title: Effect of volume unloading surgery on coronary flow dynamics in patients with aortic atresia.
abstract: OBJECTIVE
  The objectives of this study were to define physiologic effects on and a clinical correlate to coronary blood flow during volume unloading surgery in patients with aortic atresia.
  
  
  METHODS
  Twenty-two patients with aortic atresia (group I, 13 patients with stage I reconstruction undergoing hemi-Fontan operation; group II, 9 patients with hemi-Fontan undergoing Fontan operation) underwent perioperative transesophageal echocardiography. Doppler spectral patterns, peak velocity, velocity time integral, and blood flow in the native ascending aorta were measured. Preoperative hemodynamics and postoperative clinical data were analyzed. Significance was defined as p < 0.05.
  
  
  RESULTS
  Higher values of coronary blood flow (982.9 +/- 321.7 vs 548.6 +/- 333.8 ml/min per square meter), velocity time integral (20.7 +/- 5.6 vs 12.6 +/- 4.0 cm), and peak velocity (96.1 +/- 21.4 vs 51.0 +/- 18.2 cm/sec) were found before operation in group I than after operation and in group II at both times. Flow changed from predominately systolic in preoperative group I to both systolic and diastolic after operation and in group II. Before operation in groups I and II, a number of hemodynamic parameters such as superior vena cava oxygen saturation correlated with coronary blood flow dynamics. After operation in group II, urine output (r = 0.86) and central venous pressure (r = -0.85) correlated with coronary blood flow dynamics.
  
  
  CONCLUSIONS
  Coronary blood flow parameters were higher in group I as a result of the increased energy needs required to pump to two circulations. No changes were found in group II. A number of coronary blood flow parameters correlated with preoperative hemodynamics and postoperative clinical data. These parameters appear to be useful in assessing the performance status of the myocardium after the Fontan operation, consistent with the notion that myocardial perfusion relates directly to ventricular function.
authors.affiliation: Department of Pediatrics, The Children's Hospital of Philadelphia, The University of Pennsylvania School of Medicine, 19104, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Fogel
authors.forename: J
authors.initials: J
authors.lastname: Rychik
authors.forename: J
authors.initials: J
authors.lastname: Vetter
authors.forename: M T
authors.initials: MT
authors.lastname: Donofrio
authors.forename: M
authors.initials: M
authors.lastname: Jacobs
mesh_terms: D001011:Aorta / Q000002:abnormalities*; D003326:Coronary Circulation; D017548:Echocardiography, Transesophageal; D018729:Fontan Procedure / Q000379:methods; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007223:Infant; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption; D011446:Prospective Studies; D013318:Stroke Volume