Cardiac repolarization evolves differently during the course of benign and disabling multiple sclerosis.

Area of Science:

• Cardiology
• Neurology
• Autonomic Nervous System Function

Background:

• Cardiac repolarization is influenced by the autonomic nervous system.
• Multiple sclerosis (MS) is associated with prolonged cardiac repolarization, but the underlying mechanisms are unclear.

Purpose of the Study:

• To longitudinally investigate differences in cardiac repolarization changes between benign and disabling forms of relapsing-remitting multiple sclerosis (RRMS).

Main Methods:

• 43 RRMS patients (benign EDSS ≤2, disabling EDSS >2) underwent electrocardiogram (ECG) at symptom onset (ECG1) and follow-up (ECG2).
• Heart rate (HR) corrected QT intervals (QTc), a measure of cardiac repolarization, were assessed.

Main Results:

• At follow-up (ECG2), patients with disabling RRMS had significantly higher HR and prolonged QTc compared to benign RRMS patients.
• HR increased and QTc prolonged during the disease course exclusively in the disabling RRMS group.
• No significant differences in HR or QTc were observed at symptom onset (ECG1) between the groups.

Conclusions:

• Deterioration of cardiac autonomic regulation occurs during the disease progression of disabling RRMS, but not benign RRMS.
• Cardiac autonomic regulation assessment should be integrated into RRMS disease course evaluations.
• Disabling RRMS patients may face increased cardiovascular risk due to autonomic nervous system dysfunction.