Concealed conduction in atrial tachyarrhythmia illustrated in a heartbeat

Abstract

Concealed conduction is not seen directly on the surface electrocardiogram but is evident from its effect on subsequent impulses; it includes concealed incomplete penetration of the atrioventricular (AV) junction during atrial fibrillation (AF) and contributes mechanistically to so-called “slow AF.”1 Manifestations of concealed conduction are numerous. We present a case that demonstrates a common consequence: unexpected failure of propagation of an impulse from atrium to ventricle.2