Reversibility by dipyridamole of thallium-201 myocardial scan defects in patients with sarcoidosis.
OBJECTIVE
In order to clarify the significance of anginal pain and myocardial thallium-201 scan defects in cardiac sarcoidosis, the pharmacologic effect of dipyridamole on myocardial perfusion was assessed by planar thallium-201 myocardial scintigraphy in patients with sarcoidosis.


METHODS
Thallium-201 myocardial scintigraphy was performed at rest and after 0.56 mg/kg intravenous dipyridamole during four minutes in 16 patients with sarcoidosis. The myocardial scan (45-degree and 70-degree left anterior oblique, and anterior views) was divided into 15 segments. Results were evaluated by the number of segmental defects and with a global perfusion score (from 0 to 60) by a semi-quantitative index depending on the size and severity of myocardial thallium-201 defects.


RESULTS
Thirteen of the 16 patients showed partial or total reversion of their thallium-201 defects on redistribution scanning either at rest or after dipyridamole. The mean (+/- SD) number of myocardial perfusion defects that were present in all the patients decreased from 5.31 +/- 1.78 at rest to 3.25 +/- 2.52 after redistribution (p less than 0.001) and to 2.19 +/- 2.10 after dipyridamole (p less than 0.001). The mean global perfusion score increased from 53.2 +/- 3.0 at rest to 56.2 +/- 2.9 after redistribution (p less than 0.001) and to 57.2 +/- 2.7 after dipyridamole (p less than 0.001). A significant correlation (r = 0.82, p less than 0.001) was found between the increase of global perfusion score on redistribution and after dipyridamole.


CONCLUSIONS
The reversibility of myocardial scan defects is a common finding in sarcoidosis. It makes unlikely the role of scar fibrosis or extensive confluent granulomas as a mechanism for such defects. The effect of dipyridamole suggests the presence of reversible disorders lying at the coronary microvascular level.
Tellier
P
P
Service of Nuclear Medicine, Chu Xavier Bichat, Paris, France.
Paycha
F
F
Antony
I
I
Nitenberg
A
A
Valeyre
D
D
Foult
J M
JM
Battesti
J P
JP
D000328:Adult; D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003326:Coronary Circulation / Q000187:drug effects*; D004176:Dipyridamole / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D012507:Sarcoidosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013794:Thallium Radioisotopes
D013794:Thallium Radioisotopes; D004176:Dipyridamole