Blood pressure and both venous and urinary catecholamines after cerebral infarction

Blood pressure, both venous and urinary catecholamines and plasma renin activity (PRA) were studied in 10 patients (6 men and 4 women, mean age 70 +/- 10 years) on the first three days after cerebral infarction. Blood pressure fell significantly (p less than 0.02) on the second and third day after stroke. There was a small but significant (p less than 0.01) decrease in plasma epinephrine concentration on the third day. The norepinephrine values remained constant on the three days. The PRA showed a significant (p less than 0.01) rise on the third day. No significant correlation was detected between the course of the blood pressure and the plasma catecholamines or PRA. When blood pressure was correlated with the urinary catecholamines, however, a significant correlation with epinephrine (r = 0.45; p less than 0.05) and with norepinephrine (r = 0.44; p less than 0.05) was found. We conclude that the changes in blood pressure after stroke are at least partly mediated by the changes in catecholamine production.