Cerebral blood flow, haematocrit and viscosity in subjects with a high oxygen affinity haemoglobin variant

Publisher Website
Google Scholar
Abstract
The cerebral blood flow is low in primary polycythemia. This is possibly due to the viscosity increase which accompanies the elevated hematocrit. Cerebral blood flow was measured by a non-invasive 133Xe technique in 6 subjects with an elevated hematocrit secondary to a Hb variant with increased O2 affinity. Flow was significantly higher than normal and 81% higher than in 11 subjects of comparable age, matched for hematocrit and viscosity, but without the Hb variant. In patients with this unusual type of polycythemia, cerebral blood flow is high despite the elevated blood viscosity. Implications are discussed.