Conduction Gap of Left Atrial Anterior Wall Linear Ablation Undetected by Left Atrial Appendage Pacing but Revealed by Left Lateral Ridge Pacing.

Confirmation of counterclockwise conduction block across the left atrial anterior wall linear lesion is usually performed during left atrial appendage pacing. However, even when endocardial conduction block across the left atrial anterior wall linear lesion is suggested during left atrial appendage pacing, an epicardial connection between the left lateral ridge and the left atrial anterior wall can be a cause of residual conduction gap. In such a situation, assessment during pacing with the left lateral ridge capture should be considered.