The answer is that yes, this may be a problem and your doctors are doing the right thing by progressively working toward the diagnosis. The CT scan
will allow them to see the soft tissues inside your chest including your heart, lung and blood vessels and will give them a better idea of what is going on. If it is indeed a mass, they can arrange for a biopsy
. If it is a vascular issue, you may be referred to a vascular specialist. Try and relax until the CT is done unless you have other worrisome symptoms which develop between now and then.