Adenosine has become widely used because of its diagnostic and therapeutic value in the emergency management of arrhythimias. it produces transient heart block by slowing conduction through tile AV node and thus terminates supraventricular tachycardias that involve the atrioventricular node. Bradyarrhythmias of short duration are common side effects of the use of this drug. Premature atrial and ventricular beats have also been reported. The very short half-life and lack of serious adverse effects generally lead to the consideration that adenosine is a safe drug. We describe a 56-year-old woman with a supra ventricular tachycardia. To terminate this rhythm disorder intravenous adenosine was given. Interruption of tile supra ventricular tachycardia was followed by non-sustained polymorphic ventricular tachycardi
