| Autor: |
Heikki, Huhta, Juulia, Junno, Mervi, Haapsamo, Tiina, Erkinaro, Pasi, Ohtonen, Lowell E, Davis, A Roger, Hohimer, Ganesh, Acharya, Juha, Rasanen |
| Rok vydání: |
2017 |
| Předmět: |
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| Zdroj: |
Experimental physiology. 103(1) |
| ISSN: |
1469-445X |
| Popis: |
What is the central question of this study? The fetal aortic isthmus has an important physiological role, allowing communication between the left and right ventricular outputs, which are arranged in parallel. Can the aortic isthmus provide unrestrictive communication between the left and right ventricular circulations during occlusion of the ascending aorta? What is the main finding and its importance? During occlusion of the ascending aorta, fetal carotid artery perfusion pressure fell significantly, showing that the aortic isthmus failed to redirect blood flow and pressure from the ductus arteriosus to the aortic arch. This suggests that the aortic isthmus cannot provide unrestrictive communication between left and right ventricular circulations. The fetal aortic isthmus (AoI) allows communication between left (LV) and right ventricular (RV) outputs and represents an arterial watershed between the brachiocephalic (brain) and subdiaphragmatic (placenta) circulations. To understand the capability of the AoI to maintain the balance between the upper and lower body circulations, we performed a complete occlusion of the fetal ascending aorta in nine chronically instrumented sheep at near term gestation. We hypothesized that the occlusion would significantly decrease LV output and concomitantly increase RV output in order to maintain adequate systemic cardiac output and perfusion pressure to the fetal brain circulation through retrograde filling of the AoI. Fetal cardiac function and haemodynamics were assessed by pulsed and tissue Doppler at baseline, 15 and 60 min after occlusion of the ascending aorta and 15 min after occlusion was released. Carotid artery and jugular vein pressures were monitored. Occlusion of the ascending aorta increased (P 0.002) RV output from [mean (SD)] 684 (369) to 907 (414) ml min |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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