Cardiac Autonomic Function in Long COVID-19 Using Heart Rate Variability: An Observational Cross-Sectional Study

• Published in: Journal of clinical medicine Vol. 12; no. 1; p. 100
• Main Authors: Menezes Junior, Antonio da Silva, Schröder, Aline Andressa, Botelho, Silvia Marçal, Resende, Aline Lazara
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 22-12-2022; MDPI
• Subjects: Clinical medicine; Coronaviruses; COVID-19; Cross-sectional studies; Electrocardiography; Software; United States > US; inflammatory markers; autonomic nervous system; heart rate variability; long-term COVID-19
• ISSN: 2077-0383; 2077-0383
• DOI: 10.3390/jcm12010100

Heart rate variability is a non-invasive, measurable, and established autonomic nervous system test. Long-term COVID-19 sequelae are unclear; however, acute symptoms have been studied.
To determine autonomic cardiac differences between long COVID-19 patients and healthy controls and evaluate associations among symptoms, comorbidities, and laboratory findings.
This single-center study included long COVID-19 patients and healthy controls. The heart rate variability (HRV), a quantitative marker of autonomic activity, was monitored for 24 h using an ambulatory electrocardiogram system. HRV indices were compared between case and control groups. Symptom frequency and inflammatory markers were evaluated. A significant statistical level of 5% (
-value 0.05) was adopted.
A total of 47 long COVID-19 patients were compared to 42 healthy controls. Patients averaged 43.8 (SD14.8) years old, and 60.3% were female. In total, 52.5% of patients had moderate illness. Post-exercise dyspnea was most common (71.6%), and 53.2% lacked comorbidities. CNP, D-dimer, and CRP levels were elevated (
-values of 0.0098, 0.0023, and 0.0015, respectively). The control group had greater SDNN24 and SDANNI (OR = 0.98 (0.97 to 0.99;
= 0.01)). Increased low-frequency (LF) indices in COVID-19 patients (OR = 1.002 (1.0001 to 1.004;
= 0.030)) and high-frequency (HF) indices in the control group (OR = 0.987 (0.98 to 0.995;
= 0.001)) were also associated.
Patients with long COVID-19 had lower HF values than healthy individuals. These variations are associated with increased parasympathetic activity, which may be related to long COVID-19 symptoms and inflammatory laboratory findings.