Mechanisms Underlying Atrioventricular Nodal Conduction and the Reentrant Circuit of Atrioventricular Nodal Reentrant Tachycardia Using Optical Mapping

The findings of multiple nondiscrete AV nodal pathways and asymmetric transitional zone provide a biophysical basis for understanding normal and abnormal AV node electrophysiology. Unidirectional block occurring at the transitional zone transforms the nondiscrete pathways model into a classic dual pathways physiology for AVNRT.