title: Atrial dominance in the human embryonic heart: a study of cardiac function at 6-10 weeks of gestation.
abstract: OBJECTIVE
  To investigate the difference in forces developed by atrial and ventricular myocardium during contraction in human embryos using a novel method.
  
  
  METHODS
  This was a cross-sectional study of 115 pregnancies examined at 6-10 weeks of gestation. Ventricular inflow and outflow velocities were obtained by Doppler echocardiography and the relative force development was evaluated by calculating the ratio between atrial and ventricular ejection force (EF).
  
  
  RESULTS
  Data from 97 embryos with monophasic ventricular filling were analyzed. Both inflow and outflow cardiac velocities increased with advancing gestational age (P < 0.001). The mean peak inflow velocity (31.7 ± 10.2 cm/s) was significantly higher (P < 0.0001) than the outflow velocity (19.6 ± 6.1 cm/s). The EFinflow /EFoutflow ratio was more than 1.0 in all but four (96%) cases.
  
  
  CONCLUSIONS
  Our study indicates the possibility of atrial dominance in the embryonic period of heart development, which may have clinical implications, as deviations from this normal pattern may indicate human embryonic cardiac dysfunction.
authors.affiliation: Department of Obstetrics and Gynecology, Medical University of Silesia, Katowice, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Wloch
authors.affiliation: Department of Obstetrics and Gynecology, Medical University of Silesia, Katowice, Poland.
authors.forename: W
authors.initials: W
authors.lastname: Rozmus-Warcholinska
authors.affiliation: Department of Obstetrics and Gynecology, Medical University of Silesia, Katowice, Poland.
authors.forename: W
authors.initials: W
authors.lastname: Cnota
authors.affiliation: Perinatal Cardiology, All Children's Hospital, Pediatrix Medical Group, University of Florida, St Petersburg, FL, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Huhta
authors.affiliation: Women's Health and Perinatology Research Group, Department of Clinical Medicine, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway.|Department of Obstetrics and Gynecology, University Hospital of Northern Norway, Tromsø, Norway.
authors.forename: G
authors.initials: G
authors.lastname: Acharya
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology*; D003430:Cross-Sectional Studies; D015150:Echocardiography, Doppler; D005260:Female; D005865:Gestational Age; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000196:embryology; D006801:Humans; D011247:Pregnancy; D013318:Stroke Volume / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: Doppler; cardiac function; heart; human embryo