Treadmill exercise test with dual isotope scintigraphy documents the second window of preconditioning in humans.

Background: In experimental studies, two windows of preconditioning have been identified, one lasting 1-2h and a second one (SWOP) starting 24h later and lasting 3-4 days. We sought to document SWOP in humans, using scintigraphy as an objective method of imaging.

Methods: Nineteen male patients, aged 62+/-7 years with documented coronary artery disease underwent two treadmill exercise tests (at baseline and 30 h later) and three tomographic perfusion studies (during the first exercise test, during the redistribution phase 4 h later and during the second exercise test 30 h later) with two different isotopes.