Functional Assessment of Fetal Heart: Normative Data for Tissue Doppler Indices and Other Echocardiographic Parameters for Indian Population

Abstract

Objective: To establish normative data for tissue Doppler indices and other parameters for ventricular function assessment in fetal imaging for the Indian population and to assess the variation of these parameters with gestational age. Materials and Methods: A prospective study involving 172 fetuses diagnosed as having normal cardiac structure and function. Mothers were advised for fetal echocardiography for several indications; however, mothers with diabetes (both gestational and pregestational), placental dysfunction, fetuses with intrauterine growth retardation, and multiple gestation were excluded as these could affect the fetal cardiac function despite a normal cardiac structure. Peak myocardial velocity was measured during systole (S'), early diastole (E'), and late diastole (A') using spectral tissue Doppler. Pulsed Doppler was used to measure the inflow early (E) and late (A) diastolic velocities and the diastolic filling period (DFP). M-mode was used to measure the tricuspid and mitral annular peak systolic excursion (TAPSE and MAPSE). Results: Normative data for tissue Doppler velocities and various other parameters for functional assessment of fetal heart were derived from the 172 normal fetuses. On tissue Doppler imaging (TDI), the mean values for the peak systolic and diastolic velocities at the lateral and medial mitral annulus and at the lateral tricuspid annulus and ratio of early and late diastolic velocity (E'/A') increased while the (E/E') ratio decreased with gestational age. Other parameters that increased with age are TAPSE, MAPSE, and the DFP at the tricuspid and mitral valves. The left and right ventricular myocardial performance index did not show any variation with gestation. Conclusion: TDI has already been documented as a useful technique in fetal cardiac imaging. The normative data so derived for various parameters can be used as a future reference. These parameters can prove very useful in fetal cardiac functional evaluation and detection of systolic or diastolic dysfunction at an early stage which may have long-term and prognostic implications.