RESUMO
Atrial Fibrillation (AF) is the most common cardiac arrhythmia of clinical significance; it increases the risk of mortality due to stroke. The mechanisms behind cerebral thromboembolism in AF are associated with a prothrombotic state, demonstrated by higher levels of von Willebrand Factor (vWF), a multimeric glycoprotein that plays a crucial role in platelet adhesion and aggregation and it has been proposed as a biomarker of endothelial dysfunction. Plasma vWF levels are elevated in patients with nonvalvular Atrial Fibrillation (NVAF) associated to the presence of cardiovascular risk factors. The variability in vWF plasma levels in healthy subjects has a wide distribution, but there is no description available of the variability in AF patients and among types of AF. The aim of this study was to determine the variability of vWF plasma concentrations in patients with NVAF, associated to cardiovascular risk factors. Search strategy included PubMed and Ovid. Keywords used were "Atrial Fibrillation" and "von Willebrand Factor". It includes original articles, with analysis of plasma vWF levels by ELISA, without acute stroke. Review articles and meta-analysis were excluded. Reviewed studies include 22 trials and 6542 patients with nonvalvular AF associated to cardiovascular disease risk factors: age, sex, hypertension, heart failure, diabetes mellitus, prior stroke, coronary artery disease. Variability in vWF plasma levels was wide, with minimum values of 77 IU/dl and maximum values of 245 IU/dl and a mean of 146 IU/dl. Age of patients ranged between 54 and 78 years, and the percentage of males ranged between 23% and 80%. According to type of AF vWF levels were as follows, in paroxysmal AF: 92-264 IU/dl; persistent AF: 76-234 IU/dl; permanent AF: 91-247 IU/dl. The variability in vWF plasma levels is affected by risk factors and the AF type, however vWF levels in AF patients are higher when compared with healthy subjects.
RESUMO
Left ventricular hypertrophy (LVH) prevalence is very high in end stage renal disease (ESRD). It's a predictor of cardiac death in peritoneal dialysis patients. Noradrenalin, Angiotensin II and aldosterone are involved incardiac hypertrophy. Dopamine, acting at DA2 receptors inhibits norephinephrin release, antagonizes aldosterone and down-regulates AT1 receptor numbers, suggesting that DA2 agonists, like bromocriptine (BEC) could regress LVH. The objective of this study was to evaluate the changes in left ventricular mass in patients with ESRD in continuous ambulatory peritoneal dialysis (CAPD), by adding BEC to the treatment. An open clinical trial was conducted. Twenty patients were enrolled. Five formed the control group. Fifteen patients in the experimental group received BEC 2.5 mg three times daily over three months. M mode echocardiography and prolactin plasma levels were measured at the beginning and at the end of the study. The statistical analysis was performed using Student t test. The echocardiography reports showed a 24.4% decreased in left ventricular mass index (LVMI); the interventricular septum decreased 11.3%, the ejection fraction was not modified. The control group showed no difference. BEC-mediated decreases in left-ventricular mass in LVH patients on dialysis suggest that Dopaminergic agonists could be useful in caring for patients with ESRD and LVH.