Influence of peripheral arterial disease and supervised walking on heart rate variability

ObjectiveTo examine the influence of peripheral arterial disease (PAD) on heart rate variability (HRV) in patients, and to examine the influence of an intense long-term (12 months) exercise program on HRV in PAD patients.MethodsThis study involved ambulatory patients attending a local hospital and university center. Participants were twenty-five patients with diagnosed PAD and intermittent claudication and 24 healthy, age-matched adults. Interventions involved random allocation of PAD patients to 12 months of conservative medical treatment (Conservative) or medical treatment with supervised treadmill walking (Exercise). The main outcome measures were time- and frequency-domain, nonlinear HRV measures during supine rest, and maximal walking capacity prior to and following the intervention.ResultsDespite significantly worse walking capacity (285 ± 190 m vs 941 ± 336 m; P < .05), PAD patients exhibited similar resting HRV to healthy adults. At the 12-month follow-up, Exercise patients exhibited a significantly greater improvement in walking capacity (183% ± 185% vs 57% ± 135%; P = .03) with similar small nonsignificant changes in HRV compared with Conservative patients.ConclusionsThe current study demonstrated that PAD patients exhibited similar resting HRV to healthy adults with 12 months of intense supervised walking producing similar HRV changes to that of conservative medical treatment. The greater walking capacity of healthy adults and PAD patients following supervised exercise does not appear to be associated with enhanced HRV.