Blood pressure during the first minutes of focal cerebral ischemia

Study objective: To determine whether blood pressure declines spontaneously during the first minutes and hours of focal cerebral ischemia. Design: Multiple blood pressure measurements as part of an urgent stroke therapy trial (treatment within 90 minutes of stroke onset). Setting: Thirteen hospitals in three metropolitan communities. Participants: Sixty-nine patients (mean age, 65 ± 9 years) with acute ischemic stroke who were participants in a phase I urgent stroke therapy trial of recombinant tissue plasminogen activator. Main outcome measure: Blood pressures recorded at the scene of stroke by life-squad personnel, in the emergency department, and in the ICU. Results: The mean time from stroke onset to the time of first blood pressure measurement was 19 ± 13 minutes. Twenty-four of the 69 patients in the urgent stroke therapy trial had an initial systolic blood pressure of at least 160 mm Hg. Of these, 23 had a significant decline in systolic and diastolic blood pressure during the first 90 minutes after the onset of stroke (mean change in systolic pressure, -29 ± 22 mm Hg, P < .001; mean change in diastolic pressure, -10 ± 14mm Hg, P < .01). No patients received antihypertensive therapy during the time in which the decline in blood pressure was noted. Conclusion: Mildly or moderately elevated blood pressure frequently declines spontaneously during the first minutes and hours of focal cerebral ischemia and generally does not require urgent pharmacologic treatment.