premature constriction of Ductus arteriosus
2015. 10. 8.
1. Drug induced DA constriction is reversible a few days after cessation of treatment.
2. Do not use prostaglandin synthetase inhibitors after 32 weeks' gestation and for a prolonged period.
3. Delivery concomitant with fetal DA constriction is associated with a high risk for the development of pulmonary hypertension in the newborn.
4. Constriction of the DA is not reliably diagnosed on 2-D ultrasound as color and pulsed Doppler is essential for its diagnosis. The four-chamber view show hypo-Kinetic,dilated RV due to volume overload. TR is holosystolic with maximum velocities greater than 200 cm / sec.
5. DA peak systolic normal level is 100 to 120 cm/ sec，PI normal greater than 2
6. DA constriction peak systolic around 200 to 300 cm/ sec and distolic velocities greater than 35 cm/ sec eith PI less than 1.9 ，stopping the drug therapy will lead in reversal of the finding within 24 to 48 hours ，but TR may last longer.
7. Narrow segment of the DA at 34 weeks starting from the pulmonary part toward the DAO in the normal fetus.