Pulsed Doppler Measurement of Left Ventricular Output as Early Predictor of Symptomatic Patent Ductus arteriosus in Very Preterm Infants

Abstract

High left ventricular output (LVO) values are associated with symptomatic left-to-right ductal shunting in preterm infants. However, LVO data prior to the occurrence of symptomatic patent ductus arteriosus (SPDA) are lacking. To determine whether serial measurements could predict a SPDA, we measured LVO from day 1 until day 10 with pulsed Doppler echocardiography in 25 preterm infants with birth weights of less than 1,250 g and hematocrits of more than 0.40. Eleven infants never developed patent ductus arteriosus symptoms and had LVO values within the normal range (190–310 ml/min/kg) with only minimal daily variations. The remaining 14 infants developed SPDA which required treatment with indomethacin, ductal Hgation, or fluid restriction on days 2–5. From day 1 until day 5 their mean LVO values were significantly higher compared to the group without left-to-right ductal shunt and this increase was secondary to higher stroke volume values. An increase in LVO of more than 60 ml/min/kg consistently preceded SPDA by at least 24 h. Serial measurements of LVO using a single-pulsed Doppler approach can be used for early prediction of SPDA.

Echocardiographic post-neonatal progress of preterm neonates with patent ductus arteriosus

“…Observou-se que o aumento do débito cardíaco, na presença de PCA, chegou a aproximadamente 40 ml/min/kg (±10 ml/min/kg), o que representou um acréscimo médio de 30% do valor do débito cardíaco basal desses RN. Esse resultado está de acordo com outros da literatura, como os encontrados por Walther et al, que, em RN com peso ao nascer menor do que 1.250 g, encontraram um aumento de cerca de 60 ml/min/kg do débito cardíaco aórtico na presença de canal arterial com repercussão hemodinâmica 19 . Ainda Lindner et al observaram um aumento do débito cardíaco aórtico em até 50% do valor basal, sendo que, após o fechamento desse canal arterial, o valor do débito cardíaco retornou ao valor basal 11 .…”

Longitudinal changes in the diameter of the ductus arteriosus in ventilated preterm infants: correlation with respiratory outcomes.

“…Forty three of these infants had hyaline membrane disease, eight were ventilated for prematurity and pulmonary immaturity. The study was conducted over 12 This was performed with an Acuson 128/XP10 scanner with a 7 MHz transducer, incorporating colour flow, pulsed wave, and continuous wave Doppler. Scans were performed daily for the first seven days of life, twice in the second week, and then periodically as indicated until discharge home or to the referring hospital.…”

“…Surfactant treatment comprised two doses of Exosurf, 12 hours apart, administered as rescue treatment when the alveolar to arterial oxygen ratio was less than 0-22.…”

Evolução ecocardiográfica de recém-nascidos com persistência do canal arterial

“…This result is in agreement with others in the literature, such as findings described by Walther et al, who observed an increase in the aortic cardiac output of NB with birth weights below 1,250 g of around 60 ml/min/kg, in the presence of ductus arteriosus and with hemodynamic repercussions. 19 Lindner et al observed an increase in aortic cardiac output of up to 50% against baseline and also observed that, after ductal closure, the cardiac output level returned to baseline. 11 One measurement that has always been much used in the literature top assess the repercussions of ductus arteriosus is the left atrium/aorta ratio, with a ratio of more than 1.5 exhibiting high sensitivity and specificity for detecting ductus arteriosus, as reported by Iyer & Evans.…”