Dobutamine combined with low-level exercise for myocardial perfusion scintigraphy

Increased abdominal background activity is one of the limitations of dobuta mine myocardial perfusion scintigraphy which may interfere with interpretat ion of the images. In this study, we evaluated the value of low-level exerc ise supplementation to dobutamine infusion in improving image quality. The control group (n = 32, Group A) received dobutamine alone, while the study group received dobutamine plus low-level exercise for the last 2 min of dob utamine administration (n = 26, Group B). One hundred and eleven MBq of Tl- 201 was injected 1 min before cessation of peak dose. The ratios of cardiac /hepatic (C/HEP), cardiac/subdiaphragmatic (C/INF) and cardiac/pulmonary (C /PUL) were calculated from anterior planar images taken immediately followi ng the test. Cardiac/non-cardiac activity was also visually graded on a thr ee-point scale. Visual evaluation showed improved cardiac/non-cardiac ratio s as confirmed by significantly higher C/HEP and C/INF ratios for Group B ( 1.5+/-0.3 and 1.7+/-0.2, respectively) compared to corresponding values in Group A (1.2+/-0.4 and 1.4+/-0.4, respectively) (P < 0.05). The cardiac/pul monary (C/PUL) ratio was also higher for Group B (2.3+/-0.5) as compared to corresponding Value in Group A (2.0+/-0.6, respectively), but this differe nce did not reach statistical significance (P > 0.05). No difference in the frequency of side Effects and ECC changes were detected between the two gr oups (P > 0.05). Low-level exercise supplementation to dobutamine infusion for myocardial perfusion scintigraphy is a safe method and leads to a signi ficant decrease in uptake by the areas adjacent to the heart, improving ima ge quality. ((C) 2000 Lippincott Williams & Wilkins).