Autonomic Nervous System Affection Due to Post Covid Syndrome
Condition: Long Covid19; Autonomic Dysfunction
MeSH terms: Post-Acute COVID-19 Syndrome; Autonomic Nervous System Diseases; Primary Dysautonomias
Study type: Observational [Patient Registry]

Summary: 
      Post-Covid syndrome is defined as symptoms that develop in addition to respiratory symptoms
      in individuals who have had Covid-19 infection for more than 12 weeks. Symptoms such as
      fatigue, headache, cognitive impairment, dyspnea, heart palpitations, heat intolerance,
      digestive system disorders, sleep disorders, dermal problems, orthostatic intolerance come to
      the fore in individuals with post-Covid syndrome. It has been tried to be revealed in some
      studies that Covid-19 infection affects the autonomic nervous system (ANS) and the
      relationship between Post-Covid 19 syndrome and ANS dysfunction. Heart rate variability (HRV)
      measurement method can be used to evaluate ANS activity. HRV is a non-invasive method and is
      a measure of the change in heart rate over a period of time. HRV is a scalar quantity that
      shows the time between two beats of the heart and defines the oscillations between the R-R
      intervals. In HRV measurements, time-dependent and frequency-dependent measurement results
      are obtained and from these measurements, time-dependent RMSSD (square root of the square of
      the difference of the R-R intervals) and frequency-dependent high-frequency (HF) and low
      frequency (LF) measurement components are used in relation to the sympathetic nervous system
      (CNS) and parasympathetic nervous system (PSS). HRV can be measured in short-term (5 minutes)
      in terms of measurement time. The aim of this study is to clearly reveal the relationship
      between Post-Covid 19 syndrome and ANS dysfunction and to provide standardization related to
      HRV measurement method and sub-parameters.
    

Detailed description: 
      SARS-CoV-2 virus emerged with severe acute respiratory tract infection and pneumonia when
      turned into a chronic disease that can cause permanent symptoms in recovering individuals.
      Prolonged Covid-19 syndrome or Post-Covid 19 syndrome is defined as symptoms that develop in
      addition to respiratory symptoms in individuals who have had Covid-19 infection for more than
      12 weeks. Symptoms such as fatigue, headache, cognitive impairment, dyspnea, heart
      palpitations, heat intolerance, digestive system disorders, sleep disorders, dermal problems,
      orthostatic intolerance come to the fore in individuals with post-Covid syndrome. It has been
      tried to be revealed in some studies that Covid-19 infection affects the autonomic nervous
      system (ANS) and the relationship between Post-Covid 19 syndrome and ANS dysfunction. It is
      known that the cytokine storm caused by Covid-19 is caused by sympathetic activation that
      induces the release of proinflammatory cytokines, and the virus is associated with
      autoantibodies such as α(alpha) and β(beta) adrenoceptors and muscarinic receptors and in
      this case it causes autoimmunological disorder and ANS dysfunction. ANS consists of
      craniosacral parasympathetic fibers and cervicothoracic sympathetic fibers and consists of a
      complex network structure that provides homeostasis of the body. The parasympathetic nervous
      system predominates in quiet "rest and digest" conditions, while the sympathetic nervous
      system drives the "fight or flight" response in stressful situations. Heart rate variability
      (HRV) measurement method can be used to evaluate ANS activity. HRV is a non-invasive method
      and is a measure of the change in heart rate over a period of time. HRV is a scalar quantity
      that shows the time between two beats of the heart and defines the oscillations between the
      R-R intervals. In HRV measurements, time-dependent and frequency-dependent measurement
      results are obtained and from these measurements, time-dependent RMSSD (square root of the
      square of the difference of the R-R intervals) and pNN50 (the proportionality coefficient
      obtained by dividing the total number of R-R intervals by NN50), frequency-dependent
      high-frequency (HF) and low frequency (LF) measurement components are used in relation to the
      sympathetic nervous system (CNS) and parasympathetic nervous system (PSS). HRV can be
      measured in 3 different ways, as ultra short-term (<5 minutes), short-term (5 minutes) and
      long-term (24 hours), in terms of measurement time, and these values provide different
      results from each other. While 24-hour long-term measurements are preferred in cardiac
      diseases with a risk of mortality, short-term and ultra short-term measurements may be
      preferred in measuring the effect of chronic and metabolic diseases on HRV. The aim of this
      study is to clearly reveal the relationship between Post-Covid 19 syndrome and ANS
      dysfunction and to provide standardization related to HRV measurement method and
      sub-parameters.

      Our study in which investigated the effect of post-Covid 19 syndrome on the autonomic nervous
      system, will be carried out in the Bahçeşehir University Institute of Health Sciences.
      Written consent will be obtained from the participants, indicating that they agreed to
      participate in the study and the content of the study was presented verbally and in writing
      form. Patients will be taken a short 5-minute measurement for HRV measurement once during the
      study. Before the evaluation, sociodemographic information will be obtained from the
      participants in the form of a questionnaire and the symptoms experienced by the participants
      were recorded. Participants will be warned not to exert excessive effort and not to take any
      medication or treatment before the measurement. In the research form given to the patients,
      the symptoms of individuals with Post-Covid 19 syndrome will be marked and the percentage of
      these symptoms was calculated. These symptoms will be determined as fatigue, headache,
      cognitive impairment, dyspnea, heart palpitation, heat intolerance, digestive system
      disorders, sleep disturbance, dermal problems, orthostatic intolerance.

      A total of 60 participants whom between the ages of 18-45 will include in our study,
      including 20 participants (n=20) who experience Post-Covid 19 syndrome, participants who
      fully recover after Covid-19 (n=20) and participants who has never have Covid-19 (n=20). In
      order for the study groups to be homogeneous, the ratio of the number of men and women in the
      groups will tried to be equal.

      The Polar H10 wearable HRV measurement technology, which we use in our study and produced by
      Polar Electro company, is a device that helps to measure the R-R interval at rest and at
      different activity intensities (Picture 1). In the study conducted by Schweizer et al., it
      shows that the Polar H10 device had 99.6% R-R interval signal quality during 5 different
      activities (16).

      In our research, the measurements will made with the Polar H10 device were analyzed on the
      computer with the Kubios Software 3.5.0 program (https://www.kubios.com). With this program,
      it is possible to apply time dependent, frequency dependent and nonlinear analysis method.
    

Intervention name(s): Heart Rate Variability Measurement
Intervention type(s): Other
Intervention description(s): The heart rate variability of the participants will be measured with the Polar H10 device with a measurement time of 5 minutes.
Observational model: Case-Control
Time perspective: Other
Sampling method: Probability Sample
Study population: 
        It consists of participants who have not had Covid 19 and who have and did not show
        prolonged symptoms afterward.