Hyperventilation syndrome: a review

This article has dealt with the psychophysiological phenomenon known as "hyperventilation syndrome." Published research on this syndrome dates back at least a century to Da Costa's classic investigation involving "soldier's heart". Various labels such as "effort syndrome," "anxiety neurosis," "neurocirculatory asthenia," "vasoregulatory asthenia," and "irritable heart," have been employed over the past century to describe this syndrome. The use of different labels to describe this syndrome seems to be inappropriate. While the symptoms associated with these diagnostic labels appear to be remarkably similar, the treatment for the syndrome often differs as a function of the diagnostic label. Symptoms include breathlessness or dyspnea with effort, parathesia, trembling, tachycardia, tetany, carpopedal spasms, and convulsions in the case of a full-blown attack. Hyperventilation, a normal consequence of vigorous exercise and/or high temperatures, can often occur in some individuals for no apparent reason. Hyperventilation, and the resulting physiological changes, are often associated with decrements in psychomotor performance along with increased error rates. The symptoms which characterize the hyperventilation syndrome can be readily produced in certain "types" of individuals within minutes by requiring the individual to overbreathe or through introduction of a CO2 challenge. The symptoms, once produced, can be quickly reversed by placing a paper sack over the subject's head and requiring him/her to rebreathe expired air. Overbreathing and CO2 challenges do not, however, produce full-blown hyperventilatory attacks in most individuals. That is, some individuals or "types" appear to be especially sensitive to the effects of overbreathing and/or CO2 loading.(ABSTRACT TRUNCATED AT 250 WORDS)