title: Analysis of myocardial temperature changes in conventional isolated coronary artery bypass grafting.
abstract: BACKGROUND
  To determine whether cold blood cardioplegia (CBCP) can get over coronary artery lesions, we analyzed the relationship between myocardial temperature changes and lesion severity of major coronary arteries.
  
  
  RESULTS
  From April 1991 to October 2003, we measured myocardial temperature before and after antegrade and retrograde delivery of CBCP in 492 patients undergoing conventional coronary artery bypass grafting. Stenotic severity of three major coronary arteries was classified into four grades according to preoperative coronary arteriography; grade 0 for 50 % or less, 1 for 75 %, 2 for 90 %, 3 for 99 % or 100 %. We analyzed relationships between myocardial temperature changes [ΔT-A (antegrade) & ΔT-R (retrograde)] and the coronary artery lesion's severity. Average ΔT-A of the right coronary artery had no relationship with stenotic grades. Mean ΔT-A of the left anterior descending (LAD) became less and less in proportion to its stenotic grade [9.7 °C for grade 0, 8.2 °C for grade 1, 7.1 °C for grade 2, and 6.0 °C for grade 3, respectively, (p = 0.0042)]. ΔT-A of the circumflex artery showed similar but weaker tendency than those of LAD. Significant inverse correlations were found between ΔT-A and ΔT-R1 in each territory (p < 0.001).
  
  
  CONCLUSIONS
  Antegrade delivery was less effective in situations with tight proximal lesion, especially in the LAD territory. Retrograde delivery supplemented antegrade delivery. Myocardial temperature monitoring enables us to deal with inadequate cardioplegic delivery, and is a good indicator of myocardial protection.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Yokkaichi Municipal Hospital, Shibata, Yokkaichi, 2-2-37, Japan, cvsokamoto@yokkaichihp01.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Okamoto
authors.forename: Akinori
authors.initials: A
authors.lastname: Tamenishi
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Nishi
authors.forename: Takao
authors.initials: T
authors.lastname: Niimi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001831:Body Temperature / Q000502:physiology*; D017023:Coronary Angiography; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000503:physiopathology / Q000601:surgery*; D003331:Coronary Vessels / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006324:Heart Arrest, Induced / Q000379:methods; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D009206:Myocardium; D012189:Retrospective Studies; D016896:Treatment Outcome