This long-term covid: vascular deterioration in the center of the chest eludes traditional cardiac testing. Long-term Covid is characterized by fatigue. The fatigue is intermittent and dependent on exercise. The organs are functioning fine, they just do not get enough oxygen when the artery between the lungs and the heart shrinks during exercise. So with fully functioning organs, a test will not detect heart or lung failure, the organs have not failed, the organs just fail to get enough oxygen during exercise.
An invasive test- iCPET – diagnoses the condition by taking blood oxygen measurements during a stress test. But no one uses that test for long-term Covid. This testing and measurement of what is happening inside the body during a medical test portend to bring new levels of medical diagnosis.
The reason that the constriction of the vessels that carry oxygen to the heart from the lungs is intermittent is that the constriction is intermittent, only triggered by exercise. The constriction that is intermittent can only be seen by an invasive test that measures the amount of oxygen being transmitted between the heart and lungs during exercise.
Long-term covid is characterized by exercise intolerance. Intermittent, supplemental oxygen can alleviate that condition by getting oxygen to the organ.