Plasma norepinephrine in stroke.

Cardiac arrhythmias, myocardial necrosis and ECG abnormalities in stroke may result from abnormally high levels of sympathetic activity. To examine this possibility, plasma norepinephrine, epinephrine and dopamine were measured in 74 patients with cerebral infarction, 18 with transient ischemic attacks and 33 non-stroke controls. Mean norepinephrine, epinephrine and dopamine values (pg/ml) in cerebral infarction (433.2, 81.6, 75.6 were higher (p less than 0.01) than in controls (281.1, 60.1, 40.5, respectively). Transient ischemic attacks produced values intermediate to these two groups (391.3, 80.9, 54.9). The elevated catecholamine concentrations in cerebral infarction could not be explained by differences in age, blood pressure, heart rate, stress, type or severity of stroke. The high plasma norepinephrine in the stroke group is consistent with an increase in peripheral sympathetic activity which could produce the cardiac abnormalities of cerebral infarction.