Diagnosing pseudo-conduction block across an anteromedial mitral ablation line: Limitations of bidirectional and differential pacing

Macroreentrant or scar-related reentrant atrial tachycardias, including perimitral atrial flutter, are often seen in patients with a history of atrial fibrillation ablation.1 Multiple strategies for ablating this arrhythmia have been proposed, but traditionally the lateral mitral isthmus line (mitral annulus to the left inferior pulmonary vein) has been the preferred approach. Achieving a line of block across the isthmus can prove difficult...