title: Effects of preload alterations on peak early diastolic mitral annulus velocities evaluated by tissue Doppler echocardiography.
abstract: OBJECTIVE
  Tissue Doppler echocardiography is proposed to be a relatively preload independent tool for assessment of diastolic function. No data exist on anaesthetized patients in whom myocardial contractility, vascular tone and baroreceptor reflexes are depressed. The aim of this study was to evaluate the effects of preload alterations on tissue velocities in patients during general anaesthesia for coronary arterial bypass surgery.
  
  
  METHODS
  Fifteen patients referred for elective aorto-coronary bypass surgery were examined by tissue Doppler echocardiography. Early diastolic velocities in the septal and lateral portion of the mitral annulus were measured during preload interventions induced by tilting of the operating table in patients during general anaesthesia both before surgery and after chest closure. To verify changes in preload we used right atrial pressure and pulmonary artery occlusion pressure.
  
  
  RESULTS
  Tissue velocities in both the septal and lateral portion of the mitral annulus were significantly higher when preload was increased, compared to when it was decreased. Alterations in diastolic velocities in the septal portion of the mitral annulus prior to surgery: 0.8 +/- 0.2 cm s-1, P < 0.001, after surgery: 1.1 +/- 0.2 cm s-1, P < 0.001. Alterations in diastolic velocities in the lateral portion of the mitral annulus prior to surgery: 1.4 +/- 0.2 cm s-1, P < 0.001, after surgery: 1.1 +/- 0.3 cm s-1, P < 0.01. Concomitant changes in right atrial pressure and pulmonary artery occlusion pressure were 11 +/- 1 and 12 +/- 1 mmHg before surgery and 13 +/- 1 and 12 +/- 1 mmHg after surgery (P < 0.001 for all), respectively.
  
  
  CONCLUSIONS
  These results show that tissue velocities of the mitral annulus are preload dependent in patients during general anaesthesia both before and after coronary surgery.
authors.affiliation: Department of Anaesthesiology, Ullevål University Hospital, Kirkeveien 166, 0407 Oslo, Norway. alf.arne.jonassen@uus.no
authors.forename: A A
authors.initials: AA
authors.lastname: Jonassen
authors.forename: R
authors.initials: R
authors.lastname: Bjørnerheim
authors.forename: T
authors.initials: T
authors.lastname: Edvardsen
authors.forename: T
authors.initials: T
authors.lastname: Veel
authors.forename: K A
authors.initials: KA
authors.lastname: Kirkebøen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000768:Anesthesia, General / Q000379:methods*; D001783:Blood Flow Velocity / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D001026:Coronary Artery Bypass / Q000379:methods; D003327:Coronary Disease / Q000503:physiopathology / Q000601:surgery; D003971:Diastole / Q000187:drug effects*; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000187:drug effects; D008991:Monitoring, Physiologic / Q000379:methods; D009200:Myocardial Contraction / Q000187:drug effects; D011187:Posture; D011651:Pulmonary Artery / Q000187:drug effects