Intravenous adenosine therapy accelerating rate of paroxysmal supraventricular tachycardia

Two cases of paroxysmal supraventricular tachycardia are reported in which the administration of adenosine produced sustained elevation of the rate of paroxysmal supraventricular tachycardia. In each case, sinus rhythm was restored readily through the use of intravenous verapamil. This adverse reaction to adenosine has not been previously described.