Chronic Pulmonary Regurgitation Research Articles

Management of Fallot's Uncorrected Tetralogy in Adulthood: A Narrative Review.

The majority of cyanotic congenital cardiac defects are caused by the tetralogy of Fallot. Some symptoms include a biventricular connection of the aortic root, right ventricular hypertrophy, blockage of the right ventricular outflow tract, and a ventricular septal defect. Our understanding of tetralogy of Fallot (TOF) has significantly advanced since it was first described in 1888, and early diagnosis has led to improved surgical management and increased life expectancy. Adults with unrepaired and repaired TOF present with a range of late complications, including heart failure, the need for re-interventions, and late arrhythmias. Right ventricular (RV) failure, often caused by chronic pulmonary regurgitation, is a significant cause of heart failure in patients with TOF. Current treatment options are limited, and mainstay surgical procedures such as pulmonary-valve replacement (PVR), trans-annular repair (TAR), or infundibular widening repair have not shown a significant reduction in preventing right ventricular (RV) failure or death. Here, we explain the mechanisms of RV failure in ToF, chronic pulmonary regurgitation, heart failure, and secondary polycythemia. HF management in untreated adults is discussed. The progression of the disease, as well as complications, are also discussed. The treatment plan and the need to investigate the best management approach for this unsolved problem are included. This review aims to fill the knowledge gaps and supply valuable information regarding mechanisms of RV failure, chronic pulmonary regurgitation, and secondary polycythemia. To summarize, a new combat strategy must be found to battle RVF, and a more profound vision of these mechanisms is required. If it is not corrected, it will be one of the future research lines that will contribute to designing more efficacious treatment techniques for adults with TOF.

Outcomes After Pediatric Pulmonary Valve Replacement in Patients With Tetralogy of Fallot

BackgroundPeople with tetralogy of Fallot might require a transannular patch during primary repair, which leads to pulmonary valve regurgitation. Pulmonary valve replacement (PVR) is performed to prevent complications of chronic pulmonary regurgitation, but the optimal timing of PVR remains a matter of debate. In this study we aimed to assess the association of PVR performed in children younger than 18 years of age with the rate of hospitalizations, interventions, and mortality. MethodsThis was a retrospective observational cohort of people with tetralogy of Fallot born in Québec between 1982 and 2015, using a combination of clinical and administrative data. Marginal means and rates models and survival curves were used to compare outcomes of patients with pediatric PVR (younger than 18 years) and those without. Outcomes of interest were rates of cardiac hospitalizations, all-cause hospitalizations, cardiac interventions, and mortality. Groups were balanced using models weighed on the inverse probability of receiving pediatric PVR. ResultsOf the 316 eligible patients, 58 (18.4%) received a pediatric PVR. Compared with patients who did not receive pediatric PVR, they were at increased risk of cardiac hospitalizations, although the rates of cardiac hospitalization were low: 0.50 vs 0.09 hospitalizations per 20 years (hazard ratio [HR] = 4.71 [95% confidence interval (CI), 2.22-9.96]). Patients who received a pediatric PVR had a comparable risk of all-cause hospitalizations (HR = 0.95 [95% CI, 0.71-1.26]) and of cardiac interventions (HR = 1.13 [95% CI, 0.72-1.77]). ConclusionsPatients who underwent pediatric PVR had higher rates of cardiac hospitalizations, but similar rates of all-cause hospitalizations, cardiac procedures, and mortality. In this observational cohort, pediatric PVR was not associated with an improved outcome.

Pulmonary valve replacement in tetralogy of Fallot - who and how?

Pulmonary regurgitation is the most common complication in repaired tetralogy of Fallot patients. Severe chronic pulmonary regurgitation can be tolerated for decades, but if not treated, it can progress to symptomatic, irreversible right ventricular dilatation and dysfunction. We investigated clinical associations with pulmonary valve replacement among patients with significative pulmonary regurgitation and how interventional developments can change their management. All adult patients with repaired tetralogy of Fallot who were followed at an adult CHD Clinic at a single centre from 1980 to 2022 were included on their first outpatient visit. Follow-up was estimated from the time of correction surgery until one of the following events occurred first: pulmonary valve replacement, death, loss to follow-up or conclusion of the study. We included 221 patients (116 males) with a median age of 19 (18-25). At a median age of 33 (10) years old, 114 (51%) patients presented significant pulmonary regurgitation. Among patients with significant pulmonary regurgitation, pulmonary valve replacement was associated with male gender, older age at surgical repair, and longer QRS duration in adulthood. Pulmonary valve replacement was performed in 50 patients, including four transcatheter pulmonary valve implantations, at a median age of 34 (14) years. Pulmonary regurgitation affects a large percentage of tetralogy of Fallot adult patients, requiring a long-term clinical and imaging follow-up. Sex, age at surgical repair and longer QRS are associated with the need of PVR among patients with significative pulmonary regurgitation. Clinical practice and current literature support TPVI as the future gold standard intervention.

Right ventricular dilatation score: a new assessment to right ventricular dilatation in adult patients with repaired tetralogy of Fallot

BackgroundPatients with repaired tetralogy of Fallot (rTOF) experience long-term chronic pulmonary valve regurgitation resulting in right ventricular (RV) dilatation. According to current guidelines, the evaluation of patients with rTOF for RV dilatation should be based on cardiac magnetic resonance (CMR). However, for many asymptomatic patients, routine CMR is not practical. Our study aims to identify screening methods for CMR based on echocardiographic data, with the goal of establishing a more practical and cheap method of screening for severity of RV dilatation in patients with asymptomatic rTOF.MethodsThirty two rTOF patients (mean age, 21(10.5) y, 21 males) with moderate to severe pulmonary regurgitation (PR) were prospectively recruited. Each patient received CMR and echocardiogram examination within 1 month prior to operation and collected clinical data, and then received echocardiogram examination at discharge and 3–6 months post-surgery.ResultsRV moderate-severe dilatation was defined as right ventricular end-diastolic volume index (RVEDVI) ≥ 160 ml/m2 or right ventricular end-systolic volume index (RVESVI) ≥ 80 ml/m2 in 15 of 32 patients (RVEDVI, 202.15[171.51, 252.56] ml/m2, RVESVI, 111.99 [96.28, 171.74] ml/m2). The other 17 (RVESDI, 130.19 [117.91, 139.35] ml/m2, RVESVI = 67.91 [63.35, 73.11] ml/m2) were defined as right ventricle mild dilatation, i.e., RVEDVI < 160 ml/m2 and RVESVI < 80 ml/m2, and the two parameters were higher than normal values. Compared with the RV mild dilatation group, patients of RV moderate-severe dilatation have worse cardiac function before surgery (right ventricular ejection fraction, 38.92(9.19) % versus 48.31(5.53) %, p < 0.001; Left ventricular ejection fraction, 59.80(10.26) versus 66.41(4.15), p = 0.021). Patients with RV moderate-severe dilatation faced longer operation time and more blood transfusion during operation (operation time, 271.53(08.33) min versus 170.53(72.36) min, p < 0.01; Intraoperative blood transfusion, 200(175) ml versus 100(50) ml, p = 0.001). Postoperative RV moderate-severe dilatation patients have poor short-term prognosis, which was reflected in a longer postoperative hospital stay (6.59 [2.12] days versus 9.80 [5.10] days, p = 0.024) and a higher incidence of hypohepatia (0[0] % versus 4[26.7] %, p = 0.023). Patients with RV dilatation score > 2.35 were diagnosed with RV moderate-severe dilatation (AUC = 0,882; Sensitivity = 94.1%; Specificity = 77.3%).ConclusionsRV moderate-severe dilatation is associated with worse preoperative cardiac function and short-term prognosis after PVR in rTOF patients with moderate to severe PR. The RV dilatation score is an effective screening method. When RV dilatation score > 2.35, the patient is indicated for further CMR examination and treatment.

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.

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.

Right Ventricular Flow Vorticity Relationships With Biventricular Shape in Adult Tetralogy of Fallot.

Remodeling in adults with repaired tetralogy of Fallot (rToF) may occur due to chronic pulmonary regurgitation, but may also be related to altered flow patterns, including vortices. We aimed to correlate and quantify relationships between vorticity and ventricular shape derived from atlas-based analysis of biventricular shape. Adult rToF (n = 12) patients underwent 4D flow and cine MRI imaging. Vorticity in the RV was computed after noise reduction using a neural network. A biventricular shape atlas built from 95 rToF patients was used to derive principal component modes, which were associated with vorticity and pulmonary regurgitant volume (PRV) using univariate and multivariate linear regression. Univariate analysis showed that indexed PRV correlated with 3 modes (r = −0.55,−0.50, and 0.6, all p < 0.05) associated with RV dilatation and an increase in basal bulging, apical bulging and tricuspid annulus tilting with more severe regurgitation, as well as a smaller LV and paradoxical movement of the septum. RV outflow and inflow vorticity were also correlated with these modes. However, total vorticity over the whole RV was correlated with two different modes (r = −0.62,−0.69, both p < 0.05). Higher vorticity was associated with both RV and LV shape changes including longer ventricular length, a larger bulge beside the tricuspid valve, and distinct tricuspid tilting. RV flow vorticity was associated with changes in biventricular geometry, distinct from associations with PRV. Flow vorticity may provide additional mechanistic information in rToF remodeling. Both LV and RV shapes are important in rToF RV flow patterns.

Cardiopulmonary Exercise Testing in Repaired Tetralogy of Fallot: Multiparametric Overview and Correlation with Cardiac Magnetic Resonance and Physical Activity Level.

Patients with repaired Tetralogy of Fallot (rToF) typically report having preserved subjective exercise tolerance. Chronic pulmonary regurgitation (PR) with varying degrees of right ventricular (RV) dilation as assessed by cardiac magnetic resonance imaging (MRI) is prevalent in rToF and may contribute to clinical compromise. Cardiopulmonary exercise testing (CPET) provides an objective assessment of functional capacity, and the International Physical Activity Questionnaire (IPAQ) can provide additional data on physical activity (PA) achieved. Our aim was to assess the association between CPET values, IPAQ measures, and MRI parameters. All rToF patients who had both an MRI and CPET performed within one year between March 2019 and June 2021 were selected. Clinical data were extracted from electronic records (including demographic, surgical history, New York Heart Association (NYHA) functional class, QRS duration, arrhythmia, MRI parameters, and CPET data). PA level, based on the IPAQ, was assessed at the time of CPET. Eighty-four patients (22.8 ± 8.4 years) showed a reduction in exercise capacity (median peak VO2 30 mL/kg/min (range 25–33); median percent predicted peak VO2 68% (range 61–78)). Peak VO2, correlated with biventricular stroke volumes (RVSV: β = 6.11 (95%CI, 2.38 to 9.85), p = 0.002; LVSV: β = 15.69 (95% CI 10.16 to 21.21), p < 0.0001) and LVEDVi (β = 8.74 (95%CI, 0.66 to 16.83), p = 0.04) on multivariate analysis adjusted for age, gender, and PA level. Other parameters which correlated with stroke volumes included oxygen uptake efficiency slope (OUES) (RVSV: β = 6.88 (95%CI, 1.93 to 11.84), p = 0.008; LVSV: β = 17.86 (95% CI 10.31 to 25.42), p < 0.0001) and peak O2 pulse (RVSV: β = 0.03 (95%CI, 0.01 to 0.05), p = 0.007; LVSV: β = 0.08 (95% CI 0.05 to 0.11), p < 0.0001). On multivariate analysis adjusted for age and gender, PA level correlated significantly with peak VO2/kg (β = 0.02, 95% CI 0.003 to 0.04; p = 0.019). We observed a reduction in objective exercise tolerance in rToF patients. Biventricular stroke volumes and LVEDVi were associated with peak VO2 irrespective of RV size. OUES and peak O2 pulse were also associated with biventricular stroke volumes. While PA level was associated with peak VO2, the incremental value of this parameter should be the focus of future studies.

Usefulness of Right Ventricular Free Wall Strain Obtained with Two-Dimensional Speckle-Tracking Echocardiography in Patients with Repaired Tetralogy of Fallot and Pulmonary Regurgitation.

Right ventricular (RV) dysfunction caused by chronic pulmonary regurgitation (PR) is a major determinant of clinical outcome in adults with repaired tetralogy of Fallot (rTOF). However, the accurate assessment of RV function by conventional echocardiography remains challenging. This study tested the feasibility and usefulness of RV free-wall (RVFW) strain obtained by two-dimensional (2D) speckle-tracking echocardiography (STE) in evaluation of RV function in adults with rTOF by comparing cardiac magnetic resonance (CMR) imaging. We enrolled 22 consecutive patients (male/female, 8/14; mean age, 25.0 years) with rTOF who underwent transthoracic echocardiography at Tohoku University Hospital from July 2016 to June 2019. We measured RVFW strain by STE and compared them with 22 hemodynamically normal subjects (NOR) (male/female, 9/13; mean age, 32.0 years). The correlation between RV strain and CMR-derived RV ejection fraction (RVEF) or PR fraction (PRF) were also evaluated. All rTOF patients had more than moderate PR but were near asymptomatic. RVFW longitudinal strain (RVFW-LS) was significantly decreased in the rTOF group compared with that in the NOR group (-19.6 vs. -24.7, P < 0.01). In the rTOF group, RVFW-LS correlated with PRF (r = 0.44, P < 0.05), whereas RVFW circumferential strain at the mid-ventricular level correlated with RVEF (r = 0.57, P < 0.01). Intra-observer variability of RVFW strain was acceptable. These results indicate that RV systolic function and PR severity in rTOF could be assessed by RVFW strain measured by 2D STE. This method is feasible and can be used as a complement to CMR imaging.

Global and regional right ventricular mechanics in repaired tetralogy of Fallot with chronic severe pulmonary regurgitation: a three-dimensional echocardiography study

BackgroundData about the right ventricular (RV) mechanics adaptation to volume overload in patients with repaired tetralogy of Fallot (rToF) are limited. Accordingly, we sought to assess the mechanics of the functional remodeling occurring in the RV of rToF with severe pulmonary regurgitation.MethodsWe used three-dimensional transthoracic echocardiography (3DTE) to obtain RV data sets from 33 rToF patients and 30 age- and sex- matched controls. A 3D mesh model of the RV was generated, and RV global and regional longitudinal (LS) and circumferential (CS) strain components, and the relative contribution of longitudinal (LEF), radial (REF) and anteroposterior (AEF) wall motion to global RV ejection fraction (RVEF) were computed using the ReVISION method.ResultsCorresponding to decreased global RVEF (45 ± 6% vs 55 ± 5%, p < 0.0001), rToF patients demonstrated lower absolute values of LEF (17 ± 4 vs 28 ± 4), REF (20 ± 5 vs 25 ± 4) and AEF (17 ± 5 vs 21 ± 4) than controls (p < 0.01). However, only the relative contribution of LEF to global RVEF (0.39 ± 0.09 vs 0.52 ± 0.05, p < 0.0001) was significantly decreased in rToF, whereas the contribution of REF (0.45 ± 0.08 vs 0.46 ± 0.04, p > 0.05) and AEF (0.38 ± 0.09 vs 0.39 ± 0.04, p > 0.05) to global RVEF was similar to controls. Accordingly, rToF patients showed lower 3D RV global LS (-16.94 ± 2.9 vs -23.22 ± 2.9, p < 0.0001) and CS (-19.79 ± 3.3 vs -22.81 ± 3.5, p < 0.01) than controls. However, looking at the regional RV deformation, the 3D CS was lower in rToF than in controls only in the basal RV free-wall segment (p < 0.01). 3D RV LS was reduced in all RV free-wall segments in rToF (p < 0.0001), but similar to controls in the septum (p > 0.05).Conclusions3DTE allows a quantitative evaluation of the mechanics of global RVEF. In rToF with chronic volume overload, the relative contribution of the longitudinal shortening to global RVEF is affected more than either the radial or the anteroposterior components.

Comparison of Long-term Outcomes of Valve-Sparing and Transannular Patch Procedures for Correction of Tetralogy of Fallot

The choice of the right surgical technique for correction of tetralogy of Fallot (TOF) is contentious for patients with a moderate to severe right outflow tract obstruction. The use of a transannular patch (TAP) exposes patients to chronic pulmonary regurgitation, while valve-sparing (VS) procedures may incompletely relieve pulmonary obstruction. To compare 30-year outcomes of TOF repair after a VS procedure vs TAP. This retrospective population-based cohort study was conducted among all patients with TOF born in the province of Quebec, Canada, from 1980 to 2015 who underwent complete surgical repair. Patients who received a TAP or VS procedure were matched using a propensity score based on preoperative factors in a 1:1 ratio. Data were analyzed from March 2020 through April 2021. The study groups were individuals who received TAP and those who received VS. The VS group was further stratified by the presence of residual pulmonary stenosis. The primary outcome was all-cause mortality, with 30-year survival evaluated using Cox proportional-hazards models. Secondary outcomes included the cumulative mean number of cardiovascular interventions, pulmonary valve replacements (PVRs), and cardiovascular hospitalizations were evaluated using marginal means/rates regressions. Among 683 patients with TOF (401 patients who underwent TAP [58.7%] and 282 patients who underwent a VS procedure [41.3%]), adequate propensity score matching was achieved for 528 patients (264 patients who underwent a VS procedure and 264 patients who underwent TAP). Among this study cohort, 307 individuals (58.1%) were men. The median (interquartile range [IQR]) follow-up was 16.0 (8.1-25.4) years, for a total of 8881 patient-years, including 63 individuals (11.9%) followed up for more than 30 years. Individuals who received a VS procedure had an increased 30-year survival of 99.1% compared with 90.4% for individuals who received TAP (hazard ratio [HR], 0.09 [95% CI, 0.02-0.41]; P = .002). Patients who underwent TAP had an increased 30-year cumulative mean number of cardiovascular interventions compared with patients who underwent a VS procedure without residual pulmonary stenosis (2.0 interventions [95% CI, 1.5-2.7 interventions] vs 0.7 interventions [95% CI, 0.5-1.1 interventions]; mean ratio [MR], 0.36 [95% CI, 0.25-0.50]; P < .001) and patients who underwent a VS procedure with at least moderate residual stenosis (1.3 interventions [95% CI, 0.9-1.9 interventions]; MR, 0.65 [0.45-0.93]; P = .02). Results were similar for PVR, with a 30-year cumulative mean 0.3 PVRs [95% CI, 0.1-0.7 PVRs] for patients who underwent a VS procedure without residual pulmonary stenosis (MR, 0.22 [95% CI, 0.12-0.43]; P < .001) and 0.6 PVRs (95% CI, 0.2-1.5 PVRs) for patients with at least moderate residual stenosis (MR, 0.44 [95% CI, 0.21-0.93]; P = .03), compared with 1.4 PVRs (95% CI, 0.8-2.5 PVRs) for the TAP group. No statistically significant difference was found for cardiovascular hospitalizations. This study found that patients who underwent a VS procedure had increased 30-year survival, fewer cardiovascular reinterventions, and fewer PVRs compared with individuals who underwent TAP, even in the presence of significant residual pulmonary stenosis. These findings suggest that it is beneficial to perform a VS procedure when possible, even in the presence of moderate residual stenosis, compared with the insertion of a TAP.

QRS Duration During Follow-Up of Tetralogy of Fallot: How Valuable is it? Analysis of ECG Changes in Relation to Pulmonary Valve Implantation.

Long-term results after tetralogy of Fallot (TOF) repair are determined by the extent of right ventricular remodeling to chronic pulmonary regurgitation entailing progressive RV dysfunction and a risk of developing ventricular arrhythmia. Pulmonary valve replacement (PVR) can alleviate this burden. As a predictor of ventricular arrhythmia, QRS duration remains a strong parameter in this decision. We performed a retrospective analysis of all PVR patients between 2005 and 2018, studying the time evolution of electrocardiographic parameters before and after PVR through linear mixed model analysis. 42 TOF patients underwent PVR. The median timespan between primary repair and PVR was 18years (IQR 13-30). The indication for PVR was primarily based on the association of exercise intolerance (67%) and significant RV dilation on cMRI (median RVEDVi 161ml/m2 IQR 133-181). Median QRS length was 155ms (IQR 138-164), 4 (10%) patients had a QRS > 180ms. QRS duration increased significantly before PVR, but barely showed regression after PVR. Changes of QRS duration after PVR were independent of RV dilation. In conclusion, when the decision for PVR in TOF patients is primarily based on RV volume and/or function threshold, QRS duration > 180ms is rarely observed. In contrast with the significant increase of QRS duration before PVR, QRS length regression appears to be independent of the extent of RV dilation or QRS > 160ms. Considering that the decision for PVR is based on mechanical RV characteristics, the utility of serial follow-up of QRS duration in contemporary operated TOF patients becomes questionable in absence of clinical arguments for ventricular arrhythmia.

The reduced left ventricular stroke volume does not fully recover after pulmonary valve replacement in patients with repaired tetralogy of Fallot.

The present study was conducted to investigate the decrease in left ventricular stroke volume index (LVSVI) that is caused by pulmonary regurgitation-induced right heart dysfunction and its clinical implications before and after pulmonary valve replacement (PVR). Between January 2010 and December 2019, 30 adults who underwent surgical PVR for chronic pulmonary regurgitation with right ventricular dilation late after tetralogy of Fallot (TOF) repair were included. All patients were evaluated using cardiac magnetic resonance before PVR. The median interval from TOF repair to PVR was 29 [25th, 75th percentile: 25, 37] years. The median pulmonary regurgitation fraction and right ventricular end-diastolic volume index were 56 [48, 66] % and 203 [187, 239] ml/m2. Twenty-three patients (76.7%) were re-evaluated 1 year after PVR. Before PVR, the median LVSVI was 40 [35, 46] ml/beat/m2. A lower LVSVI was associated with a longer interval from TOF repair to PVR (r = -0.40, P = 0.029) and a lower right ventricular ejection fraction (r = 0.52, P = 0.004). A lower LVSVI was not associated with a higher right ventricular end-diastolic volume index. LVSVI remained unchanged after PVR. The patients were subdivided into Normal-stroke volume index (SVI) and Subnormal-SVI groups using the preoperative LVSVI cut-off value of 35 mL/beat/m2. Compared with the Normal-SVI group, the Subnormal-SVI group had a higher incidence of ablation therapy before PVR (4.7 vs 2.3 patient-years, P = 0.044). After PVR, LVSVI in the Subnormal-SVI group was still lower (40 [34, 42] vs 44 [42, 47] ml/beat/m2, P = 0.038) despite the right ventricular end-diastolic volume index normalization. There was no difference in the clinical event incidence between the 2 groups during the follow-up period. Brain natriuretic peptide level in the Subnormal-SVI group was higher within 3 years after PVR (P = 0.046). Reduced left ventricular stroke volume did not fully recover after PVR. PVR for patients with repaired TOF should be performed before the left ventricular stroke volume begins to decrease.

Moving beyond size: vorticity and energy loss are correlated with right ventricular dysfunction and exercise intolerance in repaired Tetralogy of Fallot

BackgroundThe global effect of chronic pulmonary regurgitation (PR) on right ventricular (RV) dilation and dysfunction in repaired Tetralogy of Fallot (rTOF) patients is well studied by cardiovascular magnetic resonance (CMR). However, the links between PR in the RV outflow tract (RVOT), RV dysfunction and exercise intolerance are not clarified by conventional measurements. Not all patients with RV dilation share the same intracardiac flow characteristics, now measurable by time resolved three-dimensional phase contrast imaging (4D flow). In our study, we quantified regional vorticity and energy loss in rTOF patients and correlated these parameters with RV dysfunction and exercise capacity.MethodsrTOF patients with 4D flow datasets were retrospectively analyzed, including those with transannular/infundibular repair and conduit repair. Normal controls and RV dilation patients with atrial-level shunts (Qp:Qs > 1.2:1) were included for comparison. 4D flow was post-processed using IT Flow (Cardioflow, Japan). Systolic/diastolic vorticity (ω, 1/s) and viscous energy loss (VEL, mW) in the RVOT and RV inflow were measured. To characterize the relative influence of diastolic vorticity in the two regions, an RV Diastolic Vorticity Quotient (ωRVOT-Diastole/ωRV Inflow-Diastole, RV-DVQ) was calculated. Additionally, RVOT Vorticity Quotient (ωRVOT-Diastole/ωRVOT-Systole, RVOT-VQ) and RVOT Energy Quotient (VELRVOT-Diastole/VELRVOT-Systole, RVOT-EQ) was calculated. In rTOF, measurements were correlated against conventional CMR and exercise stress test results.Results58 rTOF patients, 28 RV dilation patients and 12 controls were included. RV-DVQ, RVOT-VQ, and RVOT-EQ were highest in rTOF patients with severe PR compared to rTOF patients with non-severe PR, RV dilation and controls (p < 0.001). RV-DVQ positively correlated with RV end-diastolic volume (0.683, p < 0.001), PR fraction (0.774, p < 0.001) and negatively with RV ejection fraction (− 0.521, p = 0.003). Both RVOT-VQ, RVOT-EQ negatively correlated with VO2-max (− 0.587, p = 0.008 and − 0.617, p = 0.005) and % predicted VO2-max (− 0.678, p = 0.016 and − 0.690, p = 0.001).ConclusionsIn rTOF patients, vorticity and energy loss dominate the RVOT compared to tricuspid inflow, correlating with RV dysfunction and exercise intolerance. These 4D flow-based measurements may be sensitive biomarkers to guide surgical management of rTOF patients.

Echocardiographic comparison between pulmonary valve preservation and transannular patch techniques in children with repaired Tetralogy of Fallot

Abstract Funding Acknowledgements Type of funding sources: None. INTRODUCTION Many centers have recently adopted pulmonary valve (PV) preservation procedures to prevent the detrimental long-term effects of chronic pulmonary regurgitation after tetralogy of Fallot (ToF) repair. PURPOSE The aim of our study was to investigate pulmonary valve (PV) and right ventricular function by echocardiography in paediatric patients with repaired Tetralogy of Fallot (ToF), comparing PV preservation surgical strategies to standard transannular patch (TAP) repair. METHODS All patients undergoing transatrial-transpulmonary repair for ToF at our institution between January 2007 and May 2020 were reviewed retrospectively. Patients were divided into 2 main groups, according to the different techniques used: patients undergoing a PV preservation strategy and patients undergoing TAP repair. All patients underwent standard echo-Doppler study including RV end-diastolic area (RVEDA), end-systolic area (RVESA), fractional area change (FAC) and TAPSE; PR was assessed by Color Doppler, continuous-wave (CW) Doppler and derived parameters such as pressure half time (PHT) and pulmonary regurgitation (PR) index. By speckle tracking we measured also, in a subgroup of patients, right atrial strain (RAS), RV and left ventricle (LV) global longitudinal strain (RVGLS, LVGLS) and their time to peak (TTP) values. RESULTS Overall, 82 patients underwent a successful PV preservation strategy while 34 underwent a standard TAP repair. At index surgery, BSA (0.31 ± 0.1 m2, P = 0.3), age (4.8 ± 0.3 months, P = 0.5) and preoperative PV Z-score (-3.20 ± 0.1, P = 0.1) did not different between groups. Five-year actuarial freedom from moderate/severe PV regurgitation was significantly higher in the PV preservation group compared to the TAP (61.3% [95% CI: 48-73%] vs 25.9% [95% CI: 12-43%], respectively; p = 0.02). After adjusting for age, gender, BSA, and type of PV, the use of a TAP was still significantly associated with an increased risk for PV regurgitation at follow up (HR: 1.85, 95% CI: 1.09, 3.15; p = 0.02). At a mean follow-up of 6.9 ± 0.3 years, patients undergoing PV preservation showed an increased right ventricular fractional area change (46.9 ± 0.8% vs 42.5 ± 1.7%, P &amp;lt; 0.001) and tricuspid annular plane systolic excursion (TAPSE) z-score (-3.36 ± 0.3% vs -4.7 ± 0.4%, P = 0.005), while maintaining better PV competence in terms of pulmonary regurgitation index (87.9 ± 1.2% vs 82.7 ± 2.4%, P = 0.02). At speckle tracking subanalysis, patients undergoing PV preservation (n= 23), compared to the TAP group (n = 13) showed also higher values of RAS (37.5 ± 6.0% vs 29.3 ± 8.2% , P &amp;lt; 0.006), shorter right TTP (319 ± 39ms vs 357.5 ± 45.2 ms, P &amp;lt; 0.01) and higher values of LVGLS (-20,6 ± 4,2% vs -17.5 ± 3.0, P &amp;lt; 0.03). CONCLUSIONS Surgical repair of ToF with PV preservation provides excellent outcomes in terms of PV competence and right ventricular function and should be advocated whenever possible. Abstract Figure. Degree of pulmonary regurgitation

Pulmonary valve replacement via left anterior minithoracotomy: Lessons learned and early experience.

Median sternotomy has been the standard for pulmonary valve replacement (PVR) in patients with free pulmonary regurgitation (PR) and right ventricular enlargement. With the introduction of transcatheter therapy, the search for an alternate to sternotomy is mandated. We present our early experience with a limited anterior left thoracotomy approach. We used a left anterior mini-thoracotomy in six male patients (15 ± 1.94 years of age) who developed progressive right ventricular enlargement due to chronic PR. Primary diagnoses were tetralogy of Fallot in five patients and pulmonary atresia with an intact septum in another. Four patients had previous median sternotomy with transannular patch repair. The mean right ventricular end-diastolic volume index was 189 ± 27.13 ml/m2 . The procedure was feasible in all patients. All patients had satisfactory adult size pulmonary bioprosthesis (25 or 27 mm valve), with a mean peak gradient of 18 ± 2.40 mmHg across the prosthesis at discharge. All patients were extubated intraoperatively at the end of the procedure and required no intraoperative transfusions. There were no early or late mortalities. Early morbidities included left hemidiaphragm paralysis in one patient, and re-sternotomy for prosthetic valve endocarditis in one. One patient required late reoperation for a common femoral artery pseudoaneurysm. Minimally invasive access for PVR is feasible in both primary and repeat settings, through a limited anterior left minithoracotomy in the absence of intracardiac shunts and the need for other concomitant cardiac procedures. Longer-term studies with a larger number of patients are needed to compare the efficacy of this approach to standard sternotomy.

Abstract 15118: Pulmonary Valve Preservation During Tetralogy of Fallot Repair is Associated With Enhanced Pulmonary Valve and Right Ventricular Function

Introduction: Many centers have recently adopted pulmonary valve (PV) preservation procedures to prevent the detrimental long-term effects of chronic pulmonary regurgitation after tetralogy of Fallot (ToF) repair. Hypothesis: Here, we investigated PV and right ventricular function after PV preservation surgical strategies compared to standard transannular patch (TAP) repair. Methods: All patients undergoing transatrial-transpulmonary repair for ToF with PV stenosis at our institution between January 2007 and May 2020 were reviewed retrospectively. Patients were divided into 2 main groups, according to the different techniques used: patients undergoing a PV preservation strategy and patients undergoing TAP repair. Results: Overall, 82 patients underwent a successful PV preservation strategy while 34 underwent a standard TAP repair. At index surgery, BSA (0.31±0.1 m 2 , P=0.3), age (4.8±0.3 months, P=0.5) and preoperative PV Z-score (-3.20±0.1, P=0.1) did not differ between groups. Five-year actuarial freedom from moderate/severe PV regurgitation was significantly higher in the PV preservation group compared to the TAP (61.3% [95% CI: 48-73%] vs 25.9% [95% CI: 12-43%], respectively; p=0.02). After adjusting for age, gender, BSA, and type of PV, the use of a TAP was still significantly associated with an increased risk for PV regurgitation at follow up (HR: 1.85, 95% CI: 1.09, 3.15; p=0.02). At a mean follow-up of 6.9±0.3 years, patients undergoing PV preservation showed an increased right ventricular fractional area change (46.9±0.8% vs 42.5±1.7%, P&lt;0.001) and tricuspid annular plane systolic excursion z-score (-3.36±0.3% vs -4.7±0.4%, P=0.005), while maintaining better PV competence in terms of pulmonary regurgitation index (87.9±1.2% vs 82.7±2.4%, P=0.02). Conclusions: Surgical repair of ToF with PV preservation provides excellent outcomes in terms of PV competence and right ventricular function and should be advocated whenever possible.

Study of the time-relationship of the mechano-electrical interaction in an animal model of tetralogy of Fallot: implications for the risk assessment of ventricular arrhythmias.

The long-term outcome of tetralogy of Fallot (TOF) is determined by progressive right ventricular (RV) dysfunction through pulmonary regurgitation (PR) and the risk of malignant arrhythmia. Although mechano-electrical coupling in TOF is well-known, its time effect on the inducibility of arrhythmia remains ill-defined. The goal of this study was to investigate the mechano-electrical properties at different times in animals with chronic PR. PR was induced by a transannular patch with limited RV scarring in infant pigs. Haemodynamic assessment included biventricular pressure-volume loops after 3 (n = 8) and 6 months (n = 7) compared to controls (n = 5). The electrophysiological study included endocardial monophasic action potential registration, intraventricular conduction velocity and induction of ventricular arrhythmia by burst pacing. Progressive RV dilation was achieved at 6 months (RV end-diastolic volume 143 ± 13 ml/m2-RV end-systolic volume 96 ± 7 ml/m2; P < 0.001), in association with depressed RV contractility (preload recruitable stroke work-slope: 19 ± 1 and 11 ± 3 Mw.ml-1.s-1 for control and 6 m; P < 0.001) and left ventricular contractility (preload recruitable stroke work-slope: 60 ± 13 and 40 ± 11 Mw.ml-1.s-1 for control and 6 m; P = 0.005). Concomitant to QRS prolongation, monophasic action potential90-duration and dispersion at the RV and left ventricle were increased at 6 months. Intraventricular conduction was delayed only in the RV at 6 months (1.8 ± 0.2 and 2.4 ± 0.6 m/s for group 6M and the control group; P = 0.035). Sustained ventricular arrhythmias were not inducible. In animals yielding the sequelae of a contemporary operation for TOF, mechano-electrical alterations are progressive and affect predominantly the RV after midterm exposure of PR. Because ventricular arrhythmias were not inducible despite significant RV dilation, the data suggest that the haemodynamic RV deterioration effectively precedes the risk of inducing sustained arrhythmia after TOF repair and opens a window for renewed stratification of contemporary risk factors of ventricular arrhythmias in patients operated on with currently used pulmonary valve- and RV-related techniques.

COMING TO THE RIGHT DECISION FOR SEVERE PULMONARY REGURGITATION AND BIVENTRICULAR DYSFUNCTION

Chronic pulmonary regurgitation (PR) leads to RV dilatation and dysfunction, and can also induce LV failure through ventricular-ventricular (VV) interaction. Pulmonary valve replacement (PVR) is advocated to prevent this pathophysiology. A 51-year-old woman with a dysplastic pulmonary valve, severe

The impact of pulmonary regurgitation on right ventricular size and function in patients with repaired tetralogy of Fallot and additional haemodynamic abnormalities.

PurposeRight ventricular (RV) outflow tract obstruction (RVOTO) was demonstrated to be protective against RV dilatation in patients with repaired tetralogy of Fallot and chronic pulmonary regurgitation (PR). We hypothesised that the presence of additional haemodynamic abnormalities (more than mild tricuspid regurgitation, residual ventricular septal defect) reduces this protective association. Accordingly, we aimed to assess the impact of PR on RV size and function in this population.Material and methodsConsecutive patients with additional haemodynamic abnormalities after tetralogy of Fallot (TOF) repair, who had undergone cardiovascular magnetic resonance, were included.ResultsOut of 90 patients studied, 18 individuals (mean age 32.5 ± 10.7 years, 72.2% males) met the inclusion criteria. There were no differences in RV volumes and ejection fraction between patients with and without RVOTO. Neither PR fraction (PRF) nor PR volume (PRV) correlated with RV end-diastolic volume (r = 0.36; p = 0.15 and r = 0.37; p = 0.14, respectively, for PRF and PRV) or RV end-systolic volume (r = 0.2; p = 0.42 and r = 0.19; p = 0.45, respectively, for PRF and PRV). Similarly, no significant correlations were observed between PRF or PRV and RV ejection fraction (r = –0.04; p = 0.87 and r = –0.03; p = 0.9, respectively).ConclusionsAdditional haemodynamic abnormalities are associated with the abolition of the protective effect of RVOTO on RV size. There was no significant relationship between measures of PR and RV volumes in patients after TOF repair with concomitant haemodynamic abnormalities. These abnormalities acted as confounding factors in the assessment of the impact of pulmonary regurgitation on RV size and function.