Dobutamine gated blood pool scintigraphy predicts the improvement of cardiac sympathetic nerve activity, cardiac function, and symptoms after treatment in patients with dilated cardiomyopathy.
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.
Kasama
Shu
S
Second Department of Internal, Gunma University School of Medicine, Maebashi, Japan. s-kasama@bay.wind.ne.jp
Toyama
Takuji
T
Hoshizaki
Hiroshi
H
Oshima
Shigeru
S
Taniguchi
Koichi
K
Suzuki
Tadashi
T
Kurabayashi
Masahiko
M
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
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D004071:Digitalis Glycosides; D004232:Diuretics; D007457:Iodine Radioisotopes; D019797:3-Iodobenzylguanidine; D004280:Dobutamine; D008790:Metoprolol