Autonomic dysfunction in COVID-19 patients receiving mechanical ventilation: A cross-sectional study

Area of Science:

• Cardiology
• Intensive Care Medicine
• Autonomic Nervous System Research

Background:

• Coronavirus disease 2019 (COVID-19) is known to cause cardiac damage, evidenced by elevated troponin levels and increased incidence of arrhythmias, myocarditis, and acute coronary syndrome.
• Mechanical ventilation is a critical intervention for severe COVID-19 cases, but its impact on cardiac function, particularly autonomic control, remains an area of investigation.

Purpose of the Study:

• To investigate the effects of COVID-19 on cardiac autonomic control in mechanically ventilated patients within an intensive care unit (ICU) setting.
• To compare heart rate variability (HRV) indices between COVID-19-positive and COVID-19-negative patients undergoing mechanical ventilation.

Main Methods:

• A cross-sectional analytical study was conducted in a tertiary hospital involving mechanically ventilated ICU patients.
• Patients were categorized into COVID-19-positive (COVID(+)) and COVID-19-negative (COVID(-)) groups, with clinical data and HRV recordings collected using a heart rate monitor.

Main Results:

• The study included 82 patients (36 COVID(-) and 46 COVID(+)). Overall HRV indices were lower in mechanically ventilated patients compared to reference values.
• While no significant differences were found in basic HRV intervals (NN, SDNN, RMSSD) between groups, the COVID(+) group showed a statistically significant increase in the low frequency (LF) component (P=0.05), a decrease in the high frequency (HF) component (P=0.045), and an elevated LF/HF ratio (P=0.048).
• A weak positive correlation was observed between the LF/HF ratio and length of stay in the COVID(+) group.

Conclusions:

• Mechanically ventilated patients exhibit diminished overall heart rate variability.
• COVID-19 patients on mechanical ventilation demonstrate reduced vagal components of HRV, indicating impaired autonomic control.
• These findings highlight the clinical relevance of autonomic dysfunction in COVID-19 patients, as such impairments are linked to an increased risk of cardiac mortality.