title: Transesophageal echocardiography estimation of coronary sinus blood flow for the adequacy of revascularization in patients undergoing off-pump coronary artery bypass graft.
abstract: OBJECTIVE
  Physiologically coronary sinus (CS) drains the left coronary artery (LCA) territory. Stenosis of the branches of LCA may decrease the coronary sinus blood flow (CSBF). Any intervention that aims at restoring the flow of the stenosed vessel increases coronary artery flow that should consequently increase the CSBF. Hence, this study was undertaken to assess the CSBF before and after each branch of LCA to determine the adequacy of surgical revascularization in patients undergoing elective off pump coronary artery bypass grafting (OPCAB) using transesophageal echocardiography (TEE).
  
  
  METHODS
  Thirty consecutive patients scheduled for elective OPCAB were enrolled. CSBF was assessed before and after each branch of LCA revascularization using TEE. Left internal mammary artery (LIMA) Doppler was also obtained post LIMA to left anterior descending (LAD) grafting.
  
  
  RESULTS
  Hemodynamic and echocardiographic variables were compared by means of Student's t-test for paired data before and after revascularization. The CSBF per beat (1.28 ± 0.71), CSBF per minute (92.59 ± 59.32) and total velocity time integral (VTI) (8.93 ± 4.29) before LAD grafting showed statistically significant increase to CSBF per beat (1.70 ± 0.89), CSBF per minute (130.72 ± 74.22) and total VTI (11.96 ± 5.68) after LAD revascularization. The CSBF per beat (1.67 ± 1.03), CSBF per minute (131.91 ± 86.59) and total VTI (11.00 ± 5.53) before obtuse marginal (OM) grafting showed statistically significant increase to CSBF per beat (1.91 ± 1.03), CSBF per min (155.20 ± 88.70) and total VTI (12.09 ± 5.43) after OM revascularization. In 9 patients, color flow Doppler of LIMA could be demonstrated which showed diastolic predominant blood flow after LIMA to LAD grafting.
  
  
  CONCLUSIONS
  Demonstration of CSBF was simple and monitoring the trend of CSBF values before and after each graft of LCA territory will guide to determine the adequacy of surgical revascularization.
authors.affiliation: Department of Cardiac Anaesthesiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Jayanagar, India.
authors.forename: P S
authors.initials: PS
authors.lastname: Nagaraja
authors.forename: Naveen G
authors.initials: NG
authors.lastname: Singh
authors.forename: T A
authors.initials: TA
authors.lastname: Patil
authors.forename: V
authors.initials: V
authors.lastname: Manjunath
authors.forename: S R
authors.initials: SR
authors.lastname: Prasad
authors.forename: A M
authors.initials: AM
authors.lastname: Jagadeesh
authors.forename: K Ashok
authors.initials: KA
authors.lastname: Kumar
mesh_terms: D047549:Coronary Artery Bypass, Off-Pump; D054326:Coronary Sinus / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D023921:Coronary Stenosis / Q000503:physiopathology / Q000601:surgery*; D015150:Echocardiography, Doppler; D017548:Echocardiography, Transesophageal; D006439:Hemodynamics; D006801:Humans; D008323:Mammary Arteries / Q000000981:diagnostic imaging; D016896:Treatment Outcome