Randomized clinical trial on acute effects of i.v. iron sucrose during haemodialysis

Aim: Haemodialysis induces endothelial dysfunction by oxidation and inflammation. Intravenous iron administration during haemodialysis could worsen endothelial dysfunction. The aim of this study was to ascertain if iron produces endothelial dysfunction and the possible neutralizing effect of N‐acetylcysteine when infused before iron. The oxidative and inflammatory effects of iron during haemodialysis were also assessed. Methods: Forty patients undergoing haemodialysis were studied in a randomized and cross‐over design with and without N‐acetylcysteine infused before iron sucrose (50 or 100 mg). Plasma Von Willebrand factor (vWF), soluble intercellular adhesion molecule‐1 (sICAM‐1) levels, malondialdehyde, total antioxidant capacity, CD11b/CD18 expression in monocytes, interleukin (IL)‐8 in monocytes and plasma IL‐8 were studied at baseline and during haemodialysis. Results: Haemodialysis produced significant (P < 0.001) increase in plasma vWF, sICAM‐1, malondialdehyde, IL‐8 and CD11b/CD18 expression in monocytes, as well as decrease in total antioxidant capacity. Iron induced significant increase in plasma malondialdehyde and IL‐8 in monocytes, but had no effect on total antioxidant capacity, CD11b/CD18 expression, plasma IL‐8, vWF and sICAM‐1. The addition of N‐acetylcysteine to 50 mg of iron produced a significant (P = 0.040) decrease in malondialdehyde. Conclusion: Standard (100 mg) and low (50 mg) doses of iron during haemodialysis had no effects on endothelium. Iron only had minor effects on inflammation and produced an increase in oxidative stress, which was neutralized by N‐acetylcysteine at low iron dose. Haemodialysis caused a significant increase in oxidative stress, inflammation and endothelial dysfunction markers.     

Myopotential Inhibition of Unipolar AV Sequential (DVI) Pacemaker

Whereas myopotential inhibition of QRS-inhibited (VVI) pacemakers is well known, its occurrence in patients with AV sequential (DVI) pacemakers has not been reported. The present communication deals with spontaneous and induced myopotential inhibition of a multiprogrammable Intermedics unipolar AV sequential (DVI) pacemaker. The bedside maneuvers that were performed in the patient exposed the problem, therefore serving to establish the diagnosis. Although external adjustment of the sensitivity was the simple, non-invasive solution in this case, more studies are required to determine the success rate of this approach as well as the incidence and clinical significance of myopotential inhibition of unipolar DVI pacemakers.