J Nucl Med 1998 Nov;39(11):1841-4
Impairment of cardiac neuronal function in acute myocarditis: iodine-123-MIBG
scintigraphy study.
Agostini D, Babatasi G, Manrique A, Saloux E, Grollier G, Potier JC, Bouvard G.
Abnormalities of norepinephrine uptake have been found to reflect impairment in
adrenergic nerve function that has influenced the cardiac outcome of patients
with heart failure. The aim of this study was to explore the cardiac neuronal
function by using 123I-metaiodobenzylguanidine (MIBG) scintigraphy in patients
with acute myocarditis. METHODS: We studied 15 patients (age range 42 +/- 10 yr)
with clinical, biological, electrocardiographic and radionuclide left
ventricular ejection fraction (LVEF) (41% +/- 7%) data indicating myocarditis
and 10 normal subjects (age range 36 +/- 7 yr, mean radionuclide LVEF 69% +/-
8%, p < 0.05). Fourteen patients had positive histologic findings of
myocarditis and 1 had nonspecific histological data. All patients underwent
planar cardiac imaging after intravenous injection of 185 MBq 123I-MIBG and
right ventricular biopsy within 7 days. A chest anterior view was acquired 4 hr
later. Heart-to-mediastinum ratio activity was measured, as previously described
in our laboratory. RESULTS: Significant impairment of cardiac neuronal uptake of
MIBG was observed and based on a reduction of heart-to-mediastinum ratio (148%
+/- 16% versus 234% +/- 36%, p < 0.05). A significant correlation was
observed between LVEF and MIBG uptake in patients (y = 1.58x +/- 83.7, r = 0.72,
p < 0.01). CONCLUSION: Acute myocarditis is associated with an injury of the
cardiac adrenergic neuronal function. In addition to the inflammatory injury of
the myocytes, the impairment of adrenergic function may be involved in the
cardiac pump failure induced by myocarditis.
