The most common symptom is fatigue which has a typical pattern of becoming worse 12-24 hours after some particular physical or emotional stress, in contrast to most other causes of fatigue which produce fatigue close to the time of stress. Though the name refers to what is usually only a minor change in one of the heart valves, most people with MVP Syndrome do not have heart disease. Rather, the illness arises from abnormalities in the way nerves control certain bodily functions such as heart rate, blood pressure, and blood flow. An illness of the autonomic nervous system is called a dysautonomia, so often MVP Syndrome is also called MVP Dysautonomia. Our research has identified several biochemical abnormalities in the autonomic nervous system which partially explain how the dysautonomia arises.
Adrenaline is central to controlling heart rate, blood pressure and blood flow.
In MVP Syndrome one of the proteins which adrenaline uses to control these functions is abnormally sensitive, so the tissues over-react to the person's blood adrenaline. We have shown that the gene for this protein is normal, so we await further studies to find out how the protein gets to be over-reactive. Other illnesses can mimic MVP Syndrome, including panic disorder, anxiety, migraine headaches, esophageal disease, and some chronic infections. Typically a doctor can distinguish between MVP Syndrome and these other illnesses by doing a careful history, physical examination, and when necessary, some laboratory studies. In unusual situations some special studies are required.