Impact of an abbreviated adenosine protocol incorporating adjunctive treadmill exercise on adverse effects and image duality in patients undergoing stress myocardial perfusion imaging

Background. Limited data are available about the effects of adjunctive trea dmill exercise on adverse effects and the image quality of adenosine perfus ion imaging. This study compared the incidence of adverse effects and image quality between standard 6-minute adenosine perfusion imaging and a stress test incorporating a 4-minute adenosine infusion with low-level treadmill exercise. Methods and Results. Nineteen patients underwent both a 6-minute adenosine technetium-99m sestamibi single photon emission computed tomography (SPECT) imaging study and a 4-minute adenosine Tc-99m sestamibi SPECT study with 6 minutes of simultaneous low-level treadmill exercise. Symptoms were record ed at 1-minute intervals during the stress and recovery periods. Heart-to-l iver and heart-to-lung count ratios were determined from anterior planar im ages. More adverse effects were experienced during the standard adenosine s tudy than during the adenosine study with low-level exercise (2.7 +/- 1.4 v s 1.4 +/0 1.1, P =.0003). The duration adverse effects were experienced was longer during the standard 6-minute adenosine protocol (6.6 +/- 2.1 minute s vs 3.2 +/- 2.8 minutes, P <.0001). Additionally, the symptom-severity sco res were higher with the standard adenosine study (15.5 +/- 9.8 vs 4.5 +/- 5.1, P <.0001). The heart-to-liver ratios were noted to be higher in the 4- minute adenosine protocol with low-level exercise (1.0 +/- 0.3 vs 0.6 +/- 0 .2, P =.0003). Conclusions. In comparison with standard 6-minute adenosine perfusion imagi ng, a protocol incorporating a 4-minute adenosine infusion with low-level t readmill exercise results in a marked reduction in the quantity and severit y of adverse effects and an improvement in image quality.