Dynamics of Concatenation between Cardiac Output and Indices of Arterial Blood Presure during Graded Exercise Stress in Endurance Cohort

Abstract

Research background and hypothesis. Potential mechanisms through which muscle perfusion is altered during
prolonged exercise are not fully understood. The methods applied in the  analysis of human data are very important  
because  many crucial variables are not directly measureble or even identifiable.
Research aim  was to  find out the peculiarities in concatenation between  central and peripheral cardiovascular
changes under conditions of increasing fatigue.
Research methods. Well-trained endurance runners underwent a 50 W increase in workload (bicycle ergometry)
every 6 minutes and they exercised until inability to continue the task. Dynamics of concatenation between cardiac
output and systolic arterial blood pressure (ABP), diastolic ABP and total peripheral resistance were assessed using
a method based on matrix theory proposed by Lithuanian scientists.
Research results. The increase of cardiac output during exercising has the same tendency of stepwise increase
of workload, but changes of systolic and diastolic ABP with accumulation of fatigue could be characterized as linear
type dependent with the time of exercising. The concatenation between the changes in cardiac performance and
behaviour of peripheral vasculature increased at onset of exercising and the decrease or loss of the concatenation led
up to inability to continue exercising.
Discussion and conclusions. The importance of peripheral factors, i. e. decrease of diastolic blood pressure,
reduction  of  total  peripheral  vascular  resistance  plays  an  increasingly  significant  role  for  cardiac  output  during
continuous exercising. The concatenations between the changes of these indices and cardiac output increase and in
the case of high-grade fatigue concatenations begin to decline.

Keywords: cardiac output, periferal vascular resistance, concatenation.