title: Altered maternal left ventricular contractility and function during normal pregnancy.
abstract: OBJECTIVE
  To evaluate maternal left ventricular (LV) systolic and diastolic function during normal pregnancy by non-invasive measures of LV contractility incorporating loading conditions.
  
  
  METHODS
  Sixty-five women were examined using echocardiography, including tissue Doppler and two-dimensional speckle tracking, and subclavian artery pulse trace recordings at gestational weeks 14-16, 22-24 and 36, and at 6 months postpartum.
  
  
  RESULTS
  The mean ± SD age of the women was 32.0 ± 4.6 years. Cardiac output and LV end-diastolic volume were on average 20% and 23% higher, respectively, during pregnancy, compared to that at 6 months postpartum (both, P < 0.01). LV ejection fraction, global peak systolic strain and rate-corrected LV velocity of circumferential fiber shortening (Vcfc) were 11%, 6% and 6% lower, respectively, at 36 weeks' gestation compared to at 6 months postpartum (all, P < 0.01). Afterload, measured as LV end-systolic wall stress (ESWS) increased by 10% between 14-16 and 36 weeks' gestation (P < 0.01). Analysis of the relationship between Vcfc and ESWS revealed that LV contractility was lower during pregnancy than at 6 months postpartum. Changes in diastolic function were demonstrated by 11% lower mitral early diastolic (E) wave velocity, 8% lower tissue Doppler early diastolic velocity (e') and 13% higher left atrial area (all P < 0.01) during pregnancy. Tissue Doppler E/e' remained unaltered (P = 0.78).
  
  
  CONCLUSIONS
  During normal pregnancy, LV contractility is lower than it is at 6 months postpartum. This is associated with increased LV and left atrial area, whereas filling pressures are unchanged. These findings suggest that pregnancy exerts a larger load on the cardiovascular system than previously assumed.
authors.affiliation: National Resource Centre for Women's Health, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: M E
authors.initials: ME
authors.lastname: Estensen
authors.forename: J O
authors.initials: JO
authors.lastname: Beitnes
authors.forename: G
authors.initials: G
authors.lastname: Grindheim
authors.forename: L
authors.initials: L
authors.lastname: Aaberge
authors.forename: O A
authors.initials: OA
authors.lastname: Smiseth
authors.forename: T
authors.initials: T
authors.lastname: Henriksen
authors.forename: S
authors.initials: S
authors.lastname: Aakhus
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D015331:Cohort Studies; D003971:Diastole / Q000502:physiology; D004452:Echocardiography / Q000379:methods; D005260:Female; D006801:Humans; D009200:Myocardial Contraction / Q000502:physiology*; D011247:Pregnancy / Q000502:physiology*; D013348:Subclavian Artery / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*