A case of ventricular noncompaction associated with heterotaxy and atrioventricular block diagnosed at 15 weeks of gestation using superb microvascular imaging.

We present a case of fetal atrioventricular block, heterotaxy, and ventricular noncompaction observed longitudinally from the first to early second trimesters using B-mode and Doppler imaging, including superb microvascular imaging. At 12 weeks of gestation, the atrial and ventricular rates were 133 and 67 beats/min, respectively, and dextrocardia was noted. At 15 weeks of gestation, detailed sonography revealed ventricular septal defect, interruption of the inferior vena cava, dilated azygos vein, and double-outlet right ventricle. In addition, superb microvascular imaging revealed irregular contours in the anatomical left ventricular wall, indicating prominent trabeculations of the ventricle, which were characteristic findings of ventricular noncompaction. At 21 weeks of gestation, intrauterine fetal death occurred, and the autopsy revealed complex congenital heart disease, including ventricular noncompaction.

Revisions of clinical protocols using the Plan Do Check Act cycle improved outcomes of extremely preterm infants at 2 years.

AIM: Clinical quality improvement is often cumbersome due to established protocols. We aimed to investigate whether outcomes of preterm infants improve with protocol revisions using iteration cycles. METHODS: Preterm infants born <28 weeks gestation between January 2006 and December 2015 were retrospectively analysed. Protocols were revised using Plan Do Check Act cycle. Death and serious adverse events at term were reviewed in six-monthly quality improvement meetings. Adverse outcome of death or motor/sensory impairments at two years was compared before and after two major protocol changes, which were implemented in January 2008 and January 2012. RESULTS: Based on the appraisal for period 2006-2007, strategies for surfactant, narcotics, parenteral nutrition, respiratory gas humidity and prophylactic indomethacin and antibiotics were changed for period 2008-2011. For period 2012-2015, stabilisation of infants was accelerated via very early catheterisation. Of 162 infants (84 males, 25.5 ± 1.5 weeks gestation) within the whole cohort, 63 developed adverse outcomes, which were fewer for periods 2008-2011 (p = 0.013) and 2012-2015 (p = 0.035) compared with period 2006-2007 (adjusted for gestational age, Apgar scores and sex). CONCLUSION: Careful bottom-up revisions of protocols using iteration cycles, accounting for local settings, successfully improved the outcomes of preterm infants.

Simple method to distinguish the type of fetal premature contraction using arterial Doppler time interval measurements.

AIM: The purpose of this study was to establish a simple method to distinguish premature ventricular contractions (PVC) from premature atrial contractions (PAC) using a fetal Doppler ultrasound arterial pulse waveform to measure time intervals between sinus node restarting. METHODS: We retrospectively identified 14 fetuses with premature contraction (8 with PAC, 6 with PVC). We measured two distinct parts of time intervals using an arterial pulsed-wave Doppler: the two consecutive waveforms just before the premature contraction (2-V interval) and two consecutive waveforms including the premature contraction (XV interval) to measure time intervals between sinus node restarting. We then evaluated the time difference between the 2-V and XV intervals in PVC compared to PAC. RESULTS: For PVC, the difference between the 2-V interval and the XV interval was significantly shorter than that for PAC. A cut-off point of 33 ms, where a difference ≤33 ms was clearly shown to be associated with a PVC and a difference more than 33 ms signified a PAC was demonstrated. CONCLUSION: The 2-V and XV interval measurements, used to measure time intervals between sinus node restarting, could easily distinguish PVC from PAC in utero. Therefore, this study could potentially be a feasible and effective method for obstetricians or sonographers to employ usefully.

Maternal predictive factors for fetal congenital heart block in pregnant mothers positive for anti-SS-A antibodies.

OBJECTIVE: To determine the maternal predictive factors for fetal congenital heart block (CHB) in pregnancy in mothers positive for anti-SS-A antibodies. METHODS: The Research Team for Surveillance of Autoantibody-Exposed Fetuses and Treatment of Neonatal Lupus Erythematosus, the Research Program of the Japan Ministry of Health, Labor and Welfare, performed a national survey on pregnancy of mothers positive for anti-SS-A antibodies. We analyzed 635 pregnant mothers who tested positive for anti-SS-A antibodies before conception but had no previous history of fetal CHB. We performed univariate and multivariate analysis (models 1, 2, and 3 using different set of independent variables) investigated the relation between risk of fetal CHB and maternal clinical features. RESULTS: Of the 635 pregnant mothers, fetal CHB was detected in 16. Univariate analysis showed that fetal CHB associated with use of corticosteroids before conception (OR 3.72, p = 0.04), and negatively with use of corticosteroids (equivalent doses of prednisolone (PSL), at ≥10 mg/day) after conception before 16-week gestation (OR 0.17, p = 0.03). In multivariate analysis, model 1 identified the use of corticosteroids before conception (OR 4.28, p = 0.04) and high titer of anti-SS-A antibodies (OR 3.58, p = 0.02) as independent and significant risk factors, and model 3 identified use of corticosteroids (equivalent doses of PSL, at ≥10 mg/day) after conception before 16-week gestation as independent protective factor against the development of fetal CHB (OR 0.16, p = 0.03). Other maternal clinical features did not influence the development of fetal CHB. CONCLUSION: The results identified high titers of anti-SS-A antibodies and use of corticosteroids before conception as independent risk factors, and use of corticosteroids (equivalent doses of PSL, at ≥10 mg/day) after conception before 16-week gestation as an independent protective factor for fetal CHB.

Fetal bradyarrhythmia associated with congenital heart defects - nationwide survey in Japan.

BACKGROUND: Because there is limited information on fetal bradyarrhythmia associated with congenital heart defects (CHD), we investigated its prognosis and risk factors. METHODS AND RESULTS: In our previous nationwide survey of fetal bradyarrhythmia from 2002 to 2008, 38 fetuses had associated CHD. Detailed clinical data were collected from secondary questionnaires on 29 fetuses from 18 institutions, and were analyzed. The 29 fetuses included 22 with isomerism, 4 with corrected transposition of the great arteries (TGA) and 3 with critical pulmonary stenosis; 14 had complete atrioventricular block (AVB), 8 had second-degree AVB, and 16 had sick sinus syndrome; 5 died before birth, and 10 died after birth (5 in the neonatal period). Neonatal and overall survival rates for fetal bradyarrhythmia with CHD were 66% and 48%, respectively. Pacemaker implantation was needed in 17 cases (89%). Beta-sympathomimetics were administered in utero in 13 cases and were effective in 6, but were not associated with prognosis. All cases of corrected TGA or ventricular rate ≥70 beats/min survived. A ventricular rate <55 beats/min had significant effects on fetal myocardial dysfunction (P=0.02) and fetal hydrops (P=0.04), resulting in high mortality. CONCLUSIONS: The prognosis of fetal bradyarrhythmia with CHD is still poor. The type of CHD, fetal myocardial dysfunction, and fetal hydrops were associated with a poor prognosis, depending on the ventricular rate.

Risk Factors for COVID-19 Cluster Infection in Hospitalized Patients.

Introduction In Japan, in the seventh wave of coronavirus disease 2019 (COVID-19) from July 2022 to September 2022, followed by the eighth wave of COVID-19 from November 2022 to January 2023, nosocomial clusters became more frequent in many healthcare facilities. If a cluster occurs in a hospital, the restrictions on general healthcare and the impact on hospital management, as well as the impact on community healthcare, are enormous. We analyzed the risk factors for COVID-19 cluster infection in hospitalized patients. Methods We retrospectively collected cases of COVID-19 infection among hospitalized patients in the seventh and eighth waves. The occurrence of a COVID-19 patient in a hospitalized patient was defined as one event. Results A total of 40 events were observed in the seventh and eighth waves. There were 17 events that developed into clusters. The following factors showed a significant association with cluster infection in a univariate analysis: "seventh wave," "originated from healthcare worker," and "initial examination according to contact list." The multivariate analysis revealed that "originated from healthcare worker" was independently associated with cluster infection. Conclusion Preventing the development of COVID-19 clusters is very important for nosocomial infection control. Our study suggests that COVID-19 infection in a healthcare worker is a risk factor for the development of a cluster. When healthcare workers are infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), it is often due to household transmission. Measures against household transmissions are important to prevent infection among healthcare workers.

Difficulty in the Diagnosis of Biliary Atresia Splenic Malformation Syndrome In Utero.

The fetus of a 30-year-old pregnant Japanese woman was diagnosed with absence of inferior vena cava (IVC) and azygos continuation of interrupted IVC without cardiac anomalies at 34 weeks of gestation, and a healthy male neonate weighing 2,910 g was delivered at 37 weeks of gestation. On day 42 after birth, direct bilirubin predominant hyperbilirubinemia and high serum gamma-GTP levels were detected. Computed tomography revealed the presence of a lobulated and accessory spleen, and laparotomy demonstrated type III biliary atresia (BA), confirming the final diagnosis of BA splenic malformation (BASM) syndrome. In retrospect, non-visualization of the gallbladder was missed in utero. The combination of the absence of IVC and BA without cardiac anomalies is far less likely to occur in left isomerism. Although BA remains difficult to detect in utero, special attention should be paid to cases of BA associated with findings of left isomerism, including the absence of IVC, to enable early diagnosis and treatment of BASM.

Evaluation of transplacental treatment for fetal congenital bradyarrhythmia: ­ nationwide survey in Japan ­.

BACKGROUND: There are few large studies of fetal congenital bradyarrhythmia. The aim of the present study was to investigate the effects and risks of transplacental treatment for this condition. METHODS AND RESULTS: Using questionnaires, 128 cases of fetal bradyarrhythmia were identified at 52 Japanese institutions from 2002 to 2008. Of the 128 fetuses, 90 had structurally normal hearts. Among these 90 fetuses, 61 had complete atrioventricular block (CAVB), 16 had second-degree AVB, 8 had sinus bradycardia, and 5 had other conditions. The 61 CAVB fetuses were divided into those who did (n = 38) and those who did not (n = 23) receive transplacental medication. Monotherapy with ß-sympathomimetics, steroid monotherapy, and combination therapy with these agents was given in 11, 5 and 22 cases, respectively. Beta-sympathomimetics improved bradycardia (P<0.001), but no medication could significantly improve the survival rate. Fetal hydrops was associated with a 14-fold increased risk of perinatal death (P = 0.001), and myocardial dysfunction was a significant risk factor for poor prognosis (P = 0.034). Many adverse effects were observed with steroid treatment, with fetal growth restriction increasing significantly after >10 weeks on steroids (P = 0.043). CONCLUSIONS: Treatment with ß-sympathomimetics improved bradycardia, but survival rate did not differ significantly in fetuses with and without transplacental medication. It is recommended that steroid use should be limited to <10 weeks to avoid maternal and fetal adverse effects, especially fetal growth restriction and oligohydramnios.

Levothyroxine replacement therapy and refractory hypotension out of transitional period in preterm infants.

BACKGROUND: Recent studies suggest that refractory hypotension from causes other than septicaemia or cardiac failure is common in extremely preterm infants even out of the transitional period. Marked response to low-dose cortisol suggests underlying adrenal insufficiency, although the exact mechanism remains unknown. METHODS: To investigate potential triggers for and related short-term outcomes of early-onset (

Increase of child car seat temperature in cars parked in the outpatient parking lot.

BACKGROUND: A guideline for the safe use of child car seats (CS) was published by the Japan Pediatric Society in 2008. There have been few studies of the increase of temperature of a CS in parked cars. The aim of this study was to determine the change in the temperature of the CS in cars parked in full sun. METHODS: The temperature of CS was measured during summer (July and August) in 2006, 2007, and 2008. The CS used in this study (n= 50) were for children (≤ 6 years old) who were taken by car to Sugimura Children's Medical Clinic. Temperatures were only measured on sunny days. Measurements were performed from 09.00 to 17.00 hours. Thermochron (Thermochron i-Button: G type, Maxim Integrated Products, CA, USA) was used to measure the temperatures. The maximum temperatures of CS were compared in time at the clinic, taking into consideration seat colors, and car colors. RESULTS: Of the 50 cars, three cars were excluded due to being in the shade while the temperature was measured. A total of 47 cars were used for this study. The temperature of the CS ranged from 38.0 to 65.5°C (47.8 ± 5.8°C). Eighteen CS (38.3%) reached a temperature of 50°C or above. The maximum temperature of the 13.00-15.00-hours group was significantly higher than that of the 09.00-11.00-hours group (P= 0.035). The CS temperatures in the black car group were significantly higher than those of the white car group (P= 0.013). CONCLUSION: CS may become very hot while a car is parked in sun, especially if the car and the CS are black, so the CS should be cooled before a young child is placed in it. Guardians of small children should be aware of this risk.

Impact and issues of detecting fetal congenital heart defects in Kyushu, Japan.

AIM: To determine the current status of fetal CHD screening in our region and to establish a CHD screening system in Japan. MATERIAL AND METHODS: Subjects were 168 fetuses prenatally-diagnosed with CHD at four referral centers in Japan from 2003 to 2007. Subjects were divided into two groups: group A (n = 84) included cases without extracardiac sonographic abnormalities and known risk factors for CHD and group B (n = 84) included those with extracardiac sonographic abnormalities or risk factors. The diagnostics and outcomes between the groups were analyzed. RESULTS: There were more cases of single ventricle and restrictive ductus arteriosus and fewer cases of ventricular septal defect and double outlet right ventricle in group A than in group B (P < 0.05). In group A, the most frequent referral reason was an abnormal four-chamber view. In group B, 37 cases had chromosomal anomalies. The mortality rates in group B were higher than those in group A (P < 0.05). There were no differences in mortality rates between fetuses without chromosomal anomalies in group B and group A. CONCLUSION: Prenatally-diagnosed CHD were mostly limited to those cases with obvious abnormalities in the four-chamber view or those with chromosomal anomalies. Prenatal detection of CHD is useful for the prediction of outcomes.

Brain-type natriuretic peptide at birth reflects foetal maturation and antenatal stress.

AIM: Antenatal stress, maturation and other foetal conditions affect the postnatal cardiovascular function. Atrial- (ANP) and brain-type natriuretic peptide (BNP) play important roles in regulating extracellular fluid volume and blood pressure, which may surrogate the foetal cardiovascular condition. The aim of this study was to investigate the dependence of serum ANP and BNP at birth on antenatal variables in high-risk infants. METHODS: Plasma ANP and BNP levels in the umbilical cord blood were compared with antenatal clinical information in 280 infants. RESULTS: High levels of ANP and BNP were associated with multiple pregnancy, antenatal magnesium sulphate and foetal distress. Caesarean section (CS) was paradoxically associated with low ANP and high BNP; low ANP was related with CS before labour whereas high BNP was related with CS after the commencement of labour. High BNP levels further correlated with younger gestational age and intrauteral growth restriction. With regard to short-term postnatal variables, high BNP levels were associated with low Apgar scores and respiratory failure whereas high ANP only correlated with the latter. CONCLUSION: High natriuretic peptide levels were associated with prematurity at birth, uteral contraction and antenatal stress: cord blood ANP and BNP may be a useful surrogate marker for hidden antenatal stress.

Association between the frequency of disposable diaper changing and urinary tract infection in infants.

BACKGROUND: Often diapers are not changed after infants pass urine. AIM: To define the association between the frequency of changing diapers and urinary tract infection (UTI) in infants. METHODS: Urine samples were tested in 131 infants (aged from 2 months to 2.5 years) who had a temperature > or =38 degrees C. The authors investigated the number of times diapers were changed daily. A total of 128 infants, excluding 3 cases, were divided into 2 groups: group A, without UTI (n = 96); group B, with UTI (n = 32). The number of times diapers were changed was compared between the groups. RESULTS: In group A and group B, the number of times diapers were changed daily were 7.5 +/- 1.4 and 4.7 +/- 1.4, respectively. The number of times diapers were changed was significantly lower (P < .0001) in group B than in group A. CONCLUSIONS: Among infants wearing disposable diapers, there is an increased risk of UTI as the frequency of changing diapers decreases.

Antenatal Therapy for Fetal Supraventricular Tachyarrhythmias: Multicenter Trial.

BACKGROUND: Standardized treatment of fetal tachyarrhythmia has not been established. OBJECTIVES: This study sought to evaluate the safety and efficacy of protocol-defined transplacental treatment for fetal supraventricular tachycardia (SVT) and atrial flutter (AFL). METHODS: In this multicenter, single-arm trial, protocol-defined transplacental treatment using digoxin, sotalol, and flecainide was performed for singleton pregnancies from 22 to <37 weeks of gestation with sustained fetal SVT or AFL ≥180 beats/min. The primary endpoint was resolution of fetal tachyarrhythmia. Secondary endpoints were fetal death, pre-term birth, and neonatal arrhythmia. Adverse events (AEs) were also assessed. RESULTS: A total of 50 patients were enrolled at 15 institutions in Japan from 2010 to 2017; short ventriculoatrial (VA) SVT (n = 17), long VA SVT (n = 4), and AFL (n = 29). One patient with AFL was excluded because of withdrawal of consent. Fetal tachyarrhythmia resolved in 89.8% (44 of 49) of cases overall and in 75.0% (3 of 4) of cases of fetal hydrops. Pre-term births occurred in 20.4% (10 of 49) of patients. Maternal AEs were observed in 78.0% (39 of 50) of patients. Serious AEs occurred in 1 mother and 4 fetuses, thus resulting in discontinuation of protocol treatment in 4 patients. Two fetal deaths occurred, mainly caused by heart failure. Neonatal tachyarrhythmia was observed in 31.9% (15 of 47) of neonates within 2 weeks after birth. CONCLUSIONS: Protocol-defined transplacental treatment for fetal SVT and AFL was effective and tolerable in 90% of patients. However, it should be kept in mind that serious AEs may take place in fetuses and that tachyarrhythmias may recur within the first 2 weeks after birth.

The impact of intrauterine treatment on fetal tachycardia: a nationwide survey in Japan.

OBJECTIVES: To investigate the clinical course of fetal tachycardia and analyze the impact of intrauterine treatment on the postnatal treatment and patient outcomes. STUDY DESIGN: This was a retrospective review of cases of fetal tachycardia that occurred from 2004 to 2006. Data were collected from questionnaires that were sent to all 750 secondary or tertiary perinatal care centers in Japan. RESULTS: Eighty-two cases (14 with fetal hydrops) were analyzed (supraventricular tachycardia [SVT], n = 52; atrial flutter [AFL], n = 23; and ventricular tachycardia, n = 7). The overall mortality was 3.7%. Intrauterine treatment was performed for 41 fetuses (50.0%). Digoxin, flecainide and sotalol were mainly used for SVT and AFL. Fetal tachycardia resolved in 90.0% (27/30) of the cases without fetal hydrops and 90.9% (10/11) of the cases with fetal hydrops. Intrauterine treatment significantly reduced the incidence of cesarean delivery (29.3 vs. 70.7%, p < .01), preterm birth (12.2 vs. 41.5%, p = .02) and neonatal arrhythmias (48.8 vs. 78.0%, p = .01) in comparison to untreated fetuses. CONCLUSIONS: This nationwide survey revealed that intrauterine treatment was performed for approximately half of the cases of fetal tachycardia and was associated with lower rates of cesarean delivery, premature birth and neonatal arrhythmias in comparison to untreated fetuses.

Antenatal antiarrhythmic treatment for fetal tachyarrhythmias: a study protocol for a prospective multicentre trial.

INTRODUCTION: Several retrospective or single-centre studies demonstrated the efficacy of transplacental treatment of fetal tachyarrhythmias. Our retrospective nationwide survey showed that the fetal therapy will be successful at an overall rate of 90%. For fetuses with hydrops, the treatment success rate will be 80%. However, standard protocol has not been established. The objective of this study is to evaluate the efficacy and safety of the protocol-defined transplacental treatment of fetal tachyarrhythmias. Participant recruitment began in October 2010. METHODS AND ANALYSIS: The current study is a multicentre, single-arm interventional study. A total of 50 fetuses will be enrolled from 15 Japanese institutions. The protocol-defined transplacental treatment is performed for singletons with sustained fetal tachyarrhythmia ≥180 bpm, with a diagnosis of supraventricular tachycardia or atrial flutter. Digoxin, sotalol, flecainide or a combination is used for transplacental treatment. The primary endpoint is disappearance of fetal tachyarrhythmias. The secondary endpoints are fetal death related to tachyarrhythmia, proportion of preterm birth, rate of caesarean section attributable to fetal arrhythmia, improvement in fetal hydrops, neonatal arrhythmia, neonatal central nervous system disorders and neonatal survival. Maternal, fetal and neonatal adverse events are evaluated at 1 month after birth. Growth and development are also evaluated at 18 and 36 months of corrected age. ETHICS AND DISSEMINATION: The Institutional Review Board of the National Cerebral and Cardiovascular Center of Japan has approved this study. Our findings will be widely disseminated through conference presentations and peer-reviewed publications. TRIAL REGISTRATION NUMBER: UMIN Clinical Trials Registry UMIN000004270.

Use of Normothermic Default Humidifier Settings Causes Excessive Humidification of Respiratory Gases During Therapeutic Hypothermia.

Adult patients frequently suffer from serious respiratory complications during therapeutic hypothermia. During therapeutic hypothermia, respiratory gases are humidified close to saturated vapor at 37°C (44 mg/L) despite that saturated vapor reduces considerably depending on temperature reduction. Condensation may cause serious adverse events, such as bronchial edema, mucosal dysfunction, and ventilator-associated pneumonia during cooling. To determine clinical variables associated with inadequate humidification of respiratory gases during cooling, humidity of inspiratory gases was measured in 42 cumulative newborn infants who underwent therapeutic hypothermia. Three humidifier settings of 37-default (chamber outlet, 37°C; distal circuit, 40°C), 33.5-theoretical (chamber outlet, 33.5°C; distal circuit, 36.5°C), and 33.5-adjusted (optimized setting to achieve 36.6 mg/L using feedback from a hygrometer) were tested to identify independent variables of excessively high humidity >40.7 mg/L and low humidity <32.9 mg/L. The mean (SD) humidity at the Y-piece was 39.2 (5.2), 33.3 (4.1), and 36.7 (1.2) mg/L for 37-default, 33.5-theoretical, and 33.5-adjusted, respectively. The incidence of excessive high humidity was 10.3% (37-default, 31.0%; 33.5-theoretical, 0.0%; 33.5-adjusted, 0.0%), which was positively associated with the use of a counter-flow humidifier (p < 0.001), 37-default (compared with 33.5-theoretical and 33.5-adjusted, both p < 0.001) and higher fraction of inspired oxygen (p = 0.003). The incidence of excessively low humidity was 17.5% (37-default, 7.1%; 33.5-theoretical, 45.2%; 33.5-adjusted, 0.0%), which was positively associated with the use of a pass-over humidifier and 33.5-theoretical (both p < 0.001). All patients who used a counter-flow humidifier achieved the target gas humidity at the Y-piece (36.6 ± 0.5 mg/L) required for 33.5-adjusted with 33.5-theoretical. During cooling, 37-default is associated with excessively high humidity, whereas 33.5-theoretical leads to excessively low humidity. Future studies are needed to assess whether a new regimen with optimized Y-piece temperature and humidity control reduces serious respiratory adverse events during cooling.

In vivo quantitative ultrasonic evaluation of neonatal brain with a real time integrated backscatter imaging system.

We applied the integrated backscatter (IBS) imaging system to the evaluation of the normal neonatal brain of different birth-weights: extremely low-birth-weight (N=13), very-low-birth-weight (N=14), low-birth weight (N=14), and normal birth weight (N=19). The IBS values in six regions of interest, the deep white matter, subcortical white matter, choroid plexus, thalamus, lateral ventricle, and occipital bone, were compared among groups of different birth weights, gestational age, and postnatal age: at the date of birth and 28 approximately 30 days after birth. The IBS values were higher in the order of bone>choroid plexus>deep white matter>subcortical white matter>thalamus>lateral ventricle and were significantly different except for the lateral ventricle in all the groups at days 0 and 28 approximately 30. The IBS values increased with the decrease of birth weight and gestational age. There was a decrease of IBS values at day 28 compared to that of day 0 in the extremely low birth weight and very low birth weight groups; however, they remained the same in infants with low birth weights and in the normal birth weight group. Further studies to evaluate the significance of this technique for the objective diagnosis of brain insults in neonates are necessary.

In Vitro Feasibility and Accuracy of Three-Dimensional Echocardiography for Ventricular Volume Assessment in Very Small Hearts.

To evaluate the in vitro accuracy of three-dimensional echocardiography (3-DE) for estimation of ventricular volume in very small hearts, left ventricular (LV) volume was determined by 3-DE in the excised hearts of 10 guinea pigs and 10 rabbits, and right ventricular (RV) volume was determined in 20 rabbits. The effect of edge enhancement, Sigma filter, and slice distance (1 mm versus 0.5 mm) was assessed in each heart. True volumes were obtained from ventricular casts. Mean cast volume was 1.38 +/- 0.83 mL for LVs and 1.63 +/- 1.01 mL for RVs. Correlations between 3-DE and true volumes were r > 0.99 (P < 0.0001) for both ventricles. Accuracy was not affected by ventricular type, slice distance, or Sigma filter. Mean percent difference from true volume was significantly less (P = 0.03) with edge enhancement. Ventricular volume can be assessed reliably by 3-DE in very small hearts. The edge enhancement feature improved the accuracy of the measurements.