Related Experiment Video
Updated: Oct 19, 2026

Echocardiographic Characterization of Left Ventricular Structure, Function, and Coronary Flow in Neonate Mice
Published on: April 7, 2022
Doppler velocity and flow through the aortic isthmus in normal term neonates
A Ithuralde1, T Riggs, M E Hussey
1Pediatric Cardiology, William Beaumont Hospital, Royal Oak, MI 48073, USA.
Abstract:
Our hypothesis was that the relationship between the internal aortic diameter and the Doppler flow velocity across the aortic isthmus could be modeled by applying the principle of conservation of mass flow. The aortic diameter decreased at the isthmus by a mean of 18% (t = 11.02, p < 0.0001), while the flow velocity increased by a mean of 44% (t = 10.09, p < 0.0001). The mean peak mass flow rate was 34. 5 ml/s preisthmus and 32.9 ml/s at the isthmus with excellent correlation (r = 0.830). We conclude that the increase in Doppler velocity observed in the descending aorta can be explained by the normal narrowing observed at the aortic isthmus and application of the continuity equation for conservation of mass flow.
Related Concept Videos
Fetal Circulation
Two umbilical arteries transport blood from the fetus to the placenta. At the placenta, the blood absorbs oxygen and nutrients while simultaneously eliminating waste products. This oxygen-enriched and nutrient-rich blood then returns to the fetus through one...
Blood Flow
Aortic Regurgitation I: Introduction

