Abnormalities of cardiac sympathetic neuronal and left ventricular function in chronic mitral regurgitation: assessment by iodine-123 metaiodobenzylguanidine scintigraphy.
Myocardial uptake of iodine-123 meta-iodobenzylguanidine (123I-MIBG) was measured using scintigrams at rest in 12 patients with isolated, nonischemic mitral regurgitation (MR; regurgitant fraction 64% +/- 7%) and was related to the left ventricular (LV) function assessed by cardiac catheterization. Iodine-123 meta-iodobenzylguanidine activity in the upper mediastinum, liver, and lung was comparable between MR and control (n = 8) patients. The heart-to-mediastinum 123I-MIBG activity ratio 4 hours after injection was significantly (p < 0.01) decreased in MR (2.0 +/- 0.1, mean +/- SE) compared with control (2.7 +/- 0.1) with the increased clearance of MIBG. In addition, MR patients had significantly greater heterogeneity in the 123I-MIBG distribution within the myocardial images (26.1% +/- 2.1% intraimage variability for MR versus 15.6% +/- 0.8% for control, p < 0.01). Myocardial 123I-MIBG activity correlated positively with cardiac index and negatively with pulmonary capillary wedge pressure and LV volume indexes. Thus, 123I-MIBG scintigrams can be a noninvasive method for assessing the contractile dysfunction in MR.
Tsutsui
H
H
Research Institute of Angiocardiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Ando
S
S
Kubota
T
T
Kuroiwa-Matsumoto
M
M
Egashira
K
K
Sasaki
M
M
Kuwabara
Y
Y
Koyanagi
S
S
Yasui
H
H
Takeshita
A
A
D019797:3-Iodobenzylguanidine; D006328:Cardiac Catheterization; D016022:Case-Control Studies; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging* / Q000294:innervation*; D006801:Humans; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009200:Myocardial Contraction / Q000502:physiology; D013564:Sympathetic Nervous System / Q000503:physiopathology; D013794:Thallium Radioisotopes; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology
D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D013794:Thallium Radioisotopes; D019797:3-Iodobenzylguanidine