title: Impact of intraaortic balloon counterpulsation on arterial blood flow in juvenile pigs with heart failure.
abstract: OBJECTIVE
  To assess the impact of intraaortic balloon counterpulsation on coronary, renal and aortic blood flow in an animal heart failure model.
  
  
  BACKGROUND
  Heart failure exacerbations are still often treated with inotropic medications despite a lack of evidence demonstrating any benefit with these drugs. Intraaortic balloon counterpulsation may be considered in certain cases a bridge to recovery.
  
  
  METHODS
  Four juvenile pigs underwent pacemaker implantation to induce a rapid-pacing mediated dilated cardiomyopathy. After approximately 4 weeks of rapid pacing, the mean ejection fraction was reduced to 28.8+/-9.5% with a mean systolic blood pressure of 64/44 mmHg. The pigs then underwent surgical placement of flow probes around the circumflex coronary artery, renal artery and infrarenal aorta. A Millar catheter was used to calculate Dp/Dt and a Swan-Ganz to calculate cardiac output. Data were recorded at baseline and after 10 minutes of balloon pumping. The pigs were euthanized post-procedure.
  
  
  RESULTS
  Coronary blood flow was increased 9.7% by balloon counterpulsation from 38.3 +/- 12.0 to 42.0+/-11.4 ml/s (p=NS). Renal blood flow was reduced 11.9% by counterpulsation from 130.0+/-88.6 ml/s to 114.5+/-76.6 ml/s (p=NS). Infrarenal aortic blood flow was not changed (mean of 900 ml/s with and without counterpulsation); blood pressure, cardiac output and Dp/Dt were not changed after 10 minutes of pumping. There was little impact observed by changing the position of the balloon closer to or farther away from the apex of the aortic arch.
  
  
  CONCLUSIONS
  Intraaortic balloon counterpulsation did not significantly improve hemodynamics in the pig heart failure model. This may be attributed to the high compliance of the juvenile pig's aorta, thus attenuating the pressure wave generated by counterpulsation. A larger volume balloon would merit investigation for this application.
authors.affiliation: Duke University Medical Center, American Cardiovascular Research Institute, 5314 Medlock Corners Drive, Norcross, GA 30092, USA. mfischi@acrionline.org
authors.forename: Michael C
authors.initials: MC
authors.lastname: Fischi
authors.forename: Fernando
authors.initials: F
authors.lastname: Tondato
authors.forename: Ronnie
authors.initials: R
authors.lastname: Adams
authors.forename: Jianhua
authors.initials: J
authors.lastname: Cui
authors.forename: Michael
authors.initials: M
authors.lastname: Hutchison
authors.forename: Nicolas A F
authors.initials: NA
authors.lastname: Chronos
mesh_terms: D000818:Animals; D001011:Aorta / Q000503:physiopathology* / Q000601:surgery*; D001794:Blood Pressure / Q000502:physiology; D003326:Coronary Circulation / Q000502:physiology*; D015908:Counterpulsation; D004195:Disease Models, Animal; D006333:Heart Failure / Q000503:physiopathology* / Q000601:surgery*; D007423:Intra-Aortic Balloon Pumping; D008955:Models, Cardiovascular; D012079:Renal Circulation / Q000502:physiology*; D013318:Stroke Volume / Q000502:physiology; D013552:Swine