Analysis of kinetics of maximum volume of oxygen by means of the six-minute degree test in patients with cardiac insufficiency

• Grant number: 19/12707-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2019
• End date: July 31, 2020
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Audrey Borghi Silva
• Grantee: Deise Lilian Costa Dias
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Introduction: With the increase in the life expectancy of the population, together with the development of science and technology, there is a higher incidence of Heart Failure (HF) cases in Brazil and in the world, which is currently a serious public health problem, generating high expenses with health, because it is a chronic disease. HF is defined as a clinical syndrome, which occurs when the heart is no longer able to adequately supply the tissue metabolic demands, having as main clinical manifestations dyspnea and fatigue, negatively impacting daily activities such as walking and going up and down stairs . In this context, the six-minute step test (6MST) is an interesting test to evaluate functional capacity and has been shown to be an interesting tool to establish prognosis in individuals with HF. The kinetics of oxygen consumption (VO2) in its on and off phases may also be an important prognostic marker in patients with HF, however its applicability in functional tests has been little investigated. Objective: To analyze the kinetic "on" and "off" of VO2 in 6MST in patients with HF, as well as to evaluate the influence of the cycles of ascents and descents with the values obtained in kinetics. Methods: Clinically stable individuals with NYHA class I, II and III and IV systolic dysfunction with clinically stable echocardiography, with diagnostic confirmation by echocardiogram, will be included. Patients will under go a clinical evaluation that will include assessment of the disease status and its comorbidities. Subsequently, they will perform 6MST where VO2 breath-by-breath data will be collected, as well as symptoms (Borg scale), heart rate and blood pressure at rest and at peak of test. The analysis of the VO2 kinetics will be obtained by the Cardiokin software. Hypothesis: It is hypothesized that the kinetics of "on" and "off" of these patients are slowed down, especially in those that are more severe, and, moreover, that individuals with a lower number of cycle in 6MST have a kinetics of VO2 "on" and slower, as well as being more symptomatic.