Even though congenital heart disease is a common finding in down syndrome (DS) patients, some of them have anatomically normal
hearts. However, the term “normal” might not be suitable, as these patients usually suffer from functional cardiac dysfunction.
Several research highlighted that despite the absence of anatomical heart defects, subtle cardiac function derangements are
present in DS patients. We aim to assess cardiac functions by Two-dimensional echocardiography and tissue Doppler imaging
(TDI) in pediatric DS patients who have anatomically normal hearts. One hundred seventy-two patients with karyotyping confirmed
DS with anatomically normal hearts and 165 healthy normal control children were enrolled in the current study. Their cardiac
functions were assessed using both 2-dimensional echocardiography and TDI. Both patients and controls had structurally and
anatomically normal hearts. In DS patients, the right side of the heart showed a significant reduction in both systolic and diastolic
functions. Systolic dysfunction was evident by significantly decreased levels of Tricuspid annular plane systolic excursion and
systolic wave by TDI. Diastolic dysfunction of the right ventricle was evident by prolonged deceleration time by conventional
echocardiography and a significant decrease in annular tissue doppler velocity during early diastole/late diastole ratio by TDI.
The E/De ratio was significantly increased. Even with anatomically normal hearts, DS patients should undergo cardiac function
assessment by echocardiography & TDI. TDI is superior to conventional echocardiography in detecting subtle cardiac dysfunction
especially left ventricular diastolic dysfunction in DS patients. TDI showed a significant decrease in the early/atrial ratio of mitral
valve annulus and prolongation of left ventricle isometric relaxation time in DS children. Also, the left ventricle E/De ratio was
prolonged denoting elevated filling pressures and diastolic dysfunction. This indicates that the TDI has higher sensitivity to detect
diastolic dysfunction than conventional Echocardiography. Biventricular TDI-derived myocardial performance index was found to
be significantly increased in DS children.
Abbreviations: BMI = body mass index, BP = blood pressure, CXR = chest X-ray, Da = annular tissue doppler velocity during
late diastole, DCC = deceleration time of early filling, De = annular tissue doppler velocity during early diastole, DS = down
Syndrome, E/A = early/late diastolic peak velocity ratio, ECG = electrocardiogram, EF = ejection fraction, FS = fraction shortening,
HR = heart rate, ICT = isovolumetric contraction time, LV = left ventricle, PA = pulmonary artery, RR = respiratory rate, RV = right
ventricle, Sa = annular tissue doppler velocity during systole, TAPSE = tricuspid annular plane systolic excursion, TDI = tissue
Doppler imaging. |
