[Effect of the hypercapnic-hypoxic test on cardiovascular parameters in individuals with neurocirculatory dystonia].
Twenty healthy men and twelve patients with hypertensive type neurocirculatory dystonia belonging to the flying personnel were examined. They breathed a hypercapnic-hypoxia mixture formed during rebreathing in a closed circuit without a CO2 adsorber. In both groups this provocative test produced similar variations of most parameters under study. However in contrast to the healthy men, the hypertensive subjects showed a lower compensatory hyperventilation, a greater increase of blood pressure and cardiac output and a relatively small decrease of total peripheral resistance. Three test subjects displayed sinus arrhythmia. The time of test tolerance in the patients was on the average 20% shorter than in the healthy subjects. The changes can be viewed as an indication that the reserve capability of the cardiorespiratory system declines. The fact that the test is rapid, simple and safe makes it possible to use it during regular medical monitoring of the flying personnel with functional disorders of the cardiovascular system.