ECG-based prediction of atrial fibrillation development following coronary artery bypass grafting

Abstract

In patients undergoing coronary artery bypass grafting (CABG) surgery, postoperative atrial fibrillation (AF) occurs with a prevalence of up to 40%. The highest incidence is seen between the second and third day after the operation. Following cardiac surgery AF may cause various complications such as hemodynamic instability, heart attack and cerebral or other thromboembolisms. AF increases morbidity, duration and expense of medical treatments. This study aims at identifying patients at high risk of post-operative AF. Early prediction of AF would provide timely prophylactic treatment and would reduce the incidence of arrhythmia. Patients at low risk of post-operative AF could be excluded on the basis of the contraindications of anti-arrhythmic drugs. The study included 50 patients in whom lead II electrocardiograms were continuously recorded for 48 h following CABG. Univariate statistical analysis was used in the search for signal features that could predict AF. The most promising ones identified were P wave duration, RR interval duration and PQ segment level. On the basis of these, a nonlinear multivariate prediction model was made by deploying a classification tree. The prediction accuracy was found to increase over time. At 48 h following CABG, the measured best smoothed sensitivity was 84.8% and the specificity 85.4%. The positive and negative predictive values were 72.7% and 92.8%, respectively, and the overall accuracy was 85.3%. With regard to the prediction accuracy, the risk assessment 4 Author to whom any correspondence should be addressed. and prediction of post-operative AF is optimal in the period between 24 and 48 h following CABG.

Simplified 2D Bidomain Model of Whole Heart Electrical Activity and ECG Generation

“…In an earlier study [21,22], we claimed that changes in the PQ segment level (defined as elevation / depression of the segment level between P wave end and Q wave onset) and the falling P wave slope are related to premature atrial repolarization, APD shortening and loss of AP plateau, and this is often found in patients prone to atrial fibrillation [21,22]. These hypotheses were tested again with the 2D cardiac model of this study and the results (Fig.8.…”

3D Cardiac Electrical Activity Model

“…We believe the model has multilateral application potentials in education, research and in the clinical practice since it can be used as a simulator for various arrhythmias, including atrial / ventricular fibrillation, as well as able to simulate the effects of changes in tissue conductivity, action potential duration or shape on ECG morphology, with the aim of developing new ECG diagnostic algorithms, methods and tools that are predictive, preventive, personalized like in [12][13][14].…”

ECG based prediction of Atrial Fibrillation using Support Vector Classifier

“…In the earliest studies, ECG recordings over episodes lasted just a few minutes, while generally not specifying the time of ECG acquisition with reference to the termination of CABG procedure [1,9]. In our approach highresolution ECG monitoring was performed over an extended episode (up to 48 h) in the search for potential trends in the quality of prediction.…”

“…2. These points were used for the subsequent measurement of different P wave features and their trends [9,12].…”

“…Meanwhile, other earlier studies based on standard ECG (lead II or V1) or signal averaged ECG (SAECG) have shown that it is possible to predict postoperative AF with some degree of accuracy [9]. All studies based on ECG were focused only on the P wave measuring, e.g.…”