Extracardiac Doppler indices predict perinatal mortality in fetuses with Ebstein anomaly and tricuspid valve dysplasia.

OBJECTIVES: Ebstein anomaly and tricuspid valve dysplasia (EA/TVD) carry high perinatal mortality. Past studies have focused on cardiac predictors of mortality; we sought to describe the fetal echo (FE) extracardiac Dopplers in this cohort and determine their association with perinatal mortality. METHOD: Fetuses with EA/TVD at 23 centers from 2005-2011 were included for retrospective study. Doppler pattern and velocity of the umbilical artery (UA), umbilical vein (UV), ductus venosus (DV), and middle cerebral artery (MCA) were collected. Bivariate and multivariate analyzes were performed. The primary outcome measure was perinatal mortality, defined as fetal demise or neonatal death. RESULTS: Of 190 cases that met eligibility criteria, alterations were seen in 50% of UA, 16% of UV, 48% of DV, and 8% of MCA Doppler indices on the last FE (median 27.4 weeks). Independent predictors of perinatal mortality included abnormal UA Doppler pattern of absence or reversed end diastolic flow (OR 9.7) and UV velocity z score <1 (OR 2.5), in addition to diagnosis <32 weeks (OR 4.2) and tricuspid valve (TV) annulus z score ≥6 (OR 5.3). CONCLUSION: Abnormal UA Doppler pattern and decreased UV velocity are independent predictors of perinatal mortality in EA/TVD fetuses and should be used to refine mortality risk and guide perinatal management.

Challenges and lessons learned from the Pediatric Heart Network Normal Echocardiogram Database study.

BACKGROUND: The Pediatric Heart Network Normal Echocardiogram Database Study had unanticipated challenges. We sought to describe these challenges and lessons learned to improve the design of future studies. METHODS: Challenges were divided into three categories: enrolment, echocardiographic imaging, and protocol violations. Memoranda, Core Lab reports, and adjudication logs were reviewed. A centre-level questionnaire provided information regarding local processes for data collection. Descriptive statistics were used, and chi-square tests determined differences in imaging quality. RESULTS: For the 19 participating centres, challenges with enrolment included variations in Institutional Review Board definitions of "retrospective" eligibility, overestimation of non-White participants, centre categorisation of Hispanic participants that differed from National Institutes of Health definitions, and exclusion of potential participants due to missing demographic data. Institutional Review Board amendments resolved many of these challenges. There was an unanticipated burden imposed on centres due to high numbers of echocardiograms that were reviewed but failed to meet submission criteria. Additionally, image transfer software malfunctions delayed Core Lab image review and feedback. Between the early and late study periods, the proportion of unacceptable echocardiograms submitted to the Core Lab decreased (14 versus 7%, p < 0.01). Most protocol violations were from eligibility violations and inadvertent protected health information disclosure (overall 2.5%). Adjudication committee reviews led to protocol changes. CONCLUSIONS: Numerous challenges encountered during the Normal Echocardiogram Database Study prolonged study enrolment. The retrospective design and flaws in image transfer software were key impediments to study completion and should be considered when designing future studies collecting echocardiographic images as a primary outcome.

Outcomes and Predictors of Perinatal Mortality in Fetuses With Ebstein Anomaly or Tricuspid Valve Dysplasia in the Current Era: A Multicenter Study.

BACKGROUND: Ebstein anomaly and tricuspid valve dysplasia are rare congenital tricuspid valve malformations associated with high perinatal mortality. The literature consists of small, single-center case series spanning several decades. We performed a multicenter study to assess the outcomes and factors associated with mortality after fetal diagnosis in the current era. METHODS AND RESULTS: Fetuses diagnosed with Ebstein anomaly and tricuspid valve dysplasia from 2005 to 2011 were included from 23 centers. The primary outcome was perinatal mortality, defined as fetal demise or death before neonatal discharge. Of 243 fetuses diagnosed at a mean gestational age of 27±6 weeks, there were 11 lost to follow-up (5%), 15 terminations (6%), and 41 demises (17%). In the live-born cohort of 176 live-born patients, 56 (32%) died before discharge, yielding an overall perinatal mortality of 45%. Independent predictors of mortality at the time of diagnosis were gestational age <32 weeks (odds ratio, 8.6; 95% confidence interval, 3.5-21.0; P<0.001), tricuspid valve annulus diameter z-score (odds ratio, 1.3; 95% confidence interval, 1.1-1.5; P<0.001), pulmonary regurgitation (odds ratio, 2.9; 95% confidence interval, 1.4-6.2; P<0.001), and a pericardial effusion (odds ratio, 2.5; 95% confidence interval, 1.1-6.0; P=0.04). Nonsurvivors were more likely to have pulmonary regurgitation at any gestational age (61% versus 34%; P<0.001), and lower gestational age and weight at birth (35 versus 37 weeks; 2.5 versus 3.0 kg; both P<0.001). CONCLUSION: In this large, contemporary series of fetuses with Ebstein anomaly and tricuspid valve dysplasia, perinatal mortality remained high. Fetuses with pulmonary regurgitation, indicating circular shunt physiology, are a high-risk cohort and may benefit from more innovative therapeutic approaches to improve survival.

Impact of Neonatal Intervention on Left Ventricular Performance in Ebstein's Anomaly and Tricuspid Valve Dysplasia.

BACKGROUND: Severe neonatal Ebstein's anomaly (EA) and tricuspid valve dysplasia (TVD) are associated with high perinatal morbidity and mortality. The authors recently demonstrated left ventricular (LV) dysfunction and dyssynchrony to be prevalent in affected newborns and to contribute to poor outcomes. The aim of this study was to investigate the impact of patent ductus arteriosus (PDA) closure, spontaneous or surgical ligation, or right ventricular exclusion (Starnes procedure) on LV performance in neonatal EA and TVD. METHODS: Neonates with EA or TVD encountered from 2004 to 2018 at three institutions were identified. Pre- and postoperative LV function was assessed using two-dimensional, Doppler-derived deformation (six-segment vector velocity imaging) and two measures of mechanical dyssynchrony (the SD of time to peak and global dyssynchrony index), and values were compared using paired t test analysis or the Wilcoxon rank sum test. RESULTS: Before the intervention, LV function was impaired in the PDA (n = 18) and Starnes (n = 6) groups and was similar between groups. After PDA closure, LV performance did not change. After the Starnes procedure, however, LV function, including synchrony, improved significantly: fractional area change from 45 ± 5% to 58 ± 8% (P = .003), global circumferential strain from -18.2 ± 5.0% to -32.5 ± 5.5% (P = .01), cardiac index from 1.9 ± 0.3 to 3.9 ± 1.5 L/min/m2 (P = .05), and circumferential strain dyssynchrony (dyssynchrony index from 0.19 ± 0.09 to 0.04 ± 0.02 [P = .009] and SD of time to peak from 59.8 ± 18.5 to 29.9 ± 8.2 [P = .02]). CONCLUSION: The Starnes procedure results in early improvements in LV dysfunction and dyssynchrony, not observed after PDA closure in neonatal severe EA and TVD, which may benefit critically unwell neonates.

Left Ventricular Dysfunction in Neonatal Ebstein's Anomaly and Tricuspid Valve Dysplasia.

BACKGROUND: The mechanisms and prognostic importance of left ventricular (LV) dysfunction in neonatal Ebstein's anomaly (EA) and tricuspid valve dysplasia (TVD) are not well understood. The authors recently demonstrated reduced cardiac output and dyssynchrony to be common in fetal EA/TVD and therefore hypothesized that LV dysfunction may be associated with worse outcomes in neonatal EA/TVD. METHODS: A multicenter retrospective case-control study was conducted among neonatal patients with EA/TVD (n = 32) and a healthy control cohort (n = 17) encountered from 2004 to 2019. The left ventricle was assessed in the first 48 hours after birth using two-dimensional, Doppler-derived, six-segment global and segmental longitudinal strain and circumferential strain (CS) and dyssynchrony indices (the SD of time-to-peak strain and a novel global dyssynchrony index [DI], calculated as [peak segmental average - peak global average]/peak segmental average). RESULTS: Neonates with EA/TVD demonstrated reduced combined cardiac index (4.2 ± 1.5 L/min/m2 vs 6.5 ± 2.2 L/min/m2 in control subjects, P < .001), impaired LV CS (-15.4 ± 6.9 vs -26.2 ± 5.8, P < .001), and increased circumferential dyssynchrony (CS DI 0.20 ± 0.16 vs 0.09 ± 0.04 [P = .019]; SD of time-to-peak CS 63 ± 25 vs 40 ± 15 [P = .003]). Transplantation-free survival occurred in 20 of 32 patients (63%) at 6 months. Increased CS DI and absence of pulmonary valve flow (PVF) were most predictive of mortality; CS DI > 0.2 was associated with 25% survival in subjects without PVF, whereas all patients with CS DI < 0.1 survived. CONCLUSIONS: In neonates with EA/TVD and absence of PVF, there is abnormal LV deformation and compromised cardiac output in association with increased dyssynchrony. Increased CS DI is associated with increased risk for mortality in EA/TVD with no forward PVF.

Risk Factors for Mortality and Circulatory Outcome Among Neonates Prenatally Diagnosed With Ebstein Anomaly or Tricuspid Valve Dysplasia: A Multicenter Study.

Background In a recent multicenter study of perinatal outcome in fetuses with Ebstein anomaly or tricuspid valve dysplasia, we found that one third of live-born patients died before hospital discharge. We sought to further describe postnatal management strategies and to define risk factors for neonatal mortality and circulatory outcome at discharge. Methods and Results This 23-center, retrospective study from 2005 to 2011 included 243 fetuses with Ebstein anomaly or tricuspid valve dysplasia. Among live-born patients, clinical and echocardiographic factors were evaluated for association with neonatal mortality and palliated versus biventricular circulation at discharge. Of 176 live-born patients, 7 received comfort care, 11 died <24 hours after birth, and 4 had insufficient data. Among 154 remaining patients, 38 (25%) did not survive to discharge. Nearly half (46%) underwent intervention. Mortality differed by procedure; no deaths occurred in patients who underwent right ventricular exclusion. At discharge, 56% of the cohort had a biventricular circulation (13% following intervention) and 19% were palliated. Lower tricuspid regurgitation jet velocity (odds ratio [OR], 2.3 [1.1-5.0], 95% CI, per m/s; P=0.025) and lack of antegrade flow across the pulmonary valve (OR, 4.5 [1.3-14.2]; P=0.015) were associated with neonatal mortality by multivariable logistic regression. These variables, along with smaller pulmonary valve dimension, were also associated with a palliated outcome. Conclusions Among neonates with Ebstein anomaly or tricuspid valve dysplasia diagnosed in utero, a variety of management strategies were used across centers, with poor outcomes overall. High-risk patients with low tricuspid regurgitation jet velocity and no antegrade pulmonary blood flow should be considered for right ventricular exclusion to optimize their chance of survival.

Quantitative Assessment of Left Ventricular Dysfunction in Fetal Ebstein's Anomaly and Tricuspid Valve Dysplasia.

BACKGROUND: Fetal Ebstein's anomaly and tricuspid valve dysplasia (EA/TVD) are associated with high perinatal mortality relative to pulmonary atresia with intact ventricular septum (PAIVS), despite both requiring redistribution of the cardiac output (CO) to the left ventricle (LV). LV dysfunction is suspected to contribute to adverse outcomes in EA/TVD. OBJECTIVE: We sought to examine global and segmental LV function in fetal EA/TVD with comparison to normal controls and PAIVS. We hypothesized that LV dysfunction in EA/TVD is associated with abnormal LV remodeling and interventricular mechanics. METHODS: We retrospectively identified 63 cases of fetal EA/TVD (40 with retrograde ductal flow) and 22 cases of PAIVS encountered from 2004 to 2015 and compared findings to 77 controls of comparable gestational age. We measured the combined CO and global LV function using two-dimensional, Doppler-derived, deformational (six-segmental vector velocity imaging) and dyssynchrony indices (DIs; SD of time to peak), and a novel global DI. RESULTS: EA/TVD fetuses demonstrated abnormal LV global systolic function with reduced ejection fraction, fractional area change, and CO, while in PAIVS we observed a normal ejection fraction, fractional area change, and CO. PAIVS, but not EA/TVD, demonstrated increased LV sphericity, suggestive of remodeling, and associated enhanced radial function in the third trimester. In contrast, while EA/TVD fetuses had normal LV segmental longitudinal strain, there was abnormal radial segmental deformation and LV dyssynchrony with increased SD of time to peak and DI. CONCLUSIONS: Fetal EA/TVD is associated with a lack of spherical remodeling and presence of mechanical dyssynchrony, which likely contribute to reduced CO and ejection fraction. Clinical monitoring of LV function is warranted in fetal EA/TVD. Further studies incorporating quantification of LV function into prediction models for adverse outcomes are required.

Challenges With Left Ventricular Functional Parameters: The Pediatric Heart Network Normal Echocardiogram Database.

BACKGROUND: The reliability of left ventricular (LV) systolic functional indices calculated from blinded echocardiographic measurements of LV size has not been tested in a large cohort of healthy children. The objective of this study was to estimate interobserver variability in standard measurements of LV size and systolic function in children with normal cardiac anatomy and qualitatively normal function. METHODS: The Pediatric Heart Network Normal Echocardiogram Database collected normal echocardiograms from healthy children ≤18 years old distributed equally by age, gender, and race. A core lab used two-dimensional echocardiograms to measure LV dimensions from which a separate data coordinating center calculated LV volumes and systolic functional indices. To evaluate interobserver variability, two independent expert pediatric echocardiographic observers remeasured LV dimensions on a subset of studies, while blinded to calculated volumes and functional indices. RESULTS: Of 3,215 subjects with measurable images, 552 (17%) had a calculated LV shortening fraction (SF) < 25% and/or LV ejection fraction (EF) < 50%; the subjects were significantly younger and smaller than those with normal values. When the core lab and independent observer measurements were compared, individual LV size parameter intraclass correlation coefficients were high (0.81-0.99), indicating high reproducibility. The intraclass correlation coefficients were lower for SF (0.24) and EF (0.56). Comparing reviewers, 40/56 (71%) of those with an abnormal SF and 36/104 (35%) of those with a normal SF based on core lab measurements were calculated as abnormal from at least one independent observer. In contrast, an abnormal EF was less commonly calculated from the independent observers' repeat measures; only 9/47 (19%) of those with an abnormal EF and 8/113 (7%) of those with a normal EF based on core lab measurements were calculated as abnormal by at least one independent observer. CONCLUSIONS: Although blinded measurements of LV size show good reproducibility in healthy children, subsequently calculated LV functional indices reveal significant variability despite qualitatively normal systolic function. This suggests that, in clinical practice, abnormal SF/EF values may result in repeat measures of LV size to match the subjective assessment of function. Abnormal LV functional indices were more prevalent in younger, smaller children.

Anomalies of left coronary artery origin affecting surgical repair of hypoplastic left heart syndrome and Shone complex.

There has traditionally been less concern regarding coronary anomalies with left-sided congenital heart lesions such as hypoplastic left heart syndrome (HLHS)or Shone complex than with other lesions. However, coronary anomalies in this setting can profoundly affect surgical intervention, particularly when surgical repair involves the ascending aorta. We describe four patients with congenital left-sided heart lesions in which left coronary artery (LCA) anomalies substantially affected intervention and outcome. In the first two cases, the coronary anomalies were not identified prospectively and resulted in surgical injury directly to the coronary or to its surrounding region. In the latter two cases, successful identification of the coronary anomaly preoperatively allowed for modification of surgical technique and/or intervention. We conclude that detailed coronary artery assessment should be part of the routine echocardiographic evaluation of congenital left-sided heart lesions that require surgery.

Severe hypotension associated with the prone position in a child with scoliosis and pectus excavatum undergoing posterior spinal fusion.

STUDY DESIGN: Case report. OBJECTIVE: We report a case of severe hypotension associated with prone positioning in a child with scoliosis and pectus excavatum. SUMMARY OF BACKGROUND DATA: Pectus excavatum is commonly associated with scoliosis and can impact cardiac function. METHODS: Retrospective case analysis. RESULTS: After a modified Ravitch procedure to repair the pectus excavatum, the patient was able to undergo posterior spinal fusion. CONCLUSIONS: Pediatric deformity surgery requires a multidisciplinary approach.

Hypoplastic left heart syndrome with intact or highly restrictive atrial septum: outcome after neonatal transcatheter atrial septostomy.

BACKGROUND: Hypoplastic left heart syndrome (HLHS) with intact or very restrictive atrial septum is a highly lethal combination. We review our 13-year institutional experience treating this high-risk subgroup of patients with emergent catheter therapy. METHODS AND RESULTS: Infants with HLHS requiring catheter septostomy within the first 2 days of life were compared with a matched control group with adequate interatrial communication. Preoperative, early postoperative, and medium-term survival were evaluated. Earlier experience was compared with recent results to assess the effect of changes in catheterization and surgical and intensive care unit management strategies over the study period. From 1990 to 2002, 33 newborns with HLHS (11% of newborns with HLHS managed during this period) underwent urgent/semiurgent catheterization to create or enlarge an interatrial communication before surgical palliation. Preoperative and early postoperative mortality were high (48%) compared with control HLHS patients, regardless of prenatal diagnosis and despite successful catheter-based atrial septostomy with clinical stabilization. Mortality trended down during the later part of the study period. Those who survived the neonatal period had late survival, pulmonary artery pressure, and resistance similar to those of control subjects. CONCLUSIONS: Neonatal mortality in the subgroup of HLHS patients with intact or highly restrictive atrial septum remains high despite successful urgent septostomy. Persistently poor outcomes for these patients have prompted efforts at our center to develop techniques for fetal intervention for this condition, in the hope that prenatal relief of left atrial and pulmonary venous hypertension may promote normal pulmonary vascular and parenchymal development and improve both short- and long-term outcomes.

Creation of an atrial septal defect in utero for fetuses with hypoplastic left heart syndrome and intact or highly restrictive atrial septum.

BACKGROUND: Infants born with hypoplastic left heart syndrome and an intact or highly restrictive atrial septum face a neonatal mortality of at least 48% despite early postnatal left atrial decompression and palliative surgery. Prenatal left atrial decompression has been suggested as a means of improving these outcomes. This study reports the feasibility of fetal catheterization to create an interatrial communication and describes technical considerations. METHODS AND RESULTS: Seven fetuses at 26 to 34 weeks' gestation with hypoplastic left heart syndrome and intact or highly restrictive atrial septum underwent attempted prenatal intervention. Under ultrasound guidance, the atrial septum was approached with a needle introduced percutaneously from the maternal abdominal surface. In 6 of 7 fetuses, the atrial septum was successfully perforated, with balloon dilation of this iatrogenic defect resulting in a small but persistent interatrial communication. There were no maternal complications. One fetus died after the procedure. The remaining fetuses were liveborn at term, although 4 died as neonates. CONCLUSIONS: Ultrasound-guided fetal atrial septoplasty consisting of septal puncture and balloon dilation is feasible and can be performed percutaneously to minimize maternal risk. Although we have not demonstrated any positive clinical impact to date, it is our hope that further technical evolution will ultimately enable prenatal left atrial decompression and improvement of outcomes in fetuses with hypoplastic left heart syndrome and intact atrial septum.

Balloon dilation of severe aortic stenosis in the fetus: potential for prevention of hypoplastic left heart syndrome: candidate selection, technique, and results of successful intervention.

BACKGROUND: Preventing the progression of fetal aortic stenosis (AS) to hypoplastic left heart syndrome (HLHS) requires identification of fetuses with salvageable left hearts who would progress to HLHS if left untreated, a successful in utero valvotomy, and demonstration that a successful valvotomy promotes left heart growth in utero. Fetuses meeting the first criterion are undefined, and previous reports of fetal AS dilation have not evaluated the impact of intervention on in utero growth of left heart structures. METHODS AND RESULTS: We offered fetal AS dilation to 24 mothers whose fetuses had AS. At least 3 echocardiographers assigned a high probability that all 24 fetuses would progress to HLHS if left untreated. Twenty (21 to 29 weeks' gestation) underwent attempted AS dilation, with technical success in 14. Ideal fetal positioning for cannula puncture site and course of the needle (with or without laparotomy) proved to be necessary for procedural success. Serial fetal echocardiograms after intervention demonstrated growth arrest of the left heart structures in unsuccessful cases and in those who declined the procedure, while ongoing left heart growth was seen in successful cases. Resumed left heart growth led to a 2-ventricle circulation at birth in 3 babies. CONCLUSIONS: Fetal echocardiography can identify midgestation fetuses with AS who are at high risk for developing HLHS. Timely and successful aortic valve dilation requires ideal fetal and cannula positioning, prevents left heart growth arrest, and may result in normal ventricular anatomy and function at birth.

Association between cardiac tumors and tuberous sclerosis in the fetus and neonate.

A retrospective review was performed in 94 patients with > or =1 cardiac tumors seen on prenatal or neonatal echocardiography at 5 major referral centers. Tuberous sclerosis was present in 68 patients diagnosed with a cardiac tumor in utero or during the neonatal period, including 61 of 64 with multiple tumors.

Transesophageal Echocardiography During Interventional Catheterization in Congenital Heart Disease.

The rapidly expanding role of transesophageal echocardiography (TEE) in the management and treatment of congenital heart disease includes guidance of interventional cardiac catheterization procedures and monitoring of results. TEE is particularly helpful for assessing device position during device closure of atrial septal defects (ASD), ventricular septal defects, and perivalvar defects, especially when multiple or complex defects are present. It is also useful during balloon dilation of certain congenital and postoperative obstructions. Stent placement for treatment of intracardiac obstructions is facilitated by TEE guidance. The risks associated with Brockenbrough transseptal puncture and ASD enlargement, particularly in the setting of unusual atrial anatomy, may be reduced by TEE guidance of the procedure. TEE monitoring of video assisted thoracoscopic closure of patent ductus arteriousus has contributed to the high success rate of this innovative procedure. TEE imaging assists in positioning of devices and catheters, reduces radiation exposure and contrast load, and provides immediate and continuous assessment not only of results, but of potential complications of interventional procedures. As the applications of interventional catheterization in the field of pediatric cardiology increase so will the role of TEE.

Echocardiographic diagnosis of right ventricular inflow compression associated with pectus excavatum during spinal fusion in prone position.

INTRODUCTION: Pectus excavatum is commonly viewed as a benign condition. Associated alterations in hemodynamics are rare. We present an unusual case of right ventricular inflow obstruction and hemodynamic compromise as a consequence of pectus excavatum encountered during surgical intervention. CASE: a 15-year-old male with pectus excavatum and thoracolumbar scoliosis developed severe hypotension after induction of general anesthesia and placement in the prone position for elective spinal fusion. A transesophageal echocardiogram revealed anterior compression of the right heart by the sternum with peak and mean right ventricular inflow gradients of 7 and 4 mm Hg, respectively. The gradient resolved with supine positioning and was reproduced with direct compression of the sternum. CONCLUSIONS: Although pectus excavatum is generally a benign condition, the cardiologist should be aware of the potential for serious hemodynamic compromise related to positioning in these patients.

Accuracy of the fetal echocardiogram in double-outlet right ventricle.

OBJECTIVE: Double-outlet right ventricle (DORV) is a complex congenital heart defect with heterogeneous anatomy. Patients require a variety of surgical interventions, and the long-term prognosis is variable. Therefore, accurate prenatal diagnosis is important in providing parents with appropriate counseling. DESIGN: Medical records were reviewed in patients with a diagnosis of DORV who had fetal echocardiography at our institution from 1998 to 2004. Pre- and postnatal diagnoses were compared, anticipated surgical procedure was compared with surgery performed, and neonatal outcome was assessed. RESULTS: The study group consisted of 49 fetal patients with 6 in utero deaths (including 4 terminations), 2 patients lost to follow-up, and 41 live births. Postnatal echocardiograms or autopsy results were available on 42 patients. The overall accuracy of fetal echocardiography in making a correct diagnosis of DORV was 76%. Accurate prenatal prediction of the type of cardiac surgery that would be performed was made in 91% of patients who had surgery. Among live births, survival to hospital discharge was 76%. Survival was 50% in patients with extracardiac or chromosomal anomalies, compared with 92% in infants without additional anomalies. CONCLUSION: In most cases, careful evaluation by fetal echocardiography can determine essential anatomic details in fetuses with DORV with enough accuracy to allow for accurate counseling regarding the type of surgery needed. Survival is better than previously reported but is poor in patients with extracardiac or chromosomal abnormalities.

Prenatal role of the ductus arteriosus in absent pulmonary valve syndrome.

Absent pulmonary valve with ventricular septal defect is associated with ductal agenesis and markedly dilated main and branch pulmonary arteries. The less common variant with intact ventricular septum generally exhibits a patent ductus and smaller branch pulmonary arteries, and may be associated with tricuspid atresia. We identified 7 patients with the prenatal diagnosis of absent pulmonary valve, 5 with ventricular septal defect (Group 1) and 2 with an intact ventricular septum (Group 2). Imaging, color Doppler, and pulsed-Doppler recordings were analyzed. The branch and main pulmonary arteries were measured and expressed as a ratio with the descending aorta. Pulmonary regurgitation time (PRT) and diastolic acceleration time (DAT) were derived, and DAT/PRT was calculated to characterize diastolic pulmonary flow. Group 1 patients all had a large ventricular septal defect, normal biventricular size and function, and dilated main and branch pulmonary arteries. Group 2 patients had dilated main but smaller branch pulmonary arteries, moderate right ventricular dilation with severe dysfunction, and limited or absent tricuspid inflow. Group 1 demonstrated shorter acceleration time and earlier peak velocity, resulting in a smaller DAT/RT ratio. We speculate that free communication between the fetal aorta and the ventricles may limit atrial inflow and elevate diastolic pressure, affecting cardiac output, ventricular function, and atrioventricular valve development. With an intact ventricular septum, these physiologic and anatomic repercussions are limited to the right ventricle, but with a ventricular septal defect, both ventricles would experience similar consequences and cardiac performance could be critically impaired.