Effect of beta-blocker therapy on myocardial perfusion defects in thallium-201 scintigraphy in patients with dilated cardiomyopathy.
BACKGROUND
The beneficial effects of beta-blocker therapy in patients with heart failure have been confirmed. However, the effects of beta-blockers on myocardial perfusion defects are unclear. The aim of this study was to evaluate the effect of beta-blockers on myocardial perfusion defects estimated by thallium-201 myocardial scintigraphy in patients with dilated cardiomyopathy (DCM) and to investigate the relationships between beta-blocker treatment and myocardial damage and cardiac function.


METHODS
201Tl and echocardiography were performed in 37 patients before and after 6 months of beta-blocker therapy. Extent score (ES) by 201Tl was used to quantitate myocardial perfusion defects before and after treatment.


RESULTS
ES was significantly decreased by beta-blocker therapy. According to the change in ES, DCM patients were classified into three groups, patients who improved, patients showing no change and patients who deteriorated. In the improvement and no-change groups, beta-blocker therapy induced a reduction in left ventricular dimensions and an associated increase in ejection fraction. However, in the deterioration group, left ventricular dimensions and ejection fraction were unchanged. There was a significant relationship between the change in left ventricular dimension at end-diastole and the change in ES.


CONCLUSIONS
beta-Blocker therapy could attenuate myocardial perfusion defects in some patients with DCM. The improvement in left ventricular function associated with beta-blocker therapy may be related to the attenuation in myocardial perfusion defects.
Hara
Yuji
Y
Department of Internal Medicine, Ehime University School of Medicine, Toon City, Japan. yujihara@m.ehime-u.ac.jp
Inoue
Katsuji
K
Ogimoto
Akiyoshi
A
Ohtsuka
Tomoaki
T
Shigematsu
Yuji
Y
Nakata
Shigeru
S
Higaki
Jitsuo
J
D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D002227:Carbazoles / Q000627:therapeutic use; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D000077261:Carvedilol; D003326:Coronary Circulation; D004452:Echocardiography; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use; D008875:Middle Aged; D045265:Natriuretic Peptides / Q000097:blood; D011412:Propanolamines / Q000627:therapeutic use; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D016277:Ventricular Function, Left
D000319:Adrenergic beta-Antagonists; D002227:Carbazoles; D045265:Natriuretic Peptides; D011412:Propanolamines; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D000077261:Carvedilol; C021148:bevantolol; D008790:Metoprolol