Superiorly directed atrial ectopy from the left inferior pulmonary vein

Abstract

P wave morphology is often useful in planning and prognosticating invasive electrophysiology testing with an aim at ablation. It is generally believed that atrial ectopy of a pulmonary vein site of origin will be inferiorly directed. We report the case of superiorly directed P waves originating from the left inferior pulmonary vein, likely the result of a prior pulmonary vein isolation procedure. As demonstrated by our case, standard algorithms to identify the site of origin of atrial ectopy should be used with caution in patients with prior ablative procedures.