Cardiac Autonomic Dysfunction in Myasthenia Gravis and Relapsing-Remitting Multiple Sclerosis-A Pilot Study

Area of Science:

• Cardiovascular Physiology
• Autonomic Nervous System
• Neuromuscular Disorders

Background:

• Cardiac autonomic dysfunction is a recognized complication in various neurological conditions.
• Myasthenia gravis (MG) and relapsing-remitting multiple sclerosis (RRMS) are autoimmune disorders affecting neuromuscular function and potentially the autonomic nervous system.
• Understanding autonomic responses in these patient populations is crucial for comprehensive management.

Purpose of the Study:

• To assess and compare cardiac autonomic responses during a head-up tilt test (HUTT) in patients with MG and RRMS versus healthy controls (HC).
• To evaluate specific parameters including baroreflex sensitivity (BRS), heart rate variability (HRV), and blood pressure variability (BPV).
• To investigate potential differences in cardiac inotropy and autonomic balance between the patient groups and controls.

Main Methods:

• A head-up tilt test (HUTT) was performed on 23 MG patients, 23 RRMS patients, and 30 HC.
• Cardiac inotropy, BRS, HRV, and blood pressure variability (BPV) were assessed using the Task Force® Monitor.
• Autonomic parameters were analyzed during supine rest and orthostatic stress induced by HUTT.

Main Results:

• MG patients exhibited reduced BRS, parasympathetic deficiency, and sympathetic predominance compared to HC.
• MG patients showed lower cardiac inotropy, including left ventricular work index (LVWI) and cardiac index, during HUTT.
• RRMS patients demonstrated combined sympathetic and parasympathetic dysfunction, indicated by altered HRV parameters during HUTT.

Conclusions:

• Both MG and RRMS patients display significant cardiac autonomic dysfunction, distinct from healthy individuals.
• The findings suggest a need to consider cardiac and autonomic involvement in the clinical management of MG and RRMS.
• Autonomic dysfunction in these conditions may influence therapeutic strategies, including pharmacological treatments and rehabilitation.