title: Dobutamine gated blood pool scintigraphy predicts the improvement of cardiac sympathetic nerve activity, cardiac function, and symptoms after treatment in patients with dilated cardiomyopathy.
abstract: BACKGROUND
  We evaluated whether dobutamine gated blood pool scintigraphy (DOB-GBP) can predict improvement in cardiac sympathetic nerve activity and cardiac function after beta-blocker therapy in patients with dilated cardiomyopathy (DCM).
  
  
  RESULTS
  Twenty-two patients with DCM underwent DOB-GBP to measure left ventricular ejection fraction (LVEF) at rest, and during 5, 10, and 15 microg/kg/min of dobutamine infusion before therapy. Examinations were performed before and after 1 year of therapy. The heart/mediastinum count (H/M) ratio and total defect score (TDS) were determined for 123I-meta-iodobenzylguanidine images from anterior planar image and single-photon emission CT images. LVEF and left ventricular end-diastolic dimension (LVDd) were determined by echocardiography. After 1 year of treatment, the echocardiographic LVEF improved > 5% in 11 patients (group A), but did not improve in the remaining 11 patients (group B). Before treatment, TDS, H/M, LVEF, and LVDd were similar in both groups. However, there was a greater increase in the LVEF during dobutamine infusion in group A than in group B (21 +/- 8% vs 9 +/- 3%, p < 0.001). If a critical value of 15% for the DeltaLVEF was used to predict the improvement in LVEF after treatment, the sensitivity was 91% and specificity was 82%. The TDS, H/M ratio, LVDd, and New York Heart Association functional class improved in group A to a greater extent than in group B.
  
  
  CONCLUSIONS
  DOB-GBP can be used to predict improved cardiac sympathetic nerve activity, cardiac function, and symptoms after treatment in patients with DCM.
authors.affiliation: Second Department of Internal, Gunma University School of Medicine, Maebashi, Japan. s-kasama@bay.wind.ne.jp
authors.forename: Shu
authors.initials: S
authors.lastname: Kasama
authors.forename: Takuji
authors.initials: T
authors.lastname: Toyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hoshizaki
authors.forename: Shigeru
authors.initials: S
authors.lastname: Oshima
authors.forename: Koichi
authors.initials: K
authors.lastname: Taniguchi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kurabayashi
mesh_terms: D019797:3-Iodobenzylguanidine; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000503:physiopathology; D016022:Case-Control Studies; D004071:Digitalis Glycosides / Q000627:therapeutic use; D004232:Diuretics / Q000627:therapeutic use; D004280:Dobutamine; D004452:Echocardiography; D005260:Female; D015637:Gated Blood-Pool Imaging; D006321:Heart / Q000000981:diagnostic imaging / Q000294:innervation*; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use*; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D004071:Digitalis Glycosides; D004232:Diuretics; D007457:Iodine Radioisotopes; D019797:3-Iodobenzylguanidine; D004280:Dobutamine; D008790:Metoprolol