Autonomic function and cerebral autoregulation in patients undergoing carotid endarterectomy

Area of Science:

• Cardiovascular physiology
• Neurology
• Surgical outcomes

Background:

• Carotid endarterectomy (CEA) is a primary treatment for severe carotid stenosis to prevent stroke.
• Previous studies had methodological limitations in assessing CEA's acute effects on baroreflex and cerebral autoregulation.
• A novel algorithm was employed to investigate these effects.

Purpose of the Study:

• To evaluate the acute impact of carotid endarterectomy (CEA) on baroreflex sensitivity and cerebral autoregulation.
• To compare these functions in patients with carotid stenosis versus healthy controls.
• To determine if CEA alters baroreflex sensitivity or cerebral autoregulation.

Main Methods:

• Continuous recording of systemic arterial blood pressure, ECG, and respiration during metronomic breathing and Valsalva maneuver in 18 patients and 10 controls.
• Evaluation of baroreflex sensitivity and cerebral autoregulation indices using trigonometric regressive spectral analysis.
• Comparison of pre- and post-CEA data in patients with data from healthy controls.

Main Results:

• Patients with carotid stenosis exhibited impaired baroreflex sensitivity compared to controls.
• Carotid endarterectomy did not significantly alter baroreflex sensitivity or frequency spectra.
• Cerebral autoregulation, measured by phase shift, was reduced in patients but significantly improved after CEA, independent of cerebral blood flow velocity changes.

Conclusions:

• Baroreflex sensitivity and cerebral autoregulation are impaired in carotid stenosis patients, increasing stroke risk.
• Carotid endarterectomy effectively improves cerebral autoregulation but not baroreflex sensitivity.
• Future interventions targeting baroreflex function may be necessary for additional stroke risk reduction.