Open AccessTHE HEART PRELOAD AND AFTERLOAD INTERACTION AND RR INTERVALS UNDER HARD NORMOBARICHYPOXIA EXPOSURE IN HEALTHY YOUNG PERSONS
Author(s) -
A S Radchenko,
N. S. Borisenko,
Aleksandr Kalinichenko,
Yu Yu Rodionova,
Yuriy Nikolayevich Korolev,
В. Н. Голубев,
О А Чурганов
Publication year - 2013
Publication title -
obzory po kliničeskoj farmakologii i lekarstvennoj terapii
Language(s) - English
Resource type - Journals
eISSN - 2542-1875
pISSN - 1683-4100
DOI - 10.17816/rcf11340-49
Subject(s) - preload , afterload , medicine , blood pressure , heart rate , respiration , qrs complex , diastole , cardiology , hemodynamics , anesthesia , anatomy
The study wThe left ventricular end diastolic pressure (EDP) fluctuations, specific peripheral vascular resistance (SPR) and cardiointervals (RR) on the respiration frequency under hard normobaric hypoxia (FIO2 = 0.1) were studied. 7 young men (volunteers) were subject to series of hard hypoxic exposures (6 weeks, every other day, intermittently by 6 × 5 min – FIO2 = 0.1). The hypoxic tests (HT1 and HT2) – FIO2 = 0.1, 15 min continuously) were performed before and after each series. SаO2 at the last 3 m of the tests on average was 82.5 % and 92.0 % respectively (Р < 0.05). During HT1 and HT2 (in comparison with inactivity) were increased: angle of max QRS vector (VQRS) in the frontal plain (68.5° ± 16.68 and 72.94° ± 15.32; 69.62° ± 22.4 and 74.45° ± 17.98 respectively), minutes blood flow (MBF) (6.41 ± 1.98 l/min and 6.87 ± 1.27 l/min; 5,27 ± 1,02 l/min and 5.67 ± 1.19 l/min respectively) (Р < 0.05). SPR was decreased too (27.39 ± 5.45 s.u. and 25.62 ± 4.96 s.u.; 30.59 ± 6.34 s.u. and 27.93 ± 5.77 s.u. respectively) (Р < 0.05). By means of transfer function analysis was shown that EDP fluctuations at HT2 significantly outpace by time (phase) the SPR and RR fluctuations on the respiration frequency (1.19 s ± 0.64 and 1.99 s ± 0.63 or 94.39° ± 43.3 and 125.4° ± 7.54; 1.65 s ± 1.28 and 2.22 s ± 0.87 or 101.4° ± 59.6 and 152.7° ± 21.26 respectively) (Р < 0.05). The increased oxyhemoglobin saturation is a trigger of artery wall smooth muscle relaxation mechanisms and this one is changes the background for beat to beat baroreflex realization on the respiration frequency.