title: Effect of cardiac resynchronization therapy on endothelium-dependent vasodilatation in the cutaneous microvasculature.
abstract: OBJECTIVE
  Cardiac resynchronization therapy (CRT) improves hemodynamic parameters, exercise capacity, symptoms, functional status, and prognosis among patients with chronic heart failure (CHF). The role of the vascular endothelium in these improvements is largely unknown. In this study, we aimed to investigate whether the endothelium-dependent reactivity of the peripheral microcirculation improves in CHF patients during the first 2 months of CRT.
  
  
  METHODS
  We used local heating and iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) to measure endothelial function and smooth muscle function in the cutaneous microvasculature of 11 CHF patients before and 2 months after CRT.
  
  
  RESULTS
  We found that the perfusion response in the skin to local heating was increased 2 months post-CRT compared with baseline, both in terms of maximum perfusion (baseline: 113 [90-137] vs 2-months post-CRT: 137 [98-175], P=0.037) and area under curve (baseline: 1,601 [935-2,268] vs 2-months CRT: 2,205 [1,654-2,757], P=0.047). Also, the perfusion response to iontophoresis of ACh was improved (Emax: 23.9 [20.6-26.2]vs at 2-months CRT: 31.2 [29.3-33.4], P=0.005). No difference was found between the responses to SNP before and after CRT.
  
  
  CONCLUSIONS
  These results show that CRT improves endothelium-dependent vasodilatory capacity in the peripheral microcirculation within 2 months of therapy. The improvement in functional capacity that is seen in patients treated with CRT may, therefore, be in part mediated by an improvement of endothelium-dependent vasodilatory capacity.
authors.affiliation: Department of Clinical Physics, TweeSteden Ziekenhuis, Tilburg, the Netherlands. erik.tesselaar@liu.se
authors.forename: Erik
authors.initials: E
authors.lastname: Tesselaar
authors.forename: Angélique
authors.initials: A
authors.lastname: Schiffer
authors.forename: Jos
authors.initials: J
authors.lastname: Widdershoven
authors.forename: Herman
authors.initials: H
authors.lastname: Broers
authors.forename: Eric
authors.initials: E
authors.lastname: Hendriks
authors.forename: Kees
authors.initials: K
authors.lastname: Luijten
authors.forename: John
authors.initials: J
authors.lastname: Creusen
mesh_terms: D000109:Acetylcholine; D000368:Aged; D058406:Cardiac Resynchronization Therapy; D002316:Cardiotonic Agents / Q000627:therapeutic use; D005260:Female; D006333:Heart Failure / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy; D006361:Heating; D006801:Humans; D008297:Male; D055806:Microvessels / Q000187:drug effects / Q000503:physiopathology*; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000503:physiopathology; D009599:Nitroprusside; D012867:Skin / Q000098:blood supply* / Q000187:drug effects / Q000503:physiopathology; D016896:Treatment Outcome; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*
chemical_list: D002316:Cardiotonic Agents; D009599:Nitroprusside; D000109:Acetylcholine