Journal «Angiology and Vascular Surgery» • 

1997 • VOLUME 3 • №2

EVALUATION OF HEMODYNAMIC EFFECTS OF EXTRACRANIAL CAROTID STENOSES BY ADENOSINE-INDUCED VASODILATATION IN COMBINATION WITH SPECT

M.P. Plotnikov, V.Yu. Usov, A.A. Sokolov, V.M. Shipulin
Research Institute of Cardiology, Tomsk Scientific Centre,
Russian Academy of Medical Sciences,
Tomsk, Russia

Adenosine was evaluated as an intravenous agent/or the pharmacological loading test of the regional cerebral blood flow (rCBF) in combination with 99тTc-HMPAO SPECT in 12 patients with internal carotid artery (ICA) stenosis without neurologic deficit (8 subjects) or with minimal deficit (4 subjects). Also, the adenosine-induced effects on rCBFwere correlated with the anatomic severity of ICA stenosis. Six normal agematched volunteers served as control. The rest 99тTc-HMPAO SPECT data did not reveal any significant interhemispheric asymmetry of perfusion either in ICA stenosis patients or in control subjects. Ho interhemispheric asymmetry was observed in control subjects during adenosine infusion as well. In ICA stenosis patients, the adenosine test did induce interhemispheric asymmetry of perfusion, which ranged within 0.73-0.96 when quantified as an interhemispheric ratio of 99 Tc-HMPA 0 uptake. In 5 of the 12 patients with ICA stenosis, adenosine also elicited a short-term (1-1.5 mm) muscular weakness and/or skin paresthesia consistent with cerebral location of the related cortical zones in the stenosis-dependent hemisphere. No correlation was noted between the interhemispheric anatomic planimetric asymmetry of stenosis (as ratio of patent ICA vessel lumen areas) and perfusion asymmetry at rest. The planimetric asymmetry of stenosis correlated significantly with the adenosine-induced asymmetry of rCBFin ICA-dependent areas (r=0.78, p<0.02). The correlation could be observed beginning from the magnitude of 70-75% relatively to the sectional area of the contralateral intact vessel, which correlated with a 45-50% decrease in the arterial diameter as compared to the intact artery. Therefore, the conclusion can be drawn that adenosine as a potent cerebral vasodilatator may be employed as a challenging agent for functional tests of rCBFand that the adenosine test facilitates detection of the hemodynamic effects of "minor" stenoses.

P. 36

« Back

Angiologia.ru - portal for professionals
VLAANT
Lancet
HI-TECHNOLOGY MEDICINE