BREATH HOLDING INDEX IN EVALUATION OF PATIENTS WITH SEVERE SYMPTOMATIC OCCLUSIVE CAROTID ARTERY DISEASE

Introduction: Cerebrovascular reactivity in severe carotid artery disease depends on the functional capacity of collateral pathways. The aim of the study was to apply Breath holding index (BHI) method in evaluation of cerebrovascular reactivity in patients with severe carotid stenosis. Patients and methods: Using transcranial Doppler ultrasonography, the cerebrovascular reactivity to hypercapnia in the middle cerebral artery was evaluated by calculating BHI of 120 (mean age 71p ; ; 10) symptomatic patients (73 men ; mean age 66p ; ; 12 and 57 women ; mean age 74p ; ; 10) with different collateral pathways. Results: There were 20% patients who suffered TIA (10% men and 10% women), 38% of patients with first stroke event (15% men and 23% women) and 21% of patients with reccurent stroke (15% men and 6% women). Anteriorcollateral pathway (ACoA) was present in 16% of patients, Posterior collateral pathway (PCoA) and inversed flow in ophthalmic artery (OA) in 12% of patients, ACoA/PCoA in 30% of patients, ACoA/OA in 21% of patients, ACoA/ PCoA/OA in 12% of patients and cortical collaterals had 9% of patients. All mean BHI values were under 0, 7 and statistically significant difference (p<0, 05) was found depending on activation of different collateral pathways. ACoA BHI=0.52p ; ; 0.16, PCoA/OA BHI=0.33p ; ; 0.11, ACoA/PcoA BHI=0.41p ; ; 0.12, ACoA/OA BHI=0.35p ; ; 0.10, ACoA/PCoA/OA BHI=0.27p ; ; 0.1 and cortical collateralsBHI=0.13p ; ; 0.11. Conclusion: Transcranial Doppler is a realible noninvasive tool in evaluation of patients with severe symptomatic carotid occlusive disease. TCD can detect different number and type of collateral pathways which influence on the BHI values and patient prognosis.