Table 3.
Long COVID |
Control |
||
---|---|---|---|
N = 77 | N = 766 | P | |
Cardiac Responses | |||
Resting HR ≥ 100 | 4 (5.2) | 45 (5.9) | 0.41a, b |
Chronotropic incompetence | 34 (44) | 261 (34) | 0.05a, b, c |
Abnormal HR recovery | 16 (21) | 157 (20) | 0.81a, b, c |
Low Peak SBP | 16 (21) | 100 (13) | 0.046a, b, c |
Exercise ST-T abnormalities | 4 (5.2) | 33 (4.3) | 0.78a, b, c |
PVC Frequency | 0.38 | ||
None | 47 (61) | 410 (54) | |
< 5/min | 19 (25) | 263 (34) | |
≥ 5/min or pairs | 9 (12) | 80 (10) | |
VT | 2 (2.6) | 13 (1.7) | |
Symptoms of chest pain | 11 (14) | 108 (14) | 0.51 |
Pulmonary Responses | |||
Submaximal effort | 14 (18) | 134 (18) | 0.88 |
Low breathing reserve <15% | 2 (2.6) | 17 (2.2) | 0.49a, b, c |
Low O2 saturation < 93% | 3 (3.9) | 29 (3.8) | 0.84a, b, c |
V̇E/V̇CO2 nadir | 28 ± 5 | 29 ± 4 | 0.32a, b, c |
High V̇E/V̇CO2 | 11 (14) | 107 (14) | 0.80a, b, c |
Symptoms of dyspnea | 44 (57) | 501 (66) | 0.09 |
Values are mean ± SD or n (%).
Abbreviations: HR = heart rate; SBP = systolic blood pressure.
Chronotropic incompetence = HR reserve <80% predicted for age and sex; Abnormal HR recovery = HR Recovery <13 bpm if active recovery or < 18 bpm if no active recovery; Low peak SBP = peak SBP < 10th percentile for age and sex; Submaximal effort = peak respiratory exchange ratio < 1.0; Low O2 saturation = minimum O2 saturation < 93%; V̇E/V̇CO2 nadir = lowest ratio of V̇E to V̇CO2 during exercise; High V̇E/V̇CO2 = V̇E/V̇CO2 nadir >2 standard deviations from mean for age and sex.
Adjusted for age and sex.
Adjusted for beta blocker use.
Adjusted for effort based on RER.