Normative computed tomography angiography values of the main and branch pulmonary arteries in children.

Non-invasive cardiac imaging like echocardiogram, cardiac magnetic resonance imaging (CMR), and computed tomography angiography (CTA) play a key role in the diagnosis, aid in management and follow-up of congenital heart disease patients. Normative data for intracardiac and extracardiac vascular structures in children are currently available for echocardiogram, CMR, and non-gated CTA. We sought to establish systolic and diastolic normative data for main and branch pulmonary arteries in children using electrocardiogram (ECG)-gated CTA. Diameters and cross-sectional areas of the main and branch pulmonary arteries were measured in systole and diastole based on the aortic valve position (open versus closed) in 100 subjects who had ECG-gated cardiac CTA at our center between January 2015 through December 2020 and met our inclusion criteria. The allometric exponent (AE) for each parameter was derived, and the parameter/body surface area (BSAAE) was established using the previously described methods. A total of 100 children aged 0-18 years were analyzed; mean age was 5.3 years (SD, 6.1 years). Z-score curves were plotted in relation to the BSA for the mean, maximum, and minimum diameters and cross-sectional area of the main and branch pulmonary arteries for systole and diastole.   Conclusion: We report systolic and diastolic mean, maximum, and minimum diameters and cross-sectional areas along with Z-scores and normative curves for the main and branch pulmonary arteries in children derived using ECG-gated cardiac CTA. We believe our results can help identify abnormally sized main and branch pulmonary arteries. What is Known: • Normative data for intracardiac and extracardiac vascular structures in the pediatric population are available for echocardiography, cardiac MRI and non-ECG gated CTA. • Z-scores with standard deviations are commonly used in children, but SDs are not constant across body sizes due to heteroscedasticity. What is New: • Allometric exponent was derived for each parameter and the parameter/body surface area (BSA) was established. • This is the first ECG-gated CTA study to provide normative en face systolic, diastolic diameters and cross-sectional areas along with Z-scores and normative curves for the main and branch pulmonary arteries in children.

Chest pain due to coronary artery compression in an adult with CHD.

A 47-year-old with repaired ventricular septal defect and pulmonary valve stenosis as a child presents with chronic intermittent chest pain. CT evaluation for transcatheter pulmonary valve replacement revealed right coronary artery compression between a sternal wire and dilated right ventricle. Removal of the sternal wire resulted in improved symptoms.

Age-related changes in left ventricular vortex and energy loss patterns: from newborns to adults.

Left ventricular vortex formation optimizes the effective transport of blood volume while minimizing energy loss (EL). Vector flow mapping (VFM)-derived EL patterns have not been described in children, especially in those less than 1 yr of age. A prospective cohort of 66 (0 days-22 yr, 14 patients ≤ 2 mo) cardiovascularly normal children was used to determine left ventricular (LV) vortex number, size (mm2), strength (m2/s), and energy loss (mW/m/m2) in systole and diastole and compared across age groups. One early diastolic (ED) vortex at the anterior mitral leaflet and one late diastolic (LD) vortex at the LV outflow tract (LVOT) were seen in all newborns ≤ 2 mo. At >2 mo, two ED vortices and one LD vortex were seen, with 95% of subjects > 2 yr demonstrating this vortex pattern. Peak and average diastolic EL acutely increased in the same 2 mo-2-yr period and then decreased within the adolescent and young adult age groups. Overall, these findings suggest that the growing heart undergoes a transition to adult vortex flow patterns over the first 2 yr of life with a corresponding acute increase in diastolic EL. These findings offer an initial insight into the dynamic changes of LV flow patterns in pediatric patients and can serve to expand our understanding of cardiac efficiency and physiology in children.NEW & NOTEWORTHY This research article demonstrates, for the first time, echocardiographic evidence of a transition in left ventricular vortex patterns from the newborn to the adult period, with an associated change in cardiac efficiency, marked by increased energy loss, during infancy.

The Secrets of the Frogs Heart.

The heart of the African clawed frog has a double-inlet and single-outlet ventricle supporting systemic and pulmonary circulations via a truncus, and a lifespan of 25-30 years. We sought to understand the unique cardiac anatomic and physiologic characteristics, with balanced circulation and low metabolic rate, by comparing the basic anatomy structures with focused echocardiography and cardiac magnetic resonance imaging. Twenty-four adult female African clawed frogs were randomly subjected to anatomic dissection (n = 4), echocardiography (n = 10), and cardiac magnetic resonance (n = 10). All anatomical features were confirmed and compared with echocardiography and cardiac magnetic resonance imaging. The main characteristics of the cardiovascular circulation in frogs are the following: Intact interatrial septum, with two separate atrio-ventricular valves, preventing atrial mixing of oxygenated and desaturated blood. Single spongiform ventricular cavity, non-conducive for homogeneous mixing. Single outlet with a valve-like mobile spiral structure, actively streaming into systemic and pulmonary arteries. Intact interatrial septum, spongiform ventricle, and valve-like spiral in the conus arteriosus are likely responsible for balanced systemic and pulmonary circulation in frogs, in spite of double-inlet and single-outlet ventricle.

Validation of Right Atrial Area as a Measure of Right Atrial Size and Normal Values of in Healthy Pediatric Population by Two-Dimensional Echocardiography.

Right atrial (RA) size is a prognostic indicator for heart failure and cardiovascular death in adults. Data regarding use of RA area (RAA) by two-dimensional echocardiography as a surrogate for RA size and allometric modeling to define appropriate indexing of the RAA are lacking. Our objective was to validate RAA as a reliable measure of RA size and to define normal reference values by transthoracic echocardiography (TTE) in a large population of healthy children and develop Z-scores using a validated allometric model for indexing RAA independent of age, sex, and body size. Agreement between RAA and volume by 2D, 3D TTE, and MRI was assessed. RAA not volume by 2D TTE is an excellent surrogate for RA size. RAA/BSA1 has an inverse correlation with BSA with a residual relationship to BSA (r = - 0.54, p < 0.0001). The allometric exponent (AE) derived for the entire cohort (0.85) also fails to eliminate the residual relationship. The entire cohort divided into two groups with a BSA cut-off of 1 m2 to provide the best-fit allometric model (r = 0). The AE by least square regression analysis for each group is 0.95 and 0.88 for BSA < 1 m2 and > 1 m2, respectively, and was validated against an independent sample. The mean indexed RAA ± SD for BSA ≤ 1 m2 and > 1 m2 is 9.7 ± 1.3 cm2 and 8.7 ± 1.3 cm2, respectively, and was used to derive Z-scores. RAA by 2D TTE is superior to 2D or 3D echocardiography-derived RA volume as a measure of RA size using CMR as the reference standard. RAA when indexed to BSA1, decreases as body size increases. The best-fit allometric modeling is used to create Z scores. RAA/BSA0.95 for BSA < 1 m2 and RAA/BSA0.88 for those with BSA > 1 m2 can be used to derive Z scores.

Abnormalities in Left Ventricular Rotation Are Inherent in Young Children with Repaired Tetralogy of Fallot and Are Independent of Right Ventricular Dilation.

Left ventricular (LV) dysfunction is a risk factor for adverse outcomes in older children and adults with repaired Tetralogy of Fallot (rToF). Pulmonary regurgitation (PR), right ventricular (RV) dilation, and dysfunction have been shown to result in abnormal LV myocardial mechanics and dysfunction. The aim of our study was to evaluate LV rotational mechanics, especially apical rotation in young children with rToF with and without RV dilation. This is a retrospective, single center study in 28 asymptomatic young children with rToF (16 with RV dilation; 12 without RV dilation); 29 age-matched normal controls. RV and LV systolic and diastolic function was studied using conventional two-dimensional echocardiography (2DE) and speckle tracking echocardiography (STE). Rotational mechanics studied included basal and apical rotation (BR, AR), peak twist (calculated by difference between the apical and basal rotation), twist rate (TR), and untwist rate (UnTR). The mean age of the cohort was 4.7 years (± 2.3). Abnormal AR, BR, TR, and UnTR were noted in patients with rToF. The abnormalities were significant in magnitude as well as the direction of rotation; more pronounced in the absence of RV dilation. LV systolic and diastolic dysfunction as evidenced by abnormal AR and degree of untwist is inherent in rToF and not associated with RV dilation in rToF children. Abnormal BR may reflect a lack of maturation to adult type of rotational mechanics. Further longitudinal studies are required to study the progression of these abnormalities and their correlation with clinical outcomes.

Application of Virtual Three-Dimensional Models for Simultaneous Visualization of Intracardiac Anatomic Relationships in Double Outlet Right Ventricle.

Our goal was to construct three-dimensional (3D) virtual models to allow simultaneous visualization of the ventricles, ventricular septal defect (VSD) and great arteries in patients with complex intracardiac anatomy to aid in surgical planning. We also sought to correlate measurements from the source cardiac magnetic resonance (CMR) image dataset and the 3D model. Complicated ventriculo-arterial relationships in patients with complex conotruncal malformations make preoperative assessment of possible repair pathways difficult. Patients were chosen with double outlet right ventricle for the complexity of intracardiac anatomy and potential for better delineation of anatomic spatial relationships. Virtual 3D models were generated from CMR 3D datasets. Measurements were made on the source CMR as well as the 3D model for the following structures: aortic diameter in orthogonal planes, VSD diameter in orthogonal planes and long axis of right ventricle. A total of six patients were identified for inclusion. The path from the ventricles to each respective outflow tract and the location of the VSD with respect to each great vessel was visualized clearly in all patients. Measurements on the virtual model showed excellent correlation with the source CMR when all measurements were included by Pearson coefficient, r = 0.99 as well as for each individual structure. Construction of virtual 3D models in patients with complex conotruncal defects from 3D CMR datasets allows for simultaneous visualization of anatomic relationships relevant for surgical repair. The availability of these models may allow for a more informed preoperative evaluation in these patients.

Cardiovascular magnetic resonance techniques and findings in children with myocarditis: a multicenter retrospective study.

BACKGROUND: Cardiovascular magnetic resonance (CMR) is increasingly used to diagnose myocarditis in adults but its use in children is not well-established. We sought to describe the presentation, CMR protocol and findings, and outcomes in a multicenter cohort of children with myocarditis. METHODS: Thirteen hospitals retrospectively identified patients meeting the following inclusion criteria: 1) diagnosis of myocarditis by the managing physicians, 2) age <21 years, 3) CMR examination within 30 days of presentation, and 4) no congenital heart disease. Clinical data and test results, including CMR findings, were abstracted from the medical record. RESULTS: For the 143 patients meeting inclusion criteria, the median age was 16.0 years (range, 0.1-20.3) and 139 (97 %) were hospitalized at the time of CMR. The median time from presentation to CMR was 2 days (0-28). The median left ventricular ejection fraction at CMR was 56 % (10-74), with 29 (20 %) below 45 %. The median right ventricular ejection fraction was 54 % (15-72), with 11 (8 %) below 40 %. There was significant variability among centers in the types of tissue characterization techniques employed (p < 0.001). Overall, late gadolinium enhancement (LGE) was used in 100 % of studies, followed by T2-weighted imaging (T2W) in 69 %, first-pass contrast perfusion (FPP) in 48 %, and early gadolinium enhancement (EGE) in 28 %. Abnormalities were most common with LGE (81 %), followed by T2W (74 %), EGE (55 %), and FPP (8 %). The CMR study was interpreted as positive for myocarditis in 117 patients (82 %), negative in 18 (13 %), and equivocal in 7 (5 %), yielding a sensitivity of 82 %. At a median follow-up of 7.1 months (0-87), all patients were alive and 5 had undergone cardiac transplantation. CMR parameters at presentation associated with persistent left ventricular dysfunction were larger left ventricular end-diastolic volume and lower left and right ventricular ejection fraction but not abnormal LGE. CONCLUSIONS: Despite significant practice variation in imaging protocol among centers, CMR had a high sensitivity for the diagnosis of myocarditis in pediatric patients. Abnormalities were most often seen with LGE followed by T2W, EGE, and FPP. These findings should be useful in designing future prospective studies.

Two-dimensional speckle-tracking-derived segmental peak systolic longitudinal strain identifies regional myocardial involvement in patients with myocarditis and normal global left ventricular systolic function.

The presence of myocardial late gadolinium enhancement (LGE) by cardiac magnetic resonance (CMR) imaging in concert with electrocardiography and elevated biomarkers helps support the diagnosis of acute myocarditis. Two-dimensional echocardiography is limited to global and qualitative regional function assessment and may not contribute to the diagnosis, especially in the presence of normal LV systolic function. Two-dimensional speckle-tracking (2D-STE)-derived segmental peak systolic (pkS) longitudinal strain (LS) may identify segmental myocardial involvement in myocarditis. We sought to identify an association between segmental pkS, LGE, and troponin levels in patients with myocarditis. Retrospective analysis of myocardial segmental function by 2D-STE segmental strain was compared to the presence of LGE and admission peak troponin levels in patients with acute myocarditis and preserved global LV systolic function. American Heart Association 17-segment model was used for comparison between imaging modalities. Global function was assessed by m-mode-derived shortening fraction (SF). Descriptive statistics and regression analysis were utilized. Forty-four CMRs performed to evaluate for myocarditis were identified. Of the 44, 10 patients, median age 17.5 years (14-18.5 years) and median SF 35 % (28-44 %), had paired CMR and 2D-STE data for analysis, and 161/170 segments could be analyzed by both methods for comparison. PkS LS was decreased in 51 % of segments that were positive for LGE with average pkS of -14.7 %. Segmental pkS LS abnormalities were present in all but one patient who had abnormal pkS circumferential strain. Global pkS LS was decreased in patients with myocarditis. There is a moderate correlation between decreased pkS LS and the presence of LGE by CMR, 2D-STE for myocardial involvement in acute myocarditis can serve as an useful noninvasive adjunct to the existing tests used for the diagnosis of acute myocarditis and might have a role in prognostication.

Myocardial fatty foci on cardiac MRI in an adult with tuberous sclerosis complex.

We report cardiac MRI findings in a 38-year-old female Tuberous sclerosis complex (TSC) patient with regressed rhabdomyomas. Presence of myocardial fatty foci are associated with multiorgan involvement, although they are not a part of the current TSC diagnostic criteria. Presence of abnormal first pass perfusion and late Gadolinium enhancement in TSC patients should be carefully interpreted to avoid misdiagnosis.

Right and left ventricular cardiac magnetic resonance imaging derived peak systolic strain is abnormal in children with myocarditis.

PURPOSE: Cardiac Magnetic resonance (CMR) derived left ventricular longitudinal and circumferential strain is known to be abnormal in myocarditis. CMR strain is a useful additional tool that can identify subclinical myocardial involvement and may help with longitudinal follow-up. Right ventricular strain derived by CMR in children has not been studied. We sought to evaluate CMR derived biventricular strain in children with acute myocarditis. METHODS: Children with acute myocarditis who underwent CMR between 2016-2022 at our center were reviewed, this group included subjects with COVID-19 myocarditis. Children with no evidence of myocarditis served as controls Those with congenital heart disease and technically limited images for CMR strain analysis were excluded from final analysis. Biventricular longitudinal, circumferential, and radial peak systolic strains were derived using circle cvi42®. Data between cases and controls were compared using an independent sample t-test. One-way ANOVA with post hoc analysis was used to compare COVID-19, non-COVID myocarditis and controls. RESULTS: 38 myocarditis and 14 controls met inclusion criteria (mean age 14.4 ± 3 years). All CMR derived peak strain values except for RV longitudinal strain were abnormal in myocarditis group. One-way ANOVA revealed that there was a statistically significant difference with abnormal RV and LV strain in COVID-19 myocarditis when compared to non-COVID-19 myocarditis and controls. CONCLUSION: CMR derived right and left ventricular peak systolic strain using traditionally acquired cine images were abnormal in children with acute myocarditis. All strain measurements were significantly abnormal in children with COVID-19 even when compared to non-COVID myocarditis.

Normative Computed Tomography Angiography Values of the Aortic Root, Aorta and Aortic arch in Children.

Purpose: Normative values for intracardiac and extracardiac vascular structures help in understanding normal growth and changes over time in children; this normative data are not currently available for ECG-gated Computed Tomography Angiography (CTA). We sought to establish ECG-gated CTA derived normative values for the aortic root, aorta and aortic arch in children. Methods and Results: Aortic root, ascending aorta, aortic arch, and descending aorta were measured in systole and diastole in 100 subjects who had ECG-gated CTA at our center between January 2015 through December 2020 and met our inclusion criteria. The allometric exponent (AE) for each parameter was derived, and the parameter/body surface areaAE (BSAAE) was established using the previously described methods. Using this data, normalized mean, cross-sectional area, and standard deviation were calculated. Z-score curves were plotted in relation to the BSA for all measurements. Conclusion: Our study reports systolic and diastolic ECG-gated CTA Z-scores along with normative curves in relation to BSA for the aortic root, aorta and aortic arch in children.

Cryoablation of ventricular tachycardia arising from the left-coronary sinus cusp.

Ventricular tachycardia (VT) arising from the coronary sinus cusps and mimicking right-ventricular morphology is a rare entity. In this report, we report the successful cryoablation of left-coronary sinus cusp VT.

Impact of 22q11.2 deletion on the postoperative course of children after cardiac surgery.

The primary objective of this study was to describe the impact of 22q11.2 deletion (del22q11) on the clinical characteristics, postoperative course, and short-term outcomes of children undergoing surgery for congenital heart disease. The charts of all children ages 1 day-18 years who received cardiac surgery for interrupted aortic arch (IAA), tetralogy of Fallot (TOF), or truncus arteriosus (TA) repair from 1 January 2001 to 31 December 2011 were retrospectively reviewed. The patients were divided into two groups: the 22q11 group including children with del22q11 undergoing surgery for TOF, IAA, or TA and the non-22q11 or control group including children with no chromosomal or genetic abnormality undergoing surgery for TOF, IAA, or TA. Demographic information, cardiac diagnoses, noncardiac abnormalities, preoperative factors, intraoperative details, surgical procedures performed, postoperative complications, and in-hospital deaths were collected. The outcome data collected included days of inotrope use, need for dialysis, length of mechanical ventilation, intensive care unit (ICU) length of stay (LOS), hospital LOS, and mortality. The study enrolled 173 patients: 65 patients in the 22q11 group and 108 patients in the control group. Of the 65 patients in the 22q11 group, 36 (55 %) underwent repair for TOF, 13 (20 %) for IAA, and 16 (25 %) for TA. The two groups did not differ in terms of age or weight. The preexisting conditions were similar in the two groups. Unplanned noncardiac operations were more common in the children with del22q11, but delayed chest closure was similar in the two groups. The incidence of postoperative noncardiac complications such as reintubation, vocal cord paralysis, and diaphragmatic paralysis was similar in the two groups. However, increasing numbers of patients in del22q11 group needed dialysis in one form or the other during the immediate postoperative stay. The incidence of fungal infection and wound infection was higher in the del22q11 group than in the control group. Duration of mechanical ventilation, ICU LOS, and hospital LOS were similar in the two groups, except in certain subgroups. Mortality did not differ significantly between the two groups. In conclusion, children with del22q11 have a higher risk of postoperative complications after cardiac surgery, with no difference in length of mechanical ventilation, ICU LOS, hospital LOS, or mortality. However, short-term outcomes may differ in certain subgroups.

Ventricular septal defect Doppler peak gradient underestimates right ventricular systolic pressure in the presence of right bundle branch block.

Estimation of the right ventricular systolic pressure (RVSP) using echocardiographically derived maximal instantaneous gradient across the ventricular septal defect is a well-utilized tool, which can potentially underestimate the RVSP in patients with conduction abnormalities as such its utility in these patients is questionable.

Correlation of transthoracic echocardiography-derived pulmonary to systemic flow ratio with hemodynamically estimated left to right shunt in atrial septal defects.

Background: Transthoracic echocardiographic (TTE) estimation of the pulmonary to systemic flow ratio (Qp/Qs) is routinely used in clinical practice and is included in the American Society of Echocardiography Guidelines. We sought to assess its real-world applicability with a particular focus on hemodynamically significant shunt lesions. Methods: Retrospective single institutional review of TTE's in patients with secundum atrial septal defect prior to cardiac catheterization (cath) from 2012 to 2018 was performed (n = 109), those with technically limited images for Qp/Qs calculation (n = 11) and those with time interval between TTE and cath >60 days were excluded (n = 14). Qp/Qs was calculated from stored clips by previously described methods and correlated with those obtained by oximetry. Patients were subdivided into two age groups <21 (Group 1) and ≥22 years (Group 2). TTE and cath methods for Qp/Qs estimation were compared using paired t-test, Pearson's correlation coefficient, and Bland-Altman plots. Results: Eighty-four subjects met inclusion criteria (age range 3-78 years). Group 1 n = 35; median age 10 years; Group 2 n = 49; median age 49 years. Transthoracic echocardiogram was performed 19.5 ± 15 days prior to cath. Mean Qp/Qs derived by cath and TTE were 2.09 ± 0.9 versus 2.54 ± 1.2 (P < 0.0001). Overall correlation was poor between the methods (r 2 = 0.32, P < 0.0001) and continued to be poor for Groups 1 and 2 (r 2= 0.24, P = 0.003 and r 2= 0.40, P < 0.0001 respectively). Bland-Altman plots demonstrated poor agreement between the predetermined limits of agreement (-0.5-1.5). Conclusion: Transthoracic echocardiography estimated Qp/Qs, although routinely utilized in clinical practice, has poor correlation and agreement with oximetry-derived Qp/Qs. The test performs poorly in all age groups in detecting a hemodynamically significant shunt and tends to overestimate the degree of left to right shunt.

Virtual Simulated Implantation of an Adult-Sized Left Ventricular Assist Device in a Pediatric Patient.

There is very limited experience with simulated virtual implantation of left ventricular assist devices (LVADs) to assess device fitness in pediatric patients. In this clinical vignette, we report the case of a 9-year-old male patient with dilated cardiomyopathy who underwent successful placement of an LVAD after virtual simulated implantation was performed. (Level of Difficulty: Advanced.).

Utility of Multimodality Imaging in the Morphologic Characterization of Anomalous Aortic Origin of a Coronary Artery.

BACKGROUND: Anomalous aortic origin of a coronary artery from the wrong Sinus of Valsalva (AAOCA) is a rare congenital anomaly and is associated with sudden cardiac death. Morphologic features considered to be "high risk" are significant luminal narrowing, acute coronary angulation at its origin, intramural course, and long interarterial course. A consistent approach for characterization of these features is lacking. METHODS: A retrospective single-center review of all patients diagnosed with AAOCA using echocardiogram and computed tomography (CT)/magnetic resonance imaging (MRI) studies was performed. Twenty-nine patients were identified (25 using CT and 4 using MRI) with subsequent three-dimensional data sets. The MRI data sets lacked adequate resolution and were excluded. Twenty-five patients (median age 15.1, range 10-39.5 years, 72% male) were further analyzed using echocardiogram and CT. Morphologic assessment focused on luminal stenosis, coronary angulation, and interarterial length. Additional morphologic features focusing on cross-sectional area and degree of ellipticity were also assessed. RESULTS: Echocardiography tended to yield smaller measurements compared to CT and had poor interobserver reproducibility for measurements pertaining to the narrowest proximal and distal coronary segments. Computed tomography showed good inter-/intraobserver reproducibility for the same. Agreement between both modalities for coronary angulation at its origin was excellent. There was good agreement for measurements of interarterial length between echocardiography and CT, but echocardiography had superior reproducibility. Assessment of luminal cross-sectional area and elliptical shape by CT had excellent inter-/intraobserver reproducibility. CONCLUSION: The combination of echocardiography and CT characterizes morphologic features of anomalous origin of the coronary artery more reliably than either modality alone.

Primary tetralogy of Fallot repair: predictors of intensive care unit morbidity.

BACKGROUND: Primary repair of tetralogy of Fallot has low surgical mortality, but some patients still experience significant postoperative morbidity. Our objectives were to review our institutional experience with primary tetralogy of Fallot repair, and identify predictors of intensive care unit morbidity. METHODS: We reviewed all patients with tetralogy of Fallot who underwent primary repair in infancy from 2001 to 2012. Preoperative, operative, and postoperative demographic and morphologic data were analyzed. Intensive care unit morbidity was defined as prolonged intensive care unit stay (≥ 7 days) and/or prolonged duration of mechanical ventilation (≥ 48 h). RESULTS: 97 patients who underwent primary surgical repair during the study period were included in the study. The median age was 4.9 months (range 1-9 months) and the median weight was 5.3 kg (range 3.1-9.8 kg). There was no early surgical mortality. The incidence of junctional ectopic tachycardia and persistent complete heart block was 2% and 1%, respectively. The median intensive care unit stay was 6 days (range 2-21 days) and the median duration of mechanical ventilation was 19 h (range 0-136 h). Age and weight were independent predictors of intensive care unit stay, while surgical era predicted the duration of mechanical ventilation. CONCLUSION: Primary tetralogy of Fallot repair is a safe procedure with low mortality and morbidity in a medium-sized program with outcomes comparable to national standards. Age and weight at the time of surgery were significant predictors of morbidity.