[Prediction of cardiac sympathetic nerve activity and cardiac functional outcome after treatment in patients with dilated cardiomyopathy: examination using dobutamine gated blood pool scintigraphy].
OBJECTIVE
This study evaluated whether dobutamine gated blood pool scintigraphy can predict improvement of cardiac sympathetic nerve activity and cardiac function.


METHODS
Sixteen patients(10 men and 6 women, mean age 59 +/- 13 years) with dilated cardiomyopathy underwent dobutamine gated blood pool scintigraphy to measure left ventricular ejection fraction (LVEF) using tracer at 0, 5, 10 and 15 micrograms/kg/min before treatment. Patients were divided into good responders (LVEF increase > or = 15%) 8 patients(GR Group) and poor responders(LVEF increase < 15%) 8 patients (PR Group) after treatment with beta-blocker or amiodarone with a background treatment of digitalis, diuretics and angiotensin converting enzyme inhibitor. I-123 metaiodobenzylguanidine(MIBG) imaging to evaluate cardiac sympathetic nerve activity and echocardiography were performed before and at one year after treatment. MIBG imaging was obtained 4 hours after tracer injection, and the heart/mediastinum count ratio(H/M ratio) calculated from the anterior planar image and the total defect score(TDS) from the single photon emission computed tomography image. LVEF and left ventricular endo-diastolic dimension (LVDd) were measured by echocardiography and New York Heart Association(NYHA) functional class was evaluated.


RESULTS
The GR Group showed TDS decreased from 28 +/- 6 to 17 +/- 12(p < 0.05), H/M ratio increased from 1.79 +/- 0.26 to 2.07 +/- 0.32(p < 0.05), LVEF increased from 29 +/- 8% to 48 +/- 10%(p < 0.01), and LVDd decreased from 65 +/- 4 mm to 58 +/- 5 mm(p < 0.05). In contrast, the PR Group showed no significant changes in TDS, H/M ratio, LVEF and LVDd. NYHA functional class improved in both groups. The improvement was better in the GR Group than in the PR Group.


CONCLUSIONS
Dobutamine gated blood pool scintigraphy is useful to predict the improvement of the cardiac sympathetic nerve activity and cardiac function, and symptoms after treatment in patients with dilated cardiomyopathy.
Second Department of Internal Medicine, Gunma University School of Medicine.
S
S
Kasama
T
T
Toyama
H
H
Hoshizaki
S
S
Oshima
K
K
Taniguchi
T
T
Iwasaki
T
T
Suzuki
R
R
Nagai
D019797:3-Iodobenzylguanidine; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000638:Amiodarone / Q000627:therapeutic use; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology*; D002316:Cardiotonic Agents / Q000627:therapeutic use; D004071:Digitalis Glycosides / Q000627:therapeutic use; D004232:Diuretics / Q000627:therapeutic use; D004280:Dobutamine; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume / Q000502:physiology; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D015899:Tomography, Emission-Computed, Single-Photon; D014665:Vasodilator Agents / Q000627:therapeutic use; D016277:Ventricular Function, Left / Q000502:physiology*
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D002316:Cardiotonic Agents; D004071:Digitalis Glycosides; D004232:Diuretics; D014665:Vasodilator Agents; D019797:3-Iodobenzylguanidine; D004280:Dobutamine; D000638:Amiodarone