Paroxysmal Cycle Length Shortening in the Pulmonary Veins During Atrial Fibrillation Correlates with Arrhythmogenic Triggering Foci in Sinus Rhythm

INTRODUCTION: The focal origin of atrial fibrillation (AF) is identified by recording atrial ectopic beats or the ectopic activity that precedes AF. We hypothesized that arrhythmogenic pulmonary veins (PVs) also could be identified during persistent AF. METHODS AND RESULTS: Patients with persistent AF referred for focal ablation were enrolled prospectively. During AF, bipolar electrograms were recorded from each PV for a minimum of 120 seconds, as well as from the right atrium and coronary sinus. The cycle length of activity in each PV was measured during AF and plotted on a frequency histogram. Following cardioversion to sinus rhythm, arrhythmogenic PVs were identified from reinitiation of AF or from ectopic beats. Ten patients were enrolled and 37 PVs analyzed. During AF, 17 PVs demonstrated bimodal cycle length frequency histograms, with periods of paroxysmal short cycle length recording. Following cardioversion, 14 PVs were identified as arrhythmogenic as defined earlier. Each of these arrhythmogenic PVs showed paroxysmal short cycle length recording during AF. Sensitivity was 87%, specificity 91%, positive predictive value 87%, and negative predictive value 100%. CONCLUSION: The arrhythmogenic PVs responsible for the focal activity that triggers AF also demonstrate paroxysmal short cycle length recording during sustained AF. These results demonstrate that arrhythmogenic PVs still can be identified reliably, even during sustained AF.