title: Improved left ventricular function after chronic left ventricular unloading.
abstract: BACKGROUND
  This study assessed the effect of prolonged left ventricular unloading on native ventricular function.
  
  
  METHODS
  We reviewed data from 31 patients (30 men, 1 woman) supported more than 30 days (mean, 137 days; range, 31 to 505 days) with the HeartMate left ventricular assist system. The patients' mean age was 46 years (range, 22 to 64 years); 17 had idiopathic and 14 had ischemic cardiomyopathy. Data (anatomic, physiologic, hemodynamic, histologic, and biochemical) were collected at the time of HeartMate implantation, during support with the device temporarily off, and at the time of device explantation.
  
  
  RESULTS
  Routine chest roentgenogram showed improvement in cardiothoracic ratio (0.62 +/- 0.04 to 0.55 +/- 0.03; p < 0.0001). Echocardiography performed with the pump off showed a significant decrease in left ventricular end-diastolic dimension (6.81 +/- 0.87 cm to 5.39 +/- 1.08 cm; p < 0.0005) and a significant improvement in ejection fraction (0.11 +/- 0.05 to 0.22 +/- 0.17; p < 0.02). Cardiac index increased (1.96 +/- 0.52 L.min-1.m-2 to 2.93 +/- 0.73 L.min-1.m-2; p < 0.0001), mean aortic pressure increased (71.40 +/- 10.63 mm Hg to 76.33 +/- 16.84 mm Hg; p = 0.48), pulmonary capillary wedge pressure decreased (24.18 +/- 6.27 mm Hg to 14.48 +/- 3.01 mm Hg; p < 0.0001), and pulmonary vascular resistance decreased (3.34 +/- 2.00 Wood units to 2.51 +/- 0.88 Wood units; p < 0.05). Comparisons of tissue samples taken at the time of implantation and at the time of transplantation showed a marked reduction in myocytolysis. Calcium uptake, calcium-binding rates, and lipid levels normalized in patients studied. Plasma norepinephrine levels decreased to near normal levels.
  
  
  CONCLUSIONS
  Prospective studies are now indicated to determine whether device removal without transplantation may be beneficial in selected patients.
authors.affiliation: Division of Cardiopulmonary Transplantation, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, USA.
authors.forename: O H
authors.initials: OH
authors.lastname: Frazier
authors.forename: C R
authors.initials: CR
authors.lastname: Benedict
authors.forename: B
authors.initials: B
authors.lastname: Radovancevic
authors.forename: R J
authors.initials: RJ
authors.lastname: Bick
authors.forename: P
authors.initials: P
authors.lastname: Capek
authors.forename: W E
authors.initials: WE
authors.lastname: Springer
authors.forename: M P
authors.initials: MP
authors.lastname: Macris
authors.forename: R
authors.initials: R
authors.lastname: Delgado
authors.forename: L M
authors.initials: LM
authors.lastname: Buja
mesh_terms: D000328:Adult; D002118:Calcium / Q000378:metabolism; D004452:Echocardiography; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006333:Heart Failure / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D006353:Heart-Assist Devices; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D010743:Phospholipids / Q000378:metabolism; D011859:Radiography; D012519:Sarcoplasmic Reticulum / Q000378:metabolism; D016277:Ventricular Function, Left
chemical_list: D005227:Fatty Acids; D010743:Phospholipids; D002118:Calcium