Adenosine induced ventricular arrhythmias in the emergency room

While adenosine effectively terminates most supra ventricular tachycardias (S VT), rare case reports have demonstrated its proarrhythmic potential, in cluding induction of ventricular tachycardia (VT). The aim of this study wa s to define the proarrhythmic effects of adenosine in a large, unselected p opulation. During a 5-year period, adenosine was used (average dose 9.7 mg) in the emergency room to manage 187 episodes of tachycardia in 127 patient s. In two thirds of the cases, adenosine induced ventricular ectopy followi ng successful termination of SVT, including premature ventricular complexes (PVC) and nonsustained VT. The adenosine induced PVCs and VT were transien t and self-terminating. More than half had a right bundle branch block morp hology with a superior axis that suggested an origin in the inferior left v entricular septum, In conclusion, although adenosine is commonly used in cl inical practice to treat SVTs, we found that if induced PVCs and VT in two thirds of the patients. The high incidence of ventricular arrhythmias follo wing adenosine infusion was surprising but did not require further interven tion. These arrhythmias appeared to frequently originate from th e inferior left ventricular septum, suggesting that this area may be particularly sus ceptible to the proarrhythmic effects of adenosine.