RESUMO
Cardiac BRS (baroreceptor reflex sensitivity) is impaired following ischaemic stroke and predicts the risk of subsequent long-term death and disability. Impaired cardiac BRS may be due to impaired central processing of baroreceptor information following stroke or reduced baroreceptor activity due to increased large artery stiffness. We evaluated the relationship between large (aortic) artery stiffness and cardiac BRS during the acute phase of ischaemic stroke and in comparison with a group of stroke-free control subjects. Thirty-one ischaemic stroke patients were studied within 48 h of onset and again on day 14, along with 26 control subjects free of cerebrovascular disease. Cardiac BRS (determined by spectral analyses) and arterial stiffness estimated by PWVcf (carotid-femoral pulse wave velocity) using applanation tonometry were obtained. At baseline, cardiac BRS was lower in the stroke compared with the control group (4.3+/-2.3 compared with 6.5+/-4.2 ms/mmHg; P < 0.05). Cardiac BRS values were correlated with PWVcf at < 48 h (r = -0.51, P < 0.01) and on day 14 (r = -0.54, P < 0.01), but not in the control group (r = -0.27, P = not significant). In quantile regression models, taking into account the effect of all cardiovascular variables, cardiac BRS was independently related to PWVcf at baseline and on day 14 in the stroke patients, but stroke was not related to cardiac BRS level when other cardiovascular variables were considered. Wall stiffness of the arterial vessels involved in the baroreflex arc may account for, at least in part, the reduced cardiac BRS observed in acute stroke patients.
