Ponto Ótimo Cardiorrespiratório: aspectos metodológicos, fisiológicos e clínicos

• Autor(a) principal: Ramos, Plinio dos Santos
• Data de Publicação: 2015
• 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/1/8222
• topic: Cardiopulmonary Exercise Testing; Exercise; Ventilation; Oxygen Equivalent; Teste Cardiopulmonar de Exercício; Exercício; Ventilação; Equivalente de Oxigênio; Testes funcionais (Medicina); Testes funcionais do coração; Testes funcionais dos pulmões; Exercícios físicos Aspectos fisiológicos; Oxigênio Efeitos fisiológicos; CNPQ::CIENCIAS DA SAUDE::EDUCACAO FISICA

The ventilatory variables obtained through the analysis of expired gases during cardiopulmonary maximal exercise test (CPET) have been the target of several and consistent studies, both from a physiologic and clinical-epidemiological perspective; however, there is still information to be further explored. In this sense, this dissertation explores methodological, physiological and clinical aspects of the minimal value of the ventilatory equivalent for oxygen obtained in a given minute of an incremental exercise carried in a lower limb cyclergometer, and thereafter named cardiorespiratory optimal point (COP). In this context, the dissertation comprised four original studies with the following objectives: 1) to determine the COP behavior as a function of gender and age in healthy adults and its association with other CPET variables; 2) to investigate COP stability in a maximal CPET performed in a lower limb cyclergometer; 3) to analyze the COP behavior in patients with panic disorder and 4) to investigate the prognostic value of COP for all-cause mortality in individuals aged between 40 and 85 years old. In the first study, 624 healthy subjects underwent maximal CPET were selected to describe the behavior of COP. It was found that the COP increases with age, it is smaller in men 23.2 ± 4.48 vs 25.0 ± 5.14 (p <0.001), and occurs on average (44% VO2max) before AT (67% VO2max) (p <0.001). In the second study, data from two CPET performed, one year apart in average, in 222 patients were retrospectively reviewed in order to assess COP stability. A high association was found - (ri = 0.87, 95% CI 0.82 to 0.90). In the third study, COP was identified in 52 patients with panic disorder (PD) and compared with an age and gender-matched control group of identical size. Iy was found that COP did not differ between patients and controls (21.9 ± 0.5 vs 23.4 ± 0.6, p = 0.07) as well as no difference was observed for COP between the two subgroups of patients with PD - maximum and submaximal CPET (22.0 ± 0,5 vs 21.6 ± 1.3, p = 0.736). Finally, the fourth and last study assessed the prognostic value of COP in a retrospective cohort of 3331 patients undergoing CPET, where COP > 30 was associated with a higher all-cause mortality (RR = 6.86; 95% CI = 3.69 to 12.75, p <0.001) even when adjusted for age, sex, BMI and FEV1/FVC (adjusted RR = 3.72, 95% CI = 1.98 to 6.98, p <0.001), indicating that COP, a submaximal variable obtained during CPET, is a strong predictor of all-cause mortality. In summary, POC, a dimensionless and evaluator error-free variable obtained in submaximal levels of incremental exercise, may be a useful and complementary variable to be explored in CPET.