Heart rate variability stands up to bedside tests and composite autonomic symptom score-31 (COMPASS-31) questionnaire: Diagnostic tools for autonomic dysfunction in systemic sclerosis patients

Abstract

Background

Systemic sclerosis (SSc) is an autoimmune disease that affects skin, cardiovascular, pulmonary, and gastrointestinal affection. Autonomic dysfunction (AD) was observed early and even preceded fibrosis. Researchers are looking forward to evolving tools to detect subclinical AD. Aim of the work: This study aimed to evaluate parasympathetic dysfunction in SSc patients using R-R interval variation (RRIV) during both rest and deep breathing compared to control group, compare it with different tools used to assess AD and explore its relation to clinical characteristics of SSc patients. Patients and methods: This work included 40 subjects; 20 SSc cases and 20 healthy controls. All were subjected to RRIV at rest and at deep breathing, composite autonomic symptom score-31 (COMPASS-31) questionnaire for autonomic dysfunction symptoms, bedside autonomic function tests (active standing and Valsalva maneuver).Results: The mean age of patients was 35.36 ± 10.24 years, disease duration 54.12 ± 54.32 months and were 16 females and 4 males (F:M 4:1). There was a significantly higher RRIV at deep breathing in SSc (26.7 ± 23.3) compared to controls (11.4 ± 6.1)(p = 0.017). There was no significant difference in the results of bedside tests between SSc and control. The AD groups detected by bed side tests tended to have higher RRIV values at rest and during deep breathing compared to the non-AD groups. There was no correlation between RRIV measurements and COMPASS score. SSc patients with arthralgia had significantly lower RRIV at deep breathing (p = 0.042). Conclusion: The RRIV is a promising noninvasive and simple cardiovascular test for detection of early parasympathetic dysfunction in SSc patients.