Autonomic Testing in Subclinical Carotid Atherosclerosis

Inclusion Criteria: * Asymptomatic patients aged 18 years and older without a history of transient ischemic attack, stroke, or other neurologic signs or symptoms are selected to participate in the study. Exclusion Criteria: * Patients with symptomatic carotid artery stenosis were excluded if the patient had transient or permanent focal neurologic symptoms related to the ipsilateral retina or the cerebral hemisphere. * Patients with heart rhythm disorders, pacemaker, heart failure, ejection fraction less than 0.45, chronic renal failure on hemodialysis, severe liver failure, myocardial infarction, endarterectomy, carotid angioplasty, carotid dissection and carotid occlusion were excluded. * Patients receiving drugs known to interfere with autonomic function, such as beta-blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, vasodilators, statins, neuroleptics and nasal vasoconstrictors, were discontinued for 24 hours before the tests.