Carotid bifurcation stenosis: functional importance in physical exercises

BACKGROUND: The aim of this study was to analyze the physical exercise effects on the cerebral arteries hemodynamics in stenosis of the internal carotid artery (ICA) (40-69%) in asymptomatic patients. METHODS: One hundred twenty patients were divided into three main groups: 1) Group I (40) -without signs of carotid bifurcation athero-sclerosis; 2) Group II (40) -with hemodynamically insignificant stenosis of the ICA (40-49%) (Group IIA -with stenosis of the ICA 50-59% [18]; Group IIB -60-69% [22]; and 3) Group III (40) -with hemodynamically significant stenosis of the ICA (>= 70%, without occlusion). All patients underwent hemostasiograms, lipid profile determination, ultrasound Doppler of brachiocephalic arteries, digital sphygmography (SG) of the common carotid artery (CCA), computed tomography of the brain, transcranial Dopper, stress echocardiography with bicycle ergometry, and study of hemodynamics in ICA stenosis area.RESULTS: During the stress test, the majority of the patients (29 [72.5%]) of Group II experienced a volumetric blood flow decrease in the ICA, CCA on the side of stenosis. The kinetics SG parameters were lower in Group II, compared with Group I. There was a direct correlation between the degree of stenosis and the volumetric blood flow decrease. The parameters were close to the Group III patients' data. CONCLUSIONS: A "functional hemodynamically significant stenosis" of the ICA develops in stenosis of the ICA (40-69%), when a sub -maximal heart rate (HR) is reached. An additional indication for carotid endarterectomy is 40-69% stenosis and "functional hemodynamically significant stenosis." We recommend performing the stress test to the patients with stenosis of the ICA (40-69%) to detect the development of "functional hemodynamically significant stenosis" in submaximal HR.