BackgroundIt is important to include large sample sizes and different factors that
influence the six-minute walking distance (6MWD) in order to propose
reference equations for the six-minute walking test (6MWT). ObjectiveTo evaluate the influence of anthropometric, demographic, and physiologic
variables on the 6MWD of healthy subjects from different regions of Brazil
to establish a reference equation for the Brazilian population. MethodIn a multicenter study, 617 healthy subjects performed two 6MWTs and had
their weight, height, and body mass index (BMI) measured, as well as their
physiologic responses to the test. Delta heart rate (∆HR), perceived effort,
and peripheral oxygen saturation were calculated by the difference between
the respective values at the end of the test minus the baseline value. ResultsWalking distance averaged 586±106m, 54m greater in male compared to
female subjects (p<0.001). No differences were observed among the 6MWD
from different regions. The quadratic regression analysis considering only
anthropometric and demographic data explained 46% of the variability in the
6MWT (p<0.001) and derived the equation:
A second model of stepwise multiple regression including ∆HR explained 62%
of the variability (p<0.0001) and derived the equation:
ConclusionThe equations proposed in this study, especially the second one, seem
adequate to accurately predict the 6MWD for Brazilians.
Background Aortic stenosis is a valvular heart disease characterised by fixed obstruction of the left ventricular outflow. It can be managed by surgical aortic valve replacement (sAVR) or transcatheter aortic valve implantation (TAVI). This review aimed to describe the evidence supporting a cardiac rehabilitation programme on functional capacity and quality of life in aortic stenosis patients after sAVR or TAVI. Methods The search was conducted on multiple databases from January to March 2016. All studies were eligible that evaluated the effects of a post-interventional cardiac rehabilitation programme in aortic stenosis patients. The methodological quality was assessed using the PEDro scale. Meta-analysis was performed separately by procedure and between procedures. The walked distance during the six-minute walk test (6MWD) and Barthel index were evaluated. The analysis was conducted in Review Manager. Results Five studies were included (292 TAVI and 570 sAVR patients). The meta-analysis showed that a cardiac rehabilitation programme was associated with a significant improvement in 6MWD (0.69 (0.47, 0.91); P < 0.001) and Barthel index (0.80 (0.29, 1.30); P = 0.002) after TAVI and 6MWD (0.79 (0.43, 1.15); P < 0.001) and Barthel index (0.93 (0.67, 1.18); P < 0.001) after sAVR. In addition, the meta-analysis showed that the cardiac rehabilitation programme promoted a similar gain in 6MWD (4.28% (-12.73, 21.29); P = 0.62) and Barthel index (-1.52 points (-4.81, 1.76); P = 0.36) after sAVR or TAVI. Conclusions The cardiac rehabilitation programme improved the functional capacity and quality of life in aortic stenosis patients. Patients who underwent TAVI benefitted with a cardiac rehabilitation programme similar to sAVR patients.
There was no difference between the groups regarding cardiac autonomic modulation by linear and nonlinear methods, which may be due to beta-blocker use, coronary angioplasty and the exercise capacity of healthy subjects.
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