An unusual mechanism of accelerated rhythms in inferior stemi

Dual AV nodal pathway physiology has since long been recognized, both experimentally [5] and clinically [6] as a mechanism of AV nodal reentry tachycardias; the reentry mechanism requires two discrete anatomical or physiological pathways; one pathway has fast conduction and dominates conduction during sinus rhythm. The second one has slow conduction, and can become apparent for instance when an atrial premature causes unidirectional block in the fast pathway; this results in conduction to the ventricles with a long PR interval. When the conduction is sufficiently slow, it may exceed the refractory period in the fast pathway, allowing the impulse to retrogradely enter the fast pathway. Subsequently atrial activation may occur followed by antegrade conduction over the stow pathway, in this way establishing a complete reentry circuit which may perpetuate, resulting in an AV nodal reentry tachycardia. Depending on the specific characteristics of the pathways AV nodal tachycardias may be due to slow antegrade, fast retrograde conduction (slow/fast), the most frequent form, fast/slow and slow/ slow conduction respectively.