New Catheter Techniques for Recording Accessory AV Pathway Activation

Few aspects of clinical electrophysiology are more intriguing than the variability in conduction properties of accessory AV pathways [1–6] and their unusual responses to antiarrhythmic agents [7–16]. Although potential mechanisms have been proposed [17], one of the greatest limitations to testing these hypotheses has been the inability to determine the location of conduction delay and block — that is, whether block occurs within the body of the accessory pathway or at the atrial or ventricular interface. Recently developed catheter techniques for recording accessory pathway activation [18–20] have provided useful tools for determining characteristics of impulse propagation across accessory pathways [19,21–23]. This chapter describes these new recording techniques and discuss some of their limitations.