Echocardiographic and anatomic correlation of ventricular septal defect morphology in newborn Yucatan pigs

Postmortem findings in cloned and transgenic piglets dead before weaning

Important factors contributing to the well-known high mortality of piglets produced by SCNT are gross malformations of vital organs. The aim of the present retrospective study was to describe malformations found in cloned piglets, transgenic or not, dying or culled before weaning on Day 28. Large White (LW) embryos were transferred to 78 LW recipients, while 72 recipients received Göttingen embryos (67 transgenic and five not transgenic) and 56 received Yucatan embryos (43 transgenic and 13 not transgenic). Overall pregnancy rate was 76%, and there were more abortions in recipients with minipig embryos than in those with LW embryos (26% and 24% vs. 6%). Piglets (n = 815) were born from 128 sows with 6.5 ± 0.4 full-born piglets per litter. The overall rate of stillborn piglets was 21% of all born with the number of stillborn piglets ranging from one to nine in a litter. The mortality of the surviving piglets during the first month was 48%. Thus, altogether 58% of the full-born piglets died before weaning. In 87 of the 128 litters (68%), one to 12 of the piglets showed major or minor malformations. Malformations were found in 232 piglets (29.5% of all born). A single malformation was registered in 152 piglets, but several piglets showed two (n = 58) or more (n = 23) malformations (7.4% and 2.8% of all born, respectively). A significantly higher malformation rate was found in transgenic Göttingen and Yucatan piglets (32% and 46% of all born, respectively) than in nontransgenic LW (17%). There was a gender difference in the transgenic minipigs because male piglets had a higher rate of malformations (49.1%) than females (29.7%). The most common defects in the cloned piglets were in the digestive (12.2%), circulatory (9.4%), reproductive (11.3%), and musculoskeletal (9.1%) systems. Malformations of the musculoskeletal system were most frequent in Göttingen (16.3% vs. approximately 5.5% in the two other breeds), whereas abnormal cardiopulmonary systems were most frequent in Yucatan piglets (26.9% vs. 2.1% in LW and 5.3% in Göttingen). In conclusion, these results show that pig cloning results in a considerable loss of piglets and that many of these can be related to various malformations that all are also seen in noncloned piglets. Because approximately half of the cloned piglets still survive, even with eventual unknown minor malformations, use of pigs as models for human diseases is still realistic. However, continued efforts are needed to further reduce the level of malformations.

Real Time Three-Dimensional Echocardiography in Assessing Ventricular Septal Defects: An Echocardiographic-Surgical Correlative Study

BACKGROUND

Two-dimensional echocardiography (2DE) enhanced by combining with color Doppler technology has significant limitations in providing precise quantitative information, geometric assumptions to calculate chamber volume, mass, and ejection fraction. Reconstructed three-dimensional echocardiographic (3DE) systems (from multiple cross-sectional echocardiographic scans) are still cumbersome and time-consuming. Real time 3DE (RT-3DE) with shorter imaging time than with 3D reconstruction techniques can obtain qualitative and quantitative information on heart disorders. Our purpose was to investigate the feasibility and potential value of RT-3DE as a means of accurately and quantitatively estimating the size of VSD to correlate with the surgical findings.

MATERIALS AND METHODS

38 patients with VSD were examined with RT-3DE. 3D image database was postprocessed using TomTec echo 3D workstation. The results were compared with the results measured by 2 DE and surgical findings. RT-3DE produced novel views of VSD and improved quantification of the size of the defect. The sizes obtained from 3DE have equivalent correlation with surgical findings as diameter measured by 2DE (r = 0.89 vs r = 0.90). Good agreement between blinded observers was achieved by little interobserver variability.

CONCLUSION

RT-3DE offers intraoperative visualization of VSD to generate a "virtual sense of depth" without extending examining time. From an LV en face projection, the positions, sizes, and shapes of VSDs can be accurately determined to permit quantitative recording of VSD dynamics. It is a potentially valuable clinical tool to provide precise imaging for surgical and catheter-based closure of difficult perimembranous and singular or multiple muscular VSD.

Atrioventricular block after transcatheter closure of perimembranous ventricular septal defects

OBJECTIVE

To look at the presentation, treatment and outcome of patients who developed atrioventricular block after transcatheter closure of a perimembranous ventricular septal defect (PMVSD) with the Amplatzer PMVSD device.

SETTING

Three tertiary referral centres for paediatric cardiology in two countries.

RESULTS

All three patients presented within 10 days of the procedure. All three patients were treated with intravenous steroids. A permanent pacemaker was inserted in all patients but no pacemaker required activation after two months.

CONCLUSION

Complete atrioventricular block occurring in the weeks after device occlusion of a PMVSD appears to resolve quickly. Continued involvement in multicentre device databases is required to monitor safety.

Feasibility and Accuracy of Real-time 3-Dimensional Echocardiographic Assessment of Ventricular Septal Defects

The aim of this study was to evaluate feasibility, accuracy, and clinical applicability of real-time (RT) transthoracic 3-dimensional (3D) echocardiography (3DE) in the determination of the position, size, and shape of a ventricular septal defect (VSD). In all, 34 patients (age: 2 months-46 years), who were scheduled for surgical closure of a VSD, were enrolled in the study. VSD localization, shape, and dimensions were assessed and compared with measurements performed by the surgeon. Acquisition of RT-3DE datasets was feasible in 30 of 34 (88%) patients. Duration of 3D data acquisition was 6 +/- 2 minutes. Reconstruction time was 23 +/- 16 minutes. Localization and number of VSD were determined correctly by RT-3DE in all patients. There was a good correlation for VSD measurements between RT-3DE and operation (r = 0.95). RT-3DE allows accurate determination of VSD size, shape, and location. The short acquisition time and acceptable reconstruction time make this technique clinically applicable.

Three-dimensional echocardiography enhances the assessment of ventricular septal defect

By 3-dimensional echocardiography, the location, relation to the aortic and tricuspid valve, and the size of the ventricular septal defect was assessed and compared with 2-dimensional echocardiography and intraoperative findings. We concluded that 3-dimensional echocardiography accurately assesses the anatomy of the ventricular septal defect, provides additional information, and can be considered a valuable preoperative diagnostic tool.

Spontaneous closure of muscular ventricular septal defect identified by echocardiography in neonates

Muscular ventricular septal defects were diagnosed by echocardiography in 97 neonates within 7 days of birth. In 82 of the neonates (84.5%), the defect was solitary, while 15 had multiple defects. The solitary defects was located at mid-septal, apical, anterior and inlet locations in 42 (51.2%), 21 (25.6%), 14 (17.1%) and 5 (6.1%) neonates, respectively. Multiple defects occurred in the apical, anterior and mid-septal areas. The diameter of the solitary defects ranged from 1 to 6 mm (2.3 +/- 0.8 mm), while the multiple lesions were 1 to 4 mm in diameter (2.1 +/- 0.8 mm) in 28 instances in which they could measured. It proved possible to follow 79 of the patients for period of 10 to 13 months. The defects closed spontaneously in 56 (84.8%) of 66 patients with a single defect, and in 7 (53.8%) of 13 of those with multiple defects (P<0.05). For the solitary defects, the position and size were factors determining the likelihood and speed of closure. Defects located at the apical septum, or defects larger than 4 mm in diameter, closed slowly and at a later stage. Echocardiography is an useful technique in establishing of natural history of muscular ventricular septal defects encountered in neonates.

High prevalence of muscular ventricular septal defect in neonates

OBJECTIVES

This study sought to use echocardiography to evaluate the prevalence of muscular ventricular septal defect in neonates.

BACKGROUND

Ventricular septal defect is usually asymptomatic and closes spontaneously. An increase in its prevalence has been noted recently. One reason is the improved detection of small defects, especially with the increased used of echocardiography. Therefore, one would expect a higher prevalence in neonates on the basis of echocardiographic screening.

METHODS

Color Doppler echocardiography was performed in 1,053 consecutive neonates 6 to 170 h old at Western Galilee Hospital, Israel. Data on the neonates, parents and family were obtained to analyze the influencing factors. The identified patients were followed up for 1 to 10 months or until ventricular septal defect closure.

RESULTS

Muscular ventricular septal defect was found in 56 (25 male, 31 female) of the 1,053 neonates, a prevalence of 53.2/1,000 live births. All neonates were asymptomatic. Six had a systolic murmur. Electrocardiographic findings were normal in 44 (97.8%) of 45 neonates followed up, and left ventricular hypertrophy occurred in 1 (2.2%). By echocardiography, 50 ventricular septal defects (89.3%) were single and 6 (10.7%) were multiple. The defects (range 1 to 5 mm in diameter, mean [+/- SD] 2.3 +/- 0.8) occurred anywhere along the muscular septum; 43 (76.8%) were detectable only on color Doppler imaging. The left atrium and left ventricle were mildly dilated. Of 45 neonates who were followed up for 6 to 10 months or until closure of the defects, 40 (88.9%) had defects that closed spontaneously. The risk of ventricular septal defect was not significantly associated with gestational age, birth weight, birth order, maternal age, diabetes, smoking, exposure to drugs or infection, paternal age, familial congenital heart disease, religion or consanguinity.

CONCLUSIONS

There is a prevalence of muscular ventricular septal defect in neonates of 53.2/1,000 live births. The patients were asymptomatic, and 88.9% had defects that closed spontaneously within 1 to 10 months. These defects may be caused by environmental factors. In many cases, muscular ventricular septal defect may also result from delayed physiologic development.