CHANGES OF CIRCADIAN BLOOD-PRESSURE PATTE RNS FOLLOWING HEMODYNAMIC AND THROMBOEMBOLIC BRAIN INFARCTION

We investigated the changes of circadian blood pressure patterns follo wing thromboembolic and hemodynamic brain infarction, and evaluated th e relationship between circadian blood pressure variation, infarct loc ation, and activation of the autonomic nervous system following thromb oembolic stroke. Repeated 24-hour blood pressure measurements were per formed in 45 patients with a proven first ever brain infarction of dif ferent origin. Whereas circadian blood pressure variation was signific antly raised following hemodynamic infarction compared to a control gr oup (diastolic: -25.2% +/- 4.5% vs -13.8% +/- 6.5%, p < 0.005), a clea rly reduced variation was observed following thromboembolic infarction (diastolic: -5.2% +/- 6.9%). Blood pressure variation was positively related to serum norepinephrine concentration (r = 0.79, p < 0.01) fol lowing thromboembolic infarction. Patients with involvement of the ins ular cortex showed a nocturnal rise of blood pressure significantly mo re frequently (66.7% vs 11.8%, p < 0.005) and had higher norepinephrin e levels (540 pg/ml +/- 110 pg/ml vs 290 pg/ml +/- 178 pg/ml, p < 0.01 ) than patients without insular cortex infarction indicating an increa sed sympathetic activity. This was associated with a significantly mor e frequent occurrence of QT prolongation and cardiac arrhythmias.