Abstract
In order to clarify the effect of the sympathetic nervous system on the prethrombotic state in atrial fibrillation, systolic and diastolic blood pressure, heart rate, platelet count and plasma norepinephrine were measured before and after postural change (sitting from bed rest) in cerebral infarction with and without atrial fibrillation (AfCI and CI).
For the study of platelet function, platelet aggregation induced by 4.6μM ADP, plasma β-thromboglobulin and platelet factor 4 were measured.
Systolic blood pressure and platelet count did not change significantly by sitting in AfCI, while significantly increased in CI (p<0.05 and p<0.01 respectively). On the contrary plasma norepinephrine significantly increased in AfCI (p<0.05), but did not change significantly in CI. There were no significant changes by sitting in diasolic blood pressure and heart rate in both AfCI and CI.
Increases in plasma norepinephrine by sitting had significant correlations with platelet aggregation induced by 4.6μM ADP (p<0.01), plasma β-thromboglobulin (p<0.01) and platelet factor 4 (p<0.05) in cerebral circulatory disorders. These results indicate that low cardiac function in atrial fibrillation may induce high response of the sympathetic nervous system by postural change and this would promote platelet consumption.
