TY - JOUR
T1 - The ischemic window
T2 - A method for the objective quantitation of the training effect in exercise therapy for intermittent claudication
AU - Feinberg, Richard L.
AU - Gregory, Roger T.
AU - Wheeler, Jock R.
AU - Snyder, Stanley O.
AU - Gayle, Robert G.
AU - Parent, F. Noel
AU - Patterson, Robert B.
N1 - Funding Information:
Supported in part by a research grant from the Sentara-Norfolk General Hospital.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1992/8
Y1 - 1992/8
N2 - Twenty-two patients with intermittent claudication were prospectively enrolled in a 12-week program of supervised, graded treadmill exercise therapy. Severity and distribution of arterial occlusive disease were ascertained by noninvasive determination of segmental lower extremity blood pressures and waveforms. No attempt was made to modify risk factors for atherosclerotic occlusive disease. The exercise-induced reduction of the ankle pressure and its recovery were recorded over time, and the area under this curve, the "ischemic window," represents the severity of the ischemic deficit. Absolute systolic ankle pressure, ankle-brachial index, maximum walking time, claudication pain time, and the ischemic window were measured before and after exercise training in all subjects. Maximum walking time and claudication pain time increased 659% and 846%, respectively, among the 19 patients completing the 12-week program (p = 0.001; p = 0.0002). These patients underwent a mean reduction of 58.7% in the ischemic window after a standardized workload (p < 0.05), and this correlated with the degree of symptomatic improvement. Absolute ankle pressure and ankle-brachial index were unchanged after exercise training. This study confirms the utility of supervised exercise therapy in the treatment of intermittent claudication. The ischemic window is a useful method for quantifying the ischemic deficit produced by exercise and provides a reproducible means of documenting functional improvement in patients undergoing exercise training.
AB - Twenty-two patients with intermittent claudication were prospectively enrolled in a 12-week program of supervised, graded treadmill exercise therapy. Severity and distribution of arterial occlusive disease were ascertained by noninvasive determination of segmental lower extremity blood pressures and waveforms. No attempt was made to modify risk factors for atherosclerotic occlusive disease. The exercise-induced reduction of the ankle pressure and its recovery were recorded over time, and the area under this curve, the "ischemic window," represents the severity of the ischemic deficit. Absolute systolic ankle pressure, ankle-brachial index, maximum walking time, claudication pain time, and the ischemic window were measured before and after exercise training in all subjects. Maximum walking time and claudication pain time increased 659% and 846%, respectively, among the 19 patients completing the 12-week program (p = 0.001; p = 0.0002). These patients underwent a mean reduction of 58.7% in the ischemic window after a standardized workload (p < 0.05), and this correlated with the degree of symptomatic improvement. Absolute ankle pressure and ankle-brachial index were unchanged after exercise training. This study confirms the utility of supervised exercise therapy in the treatment of intermittent claudication. The ischemic window is a useful method for quantifying the ischemic deficit produced by exercise and provides a reproducible means of documenting functional improvement in patients undergoing exercise training.
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U2 - 10.1016/0741-5214(92)90114-N
DO - 10.1016/0741-5214(92)90114-N
M3 - Article
C2 - 1495149
AN - SCOPUS:0026784718
VL - 16
SP - 244
EP - 250
JO - Journal of Vascular Surgery
JF - Journal of Vascular Surgery
SN - 0741-5214
IS - 2
ER -