Role of fibrillatory waves amplitude as predictors of immediate arrhythmia termination after Maze surgery of atrial fibrillation

Cox-Maze surgery is an effective procedure to terminate atrial fibrillation (AF) in patients requiring open-heart surgery associated to another heart disease. After the intervention, AF spontaneous reversion occurs immediately in some patients, but not in others. This work analyzes 23 twelve-lead preoperative ECGs from patients in AF to predict immediate termination of the arrythmia. To carry out the prediction, three indices have been studied: the dominant atrial frequency (DAF), the sample entropy (SampEn) and the fibrillatory waves average power (fWP). Results for the DAF yielded a Sensitivity (Se), Specificity (Sp) and Accuracy (Acc) of 78%, 71% and 74%, respectively. For SampEn 78%, 79% and 78%, respectively and for fWP were 89%, 71% and 78%, respectively. Finally, to improve the prognosis capability a classification tree combining the analyzed parameters was created yielding Se, Sp and Acc of 89%, 93% and 91%, respectively. As conclusion, the combination of fWP with DAF and SampEn has provided very auspicious results to predict whether AF would terminate immediately after the Cox-Maze surgery.