Cardiovascular Responses During Constant Load Walking in Patients with Peripheral Arterial Disease

Abstract

Exaggerated increases in heart rate and blood pressure are abnormal cardiovascular responses during constant load walking in peripheral arterial disease (PAD) patients, and are markers of hemodynamic instability and increased cardiovascular risk. However, predictors of changes in heart rate and blood pressure are poorly described. Purposes. To assess the cardiovascular responses during constant load walking, and to identify predictors of this response in PAD patients. Methods. Seventy-nine patients with PAD performed a constant load treadmill test (2 mph, 0% grade). During the test, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and rate pressure product (RPP) were obtained at the fourth minute to the last minute of walking. Patients were also characterized on demographic measures, cardiovascular risk factors, baseline exercise performance measures, and vascular measures. Results. During constant load walking, there was a significant increase (p < 0.01) in SBP (+12 ± 10 mmHg), DBP (+6 ± 9 mmHg), HR (+5 ± 5 bpm) and RPP (+1920 ± 1435 mmHg x bpm). The HR and RPP responses were negatively correlated with ischemic window (r= -0.23 and r= -0.26, respectively; p<0.05) and positively correlated with the HR during the first minute of recovery from maximal graded exercise (r= 0.27 and r= 0.24, respectively; p<0.05). The increase in cardiovascular variables during walking was greater in subjects with higher BMI and in men (p < 0.05). Conclusion. Patients with PAD have an increased cardiovascular response during constant load walking, and these responses are greater in obese patients and in men. The clinical implication is that PAD patients engaged in walking training programs, particularly obese men, require frequent assessment of cardiovascular parameters to avoid exaggerated increases in BP, HR and RPP during constant work load walking. Funding by the following: NIA(R01-AG-24296); OCAST(HR04-1138;AWG); and GCRC(M01-RR-14467).