Prediction Of Postoperative Atrial Fibrillation Research Articles

Prediction of postoperative atrial fibrillation with left atrial mechanical functions and NT‐pro ANP levels after coronary artery bypass surgery: A three‐dimensional echocardiography study

Postoperative AF (POAF) is the most common cause of morbidity after coronary artery bypass surgery. In this study, we aimed to show the relationship between POAF and N-terminal pro-atrial natriuretic peptide (NT-pro ANP) levels and the relationship between mechanical functions and left atrial volume measured using preoperative three-dimensional echocardiography (3D ECHO) among patients that will undergo isolated coronary artery bypass grafting (CABG) in elective conditions. Sixty-six consecutive patients (51 male, 15 female) who were decided to undergo CABG and had normal sinus rhythm were involved in the study. Patients were followed by continuous electrocardiography monitoring and daily electrocardiogram. LA volume and mechanical functions were calculated with 3D ECHO. In addition, for the analysis of plasma levels of NT-pro ANP, blood samples were collected before the surgery. During follow-up after the operation, 15 patients (22.7%) had postoperative atrial fibrillation. LA Vmax, Vmin, VpreA values were higher (P<.001, P=.004, P<.001 respectively) Also in POAF-developed group and SR group, LAVI values were 27.56±4.2 and 20.7±4.64mL/m2 , respectively (P<.001). In POAF-developing group, NT-pro ANP levels were significantly higher (P<.001). In multiple logistic regression analysis, age (β=0.355, P=.007) and LAVI (β=0.668, P=.012) are independent predictors of POAF. It was found that 3D echocardiography can be used as a helping noninvasive method to show subclinical atrial volume and mechanical dysfunction in patients undergoing CABG. Also, blood levels of NT-pro ANP in POAF group were increased.

Postoperative atrial fibrillation prediction following isolated surgical aortic valve replacement.

ObjectivePostoperative atrial fibrillation (POAF) is the most common complication following cardiac surgery, with increased risk of stroke and high mortality. Our aim was to identify patients at risk and to design a model that could predict POAF.MethodsIn this single center study, we evaluated 1191 patients requiring isolated surgical aortic valve replacement between January 2000 and June 2014. The patients were followed during the early postoperative period until discharge.ResultsAF occurred in 342 patients (28.71%). Six variables associated with high arrhythmic risk [advanced age, body mass index, tricuspid regurgitation, prolonged ventilation, longer intensive care unit stay, and dilated left atrium (LA; volume ≥35 ml/m2)] were selected to create a multivariate prediction model. This model predicted POAF in 64.7% of cases, with a moderate discriminative power (AUC=0.65; p=0.001; 95% CI, 0.571-0.771). We also developed the CHAID (Chi-square automatic interaction detection) model showing multilevel interactions among risk factors for POAF. Age had the greatest discriminative power, with patients aged >68 years at a higher risk for POAF. In low-risk patients, the subgroup with dilated LA (volume ≥40 ml) was more prone to develop POAF. For the intermediate-risk group, history of AF was the next deciding variable, whereas for the high-risk group, it was tricuspid regurgitation (at least moderate).ConclusionThe multivariate logistic model has an acceptable predictive value. CHAID-derived model is a new tool that could be easily applied to identify patients requiring prophylactic regimens.

B-type Natriuretic Peptide and Other Risk Factors for Predicting Postoperative Atrial Fibrillation after Thoracic Surgery.

Postoperative atrial fibrillation (POAF) is associated with increased morality rate, prolonged hospitalization, and reduced long-term survival after surgery. Thus, prediction of POAF is important to assess surgical risk and provide prophylaxis. It was a prospective study of 207 consecutive patients who underwent a routine preoperative laboratory testing before thoracic surgery from October 2016 to May 2017. Comprehensive data were collected. Then stepwise multivariate logistic regression analysis was adopted to identify significant risk factors associated with POAF from various variables. As results, three variables as follows: male gender, open thoracotomy, and B-type natriuretic peptide (BNP) exceeding 59 pg/mL were considered as independent risk factors associated with POAF (p < 0.05). In patients undergoing noncardiac thoracic surgery, we found that an elevated preoperative BNP level (with the level of 59 pg/mL as a cutoff), male gender, and open-chest surgeries were significant risk factors for POAF. The identification of patients who are prone to develop POAF will provide prevention strategies to reduce this complication.

Echocardiography is useful to predict postoperative atrial fibrillation in patients undergoing isolated coronary bypass surgery: A prospective study

Postoperative atrial fibrillation is a major complication following coronary artery bypass graft. We hypothesized that, beyond clinical and electrocardiogram (ECG) data, transthoracic echocardiography could improve the prediction of postoperative atrial fibrillation. We prospectively studied 169 patients in sinus rhythm who underwent isolated coronary artery bypass graft in our institution. Clinical, biological, ECG and transthoracic echocardiography data were collected within 24 h before surgery. The patients were continuously monitored during the first five days, and then had daily 12-lead ECG afterwards until discharge. Postoperative atrial fibrillation was defined by any episode >10 min. Postoperative atrial fibrillation was found in 65 patients (38%). Compared with those without, patients with postoperative atrial fibrillation were significantly older ( p=0.008), had more frequently a history of hypertension ( p=0.009), history of atrial fibrillation ( p<0.001) and New York Heart Association class ⩾III ( p=0.004). They also had longer PR interval ( p=0.005), higher preoperative NT-pro brain natriuretic peptide level ( p=0.006), left ventricle end-diastolic volume ( p=0.002), indexed left ventricle mass ( p<0.0001), indexed maximal left atrial volume ( p<0.0001), maximal right atrial area ( p<0.001) and lower left ventricle ejection fraction ( p=0.04). In multivariate analysis, history of atrial fibrillation (odds ratio =6.1, 95% confidence interval: 1.4-26.0, p=0.02) and indexed maximal left atrial volume (odds ratio =1.13, 95% confidence interval: 1.1-1.2, p=0.001) were the only two independent predictive factors of postoperative atrial fibrillation. The addition of echocardiographic parameters improved the predictive value (χ2) of the model, from 34 to 57. A history of atrial fibrillation and indexed left atrial maximal volume are the best predictors of the occurrence of postoperative atrial fibrillation following coronary artery bypass graft. The identification of high risk population of postoperative atrial fibrillation using these two factors could lead to the development of targeted strategies to limit this frequent complication in these patients.

Preoperative Plasma Aldosterone Levels and Postoperative Atrial Fibrillation Occurrence Following Cardiac Surgery: A Review of Literature and Design of the ALDO-POAF Study (ALDOsterone for Prediction of Post-Operative Atrial Fibrillation)

Post-operative atrial fibrillation (POAF) is a major and frequent complication occurring after cardiac surgery, contributing to prolonged intensive care and hospital stays and is associated with several cardiovascular complications. The exact mechanisms and signaling pathways involved in the development of POAF seem to be multifactorial and remain to date incompletely understood. β-blockers and amiodarone are the first line preventive drugs but are partially effective and near 30% of POAF resist to these strategies. In this work, we review the current knowledge about pathophysiological POAF mechanisms and preventive pharmacological strategies. We also discuss the rational for the use of pre-operative plasma aldosterone and galectin-3 (Gal-3) levels as predictive biomarkers of POAF and the potential role of aldosterone antagonists in the POAF preventive strategy. POAF is a major complication occurring after cardiac surgery. In this context, there is some evidence indicating that renin-angiotensin-aldosterone system and Gal-3 could be very useful predictive biomarkers of POAF and potentially interesting therapeutic target to prevent POAF occurrence. We present the rationale and the design of the ALDO-POAF trial (ALDOsterone for prediction of Post- Operative Atrial Fibrillation, NCT 02814903).

Prognostic value of strain and strain rate in the prediction of postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting: a systematic literature review

Introduction: Atrial fibrillation (AF) is a common dysrhythmia postoperatively after coronary artery bypass grafting (CABG). Myocardial strain and strain-rate imaging is used for the assessment of postoperative atrial fibrillation (POAF) as a new echocardiographic method. Methods: PubMed and Scopus were searched thoroughly using the following search terms: (strain and strain rate) AND (atrial fibrillation OR AF) on March 2015 to find English articles in which the strain and strain-rate echocardiographic imaging had been used for the evaluation of AF in patients undergone CABG. Full text of the relevant papers was fully reviewed for data extraction.Result: Of overall 6 articles found in PubMed, 10 records found in Scopus and 4 articles found through reference list search, only 6 papers fully met the inclusion criteria for further assessment and data extraction. The results of strain and strain-rate assessment showed that in total of 542 patients undergoing CABG, POAF occurred in 106 patients. Studies showed that the reduction of left atrial (LA) strain rate is correlated with AF. Consistently, the results of present review showed that LA strain and strain-rate in patients who developed AF postoperatively after CABG are significantly reduced, suggesting that strain and strain-rate could be a predictor of POAF.Conclusion: Based on the obtained results, strain and strain-rate is a suitable and accurate echocardiographic technique in the assessment of left atrial function , and it might be helpful to detect the patients who are at high risk of POAF.

Voting Ensemble Stratejisi ile Postoperatif Atriyal Fibrilasyonun Tahmininde Optimal Çapraz Geçerlilik Sayısının Belirlenmesi

Voting Ensemble Stratejisi ile Postoperatif Atriyal Fibrilasyonun Tahmininde Optimal Çapraz Geçerlilik Sayısının Belirlenmesi

The role of N-terminal pro-brain natriuretic peptide in prediction of postoperative atrial fibrillation.

To analyze prognostic value of different factors in postoperative atrial fibrillation prediction. Study included 39 patients with coronary artery disease without previous paroxysmal atrial fibrillation. Multiple correlation, logistic regression and ROC-analysis were performed to create predictive model of postoperative atrial fibrillation prognosis. Authors have analyzed most of described in literature preoperative predictors of atrial fibrillation to define the role of different risk factors. Prognostic role of N-terminal pro-brain natriuretic peptide (NT-proBNP) is assessed. We revealed high informativeness of NT-proBNP to predict postoperative atrial fibrillation after on-pump coronary artery bypass grafting.

Prediction of postoperative atrial fibrillation after isolated aortic valve replacement by transesophageal two-dimensional speckle tracking

Objective To investigate the predictive value of the changes of left ventricular global longitudinal strain (GLS) during aortic valve replacement (AVR) for postoperative atrial fibrillation (POAF).Methods Ninety-six patients with symptomatic aortic stenosis and ejection fraction≥ 50％ undergoing isolated AVR were enrolled.All patients underwent intraoperative transesophageal echocardiography assessment for GLS,and were followed for the occurrence of POAF during the hospitalization.Results The incidence of POAF was 35/96 (36.5 ％).Patients with POAF were associated with increased length of hospitalization and a higher risk of low cardiac output syndrome and pulmonary complications.On univariate analysis,significant risk factors associated with POAF were E/e'ratio,left atrial volume index,GLST2 and △GLS％.On multivariable analysis,GLST2 (OR:1.19,95％ CI:1.09-1.35,P =0.022) and △GLS％ (OR:2.66 ;95 ％ CI:1.65-6.79,P ＜0.001) were independent predictors of POAF.The best cut-off values for the prediction of POAF were GLST2 ≥-1 0.50 ％ and △GLS％ ≥ 1 8.75 ％,the latter of which had the highest discriminatory power for POAF.Conclusions A significant reduction of intraoperative GLS provides independent information for predicting POAF in post-AVR patients,and may help to identify high-risk patients who are most likely to benefit from targeted prophylaxis. Key words: Echocardiography, transesophageal; Aortic valve stenosis; Heart valve prosthesis implantation ; Atrial fibrillation ; Speckle tracking imaging

Transoesophageal echocardiography for prediction of postoperative atrial fibrillation after isolated aortic valve replacement: two-dimensional speckle tracking for intraoperative assessment of left ventricular longitudinal strain.

Recent studies suggested association between impaired left ventricular long-axis function and arrhythmic events early after open heart surgery. This prospective study investigated the predictive value of a depressed intraoperative global longitudinal strain (GLS) for postoperative atrial fibrillation after isolated aortic valve replacement in patients with preserved ejection fraction. A total of 107 patients with ejection fraction ≥50% and moderate-to-severe aortic stenosis undergoing isolated aortic valve replacement were enrolled. All patients underwent intraoperative transoesophageal echocardiography before surgical incision (T1) and after closure of the sternotomy (T2) with semiautomated measurement of GLS, and were followed for the occurrence of postoperative atrial fibrillation during the hospitalization. The incidence of postoperative atrial fibrillation was 37/107 (34.6%). Patients with postoperative atrial fibrillation were associated with increased length of hospitalization and a higher risk of low cardiac output syndrome and pulmonary complications. On univariate analysis, significant risk factors associated with postoperative atrial fibrillation were E/e' ratio, left atrial volume index (LAVi), GLST2 and ΔGLS%. On multivariable analysis, GLST2 (odds ratio: 1.21; 95% confidence interval (CI): 1.06-1.56, P = 0.031) and ΔGLS% (odds ratio: 3.66; 95% CI: 1.85-6.79, P = 0.001) were independent predictors of postoperative atrial fibrillation. The best cut-off values for the prediction were GLST2 >-12.75% and ΔGLS% >19.50%, the latter of which had incremental predictive value for postoperative atrial fibrillation. A significant reduction of intraoperative GLS provides independent information for predicting postoperative atrial fibrillation in patients undergoing aortic valve replacement, and may help to identify patients who are most likely to benefit from targeted prophylaxis.

OP-231 Preoperative Left Ventricular Global Strain Predicts Postoperative Atrial Fibrillation in Patients Undergoing Coronary By-Pass Surgery

The American Journal of Cardiology MARCH 13e16, 2014 10 IN AND C -OP-231 Preoperative Left Ventricular Global Strain Predicts Postoperative Atrial Fibrillation in Patients Undergoing Coronary By-Pass Surgery. S. Topcu, K. Kalkan, Z. Lazo glu, O. Gulcu, U. Aksu, Z. Avsar, E. Aksakal. Cardiology Department, Ataturk University, Erzurum, Turkey; Department of Medical Education, Ataturk University, Erzurum, Turkey. Introduction: Preoperative left ventricular dysfunction is closely related to postoperative atrial fibrillation (POAF). Left ventricular global strain (LVGS) is more sensitive measurement of left ventricular dysfunction than conventional measurements. However, there is no studywhether left ventricular global strain assessed by speckle tracking echocardiography predicts postoperative atrial fibrillation and in patients undergoing coronary artery by-pass surgery (CABG). Methods: Fifty-one patients with sinus rhythm who undergoing to CABG were enrolled. Preoperative left ventricular four chamber, two chamber and apical long axis longitudinal strain were measured. Left ventricular global strain obtained as average of left ventricular four chamber, two chamber and apical long axis longitudinal strain. POAF was defined as documentation of AF with at least 5 min duration in 96 hours at postoperative period. Results: Postoperative atrial fibrillation occurred 19 of 51 patients (37%). The mean duration of AF was 13.1 8.2 hours and POAF was observed 2.8 1.2 days after the CABG. Patients with POAF had older, larger Left atrial volume, lower left ventricular ejection fraction and left ventricular global strain and higher syntax score. Multiple logistic regression analysis revealed only LVGS (OR:0.92, 95% CI 0.88-0.96, p1⁄40.001) was independent predictor of POAF. The ROC curve analysis revealed that AUC for LVGS in prediction of POAF was 0.787 (0.6800.894). Cut-off value of 12.1 for LVGS had 76% sensitivity and 82% specificity. Conclusion: Pre-operative left ventricular global strain wasindependently predict the postoperative atrial fibrillation in patients undergoing CABG.

Prediction of postoperative atrial fibrillation after coronary artery bypass grafting surgery: is CHA 2 DS 2 -VASc score useful?

Postoperative atrial fibrillation (POAF) is the most common arrhythmia after coronary artery bypass grafting (CABG) surgery. The identification of patients at risk for POAF would be helpful to guide prophylactic therapy. Presently, there is no simple preoperative scoring system available to predict patients at higher risk of POAF. In a retrospective observational study, we evaluated the usefulness of CHA 2 DS 2 -VASc score to predict POAF after CABG. After obtaining approval from Institutional Review Board, 729 patients undergoing CABG on cardiopulmonary bypass (CPB) were enrolled. Patients were followed in the postoperative period for POAF. A multiple regression analysis was run to predict POAF from various variables. The area under the receiver operating characteristic (ROC) curve was calculated to test discriminatory power of CHA 2 DS 2 -VASc score to predict POAF. POAF occurred in 95 (13%) patients. The patients with POAF had higher CHA 2 DS 2 -VASc scores than those without POAF (4.09 ± 0.90 vs. 2.31 ± 1.21; P < 0.001). The POAF rates after cardiac surgery increased with increasing CHA 2 DS 2 -VASc scores. The odds ratio for predicting POAF was highest with higher CHA 2 DS 2 -VASc scores (3.68). When ROC curve was calculated for the CHA 2 DS 2 -VASc scores, area of 0.87 was obtained, which was statistically significant (P < 0.0001). The CHA 2 DS 2 -VASc score was found useful in predicting POAF after CABG. This scoring system is simple and convenient to use in the preoperative period to alert the clinician about higher probability of POAF after CABG surgery.

Prediction of postoperative atrial fibrillation after cardiac surgery: Light at the end of the tunnel?

Prediction of postoperative atrial fibrillation after cardiac surgery: Light at the end of the tunnel?

Usefulness of Right Ventricular Dysfunction to Predict New-Onset Atrial Fibrillation Following Coronary Artery Bypass Grafting

Postoperative atrial fibrillation (AF) is a serious yet common complication after coronary artery bypass grafting (CABG) surgery. Risk factors for postoperative AF have been identified, including echocardiographic parameters, and these are relied on to implement preventative strategies that reduce the incidence of AF. There has yet to be a study examining the impact of echocardiographic right-sided cardiac parameters on the prediction of postoperative AF. Thus, a panel of right-sided cardiac parameters was measured in a cohort of patients undergoing isolated CABG surgery, excluding those who did not have echocardiographic assessment within 30 days before surgery and those with any history of AF. The primary outcome was postoperative AF defined as any episode of AF requiring treatment during the index hospitalization. Postoperative AF occurred in 197 of 768 patients (25.6%); these were older and more likely to have hypertension and chronic kidney disease. After adjustment for clinical and echocardiographic variables, left atrial volume index ≥34 ml/m(2) (odds ratio [OR] 1.98, 95% confidence interval [CI] 1.36 to 2.87), abnormal right ventricular myocardial performance index (OR 1.50, 95% CI 1.01 to 2.24), and advancing age (OR 1.05, 95% CI 1.03 to 1.07) were found to be independent predictors of postoperative AF. In conclusion, right ventricular myocardial performance index is a novel predictor of postoperative AF in patients undergoing isolated CABG surgery and appears to be additive to established risk factors such as age and left atrial volume.

Research progress of postoperative atrial fibrillation

Postoperative atrial fibrillation (POAF) is the most common complication after cardiac surgery, which leads to hemodynamics disorder, prolongs hospitalization and increases mortality. The underlying mechanisms behind POAF are associated with cardiomyocyte injury, sympathetic activation and inflammation. The prediction of POAF is based on correlated index from pre-, intra- and post-surgery. POAF can be treated by rhythm and heart rate control as well as and antithrombotic therapy.

Echocardiographic prediction of postoperative atrial fibrillation after aortic valve replacement for aortic stenosis: A two-dimensional speckle tracking left ventricular longitudinal strain multicentre pilot study

Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery, with increased risk of embolic events, haemodynamic instability, haemorrhagic complications and prolonged hospital stay. We sought to assess the value of preoperative left ventricular global longitudinal strain (GLS) for the prediction of POAF in a series of patients with severe symptomatic aortic stenosis who underwent aortic valve replacement (AVR). Fifty-eight consecutive patients (52% men) aged 73±9 years, with severe symptomatic aortic stenosis (aortic valve area<1cm(2) or<0.5cm(2)/m(2)), in sinus rhythm, who underwent AVR were prospectively included in three centres between 2009 and 2010. Complete preoperative echocardiography was performed in all patients, including global and segmental longitudinal strain using two-dimensional speckle tracking. The POAF incidence was 28/58 (48%). On univariate analysis, aortic valve area (P=0.04), preoperative E/e' ratio (P=0.04) and GLS (P=0.005) were associated with the occurrence of POAF. Chronic obstructive pulmonary disease (P=0.05), preoperative statin treatment (P=0.09), age≥80 years (P=0.09), left ventricular ejection fraction (P=0.09) and systolic pulmonary artery pressure (P=0.06) tended to increase the risk of POAF. The best GLS cut-off value for the prediction of POAF was -15% (82% sensitivity, 53% specificity, area under the curve 0.72). On multivariable analysis, GLS>-15% was the only independent predictor of POAF (odds ratio 7.74, 95% confidence interval [1.15-52.03]; P=0.035). Incidence of POAF is high after AVR for severe aortic stenosis. Our results suggest an additive value of the study of left ventricular myocardial deformation to classical clinical and echocardiographic variables for the prediction of POAF in this setting.

Prediction of postoperative atrial fibrillation in a large coronary artery bypass grafting cohort

The objective of this study was to identify and evaluate predictors of postoperative atrial fibrillation (POAF) in a large coronary artery bypass grafting (CABG) cohort. This was a single centre study of 7115 consecutive patients with preoperative sinus rhythm who underwent isolated CABG between January 1996 and December 2009. Independent risk factors for POAF were identified with multiple logistic regression. The predictive quality of the final model was evaluated by comparing predicted and observed events of POAF, in an effort to find patients at high risk of developing POAF. After CABG, 2270 patients (32%) developed POAF during hospital stay. Independent risk factors of POAF included advancing age (odds ratio, OR 2.0-7.3), preoperative S-creatinine ≥ 150 µmol/l (OR 1.6), male gender (OR 1.2), New York Heart Association class III/IV (OR, 1.2), smoking (OR 1.1), prior myocardial infarction (OR 1.1) and absence of hyperlipidemia (OR 0.9). The final prediction model was moderate (area under curve, 0.62; 95% confidence interval, 0.61-0.64). Patients with POAF had more postoperative complications, including a higher incidence of stroke and increased length of hospital stay. In conclusion, several risk factors for POAF were identified, but the moderate value of the prediction model confirms the difficulty of identifying patients at high risk of developing POAF after CABG.

Intracardiac expression of markers of endothelial damage/dysfunction, inflammation, thrombosis, and tissue remodeling, and the development of postoperative atrial fibrillation

Atrial fibrillation (AF) is a common complication of coronary artery bypass grafting (CABG), and may have an inflammatory and/or thrombotic etiology. We sought to determine the expression of inflammatory (interleukin [IL]-6), thrombotic (tissue factor and von Willebrand factor [VWF]) and remodeling (matrix metalloproteinase [MMP]-9 and tissue inhibitor of metalloproteinase [TIMP]-1) markers by left atrial appendage (LAA) and right atrial appendage (RAA) tissue in the prediction of postoperative AF. We determined whether the tissue expression of markers of certain different pathophysiologic mechanisms predicted the development of AF after CABG. LAA and RAA tissue was excised during CABG in 100 patients free of AF and inflammation. Tissue marker expression was quantified by immunohistochemistry and was related to 30-day postoperative AF. Overall, there were no significant differences in staining intensity of any marker between LAA tissue and RAA tissue. However, more intense expression of VWF by LAA tissue predicted the 30 patients with postoperative AF as compared with those free of AF (P = 0.006). IL-6, MMP-9 and TIMP-1 expression by RAA and LAA epicardial tissue was stronger than expression by endocardium or cardiomyocytes (all P < 0.025) but failed to predict AF. In this study, one of the largest to investigate tissue expression of pathophysiologic markers in relation to postoperative AF, we show that more intense expression of VWF by LAA tissue is a significant predictor of postoperative AF. This points towards a possible role of endothelial damage/dysfunction (as reflected by VWF changes) in the pathogenesis of postoperative AF.

ECG based prediction of Atrial Fibrillation using Support Vector Classifier

In patients undergoing Coronary Artery Bypass Grafting (CABG) surgery postoperative atrial fibrillation (AF) occurs with prevalence of up to 40%. The highest incidence is between the second and third day after the operation. Following cardiac surgery AF causes various complications, hemodynamic instability, and can cause heart attack, cerebral and other thromboemolisms. AF increases morbidity, duration and expense of medical treatment. This study aims to identify patients at high risk of postoperative AF. An early prediction of AF would provide a timely prophylactic treatment and would reduce incidence of arrhythmia. Patients at low risk of postoperative AF could be excluded from the side effects of anti-arrhythmic drugs. The investigation included 50 patients in whom lead II electrocardiograms were continuously recorded for 48 hours following CABG. Univariate statistical analysis was used in the search of signal features that might predict AF. The most promising identified features were: P wave duration, RR interval duration and PQ segment level. On the basis of these a nonlinear multivariate prediction model was made deploying a Support Vector Machine (SVM) classifier. The prediction accuracy was found uprising over the time. At 48 hours following CABG; the measured best average sensitivity was 95.9% and specificity 93.4%. The positive and negative predictive accuracy were 88.9% and 98.8%, respectively and the overall accuracy was 94.6%. In regard to the prediction accuracy, the risk assessment and prediction of postoperative AF are optimal to be done in the period between 24 and 48 hours following CABG.

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

In patients undergoing coronary artery bypass grafting (CABG) surgery, post-operative 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 and prediction of post-operative AF is optimal in the period between 24 and 48 h following CABG.