CHANGES IN CENTRAL HAEMODYNAMICS IN RESPIRATORY HYPOCAPNIA IN YOUNG MEN WITH DIFFERENT BASELINE PetCO2

Abstract

Hyperventilation is an intense breathing that exceeds the needs of the body and causes hypocapnia. There are insufficient studies of the individual features of haemodynamic parameter changes when testing for hyperventilation and after it; therefore, the changes of the central haemodynamics are analyzed while testing the regulated respiration at a rate of 30 cycles per minute in healthy young men.PetCO2 level was determined in 81 men on Datex Normocap capnograph; haemodynamic indicators were found with KHAI-medica rheography (Ukraine) for 5 minutes at rest, for 10 minutes of the regulated respiration at a rate of 30 cycles per minute and 40 minutes of recovery period after the test. The reactivity of most haemodynamics features with the regulated respiration were characterized with significant individual features and depended on baseline PetCO2 . The highest values of central hemodynamics in the background were observed in the men with baseline РеtСО2 from 38.5 to 41.74 mm Hg. Thus, the duration of the R-R intervals was 910 ± 30.7 ms, the stroke index was 37.34 ± 2.89 ml·m-2, the cardiac index corresponded to 2.4 ± 0.15 l·m-2·min-1, total peripheral resistance was 1944 ± 166.6 dy·s-1·cm-5 and volumetric emission rate was 257.1 ± 12.1 ml∙s-1. At the end of the test with hyperventilation, the persons of this group had the highest reactivity of the parameters of the cardiac index (0.42 ± 0.10 l·m-2·min-1, p <0.05), the total peripheral resistance (388 ± 109.2 dy· s -1·cm-5, p <0.05) and myocardial tension index (1.62 ± 1.05%, p <0.05). Investigated with an initial level of PetCO2 up to 38.5 mm Hg. differ in the lowest values in the background: t-R-R intervals were equal to 848 ± 27.4 ms, the shock index was 32.36 ± 2.42 ml·m-2, the cardiac index corresponded to 2.23 ± 0.11 l·m-2·min-1 and the volumetric emission rate is 227.0 ± 9.6 ml·s-1. And also in men of this group the least shifts of hemodynamic parameters under the influence of a hypocapnia are observed. Thus, the individual and typological differences of the men can increase the diagnostic value of the methods of analysis and evaluation of cardiovascular system and determine new approaches in preventive medicine and health insurance.

Keywords

• hyperventilation
• hypocapnia
• petco2
• central haemodynamics
• cardiodynamics.