title: Hemodynamic factors of thrombus formation in coronary aneurysms associated with Kawasaki disease.
abstract: BACKGROUND
  We studied the mechanism of thrombus formation in coronary aneurysms based on rheological findings.
  
  
  METHODS
  We studied 43 coronary aneurysms in 33 patients with Kawasaki disease (mean (+/- SD) age 6.1 +/- 4.3 years). These lesions were divided into three groups on the basis of maximum diameter: (i) small (group S); (ii) medium sized (group M); and (iii) large (group L) aneurysms. Using a Doppler flow guidewire and a pressure-monitoring guidewire, we measured coronary flow velocity and perfusion pressure inside aneurysms and in adjacent normal-looking vessels. We calculated the average peak velocity (APV) index, the mean coronary perfusion pressure (P) index and shear index.
  
  
  RESULTS
  The APV index and shear index decreased significantly (p < 0.005) as the aneurysm size increased (APV index in groups S, M and L was 0.893 +/- 0.149, 0.573 +/- 0.242 and 0.128 +/- 0.131, respectively; shear index in groups S, M and L was 0.750 +/- 0.149, 0.328 +/- 0.153 and 0.020 +/- 0.028, respectively). However, coronary perfusion pressure showed no relationship to aneurysm size and was not significantly different from that in adjacent normal-looking vessels.
  
  
  CONCLUSIONS
  The results of the present study suggest that the stagnation of flow and the reduction of shear stress in coronary aneurysms could initiate thrombus formation.
authors.affiliation: Department of Pediatrics, Nippon Medical School, Tokyo, Japan. rio-ma7@nms.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Kuramochi
authors.forename: T
authors.initials: T
authors.lastname: Ohkubo
authors.forename: N
authors.initials: N
authors.lastname: Takechi
authors.forename: D
authors.initials: D
authors.lastname: Fukumi
authors.forename: Y
authors.initials: Y
authors.lastname: Uchikoba
authors.forename: S
authors.initials: S
authors.lastname: Ogawa
mesh_terms: D000293:Adolescent; D001783:Blood Flow Velocity; D002648:Child; D002675:Child, Preschool; D003323:Coronary Aneurysm / Q000150:complications* / Q000000981:diagnostic imaging; D017023:Coronary Angiography; D003328:Coronary Thrombosis / Q000209:etiology* / Q000503:physiopathology; D015150:Echocardiography, Doppler; D005260:Female; D005434:Flow Cytometry; D018056:Hemorheology; D006801:Humans; D007223:Infant; D008297:Male; D009080:Mucocutaneous Lymph Node Syndrome / Q000150:complications*