Altered Cardiac Autonomic Regulation in Individuals with Myasthenia Gravis-A Systematic Review and Meta-Analysis

Area of Science:

• Cardiology
• Neurology
• Autonomic Neuroscience

Background:

• Myasthenia gravis (MG) is an autoimmune disorder affecting neuromuscular junctions.
• Cardiovascular autonomic dysfunction is increasingly recognized in MG patients.
• Understanding these autonomic changes is crucial for comprehensive patient management.

Purpose of the Study:

• To systematically review and meta-analyze studies comparing cardiovascular autonomic parameters in MG patients versus healthy controls (HCs).
• To quantify differences in heart rate variability (HRV) and blood pressure regulation between MG and HCs.
• To elucidate the specific patterns of autonomic imbalance in MG.

Main Methods:

• Systematic review and random-effects meta-analysis of observational studies.
• Searched PubMed, Web of Science, EMBASE, and SCOPUS databases up to July 7, 2023.
• Included 8 studies with 301 MG patients and 454 HCs, analyzing various cardiovascular autonomic parameters.

Main Results:

• MG patients demonstrated significantly lower expiration/inspiration ratio, baroreflex sensitivity, and HRV parameters (e.g., %50 ms, RMSSD, SDNN, HF during tilt).
• Higher systolic blood pressure and sympathovagal balance (LF/HF ratio) were observed in MG patients at rest and during tilt.
• Meta-analysis revealed significant heterogeneity for several HRV parameters, indicating variability in findings.

Conclusions:

• Patients with myasthenia gravis exhibit a distinct pattern of altered cardiac autonomic function.
• Key findings include reduced parasympathetic activity, diminished baroreflex sensitivity, and heightened sympathetic predominance.
• These autonomic alterations highlight the systemic impact of MG and warrant further investigation and clinical consideration.