Use of Cardiopulmonary Stress Testing for Patients With Unexplained Dyspnea Post–Coronavirus Disease

Donna M. Mancini; Danielle L. Brunjes; Anuradha Lala; Maria Giovanna Trivieri; Johanna P. Contreras; Benjamin H. Natelson

doi:10.1016/j.jchf.2021.10.002

Figure 1

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Patient #1 Shows Normal Ventilatory Pattern in 3 Graphs

(Top) VE increases smoothly over time. (Middle) Tight linear correlation of VE and VCO₂. (Bottom) RR (orange, left y axis) and TV (blue, right y axis) is plotted vs minute ventilation (x axis). A slow increase in RR and an early large increase in TV at the start of exercise is observed. Patients #2 and #3 show examples of the dysfunctional breathing. (Top) VE vs time in patient #2 and #3 show numerous erratic spikes. (Middle) A thicker line correlating VE with VCO₂. (Lower) Dissociation between RR and TV vs VE is observed. Total overlap of RR and TV is seen in patient #2 and an overlap of RR and TV early and late in exercise occurs in patient #3. RR = respiratory rate; VE = minute ventilation; VT = tidal volume.