EFFECTS OF ADENOSINE ON THE HEART - THERA PEUTIC AND DIAGNOSTIC POSSIBILITIES

Adenosine is a substance with many different actions on the heart. The most important effects is its action on the conduction system, causin g a marked prolongation of atrioventricular conduction time and atriov entricular refractoriness. Since the half life of adenosine is only a few seconds it is a very safe antiarrhythmic drug for the treatment of supraventricular tachyarrhythmias caused by a reentry mechanism via t he atrioventricular node. Adenosine is also a potent coronary vasodila tor. This effect enables adenosine to be used diagnostically for stres s echocardiography and as a pharmacological stress test for thallium-2 01 single-photon emission computed tomography myocardial perfusion ima ging. Adenosine also protects myocardial cells under conditions of rai sed oxygen requirement of the heart or during ischemia. In addition to assessing the importance of the effect, the underlying mechanism requ ires further investigation. The manifold actions of adenosine on the h eart have led to growing scientific interest in this substance, especi ally in the field of antiarrhythmic therapy, where adenosine represent s a new generation of drugs.