus data relating to the ambulatory care of repaired TOF patients under the age of 18 years. A set of quality metrics (QMs) was proposed by the WT. The metrics went through a two-step evaluation process. In the first step, the RAND-UCLA modified Delphi methodology was employed and the metrics were voted on feasibility and validity by an expert panel. In the second step, QMs were put through an "open comments" process where feedback was provided by the ACPC members. The final QMs were approved by the ACPC council. The TOF WT formulated 9 QMs of which only 6 were submitted to the expert panel; 3 QMs passed the modified RAND-UCLA and went through the "open comments" process. Based on the feedback through the open comment process, only 1 metric was finally approved by the ACPC council. The ACPC Council was able to develop QM for ambulatory care of children with repaired TOF. These patients should have documented genetic testing for 22q11.2 deletion. However, lack of evidence in the literature made it a challenge to formulate other evidence-based QMs.

Ten-year outcomes of monomorphic ventricular tachycardia catheter ablation in repaired tetralogy of Fallot

Monomorphic ventricular tachycardia (MVT) is common in adults with repaired tetralogy of Fallot (TOF), and is associated with sudden cardiac death. Management of MVT is not defined, and results of catheter ablation (CA) are limited. To evaluate long-term outcomes of MVT CA in repaired TOF. Thirty-four patients (mean age 32±10.3 years; 59% male) with repaired TOF underwent CA for symptomatic MVT between 1990 and 2012 in our centre; direct-current ablation (DCA) was used in 6%, radiofrequency followed by DCA in 29% and radiofrequency alone in 65%. Right ventricular (RV) dysfunction was present in 35% and left ventricular (LV) dysfunction in 21%. Mean numbers of clinical and induced MVTs were 1 and 2, respectively. Mean VT rate was 225±95bpm. Ablation targeted a single site (range 1-2), which was RV outflow tract in 85%. Primary success, defined as ventricular tachycardia (VT) termination during CA and final non-inducibility, was obtained in 82%. Seven patients (21%) required redo ablation in the first 3 months (before 2004; DCA). No death related to CA occurred. Mean follow-up time was 9.5±5.2 years. Antiarrhythmic therapy was discontinued in 71%. There were two cases of sudden cardiac death and four VT recurrences. Freedom from death and arrhythmia recurrence was 94% at 5 years, 81% at 10 years and 70% at 20 years. Global survival was 91% at 20 years. Baseline LV ejection fraction<60% was significantly associated with ventricular arrhythmia recurrence (hazard ratio 16.4, 95% confidence interval 1.8-147; P=0.01). CA can safely address macroreentrant MVT in repaired TOF patients with an acceptable long-term rate of recurrence in this high-risk population. Anatomical classification of isthmuses with electroanatomical mapping provides reproducible endpoints for CA. Attention should be given to LV systolic function in risk assessment and selection of candidates for implantable cardioverter-defibrillator.

Long-Term Efficacy of Implantable Cardioverter Defibrillator in Repaired Tetralogy of Fallot - Role of Anti-tachycardia Pacing.

Tetralogy of Fallot (TOF) is one of the common congenital heart diseases (CHD) in implantable cardioverter defibrillator (ICD) recipients, but few studies have reported the long-term outcomes of and the anti-tachycardia pacing (ATP) efficacy in repaired TOF.Methods and Results:Twenty-one repaired TOF patients with an ICD implanted between April 2003 and March 2015 were investigated retrospectively. ICD therapy and clinical outcome were analyzed. Mean patient age was 39±11 years; 62% were male; and mean age at repair surgery was 9.4±6.8 years. During a median follow-up of 5.6 years (range, 2.6-8.4 years), no patients died. Appropriate ATP were delivered in 11 patients (52%), with appropriate shocks in 5 patients (24%) and inappropriate shocks in 5 patients (24%). The success rate of ATP was 98% for fast ventricular tachycardia (VT; cycle length ≤320 ms) and 98% for slow VT (cycle length >320 ms). ATP effectiveness increased from 81.5% with the first ATP attempt to 93.7% with the second ATP attempt, to 97.5% with the third ATP attempt, and to 98.6% with the fourth or successive ATP attempt (P<0.0001, Cochran-Armitage trend test). ATP was highly effective in repaired TOF regardless of VT cycle length. Multiple ATP attempts could have an important role in VT termination, and the novel subcutaneous ICD without ATP capability should be used carefully.

Assessing utility of exercise test in determining exercise prescription in adolescent and adult patients with repaired tetralogy of fallot.

Parameters from cardiopulmonary exercise test (CPET) are useful prognostic factors for patients with repaired tetralogy of fallot (TOF). Its application in exercise prescription remains unclear. This study sought to define its role. We made current exercise recommendations in repaired TOF patients according to European Society of Cardiology (ESC) guideline, which were based on ventricular function, pressure/volume load, pulmonary artery pressure, hypoxemia and arrhythmic burden both at rest and during exercise. CPET parameters (peak oxygen consumption, oxygen uptake efficiency plateau, and E/CO2 slope), along with cardiothoracic ratio, ventricular arrhythmia, QRS duration and NYHA functional status, were used to calculate "score to exercise". 112 repaired TOF adolescent and adult aged 32.6±10.8 (14.05- to 56.99-year-old, median 30.1) years received exercise recommendations by ESC guideline, which suggested high, moderate and low intensity sports for 45 (40.2%), 45 (40.2%), and 22 (19.6%) patients, respectively. The optimal cut-off values were 67 and 77% for peak VO2, 86 and 100% for OUEP, 22 and 28 for E/CO2 slope to correlate to the exercise intensity recommendation. But, individual CPET parameter had low consistency (41-46%) in making decisions of exercise intensity compared to ESC recommendations. Using the "score to exercise", the consistency rate could be increased to 74.1%. With "score to exercise" recommended exercise intensity, follow-up result revealed no adverse event related to sports. Individual CPET parameter did not correlate well to the exercise recommendation from ESC. We proposed a scoring system, "score to exercise", which incorporates three CPET parameters with cardiothoracic ratio, ventricular arrhythmia, QRS duration and NYHA functional status. Score to exercise is easy to be assessed and provides useful information for exercise recommendation in patients with repaired TOF.

Assessing Late Cardiopulmonary Function in Patients with Repaired Tetralogy of Fallot Using Exercise Cardiopulmonary Function Test and Cardiac Magnetic Resonance.

Patients with repaired tetralogy of Fallot (TOF) usually experience progressive right ventricle (RV) dysfunction due to pulmonary regurgitation (PR). This could further worsen the cardiopulmonary function. This study aimed to compare the changes in patient exercise cardiopulmonary test and cardiac magnetic resonance imaging, and consider the implication of these changes. Our study examined repaired TOF patients who underwent cardiopulmonary exercise test (CPET) to obtain maximal (peak oxygen consumption, peak VO2) and submaximal parameters (oxygen uptake efficiency plateau, oxygen uptake efficiency plateau (OUEP), and ratio of minute ventilation to carbon dioxide production, VE/VCO2 slope). Additionally, the hemodynamic status was assessed by using cardiac magnetic resonance. Criteria for exclusion included TOF patients with pulmonary atresia, atrioventricular septal defect, or absence of pulmonary valve syndrome. We enrolled 158 patients whose mean age at repair was 7.8 ± 9.1 years (range 0.1-49.2 years) and the mean patient age at CPET was 29.5 ± 12.2 years (range 7.0-57.0 years). Severe PR (PR fraction ≥ 40%) in 53 patients, moderate in 55, and mild (PR fraction < 20%) in 50 patients were noted. The mean RV end-diastolic volume index (RVEDVi) was 113 ± 35 ml/m(2), with 7 patients observed to have a RVEDVi > 163 ml/m(2). The mean left ventricular ejection fraction (LVEF) was 63 ± 8%, left ventricular end-diastolic volume index (LVEDVi) was 65 ± 12 ml/m(2), and LVESVi was 25 ± 14 ml/m(2). CPET revealed significantly decreased peak VO2 (68.5 ± 14.4% of predicted), and fair OUEP (90.3 ± 14.1% of predicted) and VE/VCO2 slope (27.1 ± 5.3). PR fraction and age at repair were negatively correlated with maximal and submaximal exercise indicators (peak VO2 and OUEP). Left ventricular (LV) function and size were positively correlated with peak VO2 and OUEP. The results of CPET showed that patients with repaired TOF had a low maximal exercise capacity (peak VO2), but a fair submaximal exercise capacity (OUEP and VE/VCO2 slope), suggesting limited exercise capability in high intensity circumstances. PR, LV function and age at total repair were the most important determinants of CPET performance. Cardiac magnetic resonance; Cardiopulmonary exercise function; Pulmonary regurgitation; Surgical age; Tetralogy of Fallot.