title: Evaluation of sympathetic activity by 123I-metaiodobenzylguanidine myocardial scintigraphy in dilated cardiomyopathy patients with sleep breathing disorder.
abstract: 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.
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Ohmori Hospital, Toho University School of Medicine, Tokyo, Japan. maru@pd5.so-net.ne.jp
authors.forename: Shuji
authors.initials: S
authors.lastname: Nanjo
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yamashiro
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Fujimoto
authors.forename: Shohei
authors.initials: S
authors.lastname: Yamashina
authors.forename: Rine
authors.initials: R
authors.lastname: Nakanishi
authors.forename: Shunji
authors.initials: S
authors.lastname: Fukunaga
authors.forename: Aritomo
authors.initials: A
authors.lastname: Inoue
authors.forename: Atsushi
authors.initials: A
authors.lastname: Namiki
authors.forename: Hajime
authors.initials: H
authors.lastname: Nakano
authors.forename: Junichi
authors.initials: J
authors.lastname: Yamazaki
mesh_terms: 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*
chemical_list: D002395:Catecholamines; D019275:Radiopharmaceuticals; D020097:Natriuretic Peptide, Brain; D019797:3-Iodobenzylguanidine; D010100:Oxygen