A COMPARISON OF BEAT-TO-BEAT BLOOD-PRESSURE VARIABILITY IN ACUTE AND SUBACUTE STROKE PATIENTS WITH CEREBRAL INFARCTION

Cerebrovascular dysautoregulation is well recognised following acute s troke, and thus blood pressure (BP) changes may have important effects on cerebral blood flow, Whilst absolute BP levels have been shown to influence outcome in some studies, the importance of short-term BP var iability has not been addressed, We assessed beat-to-beat BP and pulse interval variability non-invasively using the Finapres device in 32 p atients with CT-diagnosed acute cerebral infarction compared to a cont rol group matched with respect to age and sex. Systolic BP variability was assessed as the standard deviation (SD) of all measurements and a s the root mean squared of successive differences (RMS; which removes the portion of variability related to the underlying BP level), Systol ic BP variability (taken as either the SD or the RMS) was significantl y greater in acute stroke patients than controls. This difference is u nlikely to reflect impaired cardiac baroreceptor sensitivity in acute stroke patients as no differences were observed in pulse interval vari ability compared to controls, but may be related to alterations in per ipheral vascular resistance mediated by centrally induced changes in s ympathetic nervous system activity. The prognostic significance of inc reased BP variability and the implications for BP management in acute stroke require further evaluation.