Estudo comparativo por analisador de gases portátil do Teste de Caminhada de Seis Minutos em portadores de insuficiência cardíaca de fração de ejeção normal e reduzida

• Autor(a) principal: Teixeira, José Antonio Caldas
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/8595
• topic: Heart failure; Walking test; Cardiopulmonary exercise test; Insuficiência cardíaca; Caminhada Fisiologia; Teste de esforço; Testes funcionais do coração; Insuficiência cardíaca; Teste de caminhada; Teste de esforço cardiopulmonar; CNPQ::CIENCIAS DA SAUDE::MEDICINA::CLINICA MEDICA::CARDIOLOGIA

With regard to the 6-Minute Walking Test (T6m), few studies use portable gas analyzers to describe and analyze the behavior of the kinetics of hemodynamic, ventilatory and metabolic variables at each minute in heart failure (HF) patients. The studies located addressed only the population suffering from heart failure with reduced ejection fraction (HFREF), with little information available on heart failure with normal ejection fraction (HFNEF). There are few descriptive studies in the literature addressing T6m in HFNEF that analyze the behavior of these kinetics, especially the metabolic and ventilatory variables. The objectives of this study are: to describe, analyze and compare the kinetics of the hemodynamic, ventilatory and metabolic variables obtained through a portable gas analyzer during the T6m for HFNEF patients compared with HFREF patients. It is a prospective analytical study with an intentional non-probabilistic convenience sample. The patients were volunteers selected by past hospital admissions for clinical diagnoses of HF. Between March 2010 and July 2013, 49 patients were identified, divided into two groups: 24 HFNEF and 25 HFREF. The HFREF was determined by the III Brazilian Guideline on HF established by the Brazilian Cardiology Society (SBC), using the same criteria as the European Society of Cardiology 2007. Each patient underwent three assessments: a familiarization T6m (T6m1), a T6m connected to a portable gas analyzer (VO2000) (T6m2) and a cardiopulmonary exercise test (CPET). It was noted that: that was no significant difference in the distances covered in the T6m between the two HF groups; the kinetics of the behavior of the hemodynamic (HR), ventilatory and metabolic variables did not vary significantly during the T6m and neither did the peak values differ significantly. The T6m represented a high-intensity percentage effort compared to the CPET for each group. Although functionally equivalent, in the CPET comparison between the two HF groups, the HFNEF group presented significantly higher scores for all variables whose estimates included pressure responses. The HFREF group had a longer recovery time in terms of oxygen consumption. We can conclude that the HFNEF group was equivalent to the HFREF group for most of the variables analyzed during the T6m. The T6m required almost maximum effort for both groups, being performed above the CPET anaerobic threshold and above 85% of the CPET peak VO2. The pressure response, the Ventilatory Equivalent for CO2 (VE/VCO2), the VE/VCO2 slope, the ventilatory power and the oxygen consumption recovery kinetics (T1/2) were the distinguishing variables between the two groups, with disadvantages for the HFREF group. With regard to the CPET, these same variables were also discriminatory for the two HF groups.(AU)