Dexmedetomidine challenge to uncover an intermittent accessory pathway

Ventricular pre-excitation is characterized by the presence of a delta wave, a short PR interval and an increased duration of QRS on the electrocardiogram (EKG); the prevalence of this EKG pattern has been estimated at one to three individuals per 1,000 persons1. However, the true prevalence is likely under-represented because at least half of known pre-excitation patients do not develop symptoms or the conductance through the accessory pathway (AP) could be intermittent. In selected cases, such as high-risk occupations as professional drivers, athletes1, or according to informed patient choice2, the ablation of a "low risk" or intermittent AP could be considered.