Reciprocal beats between sinus node and atrium were studied in isolated rabbit heart tissue by microelectrode techniques. Early premature atrial responses which entered the sinus node frequently emerged to re-excite the atrium as "echoes." When the premature atrial beats discharged some but not all nodal areas, the atrial echoes, in turn, appeared to re-enter the sinus node. Repetitive reciproc...

Strategies for redo ablation of persistent atrial fibrillation are debated. This has led to emergence additional beyond the pulmonary veins targeting dynamically mapped mechanisms. Spatiotemporal dispersion is such a technique using stable electrograms spanning more than 75% cycle length over multipolar catheter and shown benefit in recent trials. We set out study an international two centre se...