Pulse rate in long COVID: what does it signify

ABSTRACT

Background: The multisystem involvement of covid-19 lingers in post-covid phase. The significance of baseline resting pulse rate was looked for in long-covid relating to symptoms in acute phase, 2-chair test response, and echocardiography. Methods: Serial long-covid patients attending out-patient department were included. They were evaluated on demographic (age, height, weight, and BMI), characteristics, symptom score in acute phase (symptom severity in 0 to 5 scale X duration of symptoms), variables (pulse-rate and SpO2 changes) related to 2 chair test and resting Doppler echocardiography (LV ejection fraction, TSAPSE, left and right ventricular free wall GLS, and LV filling pressure. Two groups with pulse rate below or above 90/minute were compared. Results: The mean duration of acute illness for both the group is computed to be (118.44±95.95 vs. 152.77±102.25, p- value= 0.42) respectively. The baseline pulse rate were significantly different between those above (n=12) and below 90 (n=23) per minute (101±5.83 vs.72.85±8.14;p<0.0001);so is the post-exercise maximum pulse rate (p<0.004). Subjects with lower pulse rate had better height (p=0.05), weight (p=0.06), and higher anosmia (p=0.005) but lower total symptoms score (26.4±51.02 vs.29.66±66.12;p=0.008). The spirometric parameters (FVC, FEV1, FWV1/FVC) were better (although not significant) in those with lower pulse rate. The echocardiographic parameters as LVEF, TAPSE, LVFP were similar;the free wall GLS of both RV and LV were reduced in both the groups but that of RV (and LV were affected more in lower and higher pulse rate group respectively. Conclusion: Baseline pulse-rate in post covid subjects is likely related to neuro-inflammatory symptoms (anosmia) and poor LVGLS suggesting LV myocardial dysfunction.