Summary
Down syndrome (DS) is one of the most common autosomal abnormalities . It occurs in about one case per 800 live births .Each year, approximately 6000 children are born with Down syndrome.
Among live-born babies , Down syndrome is the most common chromosomal anomaly. It is characterized by the whole chromosomal aneuploidy in about 95% of cases. The remaining 5% is in the form of translocations and mosaics.
Approximately 40% to 60% of children with Down syndrome have heart defects. Even in the absence of congenital and acquired heart defects , there may also be a risk for problems with the myocardial fibrillar structure and autonomic nervous system
Echocardiography(Echo) is the technique of choice for non invasive evaluation of left ventricular function. current technology allows for assessment of overall left ventricular performance and for diastolic and systolic function. Doppler technology has greatly enhanced the diagnostic capability of two dimensional echocardiography
Tissue Doppler imaging (TDI) is a new technique that uses Doppler to quantify the velocity of myocardial tissue rather than blood .Assessment of myocardial wall velocities with respect to timing and amplitude has been suggested for quantification of global and regional systolic and diastolic function.
The study was a cross-sectional study which included a total number of 75 children divided into 2 groups Group A : 50 cases with Down syndrome between 6 months and 16 years of age , Group B : 25 healthy controls , patients in both groups were age- and sex matched.
This study showed that patients with DS who didn't have any congenital or acquired heart diseases which was confirmed by conventional Echocardiography had significant increase in the ejection fractio(EF) value in cases than controls and no difference regarding the other traditional Echo values .
By comparing the 2 groups the current study showed that Tissue doppler of the posterior wall of the cases revealed that the systolic function is not affected markedly in the form significant increase in systolic wave (Sa) with significant increase in isovolumetric contraction time (ICT)& showed diastolic dysfunction from the significant increase in E/Ea and Isovolumetric Relaxation Time (IRT) also Myocardial Performance Index (MPI) which is an assessment of global myocardial function that incorporates both systolic and diastolic was significantly increased in DS patients than controls
The septum of the DS patients showed normal systolic function with diastolic dysfunction due to significant increase in E/Ea and IRT also MPI was significantly higher in cases than controls
the anterior wall of cases showed mild systolic dysfunction in the form of significant increase in (ICT) and revealed normal diastolic function and MPI showed no significant difference between cases and controls .
Tissue Doppler Imaging offers many potential advantages in quantifying subtle impairment of ventricular performance and this study showed us there was risk of myocardial depression in DS patients even with normal conventional Echo which indicate that DS pateints must go for this simple non invasive technique and take precautions before exercise and any stressful conditions.
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