OP02.04: Cardiac biometry and function in fetuses with intracardiac echogenic foci

Abstract

Oral poster abstracts reflecting a good fetal clinical status. In apnea, the pressure of intrathoracic organs on the fetal heart, mainly the non-expanded lungs, limits ventricular distensibility. Impedance to pulmonary venous flow to the left atrium is represented by the pulsatility index. To test the hypothesis that fetal pulmonary venous flow pulsatility index is lower during fetal respiratory movements than in apnea were our purpose. Methods: Twenty-two normal fetuses of mothers without systemic disease were examined in apnea (controls) and in the presence of fetal respiratory movements (cases). Fetuses were examined by prenatal Doppler echocardiography with color flow mapping. The pulsatility index of the pulmonary vein was obtained placing the pulsed Doppler sample volume over the right upper or left lower pulmonary vein, and applying the formula [maximum velocity (systolic or diastolic)pre-systolic velocity]/mean velocity. Results: Mean gestational age was 28.9 ± 2.9 weeks. During fetal apnea, mean systolic, diastolic and pre-systolic velocities were, respectively, 0.35 ± 0.08 m/s, 0.26 ± 0.07 m/s and 0.09 ± 0.03 m/s. In the presence of fetal respiratory movements, mean systolic, diastolic and pre-systolic velocities were, respectively, 0.33 ± 0.1 m/s, 0.28 ± 0.08 m/s and 0.11 ± 0.04 m/s. Pulsatility index pulmonary vein in apnea was 1.25 ± 0.23 (1.69 to 0.82), and during fetal respiratory movements it was 0.97 ± 0.2 (1.53 to 0.61). Conclusions: We showed a significant reduction in impedance of pulmonary venous flow, represented by pulmonary vein pulsatility index, during fetal respiratory movements, reflecting modifications of the left atrial dynamics and enhancement of left ventricular compliance.