title: Preserved hyperaemic response in supraclavicular ultrasonography demonstrates function on demand of the LIMA to LAD string sign graft after CABG.
abstract: OBJECTIVE
  To correlate supraclavicular ultrasonography with angiographically patent and string sign left internal mammary artery (LIMA) to left anterior descending artery (LAD) grafts.
  
  
  METHODS
  Sixteen patients with a single LIMA anastomosis to the LAD were prospectively entered in a follow-up study. The supraclavicular ultrasonography of the LIMA origin was studied preoperatively and at 5.3+/-3.6 months and 1.7+/-0.4 year postoperatively. At the late postoperative ultrasonography electrocardiographically controlled hyperemic response was also studied for 6 min. Control angiography was performed at 1.5+/-0.8 year. Differences within groups were tested with a paired t-test and between groups with an unpaired t-test.
  
  
  RESULTS
  Control angiography showed in 13 patients (group I) a patent LIMA graft and in 3 patients (group II) a string sign LIMA graft. Preoperative blood velocities were not significantly different between groups. Postoperatively, both groups revealed higher diastolic and lower systolic blood velocities compared to preoperative values. The blood velocities at rest did not change in group I and all velocities decreased in group II in time postoperatively. The blood velocities in maximal hyperemic response increased significantly within the groups and were not significantly different between the groups. No ischemia could be detected electrocardiographically during hyperemic response and no patient presented angina.
  
  
  CONCLUSIONS
  Both groups showed a shift towards coronary type diastolic blood velocities at rest and at hyperaemic response. Significant hyperemic response was also present in string sign LIMA grafts and demonstrates response capacity to increased myocardial oxygen demand.
authors.affiliation: Department of Cardiothoracic Surgery, Thoraxcentre, Erasmus Medical Centre, Rotterdam, The Netherlands. j.m.hartman@erasmusmc.nl
authors.forename: J M
authors.initials: JM
authors.lastname: Hartman
authors.forename: H C
authors.initials: HC
authors.lastname: Kelder
authors.forename: R G A
authors.initials: RG
authors.lastname: Ackerstaff
authors.forename: H A
authors.initials: HA
authors.lastname: Swieten
authors.forename: F E E
authors.initials: FE
authors.lastname: Vermeulen
authors.forename: A J J C
authors.initials: AJ
authors.lastname: Bogers
mesh_terms: D000241:Adenosine; D001783:Blood Flow Velocity; D002968:Clavicle; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006940:Hyperemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D007387:Internal Mammary-Coronary Artery Anastomosis; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D011182:Postoperative Care; D011300:Preoperative Care; D011446:Prospective Studies; D016896:Treatment Outcome; D018617:Ultrasonography, Doppler, Pulsed / Q000379:methods*; D014654:Vascular Patency; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine