Latent Ventricular Preexcitation in Atrioventricular Accessory Pathways

Abstract

This chapter describes latent ventricular preexcitation in non-decremental, anterogradely conducting atrioventricular accessory pathways characterized by non-preexcited sinus rhythm on the 12-lead electrocardiogram. In these patients, antidromic circus movement tachycardia and preexcited atrial fibrillation can be mistaken for monomorphic and polymorphic ventricular tachycardia, respectively. The vast majority of these pathways are located far in the left free-wall. The term “latent ventricular preexcitation” should be restricted to the absence of ventricular preexcitation in anterograde accessory pathways that may be unmasked by intravenous adenosine and atrial stimulation techniques. Occasionally, latent ventricular preexcitation may occur in association with short decremental anterograde accessory pathways. In contrast, in rare anterograde atrioventricular accessory pathways that have decremental conduction properties and non-preexcited sinus rhythm, neither latent preexcitation nor accessory pathway conduction per se can be disclosed with adenosine and atrial stimulation, and thus both remain latent.