It is likely that a close association exists between findings obtained by two methods:
dobutamine stress echocardiography and 123I-MIBG scintigraphy. Both of these methods are associated with
beta-adrenergic receptor mechanisms. This study was conducted to demonstrate the relation between myocardial response to
dobutamine stress and sympathetic nerve release of
norepinephrine in the failing heart. In 12 patients with
heart failure due to
idiopathic dilated cardiomyopathy, the myocardial effects of
dobutamine stress were evaluated by low-dose
dobutamine stress echocardiography: and sympathetic nerve function was evaluated by scintigraphic imaging with
iodine-123 [123I]
meta-iodobenzylguanidine (
MIBG), an analogue of
norepinephrine. Echocardiography provided quantitative assessment of wall motion and left ventricular dilation; radiotracer studies with 123I-MIBG provided quantitative assessment of the heart-to-mediastinum (H/M) uptake ratio and washout rate. Results showed that H/M correlated with baseline wall motion (r = 0.682, p = 0.0146), wall motion after
dobutamine stress (r = 0.758, p = 0.0043), the change in wall motion (r = 0.667, p = 0.0178), and with left ventricular diastolic diameter (r = 0.837, p = 0.0007). In addition, the 123I-MIBG washout rate correlated with baseline wall motion (r = 0.608, p = 0.0360), wall motion after
dobutamine stress (r = 0.703, p = 0.0107), and with the change in wall motion (r = 0.664, p = 0.0185). Wall motion, especially in the myocardial response to
dobutamine stress, is related to sympathetic nerve activity in
heart failure.