title: Analysis of hemodynamic changes during beating heart surgical procedures.
abstract: BACKGROUND
  Coronary artery bypass grafting on the beating heart causes significant hemodynamic compromise during displacement of the heart. The precise mechanisms causing altered hemodynamics have not been clearly understood. The purpose of this study was to define the hemodynamic changes caused by displacing the heart in patients undergoing beating heart surgical procedures.
  
  
  METHODS
  Forty-four patients (35 men, 9 women; mean age, 64.5 +/- 9.6 years) underwent off-pump coronary artery bypass grafting. The hemodynamic variables were collected before and after positioning the heart for anastomosis of the left anterior descending, circumflex, and posterior descending coronary arteries.
  
  
  RESULTS
  There was a significant increase in right ventricular end-diastolic pressure during positioning for all vessels, and in left ventricular end-diastolic pressure during positioning for the left anterior descending and circumflex coronary arteries. Positioning for the circumflex artery showed the largest increase of left and right ventricular end-diastolic pressure, resulting in the greatest hemodynamic compromise.
  
  
  CONCLUSIONS
  In the clinical setting of diseased human hearts, there is a biventricular contribution to altered hemodynamics. The increase of right ventricular end-diastolic pressure in all positions suggests that the major cause of hemodynamic changes is disturbed diastolic filling of the right ventricle, especially by direct ventricular compression.
authors.affiliation: Cardiopulmonary Research Science and Technology Institute, Dallas, Texas, USA.
authors.forename: M
authors.initials: M
authors.lastname: Mathison
authors.forename: J R
authors.initials: JR
authors.lastname: Edgerton
authors.forename: J L
authors.initials: JL
authors.lastname: Horswell
authors.forename: J J
authors.initials: JJ
authors.lastname: Akin
authors.forename: M J
authors.initials: MJ
authors.lastname: Mack
mesh_terms: D000368:Aged; D000714:Anastomosis, Surgical; D001794:Blood Pressure / Q000502:physiology; D001026:Coronary Artery Bypass / Q000379:methods*; D003971:Diastole / Q000502:physiology; D005260:Female; D006324:Heart Arrest, Induced; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007431:Intraoperative Complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D013318:Stroke Volume / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology