Thallium-201 myocardial imaging in patients with coronary artery disease: comparison of intravenous adenosine and oral dipyridamole.
OBJECTIVE
To compare thallium-201 (201Tl) myocardial perfusion imaging following intravenous adenosine and oral dipyridamole.


METHODS
Open-label, randomized, comparison.


METHODS
Outpatient, university-affiliated clinic.


METHODS
Fifteen patients with angiographically documented coronary artery disease.


METHODS
Planar 201Tl myocardial perfusion imaging following both intravenous adenosine 140 micrograms/kg/min for six minutes and oral dipyridamole suspension 300 mg.


METHODS
A comparison between adenosine and dipyridamole was made in the following areas: concordance in interpretation of 201Tl scintigrams, cardiac and noncardiac 201Tl uptake and clearance, hemodynamic and electrocardiographic changes, and adverse effects.


RESULTS
The scintigraphic studies showed perfusion defects in 13 patients (87 percent) after dipyridamole and in 15 patients (100 percent) after adenosine. 201Tl uptake and clearance were quantitated in nine myocardial segments and in four extracardiac segments in each patient. 201Tl uptake was not significantly different between adenosine and dipyridamole studies in most cardiac regions. Extracardiac 201Tl uptake was significantly less in the liver and splanchnic regions following adenosine compared with dipyridamole. 201Tl clearance was not significantly different following adenosine and dipyridamole except in the anterolateral region in the anterior view. Hemodynamic changes following administration of intravenous adenosine and oral dipyridamole were not significantly different. Adverse effects were more common with adenosine than with dipyridamole. Adverse effects with adenosine were transient; however, adverse effects with dipyridamole were prolonged and required reversal with aminophylline in 2 patients. No patients required termination of the adenosine infusion or administration of aminophylline.


CONCLUSIONS
These preliminary data suggest that adenosine 201Tl imaging may be a useful alternative to dipyridamole 201Tl imaging. Although adenosine produces more frequent adverse effects, they are generally better tolerated than those associated with dipyridamole.
Mohiuddin
S M
SM
Department of Medicine, Creighton University School of Medicine, Omaha, NE.
Gupta
N C
NC
Esterbrooks
D J
DJ
Siffring
P A
PA
Frick
M P
MP
Hilleman
D E
DE
Sketch
M H
MH
D000241:Adenosine / Q000008:administration & dosage / Q000009:adverse effects; D000284:Administration, Oral; D000368:Aged; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004176:Dipyridamole / Q000008:administration & dosage / Q000009:adverse effects; D006439:Hemodynamics; D006801:Humans; D007262:Infusions, Intravenous; D008875:Middle Aged; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes
D013794:Thallium Radioisotopes; D004176:Dipyridamole; D000241:Adenosine