Walking Capacity Is Positively Related with Heart Rate Variability in Symptomatic Peripheral Artery Disease.

OBJECTIVES: The aim was to investigate the association between walking capacity and HRV in patients with symptomatic peripheral artery disease (PAD). METHODS: This was a cross sectional study. Ninety-five patients were recruited. Patients undertook a supine position for 20 minutes, with the final 10 minutes used to examine for resting HRV. Time domain, frequency domain, and non-linear indices were evaluated. A maximal treadmill test (Gardner protocol) was performed to assess maximal walking distance (MWD) and claudication distance (CD) in groups of PAD patients based upon their walking abilities (low, moderate, high). Differences between PAD patient groups were examined using non-parametric analyses, and Spearman rank correlations identified the relationship between MWD and CD, and HRV parameters. RESULTS: Symptomatic PAD patients with high MWD exhibited significantly greater HRV than patients with low MWD. Furthermore, MWD was positively associated with time domain and non-linear indices of HRV (all p < .05). However, no statistically significant correlations were observed between CD and HRV parameters or between PAD groups. CONCLUSION: A greater walking capacity is associated with better HRV in symptomatic PAD patients.

Vascular Mechanisms of Post-exercise Blood Pressure Responses in Peripheral Artery Disease.

This study aimed to analyze the vascular mechanisms involved in post-resistance decreases in blood pressure in patients with peripheral artery disease. 17 patients underwent 2 experimental sessions conducted in random order: resistance exercise (REx-3×10 reps in 8 exercises with intensity of ~ 60% of 1 RM) and control (C- resting on the exercise machines for 50 min). Before and after each experimental session, blood pressure, reflected wave indicators, pulse wave velocity, blood flow, blood flow post-reactive hyperemia and peripheral vascular resistance responses were obtained. Both sessions increased brachial systolic, diastolic and mean blood pressure (greatest increase REx: 11 mmHg; greatest increase C: 19 mmHg; P<0.01); however, the increases were greater after the C session (P<0.01). Reflected wave indicators increased only after the C session (P<0.06), while pulse wave velocity increased similarly after both sessions (P=0.66). Individual analyses indicated a large variability between patients in vascular variables responses. A single bout of REx decreased blood pressure in peripheral artery disease patients, and these responses were followed by changes in reflected wave indicators. The other factors presented high individual variability, and thus it was not possible to identify specific factors associated with blood pressure reduction in peripheral artery disease patients.