In Chapter 13, Premature Atrial Contraction, we saw some strips that showed multiple or frequent PACs. The underlying theme to these strips was that there was an underlying rhythm (either normal sinus rhythm, sinus bradycardia, or sinus tachycardia) as the baseline and PACs were occasional “events” that broke up the underlying regularity.
In this chapter, we review the first of two irregularly irregular rhythms that are composed entirely of randomly occurring ectopic atrial complexes: wandering atrial pacemaker (WAP) and multifocal atrial tachycardia (MAT).
Before we start talking about WAP in depth, we should clarify a nomenclature issue. There is some confusion between how WAP is classically defined and what occurs in true clinical practice. We will be discussing these two “variations on a theme” separately because it is easier to understand each on its own merits. Just be aware that the same term, WAP is used to describe both types of electrocardiographic presentations.