Functional Data Analysis for ECG Recordings of Paroxysmal Atrial Fibrillation Patients Before and After Pulmonary Vein Isolation

Pulmonary vein isolation is the cornestone of current ablation techniques for patients with paroxysmal atrial fibrillation in order avoid recurrences of the arrhythmia and maintain sinus rhythm. This study aimed to analyse the existence of significant variations in surface ECG after pulmonary vein isolation by means of functional data analysis. 12 consecutive unselected patients suffering from paroxysmal atrial fibrillation who underwent catheter ablation were included in the study. Each patient was monitored in sinus rhythm before and after catheter ablation. P-waves of bipolar lead II were delineated. Functional data were fitted from these segments and the first and second derivatives evaluated using them. Maximum first and second derivatives of the curves corresponding to P-waves resulted to decrease significantly when pulmonary veins were isolated (from 16.59±5.11 and 0.66±0.28 to 13.41±4.71 and 0.52±0.31, respectively). The use of these features could potentially help to identify the disconnection of pulmonary veins in a non invasive way.