title: Characterization of the non-invasive assessment of the cutaneous microcirculation by laser Doppler perfusion scanner.
abstract: OBJECTIVE
  Microcirculatory dysfunction contributes to morbidity and mortality in vascular diseases. Here, we aimed at establishing a sensitive and valid method to measure microvascular reactivity during post-occlusive reactive hyperemia (PORH) using scanning laser Doppler perfusion imaging (LDPI) of the forearm.
  
  
  METHODS
  In a first series, LDPI was methodologically evaluated on the volar forearm of healthy volunteers (n = 10) before and after one to five minutes of upper arm occlusion. In a second series, readings were performed in 20 healthy subjects and 20 patients with coronary artery disease (CAD).
  
  
  RESULTS
  Three minutes of forearm occlusion were sufficient to induce maximal vasodilation during PORH as indicated by maximal increase in perfusion unit (PU) amplitude that did not further increase after five-minute occlusion. Five-minute occlusion led to a significant prolongation of PORH with greater area under curve (AUC) suggesting longer lasting vasodilation of microvessels. The five-minute occlusion was associated with lower variability as compared with three minutes (intraindividual variability: 9-17% vs. 12-21%; interindividual variability: 13-24% vs. 14-26%). CAD patients exhibited significantly reduced amplitude (105 +/- 49 vs. 164 +/- 35 PU; p < 0.001), ratio (4.7 +/- 1.8 vs. 7.1 +/- 1.8; p < 0.001), and AUC (1656 +/- 1070 vs. 2723 +/- 864 PU x minutes; p = 0.001).
  
  
  CONCLUSIONS
  Scanning LDPI is a feasible and reproducible method for non-invasive assessment of the cutaneous microcirculatory response during PORH.
authors.affiliation: Department of Medicine, Division of Cardiology, Pneumology, and Vascular Diseases, University Hospital, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Keymel
authors.forename: Julia
authors.initials: J
authors.lastname: Sichwardt
authors.forename: Jan
authors.initials: J
authors.lastname: Balzer
authors.forename: Emilia
authors.initials: E
authors.lastname: Stegemann
authors.forename: Tienush
authors.initials: T
authors.lastname: Rassaf
authors.forename: Petra
authors.initials: P
authors.lastname: Kleinbongard
authors.forename: Malte
authors.initials: M
authors.lastname: Kelm
authors.forename: Christian
authors.initials: C
authors.lastname: Heiss
authors.forename: Thomas
authors.initials: T
authors.lastname: Lauer
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000503:physiopathology; D005260:Female; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D017078:Laser-Doppler Flowmetry / Q000379:methods*; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D010991:Plethysmography; D015203:Reproducibility of Results; D012867:Skin / Q000098:blood supply*; D014664:Vasodilation / Q000502:physiology; D055815:Young Adult