Haemodynamic limitations and exercise performance in peripheral arterial disease.

It has been frequently argued that haemodynamic limitations are poor predictors of exercise performance in people with peripheral arterial disease (PAD) and intermittent claudication. This review has tried to address this argument through a review of published data that appears to support or counterbalance it, brief consideration of some of the methodological limitations associated with these data, as well as some other considerations. The main argument rests primarily upon data about the resting ankle-brachial index (ABI) and/or blood flow after calf exercise or an ischaemic challenge; whereas the counter argument rests mainly on data about blood flow during walking or cyding exercise. Consideration of the limitations of all methods suggests that the measurement of blood flow during exercise has the greatest value in explaining differences in exercise performance amongst claudicants; whereas the other methods are relatively limited in their explanatory value. This strengthens the counter argument and undermines the main argument proposed by others. Consequently, asserting that haemodynamic limitations are poor predictors of exercise performance in claudicants is not justified in light of available evidence.