Comparison of myocardial blood flow during dobutamine-atropine infusion with that after dipyridamole administration in normal men.
OBJECTIVE
The present study was designed to compare the absolute myocardial blood flow (MBF) after intravenous dipyridamole infusion with that during dobutamine-atropine administration in normal healthy male volunteers.


BACKGROUND
Both safety and usefulness of dobutamine-atropine stress in myocardial perfusion imaging have been reported. However, no information exists on whether the magnitude ofhyperemia achieved with dipyridamole and dobutamine-atropine is comparable.


METHODS
Myocardial blood flow was measured with positron emission tomography and 15O-labeled water in 20 healthy young men (23 +/- 3 years) 1) at baseline, 2) after dipyridamole infusion (0.56 mg/kg over 4 min), and 3) during dobutamine (40 microg/kg/min) and atropine (0.25 to 1.0 mg) infusion.


RESULTS
The MBF was significantly increased during dipyridamole infusion and during dobutamine-atropine stress compared with at rest (4.33 +/- 1.23 and 5.89 +/- 1.58 vs. 0.67 +/- 0.16 ml/min/g, respectively, p < 0.0001). Moreover, dobutamine-atropine infusion produced greater MBF compared with dipyridamole (p = 0.0011), while coronary vascular resistance did not differ significantly after dipyridamole administration and during dobutamine-atropine infusion (17.6 +/- 7.9 vs. 18.6 +/- 5.6 mm Hg/[ml/min/g], respectively).


CONCLUSIONS
Near maximal coronary vasodilatation caused by dipyridamole is attainable using dobutamine and atropine in young healthy volunteers. Dobutamine in conjunction with atropine is no less effective than dipyridamole in producing myocardial hyperemia.
Tadamura
E
E
Department of Nuclear Medicine and Diagnostic Imaging, Kyoto University Graduate School of Medicine, Japan. et@kuhp.kyoto-u.ac.jp
Iida
H
H
Matsumoto
K
K
Mamede
M
M
Kubo
S
S
Toyoda
H
H
Shiozaki
T
T
Mukai
T
T
Magata
Y
Y
Konishi
J
J
D000328:Adult; D001285:Atropine; D003326:Coronary Circulation / Q000187:drug effects* / Q000502:physiology; D004176:Dipyridamole; D004280:Dobutamine; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D012016:Reference Values; D014055:Tomography, Emission-Computed
D004280:Dobutamine; D004176:Dipyridamole; D001285:Atropine