Insuficiência cardíaca: teste de caminhada versus pico de consumo de oxigênio

Abstract

The six-minute walk test (6MWT) is a simple assessment of physical capacity in patients with heart failure (HF) and can be performed in a hallway or on the treadmill 1 . It is suggested that the kind of effort during the 6MWT resemble the daily activities, enabling the patient to determine the rhythm of walking 2 .Carvalho et al 3 evaluated the reproducibility of the 6MWT in the hallway, as well as the correlation of the variables VO 2 , WD and HR in the sixth minute of the 6MWT with those of the cycle ergometer peak cardiopulmonary exercise testing (CPET) in HF. The authors demonstrated reproducibility between the 6MWTs and correlation with the CPET, concluding that the 6MWT is a reliable and low-cost assessment tool for the prescription of exercise in HF. However, the assessment of functional capacity in cycle ergometer shows a difference of 10 to 15% less when compared to that obtained with the treadmill test 4 . Thus, the correlation found in this study can be the difference between the types of tests. Moreover, the intensity of walking during the 6MWT in HF is influenced by verbal encouragement, as demonstrated by Guimarães et al 1 .Discussions about the reproducibility of the 6MWT are not recent, as well as its safe use in HF 2 . Nevertheless, in our country, there has been no longitudinal study involving a significant number of patients with HF of nonischemic, ischemic and chagasic etiology. Furthermore, the use of this test for exercise prescription is purely theoretical, making larger studies necessary to clarify its applicability for this purpose.