Comparison of coronary vasodilation with intravenous dipyridamole and adenosine

Abstract

Although both intravenous dipyridamole and adenosine have been used to produce coronary vasodilation during cardiac imaging, the relative potency of the commonly administered doses of these agents has not been evaluated. Accordingly, the coronary and systemic hemodynamic effects of intravenous adenosine (140 micrograms/kg per min) and intravenous dipyridamole (0.56 mg/kg over 4 min) were compared with a maximally dilating dose of intracoronary papaverine in 15 patients. Coronary blood flow responses were assessed using a Doppler catheter in a nonstenotic coronary artery. The protocol was discontinued in two patients because of transient asymptomatic atrioventricular (AV) block during adenosine infusion. The mean heart rate increased more with adenosine (11 +/- 9 beats/min) and dipyridamole (11 +/- 7 beats/min) than with papaverine (4 +/- 3 beats/min, p less than 0.05 vs. adenosine and papaverine). The mean arterial pressure decreased less with dipyridamole (-10 +/- 3 mm Hg) and papaverine (-9 +/- 4 mm Hg) than with adenosine (-16 +/- 5 mm Hg, p less than 0.01 vs. dipyridamole and papaverine). The peak/rest coronary blood flow velocity ratio was greater with papaverine (3.9 +/- 1.1) than with adenosine (3.4 +/- 1.2, p less than or equal to 0.05 vs. papaverine) or dipyridamole (3.1 +/- 1.2, p less than 0.01 vs. papaverine). A larger decrease in coronary resistance as measured by the coronary vascular resistance index occurred with papaverine (0.25 +/- 0.06) and adenosine (0.26 +/- 0.09) than with dipyridamole (0.31 +/- 0.10, p less than 0.01 vs. papaverine, p less than 0.05 vs. adenosine).(ABSTRACT TRUNCATED AT 250 WORDS)

The Adverse Events and Hemodynamic Effects of Adenosine-Based Cardiac MRI

“…Adenosine is a more potent coronary vasodilator than dipyridamole (5). Peripheral venous adenosine injection increases the coronary flow 3 to 4 times due to a drop in the coronary resistance, which results in an increase in the myocardial blood flow (13,14).…”

“…This now provides the basis for measuring the myocardial perfusion and coronary flow. Dipyridamole was first used as a vasodilator, but now adenosine is most commonly applied (5). Adenosine stimulates the A 2A receptor on the arterial vascular smooth muscle cells and this causes vasorelaxation.…”

Study of Coronary Sinus Flow Reserve Through Transesophageal Doppler Echocardiography in Normal Subjects

“…The effect of dipyridamole is slower and indirect, causing an increase in endogenous adenosine levels 18 . Recently, Kozà-kovà et al 19 observed a more prominent vasodilator response with continuous adenosine infusion, while the response to dipyridamole is dose-dependent, which may lead to an underestimation of the vasodilator response in patients with obstructive disease of the coronary sinus 14 . The present study proposes an evaluation of the coronary blood flow reserve by transesophageal Doppler echocardiography examining coronary sinus flow velocity in the basal state and after intravenous adenosine in continuous infusion.…”

“…As far as drugs used to evaluate coronary vasodilator capacity, adenosine and dipyridamole are Known to be effective for intravenous application. Adenosine induces quick and massive vasodilatation mainly mediated by A1 and A2 purinergic receptors, previously called P1 purinergic receptor subtype 12,13 , and may provoke depression of the sinoatrial and atrioventricular nodes, being dose-dependent, and diminution of arterial blood pressure 14,15 . Dipyridamole and adenosine have been used to evaluate CFR; both drugs produce comparable increases in the total and 1 0 3 regional coronary flow.…”

Coronary Flow: From Pathophysiology to Clinical Noninvasive Evaluation

“…Even side effects are the same, but really brief, in these cases and no aminophylline www.intechopen.com is usually required. In normal patients adenosine administration raises up to 4-5 times the coronary flow, just like high-dose dipyridamole 23 , however always much more than after dobutamine or after stress exercise. Dipyridamole can be manually injected using a syringe, but for adenosine an infusion pump is necessary and the starting dose is 100 µg/Kg/min, slowing raising up to 200 µg/Kg/min.…”