Ventricular Myocardial Deformation in Fetuses With Tetralogy of Fallot: A Necessary Field of Investigation

Review of speckle tracking analysis to measure the size, shape, and contractility of the fetal heart in fetuses with congenital heart defects

Evaluation of the fetal heart involves two approaches. The first describes a screening protocol in which the heart is imaged in transverse planes that includes the four-chamber view (4CV), left and right outflow tracts, and the 3-vessel-tracheal view. The second approach is a fetal echocardiogram that requires additional cardiac images as well as evaluating ventricular function using diagnostic tools such as M-mode and pulsed Doppler ultrasound. Speckle tracking analysis of the ventricular and atrial endocardium of the fetal heart has focused primarily on computing longitudinal global strain. However, the technology enabling this measurement to occur has recently been adapted to enable the clinician to obtain numerous additional measurements of the size, shape, and contractility of the ventricles and atrial chambers. By using the increased number of measurements derived from speckle tracking analysis, we have reported the ability to screen for tetralogy of Fallot, D-transposition of the great arteries (D-TGA), and coarctation of the aorta by only imaging the 4CV. In addition, we have found that measurements derived from speckle tracking analysis of the ventricular and atrial chambers can be used to compute the risk for emergent neonatal balloon atrial septostomy in fetuses with D-TGA. The purpose of this review is to consolidate our experience in one source to provide perspective on the benefits of speckle tracking analysis to measure the size, shape, and contractility of the ventricles and atria imaged in the 4CV in fetuses with congenital heart defects.

Adverse remodelling in tetralogy of Fallot: From risk factors to imaging analysis and future perspectives

Although contemporary outcomes of initial surgical repair of tetralogy of Fallot (TOF) are excellent, the survival of adult patients remains significantly lower than that of the normal population due to the high incidence of heart failure, ventricular arrhythmias, and sudden cardiac death. The underlying mechanisms are only partially understood but involve an adverse biventricular response, so-called remodelling, to key stressors such as right ventricular (RV) pressure-and/or volume-overload, myocardial fibrosis, and electro-mechanical dyssynchrony. In this review, we explore risk factors and mechanisms of biventricular remodelling, from histological to electro-mechanical aspects, and the role of imaging in their assessment. We discuss unsolved challenges and future directions to better understand and treat the long-term sequelae of this complex congenital heart disease.

Impaired myocardial deformation persists at 2 years in offspring of mothers with diabetes mellitus

BACKGROUND

A diabetic intrauterine environment has been proposed as a potential etiological mechanism for in utero programming of cardiac disease, and is associated with impaired fetal cardiac function. We aimed to assess cardiac function in offspring of mothers with diabetes mellitus (ODM) and determine whether fetal cardiac abnormalities persist during follow-up.

METHODS

Longitudinal observational study to evaluate and compare myocardial function in 40 ODM to age-matched control offspring (CO). Myocardial deformation was measured using speckle-tracking echocardiography (STE).

RESULTS

Significant differences were detected in global longitudinal strain (-20.9 ± 3.1 vs. -23.6 ± 2.2%; p = 0.001), global circumferential strain (-24.4 ± 3.9 vs. -26.9 ± 2.7%; p = 0.017), average radial strain (29.0 ± 9.8 vs. 37.1 ± 7.2%; p = 0.003), average longitudinal systolic strain rate (-1.24 ± 0.25/s vs. -1.47 ± 0.30/s; p = 0.011) and average circumferential systolic strain rate (-1.56 ± 0.37/s vs. -1.84 ± 0.37/s; p = 0.013) in comparison to CO up to 2 years of follow-up. Minimal differences were observed within ODM over the 2-year period.

CONCLUSION

Impaired cardiac function in ODM persists during 2 years follow-up. Functional cardiac assessment might therefore be useful to detect these unfavorable changes, independent of screening for congenital heart disease or hypertrophic cardiomyopathy in this population.

IMPACT

We demonstrate persistence of subclinical myocardial deformation abnormalities in offspring of mothers with diabetes mellitus from fetal life to early childhood years. These results extend the cellular observations in basic and translational research of developmental programming into the clinical realm. Persistence of subclinical myocardial deformation abnormalities may shed light on the known incidence of early cardiovascular disease in offspring of mother with diabetes. Cardiac myocardial strain assessment can be useful to detect these abnormalities, independent of screening for congenital heart disease or hypertrophic cardiomyopathy in this population.

Speckle-Tracking Analysis in Fetuses With Tetralogy of Fallot: Evaluation of Right and Left Ventricular Contractility and Left Ventricular Function

OBJECTIVES

This study examines fetuses with tetralogy of Fallot (TOF) and evaluates the right (RV) and left (LV) ventricular contractility and LV function using speckle-tracking analysis of the endocardium.

METHODS

The study group consisted of 44 fetuses with TOF, of which 34% had pulmonary valve atresia (N = 15) and 59% (N = 26) had pulmonary valve stenosis. The RV and LV global fractional area change, longitudinal contractility (longitudinal strain, free wall strain, septal strain, free wall and septal annular fractional shortening, and free wall and septal wall annular plane systolic excursion), and transverse contractility (24-segment fractional shortening) as well as LV functional assessment (stroke volume, cardiac output, and ejection fraction) were measured using speckle-tracking analysis. The z-scores of the measurements were compared to 200 controls.

RESULTS

Compared to controls, measurements of LV contractility in fetuses with TOF demonstrated significantly abnormal values for global contractility, longitudinal contractility, and transverse contractility of the mid and apical segments. LV function was abnormal for stroke volume (SV), cardiac output (CO), and ejection fraction (EF). In comparison, RV contractility demonstrated no significant difference between TOF and control z-score values for RV global contractility. Only two RV measurements were found to be abnormal: longitudinal contractility and transverse contractility of the apical segments.

CONCLUSION

Using multiple measurement tools to evaluate global, longitudinal, and transverse contractility, this study identified significant differences between fetuses with TOF and healthy controls, with greater contractility abnormalities seen in the LV than in the RV.

Prenatal prediction of Shone's complex. The role of the degree of ventricular disproportion and speckle-tracking analysis

OBJECTIVES

Shone's complex (SC) is characterized by sequential obstructions of left ventricular (LV) inflow and outflow. It can be associated with poor long-term prognosis when compared to Simple-Aortic Coarctation (S-CoA). We aimed to assess whether the degree of ventricular disproportion and 2D-speckle-tracking echocardiography (2D-STE) could improve the accuracy of prenatal prediction of SC.

METHODS

75 consecutive fetuses were retrospectively enrolled from January 2010 to June 2021. Fetuses were divided into 4 groups (Group 1: SC; Group 2: S-CoA; Group 3: False Positive-Coarctation of the Aorta [FP-CoA]; group 4: controls). Comparisons for echocardiographic measures and myocardial deformation indices were performed. A receiver operating characteristic (ROC) analysis was performed on the MV/TV (mitral valve/tricuspid valve ratio) and LV GLS (global longitudinal strain) values to identify cut-offs to separate group 1 and 2 fetuses.

RESULTS

SC fetuses showed a significant reduction in MV/TV when compared to S-CoA and FP-CoA fetuses (p<0.001). LV GLS in SC fetuses was significantly reduced compared to S-CoA fetuses (-13.3 ± 2.1% vs. -17.0 ± 2.2%, p=0.001). A cut-off value of 0.59 for MV/TV and -15.35% for LV GLS yielded a sensitivity of 76 and 82% and a specificity of 71 and 83% respectively in separating SC vs. S-CoA fetuses.

CONCLUSIONS

SC fetuses showed a more severe degree of ventricular disproportion and a lower LV GLS compared to S-CoA, FP-CoA and control fetuses. MV/TV and GLS are both predictors of SC. These findings may improve the quality of prenatal parental counselling.

The Chinese Experience of Imaging in Cardiac Intervention: A Bird's Eye Review

Recent scientific and technological advances have greatly contributed to the development of medical imaging that could enable specific functions. It has become the primary focus of cardiac intervention in preoperative assessment, intraoperative guidance, and postoperative follow-up. This review provides a contemporary overview of the Chinese experience of imaging in cardiac intervention in recent years.

DNA Methylation Levels of the TBX5 Gene Promoter Are Associated with Congenital Septal Defects in Mexican Paediatric Patients

The TBX5 gene regulates morphological changes during heart development, and it has been associated with epigenetic abnormalities observed in congenital heart defects (CHD). The aim of this research was to evaluate the association between DNA methylation levels of the TBX5 gene promoter and congenital septal defects. DNA methylation levels of six CpG sites in the TBX5 gene promoter were evaluated using pyrosequencing analysis in 35 patients with congenital septal defects and 48 controls. Average methylation levels were higher in individuals with congenital septal defects than in the controls (p < 0.004). In five CpG sites, we also found higher methylation levels in patients than in the controls (p < 0.05). High methylation levels were associated with congenital septal defects (OR = 3.91; 95% CI = 1.02–14.8; p = 0.045). The analysis of Receiver Operating Characteristic (ROC) showed that the methylation levels of the TBX5 gene could be used as a risk marker for congenital septal defects (AUC = 0.68, 95% CI = 0.56–0.80; p = 0.004). Finally, an analysis of environmental factors indicated that maternal infections increased the risk (OR = 2.90; 95% CI = 1.01–8.33; p = 0.048) of congenital septal defects. Our data suggest that a high DNA methylation of the TBX5 gene could be associated with congenital septal defects.