title: Effect of Hypoxemia with or without Increased Placental Vascular Resistance on Fetal Left and Right Ventricular Myocardial Performance Index in Chronically Instrumented Sheep.
abstract: Myocardial performance index (MPI) is increased in growth-restricted fetuses with placental insufficiency, but it is unknown if this is due to fetal hypoxemia or increased placental vascular resistance (Rplac). We used chronically instrumented sheep fetuses (n = 24). In 12 fetuses, placental embolization was performed 24 h before experiments. On the day of the experiment, left (LV) and right (RV) ventricular MPIs were obtained by pulsed Doppler at baseline and in the hypoxemia and recovery phases. At baseline, Rplacwas greater and fetal pO2lower in the placental embolization group, but RV and LV MPIs were comparable to those of the control group. During hypoxemia, mean LV MPI increased significantly only in fetuses with an intact placenta (0.34 vs. 0.46), returning to baseline during the recovery phase. Right ventricular MPI was unaffected. We conclude that fetal LV function is sensitive to acute hypoxemia. Exposure to chronic hypoxemia could pre-condition the fetal heart and protect its function with worsening hypoxemia.
authors.affiliation: Women's Health & Perinatal Research Group, UiT-The Arctic University of Norway, Tromsø, Norway; Department of Obstetrics and Gynecology, University Hospital of Northern Norway, Tromsø, Norway. Electronic address: abhide@sgul.ac.uk.
authors.forename: Amar
authors.initials: A
authors.lastname: Bhide
authors.affiliation: Biomedicine Unit, Department of Physiology, University Hospital of Oulu, Oulu, Finland.
authors.forename: Olli
authors.initials: O
authors.lastname: Vuolteenaho
authors.affiliation: Department of Obstetrics and Gynecology, University Hospital of Oulu, Oulu, Finland.
authors.forename: Mervi
authors.initials: M
authors.lastname: Haapsamo
authors.affiliation: Department of Anesthesiology, University Hospital of Oulu, Oulu, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Erkinaro
authors.affiliation: Department of Obstetrics and Gynecology, University of Eastern Finland, Kuopio, Finland; Oregon Health and Sciences University, Portland, Oregon, USA.
authors.forename: Juha
authors.initials: J
authors.lastname: Rasanen
authors.affiliation: Women's Health & Perinatal Research Group, UiT-The Arctic University of Norway, Tromsø, Norway; Department of Obstetrics and Gynecology, University Hospital of Northern Norway, Tromsø, Norway; Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institute, Stockholm, Sweden.
authors.forename: Ganesh
authors.initials: G
authors.lastname: Acharya
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005318:Fetal Heart / Q000503:physiopathology*; D006352:Heart Ventricles / Q000196:embryology / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D010920:Placenta / Q000098:blood supply* / Q000503:physiopathology; D011247:Pregnancy; D012756:Sheep; D016216:Ultrasonography, Prenatal / Q000379:methods*; D014655:Vascular Resistance / Q000502:physiology*
keywords: Cardiovascular function; Hypoxemia; Sheep model