Differentiation of Atrial and Pulmonary Vein Potentials Recorded Circumferentially Within Pulmonary Veins

INTRODUCTION: Accurate discrimination of atrial and pulmonary vein potentials recorded circumferentially within the pulmonary veins is important when performing segmental isolation of the pulmonary veins in patients with atrial fibrillation. METHODS AND RESULTS: Twenty patients with paroxysmal atrial fibrillation underwent pulmonary vein mapping with a decapolar Lasso catheter during sinus rhythm and during pacing in the distal coronary sinus and left atrial appendage. Bipolar and unipolar electrograms were recorded within the left superior, right superior, and left inferior pulmonary veins. The atrial potentials were larger in the left pulmonary veins than in the right superior pulmonary vein, whereas the pulmonary vein potentials in the superior pulmonary veins were larger than in the left inferior pulmonary vein. The atrial and pulmonary vein potentials usually were readily distinguished during sinus rhythm in the right superior pulmonary vein. Characteristic distribution and morphologies of the atrial potentials as well as the response to distal coronary sinus and left atrial appendage pacing were useful for differentiating the atrial and pulmonary vein potentials in the left pulmonary veins. CONCLUSION: Atrial and pulmonary vein potentials recorded circumferentially within the pulmonary veins have characteristic features that are useful in distinguishing them from each other. In the left pulmonary veins, discrimination of the atrial and pulmonary vein potentials is aided by coronary sinus or left atrial appendage pacing.