title: Multiparameter fiber optic sensor for the assessment of intramyocardial perfusion.
abstract: OBJECTIVE
  The objective of this study was to characterize a multiparameter fiber optic sensor for detection of changes in intramyocardial perfusion and to demonstrate a method of determining critical values for pH, PCO2, and PO2 to indicate onset of anaerobic metabolism.
  
  
  METHODS
  Six swine underwent a 20-minute occlusion of the left anterior descending coronary artery (LAD). Myocardial pH, PCO2, and PO2 were measured continuously in the LAD and left circumflex coronary artery (CFX) territories. Critical values for each parameter were calculated from these data.
  
  
  RESULTS
  During occlusion LAD myocardial pH declined from 7.36 +/- 0.04 to 6.85 +/- 0.04; PCO2 rose from 57.0 +/- 2.9 to 154.0 +/- 18.0 torr, PO2 fell from 78 +/- 20 to 6 +/- 5 torr. No myocardial pH or PCO2 changes were observed in the CFX region, however, CFX PO2 was affected in some animals during LAD occlusion and release. Methods for determining the ischemic threshold from these sensor data are presented.
  
  
  CONCLUSIONS
  Multiparameter fiber optic sensors reliably respond to coronary occlusion and thus have the potential to help guide myocardial protection strategies for both on- and off-pump cardiac surgery.
authors.affiliation: Division of Cardiac Surgery, University of Massachusetts Medical School, Worcester, Massachusetts, USA. babs.soller@umassmed.edu
authors.forename: Babs R
authors.initials: BR
authors.lastname: Soller
authors.forename: Charles
authors.initials: C
authors.lastname: Hsi
authors.forename: Janice
authors.initials: J
authors.lastname: Favreau
authors.forename: Ndumiso
authors.initials: N
authors.lastname: Cingo
authors.forename: Robert A
authors.initials: RA
authors.lastname: Lancey
authors.forename: Okike N
authors.initials: ON
authors.lastname: Okike
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Vander Salm
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D001794:Blood Pressure / Q000502:physiology; D002245:Carbon Dioxide / Q000378:metabolism; D003326:Coronary Circulation / Q000502:physiology; D004195:Disease Models, Animal; D005336:Fiber Optic Technology; D006339:Heart Rate / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D006940:Hyperemia / Q000378:metabolism / Q000503:physiopathology; D019157:Ischemic Preconditioning, Myocardial; D008955:Models, Cardiovascular; D017202:Myocardial Ischemia / Q000378:metabolism / Q000503:physiopathology; D015425:Myocardial Reperfusion; D055100:Optical Fibers; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology; D013552:Swine
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen