Comprehensive Approach to the Management of Patients with HLHS: Analysis of 100 Consecutive Neonates.

BACKGROUND: We report our comprehensive approach to patients with hypoplastic left heart syndrome (HLHS) and describe our outcomes in 100 consecutive neonates. METHODS: One-hundred consecutive neonates (2015-2023) were stratified into 3 pathways: Pathway(1): 77/100=77% were standard-risk and underwent initial Norwood (Stage 1). Pathway(2): 10/100=10% were high-risk with noncardiac risk factors and underwent initial Hybrid Stage 1. Pathway(3): 13/100=13% were high-risk with cardiac risk factors: 10 underwent initial Hybrid Stage 1 + ventricular assist device insertion (HYBRID+VAD), while 3 underwent primary transplantation. RESULTS: One-year mortality=9/100=9%. Pathway(1): Operative Mortality for initial Norwood (Stage 1)=2/77=2.6%. Of 75 survivors of Norwood (Stage 1): 72 underwent successful Glenn, 2 underwent successful biventricular repair, and 1 underwent successful cardiac transplantation. Pathway(2): Operative Mortality for initial Hybrid Stage 1 without VAD=1/10=10%. Of 9 survivors of Hybrid (Stage 1): 4 underwent successful cardiac transplantation, 2 died while awaiting cardiac transplantation, 3 underwent Comprehensive Stage 2 (with 1 death), and 1 underwent successful biventricular repair. Pathway(3): Of 10 HYBRID+VAD: 7/10=70% underwent successful cardiac transplantation and are alive today and 3/10=30% died on VAD while awaiting transplantation. Median VAD support time=134 days (range=56-226). (Two of three patients who were bridged-to-transplant with prostaglandin underwent successful transplantation and one died while awaiting transplantation.) CONCLUSIONS: A comprehensive approach to the management of patients with HLHS is associated with Operative Mortality after Norwood of 2/77=2.6% and an overall one-year mortality of 9/100=9%. 10/100 patients=10% were stabilized with HYBRID+VAD while awaiting transplantation. VAD facilitates survival on the waiting list during prolonged wait times.

Mind the Gap! Working Toward Gender Equity in Pediatric and Congenital Heart Disease: Present and Future.

Evidence from medicine and other fields has shown that gender diversity results in better decision making and outcomes. The incoming workforce of congenital heart specialists (especially in pediatric cardiology) appears to be more gender balanced, but past studies have shown many inequities. Gender-associated differences in leadership positions, opportunities presented for academic advancement, and recognition for academic contributions to the field persist. In addition, compensation packages remain disparate if evaluated based on gender with equivalent experience and expertise. This review explores these inequities and has suggested individual and institutional changes that could be made to recruit and retain women, monitor the climate of the institution, and identify and eliminate bias in areas like salary and promotions.

Coarctation Duration and Severity Predict Risk of Hypertension Precursors in a Preclinical Model and Hypertensive Status Among Patients.

BACKGROUND: Coarctation of the aorta (CoA) often leads to hypertension posttreatment. Evidence is lacking for the current >20 mm Hg peak-to-peak blood pressure (BP) gradient (BPGpp) guideline, which can cause aortic thickening, stiffening, and dysfunction. This study sought to find the BPGpp severity and duration that avoid persistent dysfunction in a preclinical model and test if predictors translate to hypertension status in patients with CoA. METHODS: Rabbits (n=75; 5-12/group) were exposed to mild, intermediate, or severe CoA (≤12, 13-19, ≥20 mm Hg BPGpp) for ≈1, 3, or 22 weeks using dissolvable and permanent sutures with thickening, stiffening, contraction, and endothelial function evaluated via multivariate regression. Relevance to patients with CoA (n=239; age, 0.01-46 years; median 3.7 months) was tested by retrospective review of predictors (preoperative BPGpp, surgical age, etc.) versus follow-up hypertension status. RESULTS: CoA duration and severity were predictive of aortic remodeling and active dysfunction in rabbits, and hypertension in patients with CoA. Interaction between patient age and BPGpp at surgery contributed significantly to hypertension, similar to rabbits, suggesting preclinical findings translate to patients. Machine learning decision tree analysis uncovered that preoperative BPGpp and surgical age predict risk of hypertension along with residual postoperative BPGpp. CONCLUSIONS: These findings suggest the current BPGpp threshold determined decades ago is likely too high to prevent adverse coarctation-induced aortic remodeling. The results and decision tree analysis provide a foundation for revising CoA treatment guidelines considering the interaction between CoA severity and duration to limit the risk of hypertension.

Coarctation duration and severity predict risk of hypertension precursors in a preclinical model and hypertensive status among patients.

Background: Coarctation of the aorta (CoA) often leads to hypertension (HTN) post-treatment. Evidence is lacking for the current >20 mmHg peak-to-peak blood pressure gradient (BPGpp) guideline, which can cause aortic thickening, stiffening and dysfunction. This study sought to find the BPGpp severity and duration that avoid persistent dysfunction in a preclinical model, and test if predictors translate to HTN status in CoA patients. Methods: Rabbits (N=75; 5-12/group) were exposed to mild, intermediate or severe CoA (≤12, 13-19, ≥20 mmHg BPGpp) for ~1, 3 or 22 weeks using dissolvable and permanent sutures with thickening, stiffening, contraction and endothelial function evaluated via multivariate regression. Relevance to CoA patients (N=239; age=0.01-46 years; median 3.7 months) was tested by retrospective review of predictors (preoperative BPGpp, surgical age, etc.) vs follow-up HTN status. Results: CoA duration and severity were predictive of aortic remodeling and active dysfunction in rabbits, and HTN in CoA patients. Interaction between patient age and BPGpp at surgery contributed significantly to HTN, similar to rabbits, suggesting preclinical findings translate to patients. Machine learning decision tree analysis uncovered that pre-operative BPGpp and surgical age predict risk of HTN along with residual post-operative BPGpp. Conclusions: These findings suggest the current BPGpp threshold determined decades ago is likely too high to prevent adverse coarctation-induced aortic remodeling. The results and decision tree analysis provide a foundation for revising CoA treatment guidelines considering the interaction between CoA severity and duration to limit the risk of HTN.

A Comprehensive Approach to the Management of Patients With HLHS and Related Malformations: An Analysis of 83 Patients (2015-2021).

Background: Some patients with hypoplastic left heart syndrome (HLHS) and HLHS-related malformations with ductal-dependent systemic circulation are extremely high-risk for Norwood palliation. We report our comprehensive approach to the management of these patients designed to maximize survival and optimize the utilization of donor hearts. Methods: We reviewed our entire current single center experience with 83 neonates and infants with HLHS and HLHS-related malformations (2015-2021). Standard-risk patients (n = 62) underwent initial Norwood (Stage 1) palliation. High-risk patients with risk factors other than major cardiac risk factors (n = 9) underwent initial Hybrid Stage 1 palliation, consisting of application of bilateral pulmonary bands, stent placement in the patent arterial duct, and atrial septectomy if needed. High-risk patients with major cardiac risk factors (n = 9) were bridged to transplantation with initial combined Hybrid Stage 1 palliation and pulsatile ventricular assist device (VAD) insertion (HYBRID + VAD). Three patients were bridged to transplantation with prostaglandin. Results: Overall survival at 1 year = 90.4% (75/83). Operative Mortality for standard-risk patients undergoing initial Norwood (Stage 1) Operation was 2/62 (3.2%). Of 60 survivors: 57 underwent Glenn, 2 underwent biventricular repair, and 1 underwent cardiac transplantation. Operative Mortality for high-risk patients with risk factors other than major cardiac risk factors undergoing initial Hybrid Stage 1 palliation without VAD was 0/9: 4 underwent transplantation, 1 awaits transplantation, 3 underwent Comprehensive Stage 2 (with 1 death), and 1 underwent biventricular repair. Of 9 HYBRID + VAD patients, 6 (67%) underwent successful cardiac transplantation and are alive today and 3 (33%) died while awaiting transplantation on VAD. Median length of VAD support was 134 days (mean = 134, range = 56-226). Conclusion: A comprehensive approach to the management of patients with HLHS or HLHS-related malformations is associated with Operative Mortality after Norwood of 2/62 = 3.2% and a one-year survival of 75/83 = 90.4%. A subset of 9/83 patients (11%) were stabilized with HYBRID + VAD while awaiting transplantation. VAD facilitates survival on the waiting list during prolonged wait times.

Palliation Plus Ventricular Assist Device Insertion in 15 Neonates and Infants With Functionally Univentricular Circulation.

BACKGROUND: We report 15 high-risk neonates and infants with functionally univentricular circulation stabilized with initial surgical palliation plus ventricular assist device (VAD) insertion (PALLIATION+VAD) in preparation for transplantation. METHODS: Fifteen functionally univentricular patients with ductal-dependent systemic circulation (8 hypoplastic left heart syndrome, 1 hypoplastic left heart syndrome-related malformation: 7 neonates, 2 infants) or ductal-dependent pulmonary circulation (6 hypoplastic right heart syndrome: 5 neonates, 1 infant) presented with anatomical and/or physiological features associated with increased risk for conventional univentricular palliation (large coronary sinusoids with ventricular-dependent coronary circulation, severe systemic atrioventricular valvar regurgitation, cardiogenic shock, or restrictive atrial septum). PALLIATION+VAD for patients with ductal-dependent systemic circulation was: VAD insertion plus application of bilateral pulmonary bands, stent placement in the arterial duct, and atrial septectomy, if needed. PALLIATION+VAD for patients with ductal-dependent pulmonary circulation was: VAD insertion plus stent placement in the arterial duct or systemic-to-pulmonary artery shunt with pulmonary arterioplasty, if needed. RESULTS: At PALLIATION+VAD, median age was 20 days (range, 4-143 days) and median weight was 3.47 kg (range, 2.43-4.86 kg). Ten patients (67%) survived and 5 patients (33%) died. All ten survivors are at home doing well after successful transplantation. Only 2 of 10 survivors (20%) required intubation >10 days after PALLIATION+VAD. Median length of VAD support for all 15 patients was 138 days (range, 56-226 days). CONCLUSIONS: High-risk neonates with functionally univentricular hearts who are suboptimal candidates for conventional palliation can be successfully stabilized with pulsatile VAD insertion along with initial palliation while awaiting cardiac transplantation; these patients may be extubated, enterally nourished, and optimized for transplantation while on VAD.

Combined Hybrid Procedure and VAD Insertion in 9 High-Risk Neonates and Infants With HLHS.

BACKGROUND: This report describes 9 high-risk neonates and infants with hypoplastic left heart syndrome (HLHS) who were stabilized with a combined hybrid approach and ventricular assist device (VAD) insertion (HYBRID+VAD) in preparation for heart transplantation. METHODS: A total of 9 patients with HLHS (7 neonates, 2 infants) presented with anatomic or physiologic features associated with an increased risk for conventional univentricular palliation with the Norwood operation (large coronary sinusoids or fistulas, severe tricuspid regurgitation, cardiogenic shock, restrictive atrial septum). These patients underwent combined VAD insertion (Berlin EXCOR, Berlin Heart, Inc, Berlin, Germany) and Stage 1 hybrid palliation (application of bilateral pulmonary bands, stent placement in the patent arterial duct, and atrial septectomy if needed). During this same era, at the Congenital Heart Center, University of Florida, Gainesville, Florida, 46 neonates underwent a Norwood operation, 4 neonates underwent a hybrid approach "Stage 1" without VAD, and 3 patients with HLHS were supported with prostaglandin while awaiting heart transplantation. RESULTS: At HYBRID+VAD insertion, the median age was 20 days (range, 13 to 143 days), and median weight was 3.25 kg (range, 2.43 to 4.2 kg). Six patients survive (67%), and 3 patients died (33%). Five survivors are at home doing well after successful heart transplantation, and 1 survivor is doing well in the intensive care unit on VAD support while awaiting transplantation. Only 1 of 6 survivors (16.7%) required intubation more than 10 days after HYBRID+VAD insertion. In 8 patients no longer undergoing VAD support, the median length of VAD support was 119.5 days (range, 56 to 196 days). CONCLUSIONS: High-risk patients with HLHS who are suboptimal candidates for Norwood palliation can be successfully stabilized with pulsatile VAD insertion along with hybrid palliation while awaiting cardiac transplantation. These patients may be extubated and optimized for transplantation while undergoing VAD support.

Optimized Computed Tomography Angiography Protocol for the Evaluation of Thrombus in Patients with Fontan Anatomy.

The Fontan procedure is the final stage in the palliative surgical approach to patients with single-ventricle physiology. These patients have an increased risk for thromboembolic disease in the Fontan circuit, which can be evaluated by chest computed tomography angiography (CTA) in acute settings. However, false-positive results are common secondary to unusual streaming patterns in the Fontan circuit. A biphasic CTA protocol was evaluated for the capability to clearly identify structures of the Fontan circuit that are critical for the evaluation of thromboembolic disease. The study was a retrospective chart review of Fontan patients with a chest CTA scan obtained between 2011 and 2017. Two pediatric cardiologists with additional training in cardiac CT imaging independently reviewed each CTA and awarded one point for each of 5 Fontan circuit structures clearly identified resulting in a score range of 0-5. A score of 0-2 considered not capable, 3-4 partially capable, and 5 capable to clearly identify critical structures of the Fontan circuit. During the study period, 46 CTA scans were performed on 21 patients. Of the CTA scans using a biphasic protocol, 62.5% (10/16) were considered capable to clearly identify all 5 critical structures of the Fontan circuit vs 27% (8/30) of the CTA scans using a monophasic protocol (p = 0.027). Overall our results suggest that the single-site biphasic CTA protocol has greater diagnostic capability to detect the presence of Fontan thromboembolic disease when compared to the more traditional monophasic CTA protocol. Future prospective studies are needed to confirm these findings.

Impact of 3D Printouts in Optimizing Surgical Results for Complex Congenital Heart Disease.

Planning corrective and palliative surgery for patients who have complex congenital heart disease often relies on the assessment of cardiac anatomy using two-dimensional noninvasive cardiac imaging modalities (echocardiography, cardiac magnetic resonance imaging, and computed tomography scan). Advances in cardiac noninvasive imaging now include the use of three-dimensional (3D) reconstruction tools that produce 3D images and 3D printouts. There is scant evidence available in the literature as to what effect the availability of 3D printouts of complex congenital heart defects has on surgical outcomes. Surgical outcomes of study subjects with a 3D cardiac printout available and their paired control subject without a 3D cardiac printout available were compared. We found a trend toward shorter surgical times in the study group who had the benefit of 3D models, but no statistical significance was found for bypass time, cross-clamp time, total time, length of stay, or respiratory support. These preliminary results support the proposal that 3D modeling be made readily available to congenital cardiac surgery teams, for use in patients with the most complex congenital heart disease.

Effect of prenatal diagnosis on hospital costs in complete transposition of the great arteries.

OBJECTIVE: Prenatal diagnosis of congenital heart disease (CHD) is associated with improved clinical outcomes, yet its impact on the cost of hospitalization is not well described. We hypothesized that prenatal diagnosis of complete transposition of the great arteries (d-TGA) results in lower total hospital costs compared with postnatal diagnosis. METHODS: Retrospective analysis of infants with d-TGA repaired at our center from July 2006 to 2014. Total charges from initial hospitalization until discharge were converted to costs using the cost-to-charge ratio and then converted into 2016 dollars using the consumer price index. A direct cost comparison from the hospital perspective was performed between groups. A secondary analysis included the cost of prenatal diagnosis. RESULTS: Thirty-three infants with d-TGA were identified; 8 with and 25 without prenatal diagnosis. There was no difference in baseline characteristics. Mean direct cost of hospitalization was higher in infants without prenatal diagnosis ($108 014 ± $51 305 vs $88 305 ± $22 896, P = .31). On secondary analysis, the cost of prenatal diagnosis was negligible compared with total hospital cost. CONCLUSIONS: Total cost of initial hospitalization was higher for infants without prenatal diagnosis of d-TGA. Prenatal diagnosis not only improves clinical outcomes but may also be cost saving in the current era of increasing health care costs.

Maternal hyperoxygenation: A potential therapy for congenital heart disease in the fetuses? A systematic review of the current literature.

OBJECTIVES: To assess efficacy, safety, outcomes, and intrauterine complications following maternal hyperoxygenation (MH) therapy in fetuses with congenital heart disease (CHD). METHODS: A systematic review was performed following an electronic search of databases. Articles were published before January 1, 2017, in an English-language and non-English-language journals (with English translations), and included human fetuses and expectant mothers with a fetal diagnosis of CHD who received MH. RESULTS: Ninety-six articles were identified; 72 were excluded and 24 full-text articles were reviewed. Only 9 articles met inclusion criteria and were analyzed. A total of 270 fetuses underwent MH therapy: 169 had CHD, and 101 had normal heart anatomies. Seven studies used fetal echocardiography, while 2 studies used cardiac magnetic resonance imaging (CMR). The mean gestational age at therapy was 33.4 weeks (26-38 weeks). Majority of MH protocols used 100% FiO2 with non-rebreather face mask at 8 L of flow, achieving 60%-70% FiO2 , or maternal PaO2 goal of 250 mm Hg. No significant adverse events were reported. Four studies reported increased size of the hypoplastic cardiac structures after MH. Three studies utilized acute MH to risk stratify hypoplastic left heart syndrome fetuses. Two studies assessed acute MH in the setting of CMR. CONCLUSION: The current evidence for MH therapy suggests an increase in pulmonary blood flow, and venous return, ductal flow, and heart dimensions in fetuses. MH has potential as a diagnostic and therapeutic tool in fetuses with CHD. Further randomized controlled trials are needed to ascertain whether MH therapy provides improved outcomes on fetuses with certain types of CHD.

Cardiovascular Magnetic Resonance Findings Late After the Arterial Switch Operation.

BACKGROUND: Despite its robust diagnostic capabilities in adolescents and adult patients after the arterial switch operation, little information is available on the cardiovascular magnetic resonance findings in this population. METHODS AND RESULTS: The cardiovascular magnetic resonance findings of 220 consecutive patients evaluated in our center were retrospectively reviewed (median age at cardiovascular magnetic resonance, 15.4 years; 66.8% male sex). Compared with published normal values, left and right ventricular end-diastolic volume z scores were mildly enlarged (0.48±1.76 and 0.33±1.5; P=0.0003 and 0.0038, respectively), with 26% of patients having left ventricular dilatation and 20% having right ventricular dilatation. Left ventricular dysfunction was present in 21.5% of patients (mild in most), and only 5.1% of patients had mild right ventricular dysfunction. Myocardial scar was found in 1.8% of patients. Dilatation of the neoaortic root was common (76%), and root z score increased at an average rate of 0.03 points per year. By multivariable analysis, neoaortic root dilatation was associated with worse neoaortic valve regurgitation (OR, 5.29; P=0.0016). The diameters of the thoracic aorta distal to the root were near-normal in most patients, whereas the neomain pulmonary artery was typically oval shaped with decreased anteroposterior and normal lateral diameters. CONCLUSIONS: Although the majority of arterial switch operation patients have normal ventricular size and function and myocardial scar is rare, an important minority exhibits ventricular enlargement or dysfunction. Neoaortic root dilatation, which is present in most patients and progresses over time, is strongly associated with significant neoaortic valve regurgitation. The findings of this study provide reference values against which arterial switch operation patients can be compared with their peers.

Left Ventricular Metastasis in Neuroblastoma: A Case Report.

Neuroblastoma is the most common extracranial solid tumor in children. Most common sites of metastases from neuroblastoma are bone marrow, bone and lymph nodes, however cardiac metastasis is rarely seen. Metastatic cardiac tumors are 20 to 40 times more common than primary cardiac tumors. Mechanism of cardiac metastasis can be hematogenous, lymphatogenous, and direct extension/infiltration of tumor cells. Usually right heart metastasis is seen. Left ventricular metastatic tumor has never been reported with neuroblastoma.

Goldenhar Syndrome Associated with Extensive Arterial Malformations.

Goldenhar Syndrome is characterized by craniofacial, ocular and vertebral defects secondary to abnormal development of the 1st and 2nd branchial arches and vertebrae. Other findings include cardiac and vascular abnormalities. Though these associations are known, the specific anomalies are not well defined. We present a 7-month-old infant with intermittent respiratory distress that did not improve with respiratory interventions. Echocardiogram suggested a double aortic arch. Cardiac CT angiogram confirmed a right arch and aberrant, stenotic left subclavian artery, dilation of the main pulmonary artery, and agenesis of the left thyroid lobe. Repeat echocardiograms were concerning for severely dilated coronary arteries. Given dilation, a rheumatologic workup ensued, only identifying few weakly positive autoantibodies. Further imaging demonstrated narrowing of the aorta below the renal arteries and extending into the common iliac arteries and proximal femoral arteries. Given a physical exam devoid of rheumatologic findings, only weakly positive autoantibodies, normal inflammatory markers, and presence of the coronary artery dilation, the peripheral artery narrowings were not thought to be vasculitic. This case illustrates the need to identify definitive anomalies related to Goldenhar Syndrome. Although this infant's presentation is rare, recognition of specific vascular findings will help differentiate Goldenhar Syndrome from other disease processes.

Cardiovascular magnetic resonance imaging-based computational fluid dynamics/fluid-structure interaction pilot study to detect early vascular changes in pediatric patients with type 1 diabetes.

We hypothesized that pediatric patients with type 1 diabetes have cardiac magnetic resonance (CMR) detectable differences in thoracic aortic wall properties and hemodynamics leading to significant local differences in indices of wall shear stress, when compared with age-matched control subjects without diabetes. Pediatric patients with type 1 diabetes were recruited from Children's Hospital of Wisconsin and compared with controls. All underwent morning CMR scanning, 4-limb blood pressure, brachial artery reactivity testing, and venipuncture. Patient-specific computational fluid dynamics modeling with fluid-structure interaction, based on CMR data, determined regional time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI). Twenty type 1 diabetic subjects, median age 15.8 years (11.6-18.4) and 8 controls 15.4 years (10.3-18.2) were similar except for higher glucose, hemoglobin A1c, and triglycerides for type 1 diabetic subjects. Lower flow-mediated dilation was seen for those with type 1 diabetes (6.5) versus controls (7.8), p = 0.036. For type 1 diabetic subjects, the aorta had more regions with high TAWSS when compared to controls. OSI maps appeared similar. Flow-mediated dilation positively correlated with age at diabetes diagnosis (r = 0.468, p = 0.038) and hemoglobin A1c (r = 0.472, p = 0.036), but did not correlate with aortic distensibility, TAWSS, or OSI. TAWSS did not correlate with any clinical parameter for either group. CMR shows regional differences in aortic wall properties for young diabetic patients. Some local differences in wall shear stress indices were also observed, but a longitudinal study is now warranted.

Pocket echocardiography system for detection of patent ductus arteriosus in neonates.

BACKGROUND: Neonates are commonly referred for a cardiology consult and an echocardiogram to rule out patent ductus arteriosus (PDA). OBJECTIVES: Evaluate the usefulness of current pocket echocardiography system (PES) in PDA detection compared to traditional full-featured echo system (FFES). HYPOTHESIS: The determination of the presence of a PDA in neonates can be done using PES. METHODS: Fifty newborns with orders for echo evaluation were included in this study. A 5-minute PES scan was performed first. Then a full echo study was performed on a traditional FFES. Images were evaluated by three pediatric cardiologists blinded to the patients and the FFES results. RESULTS: The overall accuracy of reviewers rating PES versus FFES to rule in PDA had low false-positive rates 9.5% (95% CI: 1.2-30%), 11.8% (95% CI: 1.5-36%), 11.1% (95% CI: 1.4-35%) and the false-negative rate to rule out PDA was 0% (95% CI: 0-18%), 5.5% (95% CI: 0.14-27%), 0% (95% CI: 0-26%) for each reviewer 1, 2, and 3, respectively. Upon further analysis, PES scan was shown not to be accurate on infants with body weight below 1000 g with encouraging results for infants above 1000 g and those >37 weeks gestational age. CONCLUSIONS: Our results suggest that the current PES could potentially be used in larger and near-term infants but has less than acceptable performance in low birth weight and premature infants in determining who should undergo a FFES study for persistent PDA diagnosis. Improvements in the technology along with developing limited training protocols for noncardiology personnel should make it possible for PES scan to be used as a screening tool and as an extension of physical examination especially in limited resource settings.

Ventricular septal defect.

BACKGROUND: Ventricular septal defects are the commonest congenital cardiac malformations. They can exist in isolation, but are also found as integral components of other cardiac anomalies, such as tetralogy of Fallot, double outlet right ventricle, or common arterial trunk. As yet, there is no agreement on how best to classify such defects, nor even on the curved surface that is taken to represent the defect. METHODS: Based on our previous pathological and clinical experiences, we have reviewed the history of classification of holes between the ventricles. We proposed that the defects are best defined as representing the area of deficient ventricular septation. This then permits the recognition of clinically significant variants according to the anatomic borders, and the way the curved surface representing the area of deficient septation opens into the morphologically right ventricle. RESULTS: Clinical manifestation depends on the size of the defect, and on the relationship between systemic and pulmonary vascular resistances. Symptoms include failure to thrive, along with the manifestations of the increase in flow of blood to the lungs. Diagnosis can be made by physical examination, but is confirmed by echocardiographic interrogation, which delineates the precise anatomy, and also provides the physiologic information required for optimal clinical decision-making. Cardiac catheterization offers additional information regarding hemodynamics, particularly if there is a concern regarding an increase in pulmonary vascular resistance. Hemodynamic assessment is rarely necessary to make decisions regarding management, although it can be helpful if assessing symptomatic adults with hemodynamically restrictive defects. In infants with defects producing large shunts, surgical closure is now recommended in most instances as soon as symptoms manifest. Only in rare cases is palliative banding of the pulmonary trunk now recommended. Closure with devices inserted on catheters is now the preferred approach for many patients with muscular defects, often using a hybrid procedure. Therapeutic closure should now be anticipated with virtually zero mortality, and with excellent anticipated long-term survival. CONCLUSION: Ventricular septal defects are best defined as representing the borders of the area of deficient ventricular septation. An approach on this basis permits recognition of the clinically significant phenotypic variants.