Increased cardiac atrial-to-ventricular length ratio in the fetal four-chamber view: a new marker for atrioventricular septal defects

Z-Score Reference Ranges for the Offset of the Tricuspid Septal Leaflet in Normal Fetuses

OBJECTIVES

To determine Z-score equations and reference ranges for mitral valve-tricuspid valve distance (MTD) and the MTD index in the fetal heart.

METHODS

A prospective cross-sectional study was performed in 899 normal singleton fetuses from 14 to 40 weeks' gestation. The MTD and interventricular septum length (IVSL) were measured offline after electronic cardiac spatiotemporal image correlation volume acquisition. The MTD index was determined as the ratio of MTD to IVSL. Z-score reference ranges of these measurements were determined against gestational age (GA) and estimated fetal weight (EFW), using regression analysis of the mean and standard deviation (SD).

RESULTS

Strong positive correlations were found between the MTD and the independent variables. A simple linear regression model was the best description of the mean and SD of MTD based on GA, while a cubic regression best fitted the mean MTD against EFW. In contrast, the MTD index decreased progressively with the independent variables. Fractional polynomials best fitted the MTD index in terms of GA and EFW.

CONCLUSION

Normal reference values and Z-scores of fetal MTD and MTD index were provided against GA and EFW, which may be useful tools for quantitative assessment of some cardiac and extracardiac diseases.

Perioperative and Anesthetic Considerations in Atrioventricular Septal Defect

Atrioventricular septal defect results from a failure of normal endocardial cushion fusion during embryologic cardiac development. This developmental aberration results in defects in the atrial and/or ventricular septum and malformation of the atrioventricular valves. The pathophysiology of atrioventricular septal defect is variable, and ranges from mild left to right shunting similar to a simple atrial septal defect to complex single-ventricle heart disease. This review focuses on the spectrum of atrioventricular septal defect from partial to complete, without associated cardiac defects.

THE CLINICAL FEATURES OF ATRIOVENTRICULAR CANAL DEFECT

Atrioventricular canal defect (AVCD) is a congenital heart defect, which occurs in 2.9 % of all congenital heart defects (CHD) and is characterized by a wide variety of anatomical forms and often don’t have clear cardiac manifestation. Untreated AVCD may lead to the development of pulmonary hypertension. Aim. To determine clinical features of AVCD in children, considering variable anatomical forms of the pathology and its association with genetic pathology. Materials and methods. Patients history and outpatient statistic records of children with AVCD, who were admitted to Lviv Regional Children’s Hospital from September 1999 till January 2016 have been analyzed (n=84). The aspects of clinical manifestation of AVCD without associated pathology have been identified (n=48). Clinical manifestation of complete (n=36) and incomplete (n=12) AVCD and clinical manifestation with and without Down syndrome have been discussed. Children with AVCD were divided into two groups: A – children with complete (n=36) and B – with incomplete (n=12) form of AVCD. Group A was divided into A1 – with trisomy 21 (n=14), A2 – without genetic pathology (n=22). Results. In group А2 – 36,36±10,26 % and in group В – 50±14,4 % children were asymptomatic. Dyspnea, increased sweating during feeds, growth retardation and frequent respiratory viral infections during early childhood period were leading symptoms. Most frequent auscultation findings were accent of II heart sound over the pulmonary artery and 2-3/6 systolic murmur over left sternal border. According to echocardiographic examination mitral valve insufficiency was predominantly of mild grade, tricuspid insufficiency and pulmonary hypertension was diagnosed in group А2 with the frequency of 9,09±6,13 %). Conclusions: The absence of clinical features in group A2 and B 36,36±10,26 and 50,00±14,40 respectively, saturation levels 92,36±0,49 % in patients without genetic pathology and 95,25±0,40 % with incomplete AVCD provide a need to adopt protocol of children examination with saturation level under 95 % and compulsory echocardiographic diagnosis within the first month of life

Differential and linear insertion of atrioventricular valves: a useful tool?

OBJECTIVE

The differential insertion of the atrioventricular valves is the ultrasonographic representation of the more apical attachment of the tricuspid valve to the septum with respect to the mitral valve. A linear insertion is present when both valves form a linear continuum and has been suggested as a marker for atrioventricular septal defects (AVSDs). The objective of this study was to evaluate the anatomical substratum of differential and linear insertions of the atrioventricular valves in normal fetal hearts and fetal hearts with an AVSD.

METHODS

The extent and position of the fibrous skeleton and attachment of the atrioventricular valves to the septum were studied in histological sections of 17 normal hearts and four hearts with an AVSD from 10 + 0 weeks' gestation to 3 days postpartum with various immunohistochemical tissue markers. In addition, spatiotemporal image correlation (STIC) volumes of 10 normal hearts and STIC volumes of eight hearts with an AVSD at 13 + 6 to 35 + 5 weeks' gestation were examined.

RESULTS

The differential insertion of the atrioventricular valves was visible in normal hearts in the four-chamber plane immediately beneath the aorta, but nearer the diaphragm a linear insertion was found. In hearts with an AVSD, a linear appearance was observed in the four-chamber plane immediately beneath the aorta. Towards the diaphragm, however, first a differential insertion and, more caudally, a linear insertion was found.

CONCLUSIONS

Both differential and linear insertions can be found in normal fetal hearts and fetal hearts with AVSD, depending on the plane in which the four-chamber view is visualized. Therefore, measurement of the differential insertion is likely to be useful only in experienced hands.

Differential insertion of the atrioventricular valves: measurement protocol to detect various congenital heart defects

OBJECTIVES

The objectives of this study were to develop reference values for the distance between the atrioventricular valves, called differential insertion of the atrioventricular valves (DIAVV), in normal fetuses using four-dimensional ultrasound with spatio-temporal image correlation and to explore if DIAVV measurement can differentiate between normal hearts and hearts with cardiac defects.

METHODS

The DIAVV was analysed longitudinally following a measurement protocol in 74 fetuses between 15 and 36 weeks gestational age. The DIAVV was measured in an apical four-chamber view of the heart in end-diastole. Furthermore, the DIAVV was measured in 70 fetuses with cardiac defects.

RESULTS

In total, 337 normal and 70 abnormal spatio-temporal image correlation volumes were examined. Longitudinal regression analysis revealed a positive relationship of the DIAVV with gestational age and fetal biometry (p < 0.0001). The DIAVV of fetuses with double outlet right ventricle, truncus arteriosus, atrioventricular septal defects, Ebstein and tetralogy of Fallot all differed from normal fetuses (p < 0.05).

CONCLUSION

Measurement of the DIAVV is a promising tool; however, a well-defined measurement protocol should be followed to accomplish the correct plane and exact moment in the cardiac cycle. This study presents new nomograms following this measurement protocol and reports an abnormal DIAVV in a wide spectrum of congenital heart disease.

Performance of different scan protocols of fetal echocardiography in the diagnosis of fetal congenital heart disease: a systematic review and meta-analysis

OBJECTIVE

The rapid progress in fetal echocardiography has lead to early detection of congenital heart diseases. Increasing evidences have shown that prenatal diagnosis could be life saving in certain cases. However, there is no agreement on which protocol is most adaptive diagnostic one. Thus, we use meta-analysis to conduct a pooled performance test on 5 diagnostic protocols.

METHODS

We searched PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials and WHO clinical trails registry center to identify relevant studies up to August, 2012. We performed meta-analysis in a fixed/random-effect model using Meta-disc 1.4. We used STATA 11.0 to estimate the publication bias and SPSS 17.0 to evaluate variance.

RESULTS

We use results from 81 studies in 63 articles to analyze the pooled accuracy. The overall performance of pooled sensitivities of spatiotemporal image correlation (STIC), extend cardiac echography examination (ECEE) and 4 chambers view + outflow tract view + 3 vessels and trachea view (4 CV+OTV+3 VTV) were around 0.90, which was significant higher than that of 4 chambers view + outflow tract view or 3 vessels and trachea view (4 CV+OTV/3 VTV) and 4 chambers view (4 CV). Unfortunately the pooled specificity of STIC was 0.92, which was significant lower than that of other 4 protocols which reached at 1.00. The area under the summary receiver operating characteristic curves value of STIC, ECEE, 4 CV+OTV+3 VTV, 4 CV+OTV/3 VTV and 4 CV were 0.9700, 0.9971, 0.9983, 0.9929 and 0.9928 respectively.

CONCLUSION

These results suggest a great diagnostic potential for fetal echocardiography detection as a reliable method of fetal congenital heart disease. But at least 3 sections view (4 CV, OTV and 3 VTV) should be included in scan protocol, while the STIC can be used to provide more information for local details of defects, and can not be used to make a definite diagnosis alone with its low specificity.

Fetal atrioventricular valve junction in normal fetuses and in fetuses with complete atrioventricular septal defect assessed by 4D volume rendering

OBJECTIVES

To assess the feasibility and clinical potential of 4D volume rendering of the atrioventricular (AV) valve junction, to standardize the acquisition method, and to display the AV valve junction morphology in normal fetuses and in those with a complete atrioventricular septal defect (AVSD).

METHODS

We performed sonography in 40 normal fetuses and 10 fetuses with complete AVSD, and volume datasets were acquired from apical and lateral four-chamber views. The render box was placed systematically. First, it included the AV valves, with the reference dot at the level of the crux of the heart. Then, it included the papillary muscles, with the reference dot in the interventricular septum at the level of the distal opening of the tricuspid valve leaflet.

RESULTS

Volume acquisition and rendering were technically possible in all cases. Volume rendering of the left ventricle showed the position of the anterolateral and posteromedial papillary muscles in 36/40 normal fetuses (90%). At the level of the right ventricle, the septal, anterior and posterior papillary muscles were visualized in 33/40 normal fetuses (82%). In cases of complete AVSD, the AV valve has five leaflets, with anterosuperior and posteroinferior bridging leaflets straddling the septa. The morphology of the anterosuperior bridging leaflets and the abnormal position of the papillary muscles could be displayed in all cases.

CONCLUSIONS

Our study suggests that some of the components of the AV junction can be reconstructed easily from sonographic volumes acquired from an apical or lateral four-chamber view. This new technique may have a role in obtaining views that are not easily accessible by standard sonography, enabling a rapid complementary assessment of normal and abnormal intracardiac anatomy.