Asystole dipyridamole

No adverse reactions normally occur in patients taking beta blockers who undergo dipyridamole-thallium-201 scintigraphy and echocardiography, but case reports suggest that very rarely bradycardia and asystole can occur. 

Adverse interactions occurred in another 2 patients taking beta blockers during diagnostic dipyridamole-thallium stress testing. One patient, who was taking atenolol, developed bradycardia then asystole, which was treated with aminophylline and atropine, and the other patient, who was taking metoprolol, developed bradycardia, which resolved after she was given aminophylline. ... 

These reports need to be set in a broad context. A very extensive study of high-dose dipyridamole echocardiography (10451 tests in 9 122 patients) noted significant adverse effects in only 96 patients, with major adverse reactions occurring in just 7 patients. Three of the 7 developed asystole and two of these patients were taking unnamed beta blockers. ... 

The value and safety of dipyridamole perfusion scintigraphy and echocardiography have been very extensively studied in very large numbers of patients, and reports of bradycardia and asystole, attributed to an interaction between dipyridamole and beta blockers, are sparse. It would therefore appear to be a relatively rare interaction (if such it is). 

Roach PJ, Magee MA, Freedman SB. Asystole and bracfycardia durii dipyridamole stress testing in patients receiving beta blockers. IntJ Cardiol (1993) 42,92-4. 

Cardiovascular Asystole has been reported during the administration of dipyridamole [140 ]. 

Veeranna V, Potluri K, Mahmood S, Macdonald L. Asystole during dipyridamole administration. Indian J Med Sd 2009 63(8) 363. ... 

Frossard M, Weiss K, Zeiner A, Leitha T. Asystole during dipyridamole infusion in patients without coronary artery disease or beta-blocker therapy. Clin Nucl Med 1997 22(2) 97-100. 

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