About the Autonomic Function Testing Laboratory

Autonomic function testing equipment (320x240)
Autonomic function testing equipment

The Autonomic Function Testing Laboratory offers comprehensive, state-of-the-art tests for the autonomic nervous system. This part of the nervous system controls and regulates the automatic functions within our body including regulation of blood pressure, heart rate, airway size and airflow to the lungs, digestive tract functions, sweat production, bladder control and sexual function. In the course of certain neurological disorders including neuropathies, particularly diabetic neuropathy, the ANS can be damaged and become dysfunctional. A comprehensive report of the findings of the tests will be sent to the patient’s physician and Dr. Harati will be available to discuss diagnostic and therapeutic implications of the results.

The Autonomic Function Testing Laboratory at the Baylor College of Medicine Neuropathy Center is now established and equipped with the state-of-the-art equipment. This laboratory is designed to quantitatively evaluate the function of the autonomic nervous system.

Main Indications for Laboratory Evaluation of ANS

  • Diagnosis of generalized autonomic failure such as diabetic autonomic neuropathy
  • Detecting the presence of limited autonomic failure such as chronic idiopathic anhidrosis and POTS (postural orthostatic tachycardia syndrome)
  • Diagnosis of small fiber neuropathy
  • Detection and evaluation of orthostatic intolerance
  • Detection of a neuropathic basis in neurocardiogenic syncope
  • Evaluation of course of the autonomic disorders and their response to therapy
  • Detection and evaluation of autonomic dysfunction in peripheral neuropathies
  • Detection of sympathetic dysfunction in certain sympathetically maintained pain

Autonomic Function Screen Tests

  • Quantitative Sudomotor Axon Reflex Test (QSART) for sweat production evaluation
  • Heart Rate Response to Deep Breathing (HRDB) for evaluation of cardiovagal function
  • Heart rate and beat to beat blood pressure changes to Valsalva Maneuver for evaluation of the cardiovagal and peripheral adrenergic function
  • Heart rate and beat to beat blood pressure response to tilt-up for evaluation of orthostatic hypotension

Our Team: Autonomic Function Testing Laboratory

Yadollah Harati, M.D.



  • (713) 798-7411

For more information or to schedule an appointment, please call (713) 798-3935 or (713) 798-2273.