Concealed antegrade penetration of the atrio-ventricular node

Abstract

We present a patient with paroxysmal, non-sustained atrial tachycardia (AT) on routine surveillance 24-hour Holter post pulmonary vein isolation (PVI). Several asymptomatic ventricular pauses are noted to follow each burst of AT. We postulate that these pauses are due to the resultant concealed penetration of the atrio-ventricular node (AVN) in combination with sino-atrial node overdrive suppression. Recognition of this physiological phenomenon may help avoid unnecessary intervention arising from Holter recording misinterpretation.