Introduction: As the number of COVID-19 cases begin to diminish it is important to turn our attention to any long-term issues that may be associated with a prior infection. Cardiovascular defects have been noted following prior SARS-CoV-2 infections. However, less is known about how a previous infection alters the cardiovascular response to exercise. Further, differences may exist during exercise between previously SARS-CoV-2 positive individuals who had symptoms (symptomatic) relative to those who did not have symptoms (asymptomatic). We hypothesized that previously symptomatic (S) COVID-19 recoveries have an altered cardiovascular response to acute exercise relative to both control (CON; never infected), and previously COVID-19 positive asymptomatic (AS) individuals.Methods: Twenty-seven subjects (CON = 9; AS = 9; S = 9) underwent 30 min of submaximal treadmill exercise. During exercise, blood pressure was recorded on the brachial artery every 5 min and 3-lead electrocardiography was measured continuously. Indirect indicators of autonomic nervous system health: heart rate variability and blood pressure variability were measured during each session. Baseline mean arterial pressure (MAP) was taken prior to exercise in seated, standing and supine positions.Results: Blood pressure was similar (p > 0.05) amongst all three groups. There were no differences between average heart rate (HR; CON = 104 ± 4 BPM vs AS = 118 ± 6 BPM vs. S = 112 ± 3 BPM), mean arterial pressure (MAP; CON = 108 ± 4 mmHg vs. AS = 105 ± 13 mmHg vs. S = 108 ± 7 mmHg) or oxygen consumption (VO2) between groups during a bout of exercise. However, the standard deviation of the inter beat intervals of normal sinus beats, a measure of heart rate variability (HRV) (CON = 138 ± 2.8 m vs. AS = 156 ± 6 m vs. S = 77.7 ± 11 m; p < 0.05) and blood pressure variability (BPV; CON = 5.18 ± 1.1 vs. AS = 12.1 ± 0.88 mmHg vs. S = 10.2 ± 10.7 mmHg; p < 0.05) were different in our S group. Further, when HRV was assessed in the frequency domain the very low frequency was different during exercise in the S group relative to the other groups.Discussion: Collectively, these data suggest that a previous symptomatic SARS-CoV-2 infection may alter heart rate and blood pressure regulation during exercise.

As the number of COVID‐19 cases begin to diminish it is important to turn our attention to any long‐term issues that may be associated with a prior infection. Cardiovascular (CV) defects have been noted following infection. However, less is known how a previous COVID‐19 infection alters CV response during exercise (EX). Furthermore, differences may exist between COVID‐19 infected individuals who had symptoms (symptomatic) when compared with those that did not have symptoms (asymptomatic) during EX. Hypothesis Previously symptomatic (S) COVID‐19 recoveries have an altered CV response to acute EX relative to both control (CON; never infected), and asymptomatic (AS) individuals who were previously infected with COVID‐19. Methods Subjects (n=14; CON=4; S=5; AS=5; Age = 21 ± 2.3) filled out a questionnaire before performing EX to determine if they were AS or S and if symptomatic what symptoms they experienced. Subjects next performed a 5‐minute warm‐up followed by 25 minutes of treadmill EX (5‐6 METS). During EX, blood pressure was recorded on the brachial artery every 5 minutes and 3‐lead electrocardiography was measured continuously. Heart rate variability (HRV) was analyzed in the time‐domain using the standard deviation of the inter beat intervals of normal sinus beats (SDNN). Blood pressure variability (BPV) was computed as the average of the absolute differences between consecutive mean arterial pressure (MAP) measurements. A one‐way ANOVA with a Tukey’s post hoc was used to determine statistical differences between groups. Data are shown as mean ± SEM. Significance was set to p<0.05. Results Baseline MAP in a seated (CON=89 ± 6 mmHg; AS=92 ± 3 mmHg; S=87± 5 mmHg), standing (CON=86 ± 2 mmHg; AS=90 ± 7 mmHg; S=86 ± 3 mmHg) and supine (CON=86 ± 3 mmHg; AS=90 ± 6 mmHg; S=86 ± 4 mmHg) position were similar amongst all three groups. There were no differences (p>0.05) between HR (CON = 104 ± 4 BPM vs. AS=118 ±6 BPM vs. S=1112± 3 BPM) or MAP (Con = 108±4 mmHg vs. AS=105±13 mmHg vs. S=108±7 mmHg) between groups during EX. However, HRV (Con=139 vs. AS =156±6ms vs. S=77.7±11ms; S vs. CON; AS; p<0.05) and BPV (Con= 139 ± AS=13±1.1 mmHg vs. S=5±1.0mmHg; S vs. CON; AS; p<0.05) were different. Conclusion Previously symptomatic subjects may have altered HRV and BPV during EX and thus indicates that experiencing symptoms associated with COVID‐19 may impact the ANS.