Enhanced echocardiographic assessment of intracardiac flow in congenital heart disease.

BACKGROUND: 4D flow magnetic resonance imaging (4D flow MRI) can assess and measure the complex flow patterns of the right ventricle (RV) in congenital heart diseases, but its limited availability makes the broad application of intracardiac flow assessment challenging. Color Doppler imaging velocity reconstruction from conventional echocardiography is an emerging alternative, but its validity against 4D flow MRI needs to be established. OBJECTIVE: To compare intracardiac flow parameters measured by color Doppler velocity reconstruction (DoVeR) against parameters measured from 4D flow MRI. METHODS: We analyzed 20 subjects, including 7 normal RVs and 13 abnormal RVs (10 with repaired Tetralogy of Fallot, and 3 with atrial-level shunts). Intracardiac flow parameters such as relative pressure difference, vortex strength, total kinetic energy, and viscous energy loss were quantified using DoVeR and 4D flow MRI. The agreement between the two methods was determined by comparing the spatial fields and quantifying the cross-correlation and normalized difference between time-series measurements. RESULTS: The hemodynamic parameters obtained from DoVeR and 4D flow MRI showed similar flow characteristics and spatial distributions. The time evolutions of the parameters were also in good agreement between the two methods. The median correlation coefficient between the time-series of any parameter was between 0.87 and 0.92, and the median L2-norm deviation was between 10% to 14%. CONCLUSIONS: Our study shows that DoVeR is a reliable alternative to 4D flow MRI for quantifying intracardiac hemodynamic parameters in the RV.

Automated isochronal late activation mapping for substrate characterization in patients with repaired tetralogy of Fallot.

AIMS: Slow conduction (SC) anatomical isthmuses (AIs) are the dominant substrate for monomorphic ventricular tachycardia (VT) in patients with repaired tetralogy of Fallot (rTF). This study aimed to evaluate the utility of automated propagational analysis for the identification of SC-AI in patients with rTF. METHODS AND RESULTS: Consecutive rTF patients undergoing VT substrate characterization were included. Automated isochronal late activation maps (ILAM) were obtained with multielectrode HD Grid Catheter. Identified deceleration zones (DZs) were compared with both SC-AI defined by conduction velocity (CV) (<0.5 m/s) and isthmuses of induced VT for mechanistic correlation. Fourteen patients were included (age 48; p25-75 35-52 years; 57% male), 2 with spontaneous VT and 12 for risk stratification. Nine VTs were inducible in seven patients. Procedure time was 140 (p25-75 133-180) min and mapping time 29.5 (p25-75 20-37.7) min, using a median of 2167 points. All the patients had at least one AI by substrate mapping, identifying a total of 27 (11 SC-AIs). Isochronal late activation maps detected 10 DZs mostly in the AI between ventricular septal defect and pulmonary valve (80%). Five patients had no DZs. A significant negative correlation between number of isochrones/cm and CV was observed (rho -0.87; P < 0.001). Deceleration zones correctly identified SC-AI (90% sensitivity; 100% specificity; 0.94 accuracy) and was related to VT inducibility (P = 0.006). Deceleration zones co-localized to the critical isthmus of induced VTs in 88% of cases. No complications were observed. CONCLUSION: Deceleration zones displayed by ILAM during sinus rhythm accurately identify SC-AIs in rTF patients allowing a safe and short-time VT substrate characterization procedure.

Surgical repair of tetralogy of Fallot in a 78-year-old woman: a case report.

BACKGROUND: Tetralogy of Fallot is a congenital heart disease mostly diagnosed and treated in early childhood. However, there are some adult cases receiving treatment. CASE PRESENTATION: We describe a 78-year-old Japanese woman who presented with severely hypertrophic right ventricle, ventricular septum defect, overriding aorta, and severe infundibular stenosis in the right ventricular outflow tract. As hypoxemia was mild and daily exertion was sufficiently possible, home oxygen therapy was introduced. After 1 month, she was referred because of a positive blood culture. The blood culture test was positive four times, therefore, the antibacterial drug was administered according to active infective endocarditis. SpO2 repeatedly decreased during hospitalization, thus oxygen was needed. As there were infective endocarditis onset and progressive hypoxemia, we planned a surgical correction. CONCLUSION: Tetralogy of Fallot was diagnosed and successfully treated with complete surgical correction, and the development of infective endocarditis was the definitive indication for surgery at this late age.

Tetralogy of Fallot complicated by multiple cerebral abscesses in a child: a case report.

INTRODUCTION: Brain abscesses are rare but potentially fatal condition and can be associated with cyanotic congenital heart disease of which 5-18.7% of these patients that develop cerebral abscess commonly have tetralogy of Fallot (TOF). CASE PRESENTATION: We report a case of 3-year-old Muganda male that presented with convulsions, cyanosis and difficulty in breathing. The patient had a combination intervention of medical treatment and surgical drainage of the abscess. Post-operative Computerized tomography scan images and pre-operative brain Computerized tomography scans were compared. The multiple rings enhancing lesions were reduced in number and sizes. The largest measured ring was 44 × 22.5×16mm compared to the previous; 42 × 41×36mm. The mass effect had reduced from 16 mm to 7.5 mm. The periventricular hypodensities persisted. Findings showed radiological improvement with residual abscesses, subacute subdural hematoma and pneumocranium. The patient was treated with intravenous ceftriaxone 1 g OD for six weeks and he showed marked improvement and was discharged home after 3 months. CONCLUSION: A comprehensive strategy involving medications, surgical drainage, and early neurosurgical consultation is vital in treating brain abscesses in uncorrected TOF. Early identification of the pathogen, appropriate antibiotic therapy, and vigilant follow-up through clinical assessments and imaging are crucial, potentially spanning a 4-8-week treatment.

A rare case of a neonate with fallot-type absent pulmonary valve and occlusion of the left main bronchus.

Fallot-type absent pulmonary valve is a rare and complex congenital heart disease. Repair surgery for this condition during the neonatal period has a mortality rate of over 50%. We reported a neonate with Fallot-type absent pulmonary valve and occlusion of the left main bronchus. The patient's pulmonary artery had unusual anatomy of a type that has not previously been reported. This case report outlines a successful treatment strategy for patients with complex congenital heart disease and airway occlusion during the neonatal period and the effect of these unusual anatomical conditions on postoperative outcomes.

Long-Term Outcomes of Cardiac Resynchronization Therapy in Patients With Repaired Tetralogy of Fallot: A Multicenter Study.

BACKGROUND: A growing number of patients with tetralogy of Fallot develop left ventricular systolic dysfunction and heart failure, in addition to right ventricular dysfunction. Although cardiac resynchronization therapy (CRT) is an established treatment option, the effect of CRT in this population is still not well defined. This study aimed to investigate the early and late efficacy, survival, and safety of CRT in patients with tetralogy of Fallot. METHODS: Data were analyzed from an observational, retrospective, multicenter cohort, initiated jointly by the Pediatric and Congenital Electrophysiology Society and the International Society of Adult Congenital Heart Disease. Twelve centers contributed baseline and longitudinal data, including vital status, left ventricular ejection fraction (LVEF), QRS duration, and NYHA functional class. Outcomes were analyzed at early (3 months), intermediate (1 year), and late follow-up (≥2 years) after CRT implantation. RESULTS: A total of 44 patients (40.3±19.2 years) with tetralogy of Fallot and CRT were enrolled. Twenty-nine (65.9%) patients had right ventricular pacing before CRT upgrade. The left ventricular ejection fraction improved from 32% [24%-44%] at baseline to 42% [32%-50%] at early follow-up (P<0.001) and remained improved from baseline thereafter (P≤0.002). The QRS duration decreased from 180 [160-205] ms at baseline to 152 [133-182] ms at early follow-up (P<0.001) and remained decreased at intermediate and late follow-up (P≤0.001). Patients with upgraded CRT had consistent improvement in left ventricular ejection fraction and QRS duration at each time point (P≤0.004). Patients had a significantly improved New York Heart Association functional class after CRT implantation at each time point compared with baseline (P≤0.002). The transplant-free survival rates at 3, 5, and 8 years after CRT implantation were 85%, 79%, and 73%. CONCLUSIONS: In patients with tetralogy of Fallot treated with CRT consistent improvement in QRS duration, left ventricular ejection fraction, New York Heart Association functional class, and reasonable long-term survival were observed. The findings from this multicenter study support the consideration of CRT in this unique population.

Aveir retrievable, 38-mm length, leadless pacemaker implantation in a 23-kg pediatric patient with congenital heart disease.

INTRODUCTION: Complications are more prevalent in pediatric patients receiving pacemaker implants. METHODS: We performed a retrospective review of a retrievable, 38 mm leadless pacemaker implantation in a 23-kg pediatric patient. CASE/DISCUSSION: An active 9-year-old, 23 kg male patient with tetralogy of Fallot with intermittent pacing need presented with a fractured lead and pacing need. He underwent implant of a retrievable leadless pacemaker (Abbott Aveir) via internal jugular vein access, without complication, and with echocardiographic guidance. His threshold was stable at 1.25 V @0.4 ms, with stable impedance and sensing at 5-month follow-up. CONCLUSION: Aveir retrievable leadless pacemakers can be implanted safely in a child with tetralogy of Fallot, as small as 23 kilograms.

Morphometrics predicts the differential regurgitant fraction in bilateral pulmonary arteries of patients with repaired tetralogy of fallot.

In patients with repaired tetralogy of Fallot (rTOF), the regurgitant fraction (RF) in left pulmonary artery (LPA) and right pulmonary artery (RPA) is usually unequal. The morphometrics may play a crucial role in this RF discrepancy. Cardiovascular MR of 79 rTOF patients and 20 healthy controls were retrospectively enrolled. Forty-four from the 79 patients were matched in age, sex and body surface area to the 20 controls and were investigated for: (1) phase-contrast flow of main pulmonary artery (MPA), LPA, and RPA; (2) vascular angles: the angles between the thoracic anterior-posterior line (TAPL) with MPA (θM-AP), MPA with RPA (θM-R), and MPA with LPA (θM-L); (3) cardiac angle, the angle between TAPL and the interventricular septum; (4) area ratio of bilateral lung and hemithorax regions. Compared with the 20 controls, the 44 rTOF patients exhibited wider θM-AP, sharper θM-L angle, and a smaller θM-L/θM-R ratio. In the 79 rTOF patients, LPA showed lower forward, backward, and net flow, and greater RF as compared with RPA. Multivariate analysis showed that the RF of LPA was negatively associated with the θM-L/θM-R ratio and the age at surgery (R2 = 0.255). Conversely, the RF of RPA was negatively associated with the left lung/left hemithorax area ratio and cross-sectional area (CSA) of LPA, and positively associated with CSA of RPA and MPA (R2 = 0.366). In rTOF patients, the RF of LPA is more severe than that of RPA, which may be related to the vascular morphometrics. Different morphometric parameters are independently associated with the RF of LPA or RPA, which may offer potential insights for surgical strategies.

Right Ventricular and Outflow Tract Functional Characteristics After Repair of Tetralogy of Fallot with Major Aortopulmonary Collaterals.

This study describes right ventricle (RV) characteristics and right ventricle to pulmonary artery (RV-PA) conduit function pre- and post-repair in patients with tetraology of Fallot with major aortopulmonary collaterals (TOF/MAPCAs). We reviewed patients who underwent single-stage, complete unifocalization, and repair of TOF/MAPCAs between 2006 and 2019 with available pre- and early postoperative echocardiograms. For a subset of patients, 6-12 month follow-up echocardiogram was available. RV and left ventricle (LV) characteristics and RV-PA conduit function were reviewed. Wilcoxon signed rank test and McNemar's test were used. 170 patients were reviewed, 46 had follow-up echocardiograms. Tricuspid valve annular plane systolic excursion (TAPSE) Z-scores were reduced from pre- (Z-score 0.01) to post-repair (Z-score -4.5, p < 0.001), improved but remained abnormal at follow-up (Z-score -4.0, p < 0.001). RV fractional area change (FAC) and LV ejection fraction were not significantly different before and after surgery. Conduit regurgitation was moderate or greater in 11% at discharge, increased to 65% at follow-up. RV-PA conduit failure (severe pulmonary stenosis or severe pulmonary regurgitation) was noted in 61, and 63% had dilated RV (diastolic RV area Z-score > 2) at follow-up. RV dilation correlated with the severe conduit regurgitation (p = 0.018). Longitudinal RV function was reduced after complete repair of TOF/MAPCAs, with decreased TAPSE and preserved FAC and LV ejection fraction. TAPSE improved but did not normalize at follow-up. Severe RV-PA conduit dysfunction was observed prior to discharge in 11% of patients and in 61% at follow-up. RV dilation was common at follow-up, especially in the presence of severe conduit regurgitation.

Association of tetralogy of Fallot and complete atrioventricular canal: a single-centre 40-year experience.

OBJECTIVES: Outcome data in tetralogy of Fallot (ToF) and complete atrioventricular canal (CAVC) are limited. We report our experience for over 40 years in this patient population. METHODS: Single-centre, retrospective analysis of patients who underwent surgical repair with the diagnosis of ToF-CAVC from 1979 to 2022, divided into 2 different periods and compared. RESULTS: A total of 116 patients were included: 1979-2007 (n = 61) and 2008-2021 (n = 55). Balanced CAVC (80%) and Rastelli type C CAVC (81%) were most common. Patients in the later era were younger (4 vs 14 months, P < 0.001), fewer had trisomy 21 (60% vs 80%, P = 0.019) and fewer had prior palliative prior procedures (31% vs 43%, P < 0.001). In the earlier era, single-patch technique was more common (62% vs 16%, P < 0.001), and in recent era, double-patch technique was more common (84% vs 33%, P < 0.001). In the earlier era, right ventricular outflow tract was most commonly reconstructed with transannular patch (51%), while in more recent era, valve-sparing repairs were more common (69%) (P < 0.001). In-hospital mortality was 4.3%. The median follow-up was 217 and 74 months for the first and second eras. Survival for earlier and later eras at 2-, 5- and 10-year follow-up was (85.1%, 81.5%, 79.6% vs 94.2%, 94.2%, 94.2% respectively, log-rank test P = 0.03). CONCLUSIONS: The surgical approach to ToF-CAVC has evolved over time. More recently, patients tended to receive primary repair at younger ages and had fewer palliative procedures. Improved surgical techniques allowing for earlier and complete repair have shown a decrease in mortality, more valve-sparing procedures without an increase in total reoperations. Presented at the 37th EACTS Annual Meeting, Vienna, Austria.

Impact of pulmonary stenosis on right ventricular global longitudinal strain in repaired tetralogy of Fallot patients post transcatheter pulmonary valve replacement.

BACKGROUND: Mixed pulmonary disease with pulmonary regurgitation (PR) and stenosis (PS) in repaired tetralogy of Fallot (rTOF) can negatively impact ventricular health. Myocardial strain has been shown to be more sensitive at detecting occult ventricular dysfunction compared to right ventricular ejection fraction (RV EF). We hypothesize that rTOF patients with predominant PS will have lower RV global longitudinal strain (RV GLS) prior to and post-transcatheter pulmonary valve replacement (TPVR). METHODS: A retrospective cohort of rTOF patients who underwent cardiac magnetic resonance (CMR) and cardiac catheterization for right ventricular pressure (RVSP) measurement were analyzed at three time points: before valve implantation, at discharge and within 18 months post-TPVR. Patients were dichotomized into three groups based on RVSP: 0%-49%, 50%-74%, and >75%. RV GLS and left ventricular (LV) GLS by speckle tracking echocardiography (STE) were obtained from the apical 4-chamber using TomTec software (TOMTEC IS, Germany). RESULTS: Forty-eight patients were included. Every 14.3% increase in preimplantation RVSP above 28% was associated with an absolute magnitude 1% lower RV GLS (p = .001). Preimplantation RVSP when 75% or higher had 3.36% worse RV GLS than the lowest bin (p = .014). Overall, average RV strain magnitude was higher when preimplantation RVSP was less than 50% and had greater improvement over the three time points. Higher post implantation RVSP correlated with lower strain magnitude. CONCLUSION: Patients with significant PS (>50%) may benefit from earlier PVR and not depend solely on RV size and EF. Myocardial strain may be a more sensitive marker of function; however, larger, prospective studies are needed.

Staged therapeutic surgery for progressive pulmonary regurgitation and pacemaker induced cardiomyopathy after the tetralogy of fallot repair.

BACKGROUND: Recently, improvements in the repair of tetralogy of Fallot have increased the need for reoperation in adulthood, and it's not rare that these reoperation candidates suffer from biventricular failure. However, there are no firm treatment guidelines, and each country, and even each facility, treats each case individually. CASE PRESENTATION: We report the successful staged treatment of pulmonary regurgitation and pacemaker-induced cardiomyopathy with biventricular failure in adulthood in a case of complete atrioventricular block after tetralogy of Fallot repair in childhood. We planned a staged therapeutic strategy with preoperative left ventricular volume reduction with medication, following surgical pulmonary valve replacement concomitant epicardial lead implantation on the lateral basal wall, placed just beneath the generator pocket through 3rd intercostal space. in addition to postoperative intervention with a defibrillator to adjust cardiac resynchronization therapy, resulted in improvement of symptoms. CONCLUSION: In a patient with biventricular failure after TOF repair, a staged treatment strategy involving medication, PVR, and CRT with a combination of epicardial and intravenous leads could be a useful treatment worth trying before heart transplantation.

Quadricuspid aortic valve in a neonate with Fallot's tetralogy.

A 3-day-old male neonate was referred to our hospital for a cardiac echocardiogram.

Transcatheter pulmonary valve replacement in surgically-created double-barrel right ventricular outflow tracts: A single center case-series.

This manuscript describes the feasibility and approach to the assessment and performance of transcatheter pulmonary valve replacement (tPVR) in patients with surgically-created "double-barrel" right ventricular outflow tracts (RVOT). Patients with tetralogy of Fallot may have coronary anomalies which prohibit the performance of traditional tetralogy of Fallot repair. In certain cases, this may necessitate the placement of a right ventricle to pulmonary artery conduit in addition to the native RVOT, which is left in situ, creating so-called "double-barrel" RVOTs. When these patients develop RVOT dysfunction later in life, they would typically be referred for reoperation due to concerns for risk of coronary compression associated with a transcatheter approach. However, whether a transcatheter approach with valve replacement in the native RVOT is feasible or safe is unknown. This was a retrospective review of patients with a surgically created "double-barrel" RVOTs who underwent cardiac catheterization for assessment of tPVR at Boston Children's Hospital. From July 2012 to July 2022, there were four patients with "double-barrel" RVOTs who underwent assessment for tPVR. The age at catheterization ranged between 22 and 39 years. In three out of four patients, coronary compression testing was negative. These three patients had successful tPVR in the native RVOT. At follow up, all three patients were free of greater than mild regurgitation by echocardiogram and had a maximum instantaneous gradient across the RVOT ranging between 20 and 33 mmHg. Performance of tPVR in patients with surgically created "double-barrel" RVOTs is feasible. The safety of this procedure depends crucially on coronary artery assessment at all stages.

Predictive value of Cardiac Magnetic Resonance: new and old parameters in the natural history of repaired Tetralogy of Fallot.

BACKGROUND: Patients with repaired Tetralogy of Fallot (rTOF) often develop pulmonary regurgitation (PR) and right ventricle (RV) dysfunction, experiencing increased mortality and morbidity rates in adulthood. Pulmonary valve replacement (PVR) timing to address PR is controversial. Cardiac Magnetic Resonance (CMR) is the gold standard for morpho-functional evaluation of complex cardiopathies. This study aims to identify CMR parameters predictive of adverse outcomes to help defining the best therapeutic management of rTOF patients. METHODS: 130 rTOF patients who underwent CMR (2006-2019) were enrolled in this retrospective single-center study. CMR, clinical, ECG and exercise data were analyzed. Univariate and multivariate analyses identified clinical and CMR parameters predictive of adverse outcomes both individually (e.g., death, arrhythmias, heart failure (HF), pharmacological therapy, QRS ≥ 160ms) and as composite outcome. RESULTS: Univariate analysis confirmed RV volumes and RV ejection fraction corrected for PR as adverse outcome predictors and identified interesting correlations: pulmonary artery bifurcation geometry and abnormal interventricular septum (IVS) motion with arrhythmias (p < .001; p = .037), HF (p = .049; p = .005), composite outcome (p = .039; p = .009); right atrium (RA) dimensions with the composite outcome and the outcomes individually (p < .001). The best predictive models by multivariate analysis included sex (male), RV and RA dilation for QRS ≥ 160ms, time form repair to CMR, age at TOF repair and IVS fibrosis for pharmacological therapy. CONCLUSIONS: Besides RV volumes, new adverse prognostic factors could guide rTOF therapeutic management: pulmonary arteries morphology, abnormal IVS motion, RV dysfunction, RA dilation. Perspective multicentric evaluation is needed to specify their effective role.

Prognostic value of right ventricular dyssynchrony in adults with repaired tetralogy of Fallot.

OBJECTIVE: Residual sequelae after surgical repair of tetralogy of Fallot (rTOF) affect clinical outcome. We investigated the prognostic impact of right ventricular (RV) dyssynchrony in adults with rTOF years after the surgical repair. METHODS: Patients from the Swiss Adult Congenital HEart disease Registry were included. NT-proBNP levels, echocardiography, exercise testing and MRI data were collected. An offline strain analysis to quantify RV-ventricular and interventricular dyssynchrony was performed. The standard deviation of the time-to-peak shortening (TTP) of six RV segments defined the RV Dyssynchrony Index (RVDI). Maximal difference of TTP between RV and left ventricular segments defined the interventricular shortening delay (IVSD). Predictors of a composite adverse event (arrhythmias, hospitalisation for heart failure and death) were identified by multivariate Cox regression analysis. Their median values were used to create a risk score. RESULTS: Out of 285 included patients (mean age 34±14 years), 33 patients (12%) experienced an adverse event during a mean follow-up of 48±21 months. No correlation was found between RVDI, IVSD and clinical events. NT-proBNP, right atrial area and peak heart rate were independent predictors of outcomes. After 4 years-follow-up, no adverse events occurred in patients at low risk (score=0 points), while an adverse event occurred in 62% of patients at high risk (score=3 points, p<0.001). CONCLUSION: In our cohort of adults with rTOF, surrogates of RV dyssynchrony did not correlate with outcomes. A multimodality approach was effective in predicting the risk for adverse events.

Tetralogy of Fallot: Hypoxia, the villain of the story?

BACKGROUND: Tetralogy of Fallot (ToF) is a cyanotic congenital heart disease, composed of four malformations: persistent communication between the right and the left ventricle, pulmonary stenosis, overriding aorta, and right ventricle hypertrophy. The etiology of this disease is not entirely known as yet, but it has been proposed that the pathology has genetic components. During embryonic development, the fetus is exposed to a physiological hypoxia to facilitate the formation of blood vessels and blood cells through de novo processes. METHODS: After researching scientific databases on the implications of oxygen on the normal and abnormal development of organs, especially the heart, we were able to propose that oxygen deprivation may be the cause of the disease. RESULTS: During this period, the hypoxia-inducible factor is activated and triggers transcriptional responses that enable adaptation to the hypoxic environment through angiogenic activation. High levels of this protein can alter certain physiological pathways, such as those related to the vascular endothelial growth factor. Research has shown that prolonged oxygen deprivation during embryological development can lead to the occurrence of congenital heart diseases, such as ToF. CONCLUSIONS: Studies using animal models have demonstrated that the deficiency or disruption of a protein called "CITED2," which plays an important role in cardiac morphogenesis and its loss, results in the alteration of pluripotent, cardiac, and neural lineage differentiation, thereby disrupting the normal development of the heart and other tissues.