Detection of Early Cardiac Affection in Post-COVID Syndrome Using Heart Rate Variability and 2D Global Longitudinal Strain Echocardiographic Assessment of the Left Ventricle

Abstract

Abstract Aim and objectives The aim of our study is to estimate the Heart Rate Variability (HRV) & two-dimensional global longitudinal strain (GLS) by speckle tracking echocardiography (2D STE) in post-COVID-19 patients after mild to moderate acute SARS COV-2 infection. Patients and Methods This study included fifty consecutive subjects between 17 & 82 years of age who were symptomatic after three weeks up to 3 months of experiencing mild to moderate COVID19 illness according to the CDC criteria of severity. Patients enrolled were coming for follow-up clinic visits at Ain Shams University Hospitals between June 2021- Jan2022. All patients had normal LVEF upon enrollment as assessed by M-mode and Modified Simpson's method. 2D Left Ventricular Global Longitudinal Strain (GLS) and 24-hours Holter monitoring were performed for all patients. Results The LVGLS and HRV were significantly impaired in the symptomatic post-COVID-19. LVGLS was below -16 in 20% of the patients while 22% were in the grey zone; between -18 and -16. SDNN was decreased (< 100 msec) in 24% of the patients. RMSSD values favored a mean below 40 msec with prevalence of 58% among the study population. LF/HF ratio was above 2 in 42% of the patients. Our research suggested a highly significant association between LVGLS and HRV; as 66.7% of patients with decreased SDNN had impaired LVGLS, as opposed to 33% who had normal LVGLS (p-value 0.000) Conclusion LVGLS measured by Speckle Tracking Echocardiography (STE) is an important bedside tool, alternative to CMR which is the gold standard, in assessing LV systolic functions post COVID-19. HRV can explain a lot of post- COVID symptoms attributed to dysautonomia. In our study, we targeted the patients having prolonged symptoms after COVID-19 illness, GLS and HRV were assessed trying to explain the cardiac involvement and if it is the cause of the so called" long COVID". We found high incidence of GLS impairment using STE as well as significant prevalence of diminished HRV. HRV (especially SDNN) and GLS were significantly correlated as 80% of the patients with impaired GLS had decreased SDNN (p-value 0.00).