J Nucl Med 2001 Jul;42(7):1017-24
Comparison of cardiac sympathetic nervous function with left ventricular
function and perfusion in cardiomyopathies by (123)i-mibg spect and
(99m)tc-tetrofosmin electrocardiographically gated spect.
Zhao C, Shuke N, Yamamoto W, Okizaki A, Sato J, Ishikawa Y, Ohta T, Hasebe N,
Kikuchi K, Aburano T.
The objective of this study was to clarify the relationship between cardiac
sympathetic nervous function (CSNF) and left ventricular (LV) function and
perfusion in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM).
METHODS: Thirty-eight cases (32 males, 6 females; mean age, 56 +/- 15 y),
consisting of 5 healthy control subjects, 15 patients with DCM, and 18 patients
with HCM, were studied with (123)I-metaiodobenzylguanidine (MIBG) and
(99m)Tc-tetrofosmin SPECT. CSNF was evaluated from cardiac uptake and washout of
MIBG, whereas LV perfusion and function were evaluated from tetrofosmin uptake
and wall thickening on electrocardiographically gated SPECT. As quantitative
parameters of global cardiac MIBG uptake and washout, the heart-to-mediastinum
ratio (H/M) and percentage washout were calculated from early and delayed planar
images. As quantitative regional parameters, the regional uptake and percentage
washout of MIBG were calculated from SPECT images dividing the left ventricle
into 12 segments. In the tetrofosmin study, the H/M and LV ejection fraction
were calculated as the parameters of global LV perfusion and function. As
quantitative regional parameters, the regional uptake and wall thickening were
also calculated for the 12 myocardial segments using the quantitative gated
SPECT software. Multiple linear regression analysis was performed to investigate
the correlations between the parameters from the 2 studies. RESULTS: In DCM and
HCM, multiple linear regression analysis of the regional parameters showed
significant correlations between LV function and CSNF (P < 0.0001) and
between LV perfusion and CSNF (P < 0.0001). According to the partial
correlation coefficients, washout and early uptake of MIBG were the most
significant factors for predicting LV function and LV perfusion, respectively.
CONCLUSION: In cardiomyopathies, CSNF was closely related to LV function. The
quantitative parameters of MIBG washout could reflect cardiac functional
impairment. Early MIBG uptake might be determined by myocardial perfusion in
cardiomyopathies.
