University of Oulu

Lantto, J, Erkinaro, T, Haapsamo, M, et al. Foramen ovale blood flow and cardiac function after main pulmonary artery occlusion in fetal sheep. Exp. Physiol. 2019; 104: 189–198. https://doi.org/10.1113/EP087423

Foramen ovale blood flow and cardiac function after main pulmonary artery occlusion in fetal sheep

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Author: Lantto, Juulia1; Erkinaro, Tiina2; Haapsamo, Mervi3;
Organizations: 1Department of Obstetrics and Gynecology, Oulu University Hospital and University of Oulu, Oulu, Finland
2Department of Anesthesiology, Oulu University Hospital, Oulu, Finland
3Department of Obstetrics and Gynecology, Satakunta Central Hospital, Pori, Finland
4Department of Surgery, Oulu University Hospital, Oulu, Finland
5Laboratory Animal Centre, Experimental Surgery, Oulu University Hospital and University of Oulu, Oulu, Finland
6Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Oregon Health & Science University, Portland, OR, USA
7Women's Health and Perinatology Research Group, Department of Clinical Medicine, Faculty of Health Science, University of Norway and University Hospital of Northern Norway, Tromsø, Norway
8Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden
9Department of Obstetrics and Gynecology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
Format: article
Version: accepted version
Access: embargoed
Persistent link: http://urn.fi/urn:nbn:fi-fe201903229651
Language: English
Published: John Wiley & Sons, 2019
Publish Date: 2019-12-22
Description:

Abstract

The foramen ovale (FO) accounts for the majority of fetal left ventricular (LV) output. Increased right ventricular afterload can cause a redistribution of combined cardiac output between the ventricles. To understand the capability of the FO to increase its volume blood flow and thus LV output, we mechanically occluded the main pulmonary artery in seven chronically instrumented near‐term sheep fetuses. We hypothesized that FO volume blood flow and LV output would increase during main pulmonary artery occlusion. Fetal cardiac function and haemodynamics were assessed by pulsed and tissue Doppler at baseline, 15 and 60 min after occlusion of the main pulmonary artery and 15 min after occlusion was released. Fetal ascending aorta and central venous pressures and blood gas values were monitored. Main pulmonary artery occlusion initially increased fetal heart rate (P < 0.05) from [mean (SD)] 158 (7) to 188 (23) beats min⁻¹ and LV cardiac output (P < 0.0001) from 629 (198) to 776 (283) ml min⁻¹. Combined cardiac output fell (P < 0.0001) from 1524 (341) to 720 (273) ml min⁻¹. During main pulmonary artery occlusion, FO volume blood flow increased (P < 0.001) from 507 (181) to 776 (283) ml min⁻¹. This increase was related to fetal tachycardia, because LV stroke volume did not change. Fetal ascending aortic blood pressure remained stable. Central venous pressure was higher (P < 0.05) during the occlusion than after it was released. During the occlusion, fetal pH decreased and PCO₂ increased. Left ventricular systolic dysfunction developed while LV diastolic function was preserved. Right ventricular systolic and diastolic function deteriorated after the occlusion. In conclusion, the FO has a limited capacity to increase its volume blood flow at near‐term gestation.

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Series: Experimental physiology
ISSN: 0958-0670
ISSN-E: 0958-0670
ISSN-L: 0958-0670
Volume: 104
Issue: 2
Pages: 189 - 198
DOI: 10.1113/EP087423
OADOI: https://oadoi.org/10.1113/EP087423
Type of Publication: A1 Journal article – refereed
Field of Science: 3121 General medicine, internal medicine and other clinical medicine
Subjects:
Funding: This work was supported by grants from the Regional Health Authority of Northern Norway (G.A.).
Copyright information: © 2018 The Authors. Experimental Physiology © 2018 The Physiological Society. This is the peer reviewed version of the following article: Lantto, J, Erkinaro, T, Haapsamo, M, et al. Foramen ovale blood flow and cardiac function after main pulmonary artery occlusion in fetal sheep. Exp. Physiol. 2019; 104: 189–198, which has been published in final form at https://doi.org/10.1113/EP087423. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.