The Positive F Wave in Lead V1 of Typical Atrial Flutter is Caused by Activation of the Right Atrial Appendage: Insight from Mapping During Entrainment from the Right Atrial Appendage

Abstract

AbstractBackgroundTypical atrial flutter (AFL) is a macroreentrant tachycardia in which intra-cardiac conduction rotates counterclockwise around the tricuspid annulus. Typical AFL has specific electrocardiographic characteristics of a negative sawtooth-like wave in the inferior lead and a positive F wave in lead V1.ObjectiveThis study analyzed the source of the positive F wave in lead V1, which has not been well elucidated.MethodsThis study included 10 patients who underwent radiofrequency catheter ablation for a typical AFL. Electroanatomical mapping was performed both during typical AFL and entrainment from the right atrial appendage (RAA). The 12-lead electrocardiogram and three-dimensional (3D) electroanatomical maps were analyzed.ResultsThe positive F wave in lead V1 changed during entrainment from the RAA in all the cases. The 3D map during entrainment from the RAA showed an area of antidromic capture around the RAA, which collided with the orthodromic wave in the anterior right atrium. This area of antidromic capture around the RAA was the only difference from the 3D electroanatomical map of tachycardia and is thought to be the cause of the disappearance of the F wave in lead V1 during entrainment.ConclusionThe analysis of the differences in the 12-lead ECG and 3D maps between tachycardia and entrainment from the RAA clearly showed that activation around the RAA is responsible for the generation of the positive F wave in lead V1 of typical AFL.