Identifying autonomic nervous system dysfunction in acute cerebrovascular attack by assessments of heart rate variability and catecholamine levels

OBJECTIVE: This study aimed to evaluate changes in the autonomic nervous system caused by cerebral lesions due to acute stroke. We assessed heart rate variability and catecholamine levels in lieu of stroke lesion localization. MATERIALS AND METHODS: A total of 60 stroke patients and 31 healthy controls were enrolled in the study. Plasma epinephrine and norepinephrine levels were measured on the first, third, and seventh days following the stroke event. Heart rate variability was evaluated with time-domain and frequency-domain analyses via 24-hour Holter monitor recordings. RESULTS: On the first and third day following the stroke, norepinephrine levels were significantly higher in all patient groups as compared to controls. Epinephrine levels on the first, third and seventh days after the stroke were significantly higher in patients with lesions in the right middle cerebral artery territory than controls. In frequency-domain analysis, patients with right middle cerebral artery territory lesions had greater low frequency and low frequency to high frequency ratio values than controls. Time-domain analysis revealed significant decreases in the standard deviation from the mean for 5-minute 288 R-R intervals in patients with lesions in the right middle cerebral artery and posterior cerebral artery territory when contrasted with controls. Patients with lesions in the right middle cerebral artery territory demonstrated the highest increase in the percentage of consecutive R-R intervals differing by more than 50 ms (pNN50) as compared to the control group. CONCLUSION: These findings indicate that autonomic dysfunction favoring an increase in sympathetic activity occurs in acute stroke patients.