Fibrillatory waves automatic delineation in atrial fibrillation surface recordings based on mathematical morphology

The estimation of atrial activation times in atrial fibrillation (AF) has become an established way to evaluate AF through several indices like organization of the arrhythmia, atrial cycle length, etc. Classic fibrillatory (f) waves delineation uses atrial electrograms because larger f waves are present in these recordings. This work introduces a new f waves delineator based on mathematical morphology (MM) able to operate on surface AF recordings. The method used lead V1 from the standard ECG. Next, ventricular activity was cancelled out and the remaining atrial activity (AA) was delineated through MM. To validate results, all the f waves were manually delineated and location error between manual and automatic annotations was computed. The average location error was lower than 7 ms and the average detection accuracy was above 98%. As conclusion, MM-based f-waves automatic delineation is able to provide reliable atrial activation times, thus allowing to quantify in a new way the AA signal pattern from surface AF recordings.