Application of Neonatologist Performed Echocardiography in the assessment of a patent ductus arteriosus

Abstract

In many preterm infants, the ductus arteriosus remains patent beyond the first few days of life. This prolonged patency is associated with numerous adverse outcomes, but the extent to which these adverse outcomes are attributable to the hemodynamic consequences of ductal patency, if at all, has not been established. Different treatment strategies have failed to improve short-term outcomes, with a paucity of data on the correct diagnostic and pathophysiological assessment of the patent ductus arteriosus (PDA) in association with long-term outcomes. Echocardiography is the selected method of choice for detecting a PDA, assessing the impact on the preterm circulation and monitoring treatment response. PDA in a preterm infant can result in pulmonary overcirculation and systemic hypoperfusion, Therefore, echocardiographic assessment should include evaluation of PDA characteristics, indices of pulmonary overcirculation with left heart loading conditions, and indices of systemic hypoperfusion. In this review, we provide an evidence-based overview of the current and emerging ultrasound measurements available to identify and monitor a PDA in the preterm infant. We offer indications and limitations for using Neonatologist Performed Echocardiography to optimize the management of a neonate with a PDA.

The effect of patent ductus arteriosus on coronary artery blood flow in premature infants: a prospective observational pilot study

“…Furthermore, even in the patients with ductal closure, the closure was not complete. As suggested by Van Laere et al PDA diameter/BW higher than 1.4 mm/kg is an important measure of large ductal shunt [19]. In our study group after treatment, the PDA diameter/BW ratio was 1.9 mm/kg, suggesting only partial duct closure.…”

“…Our study could possibly suggest a "steal effect," showing significantly lower coronary flows adjusted for weight [10,12,19,20] in the LM coronary artery between the study and comparison groups. The increase in CO in infants with hsPDA did not reach significance, as reported by others [19,21]. We also found an elevated myocardial oxygen demand in infants with PDA, being significantly higher only when compared with participants with no PDA.…”

“…On the one hand, LA/aortic root ratio above 1.5 is considered indicative of hsPDA, and our result was 1.3, with statistical difference only when compared with the group with no PDA. But on the other hand, PDA diameter and flow velocity met the definitions of hsPDA, and PDA diameter/ weight was above 1.4, which is considered a better measure of ductal shunt in previous studies [19,22]. In addition, there were clinical and laboratory measures showing that the study group did have a hemodynamic clinically significant PDA.…”

“…The ratio of left atrial to aortic root dimensions was calculated to assess PDA significance. Ductal size was also adjusted for weight [19]. Coronary flow was evaluated during diastole as the majority of coronary arterial flow occurs then.…”

“…Flow was calculated by multiplying the FI by π x coronary artery radius 2 . Cardiac output index (CO I ) (cm/min) was measured as systolic timevelocity integral measured in the left ventricular outlet times the heart rate, and was also adjusted for weight [19]. Cardiac output was calculated by multiplying the CO I by π × left ventricle outlet radius 2 .…”