title: Velocity profiles and phasic flow patterns in the non-stenotic human left anterior descending coronary artery during cardiac surgery.
abstract: OBJECTIVE
  The aim was to investigate the phasic characteristics of normal human left coronary artery flow and velocity profiles across the vessel.
  
  
  METHODS
  The phasic characteristics of flow in the human left anterior descending coronary artery, the centreline flow velocities, and the velocity profiles were measured in 10 patients during corrective surgery for atrial septal defect after closure of the defect. None of these patients had any detectable coronary artery stenosis or left ventricular hypertrophy. Measurements were made with a 20 MHz 80 channel pulsed Doppler velocimeter.
  
  
  RESULTS
  The velocity waveform displayed a diastolic-predominant pattern with a systolic to diastolic velocity ratio of 0.29(SD 0.17). Reverse flow was observed in early systole in five patients and in mid to late systole in six patients. The values of peak Reynolds number, unsteadiness parameter, and pulsatility index were 504(198), 2.5(0.6), and 5.9(4.4) respectively. The velocity profiles during diastole showed considerable variability in shape, ranging from symmetrical to skewed to M shaped patterns. The peak wall shear rate was 765(250) s-1 on the epicardial wall of the vessel and 712(301) s-1 on the myocardial wall; the difference was not statistically significant.
  
  
  CONCLUSIONS
  The velocity waveform displayed a diastolic-predominant pattern. Considerable variability in shape of the velocity profile was found and was perhaps due to the time evolution of the velocity profile within the diastolic time period.
authors.affiliation: Department of Medical Engineering and Systems Cardiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Kajiya
authors.forename: S
authors.initials: S
authors.lastname: Matsuoka
authors.forename: Y
authors.initials: Y
authors.lastname: Ogasawara
authors.forename: O
authors.initials: O
authors.lastname: Hiramatsu
authors.forename: S
authors.initials: S
authors.lastname: Kanazawa
authors.forename: Y
authors.initials: Y
authors.lastname: Wada
authors.forename: S
authors.initials: S
authors.lastname: Tadaoka
authors.forename: K
authors.initials: K
authors.lastname: Tsujioka
authors.forename: T
authors.initials: T
authors.lastname: Fujiwara
authors.forename: M
authors.initials: M
authors.lastname: Zamir
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D006348:Cardiac Surgical Procedures; D002648:Child; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D005260:Female; D006344:Heart Septal Defects, Atrial / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow / Q000502:physiology; D014463:Ultrasonography