Cardiovascular ImagingDipyridamole
drug that blocks the reabsorption and breakdown of adenosine. The resultant increase of endogenous adenosine causes vasodilatation. In the absence of coronary
artery disease, this drug augments coronary blood flow by three-to-five fold. The drug causes relative hypoperfusion of
myocardial regions served by coronary arteries with haemodynamically significant stenoses. Dipyridamole is used to induce heterogeneity of
perfusion during
nuclear perfusion imaging. It has also been used to provoke
perfusion defects during first-pass contrast-enhanced
MRI and contrast
echocardiography. The effects of dipyridamole can be rapidly reversed with
intravenous aminophylline.
CBH