Interference dissociation in the presence of dual atrioventricular nodal physiology

Introduction Dual atrioventricular nodal physiology (DAVNP) is present in 10% to 35% of the general population and is known to regress with aging. It usually manifests as a critical AH jump on electrophysiologic testing or on surface electrocardiography as a change in PR interval with subsequent tachycardia. Preferential choice of pathway engagement (slow vs fast) is dependent upon refractory periods of the pathways and conduction velocity. We present a rare manifestation of DAVNP on surface electrocardiography with alternating engagement and disengagement of the 2 pathways masquerading as AV dissociation.