engleski

Reduced cerebral vasoreactivity in severe aortic stenosis

Aim: To assess cerebral vasoreactivity in patients with severe aortic stenosis using breath holding test. Subjects and methods: Twenty patients with severe aortic stenosis diagnosed according to European Society of Cardiology guidelines were included. Their mean age was 68±9 years and 60% were female. Average peak gradient on aortic valve was 100±19 mmHg, and mean gradient 58±12 mmHg, average EF 60±10. Breath holding test was performed in supine position according to standardized procedure to determine cerebral vasoreactivity to hypercapnia. Mean blood flow velocities (MBFV) on both middle cerebral arteries were recorded using DWL Doppler-Box TCD and breath holding index (BHI) was calculated. Results: We found that the patients with severe aortic stenosis have significantly reduced cerebral vasoreactivity expressed through breath holding index (BHI ; 0.68±0.42). Severely reduced vasoreactivity with BHI less than 0.70 was found in 60% of patients, moderate (BHI from 0.70 to 1.03) in 25% and only 15% had normal values of BHI greater than 1.03. Males had slightly greater mean BHI than females (0.75±0.46 vs. 0.66±0.36, p=0.6), but the difference was not statistically significant. There was also no significant difference in mean BHI when left and right MCA were compared (0.63±0.37 vs 0.70±0.46, p=0.6).Conclusion: Severe aortic stenosis significantly reduces cerebral vasoreactivity and thus raises the risk for stroke. Further investigation is needed to determine the effect of valve replacement on vasoreactivity.

severe aortic stenosis, cerebral vasoreactivity, breath holding index

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