Study objective: To determine whether blood pressure declines spontane
ously during the first minutes and hours of focal cerebral ischemia. D
esign: Multiple blood pressure measurements as part of an urgent strok
e 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 str
oke 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 ther
apy trial had an initial systolic blood pressure of at least 160 mm Hg
. Of these, 23 had a significant decline in systolic and diastolic blo
od pressure during the first 90 minutes after the onset of stroke (mea
n change in systolic pressure, -29 +/- 22 mm Hg, P<.001; mean change i
n diastolic pressure, -10 +/- 14 mm Hg, P<.01). No patients received a
ntihypertensive therapy during the time in which the decline in blood
pressure was noted. Conclusion: Mildly or moderately elevated blood pr
essure frequently declines spontaneously during the first minutes and
hours of focal cerebral ischemia and generally does not require urgent
pharmacologic treatment.