Evaluation of sympathetic activity by 123I-metaiodobenzylguanidine myocardial scintigraphy in dilated cardiomyopathy patients with sleep breathing disorder.
BACKGROUND
Because increased sympathetic nervous activity (SNA) in patients with dilated cardiomyopathy (DCM) associated with sleep breathing disorder (SBD) is known to deteriorate the prognosis of cardiac failure, (123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy was used as the investigative tool in the present study.


RESULTS
The study group comprised 53 patients (47 men, 6 women; mean age 56+/-3 years) with chronic stable DCM. Patients were divided into SBD(+) or SBD(-) group according to 24-h pulse oximetry results. SBD(+) was defined when the 3% oxygen desaturation index was more than 15/h during sleep. In total, 32 patients were SBD(-) and 21 were SBD(+). In both groups, pulse oximetry were performed during sleep and awakening pulse rate, and measurement of the blood levels of catecholamines and B-type natriuretic peptide was performed. MIBG myocardial scintigraphy and echocardiography were performed at the same time. No significant difference was found between the 2 groups in catecholamine levels or left ventricular ejection fraction. However, MIBG had a significantly increased washout rate and a significantly decreased delayed heart to mediastinum ratio in the SBD(+) group compared with the SBD(-) group.


CONCLUSIONS
SNA is increased in DCM patients when associated with SBD. MIBG myocardial scintigraphy may be a sensitive method of detecting increased SNA.
Nanjo
Shuji
S
Division of Cardiovascular Medicine, Department of Internal Medicine, Ohmori Hospital, Toho University School of Medicine, Tokyo, Japan. maru@pd5.so-net.ne.jp
Yamashiro
Yoshihiro
Y
Fujimoto
Shinichiro
S
Yamashina
Shohei
S
Nakanishi
Rine
R
Fukunaga
Shunji
S
Inoue
Aritomo
A
Namiki
Atsushi
A
Nakano
Hajime
H
Yamazaki
Junichi
J
D019797:3-Iodobenzylguanidine / Q000008:administration & dosage*; D000328:Adult; D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002395:Catecholamines / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D011859:Radiography; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D012890:Sleep; D012891:Sleep Apnea Syndromes / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000503:physiopathology*
D002395:Catecholamines; D019275:Radiopharmaceuticals; D020097:Natriuretic Peptide, Brain; D019797:3-Iodobenzylguanidine; D010100:Oxygen