statin was stopped. The rate of the primary outcome of postoperative AF within five days of surgery was similar in both groups (21.1 and 20.5 percent, respectively; odds ratio 1.04, 95% CI 0.84-1.30). Of note, there was no difference in the rate of myocardial injury within 120 hours after surgery. In addition, rosuvastatin was associated with a significant absolute excess in the rate of postoperative acute kidney injury (24.7 versus 19.3 percent; p = 0.005). Based upon established benefits of statin therapy in patients with coronary heart disease, all patients should be on long-term statin. However, for patients who have not started statin therapy prior to CABG, we suggest waiting until after surgery, as there is no clear evidence of benefit from preoperative initiation and possible harm. (See "Coronary artery bypass surgery: Perioperative medical management", section on 'Statins'.) N-acetylcysteine N-acetylcysteine (NAC) has the potential to protect against the development of perioperative AF due to its antioxidant and anti-inflammatory properties. (See 'Pathogenesis' above.) This hypothesis was tested in a trial of 115 patients undergoing either CABG or valve surgery who were randomly assigned to either NAC or placebo given one hour before and continued for 48 hours after surgery [119]. The primary end point of an AF episode lasting longer than five minutes during hospitalization was seen in 15 patients and was significantly less common in those who received NAC (5.2 versus 21.2 percent). In a small study designed to evaluate the potential benefit of anti-inflammatory therapy (with NAC or carvedilol), 311 patients undergoing cardiac surgery who had no history of AF were randomly assigned to metoprolol, carvedilol, or carvedilol plus NAC [120]. The incidence of postoperative AF was significantly lower in the carvedilol plus NAC group compared to either of the other two interventions (35.9, 24.0, and 8.7 percent, respectively). Colchicine Colchicine reduces the incidence of the postpericardiotomy syndrome. (See "Post-cardiac injury syndromes", section on 'Prevention'.) The issue of whether colchicine can reduce the incidence of postoperative AF was addressed in a post hoc substudy. In COPPS, 360 patients undergoing cardiac surgery were randomly assigned to either colchicine 1.0 mg given twice daily on day one followed by 0.5 mg twice daily for one month (the dose was halved in patients <70 kg) or placebo [121]. The first dose was given on postoperative day three. The COPPS Prevention of Atrial Fibrillation (POAF) substudy evaluated outcomes in the 336 patients in sinus rhythm on day three. Colchicine significantly reduced the incidence of postoperative AF (12 versus 22 https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 13/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate percent; relative risk reduction 45.5 percent, 95% CI 34.0-94.0 percent) at 30 days. In addition, patients taking colchicine had a significantly shorter in-hospital stay (9.4 versus 10.3 days). There was a trend toward a higher rate of side effects (9.5 versus 4.8 percent) and drug withdrawal (11.8 versus 6.6 percent) with colchicine, but no severe side effects were recorded. In the COPPS-2 trial, 360 patients scheduled for cardiac surgery were randomly assigned to oral colchicine or placebo before surgery [122]. The drug was continued for one month after surgery. At three months, there was no significant difference between the two groups in the secondary end point of postoperative AF (34 versus 41 percent, respectively). (See "Post-cardiac injury syndromes", section on 'Prevention'.) We believe there is insufficient evidence to recommend the routine use of colchicine, in part out of a concern that it may negatively impact wound healing and that it leads to gastrointestinal side effects. The 2014 American Heart Association/American College of Cardiology/Heart Rhythm Society AF guideline states that colchicine may be considered [123,124]. This was not changed in the 2019 focused update [125]. Naproxen The potential benefit from naproxen was evaluated in the NAFARM trial, which randomly assigned 161 patients to either naproxen or placebo [126]. There was no significant difference in the rate of postoperative AF (7 versus 15 percent, respectively). The study was stopped early because of an increase in renal failure in the naproxen group. Glucocorticoid Based upon the hypothesis that perioperative inflammation may contribute to the development of AF, glucocorticoids have been suggested as prophylactic therapy. (See "Glucocorticoid effects on the immune system".) Two meta-analyses of small trials in which glucocorticoid treatment was compared to placebo or no treatment in adult cardiac surgery found 26 and 40 percent reductions in the incidence of AF, irrespective of the dose given [127,128]. However, the large, randomized SIRS trial, published after the meta-analyses, found no difference in the rate of new AF [129]. Due to their potential adverse effects on glucose metabolism, wound healing, infection, and the absence of a lowering of the risk of death, we do not recommend the routine use of glucocorticoid therapy to prevent AF. The potential role for glucocorticoid therapy for other outcomes is discussed separately. (See "Coronary artery bypass surgery: Perioperative medical management", section on 'Glucocorticoid therapy'.) https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 14/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate Prevention of complications of atrial fibrillation While beta blockers, sotalol, amiodarone, and pacing decrease the risk of postoperative AF, the evidence is less robust that the risk of complications such as stroke, death, or length of stay can be prevented. It may be difficult to demonstrate a lowering of the risk of in-hospital stroke with these therapies, as AF is only one risk factor for stroke and as the incidence of stroke is low. (See 'Adverse outcomes following atrial fibrillation' above.) The best available evidence of the impact of these interventions on the complications of AF comes from a 2006 meta-analysis of heterogenous trials, which noted the following [72]: In 29 trials that evaluated length of stay, only amiodarone and pacing shortened the average length of stay (-0.60 days, 95% CI -0.92 to -0.29 and -1.3 days 95% CI -2.55 to -0.08, respectively). In 25 trials that reported on the incidence of postoperative stroke, the risk of stroke was decreased from 1.9 to 1.1 percent with treatment (odds ratio 0.63, 95% CI 0.41-0.98). Amiodarone was the only single intervention that significantly lowered the risk of stroke compared to placebo. Our approach to prevention We recommend preventative therapy to reduce the incidence of postoperative AF, especially in patients at high risk of its development. While the evidence is not robust, prevention of AF may lead to a lowering of the risk of in-hospital stroke and a shortened length of stay. In addition, successful prevention of AF will prevent the need for anticoagulation in some patients. Beta blockers, sotalol, amiodarone, and atrial pacing are significantly more effective than placebo in lowering the rate of postoperative AF [64,71,72]. There is some evidence to support the use of antioxidant vitamins for this purpose. We prefer beta blockers to amiodarone or sotalol due to lower cost and lower risk of potential side effects and to pacing because of its relative complexity and cost. Amiodarone or sotalol is a reasonable alternative in patients who cannot tolerate beta blockade. If possible, we prefer to start beta blockers prior to CABG. We suggest metoprolol 25 mg twice daily; the dose can be titrated postoperative based on the heart rate and blood pressure. We continue this therapy until the first postoperative visit, unless there is a contraindication. The evidence to support the use of antioxidant vitamins is less robust than that for traditional antiarrhythmic drugs. While awaiting larger randomized trials, we believe it is reasonable to use antioxidant therapy as given in the small randomized trial [87]. MANAGEMENT https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 15/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate While prevention with beta blockers, amiodarone, sotalol, or pacing lowers the risk of postoperative atrial fibrillation (AF), many patients still develop AF (see 'Prevention of atrial fibrillation' above). We are uncertain as to the optimal management of these patients, in part because it is not known whether postoperative AF represents the same arrhythmia as AF occurring without cardiac surgery or if it possesses a similar natural history in terms of portending adverse events. We think the initial management should include correction of predisposing factors such as hypoxemia, electrolyte abnormalities, and hemodynamic instability as well as pain management and withdrawal of stimulating factors such as inotropic agents. Subsequent management relates to the issues of rate control versus rhythm control cardioversion and anticoagulation [130]. Options for management of AF include rate or rhythm control strategies. For patients with atrial flutter, we cardiovert to sinus rhythm prior to discharge in most cases, as this rhythm is more difficult than AF to control medically. Rate control Given the transient nature of the arrhythmia (see 'Incidence and time course' above), initial control of the ventricular response rate is an effective and relatively safe strategy in many patients who develop postoperative AF [44,131]. Rate control is most commonly achieved with beta blockers. The benefit is partly due to blockade of the augmented postoperative sympathetic state and to prevention of beta blocker withdrawal in patients on beta blockers preoperatively. Intravenous esmolol, a beta blocker with a short half-life, can be given for acute rate control if there is a concern for bradyarrhythmias, hypotension, or bronchospasm. Slowing of the ventricular rate in many AF patients receiving inotropic agents postoperatively can be achieved by lowering the dose or discontinuation of these agents. The optimal rate goal for patients with AF after cardiac surgery has not been determined. As these patients vary widely in many clinical features (co-morbidities, need for rapid ventricular rate, etc), we suggest that the optimal ventricular rate be determined on a case by case basis. In many patients, a ventricular rate of less than 110 beats per minute will prevent symptoms such as palpitations and allow for optimal cardiac performance. (See "Control of ventricular rate in patients with atrial fibrillation who do not have heart failure: Pharmacologic therapy", section on 'Evaluation and goal ventricular rate'.). Calcium channel blockers and digoxin are other atrioventricular (AV) nodal blockers that can control the ventricular rate in AF, but they are not more effective than beta blockers. In patients in whom alternate agents have not been successful in controlling the rate in atrial fibrillation, intravenous amiodarone can be used to slow the ventricular response. (See "Control of https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 16/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate ventricular rate in patients with atrial fibrillation who do not have heart failure: Pharmacologic therapy".) Rhythm control Restoration of sinus rhythm from well-tolerated postoperative AF is usually not necessary but occasionally can be beneficial. (See 'Incidence and time course' above.) Restoration of sinus rhythm is indicated in symptomatic patients or in those when rate control is difficult to achieve. An attempt at the restoration of sinus rhythm can be beneficial in patients with a low ejection fraction. In addition, cardioversion in asymptomatic patients may be reasonable when well-tolerated AF occurs near the time of anticipated hospital discharge or when it does not spontaneously terminate within 24 hours, so that oral anticoagulation can be avoided; this is particularly true in patients at high risk of bleeding. We believe that an attempt at cardioversion with either electrical or pharmacologic therapy is reasonable. The choice between the two should be made on local practice and patient conditions. Electrical therapy of AF involves direct current external transthoracic cardioversion and it is effective in approximately 95 percent of cases [132] (see "Cardioversion for specific arrhythmias"). For patients who are refractory to transthoracic cardioversion or when reversion is desirable but the patient's respiratory status makes anesthesia for electrical conversion potentially difficult, pharmacologic therapy with intravenous sotalol or amiodarone is reasonable. (See 'Sotalol' above and 'Amiodarone' above.) Amiodarone dosing regimens are available in the relevant drug monograph. The efficacy of antiarrhythmic drugs for reversion of postoperative AF is similar to that in AF not related to surgery [133-141]. (See "Atrial fibrillation: Cardioversion".) Rate versus rhythm control For patients who do not spontaneously revert to sinus rhythm within a few hours, rate control and rhythm control (with or without electrical cardioversion) appear to be comparable strategies [45,46,142]. The choice between the two strategies should take into account patient and physician preferences. Advantages of a rate control strategy include the absence of side effects from drug therapy; disadvantages include a slower resolution of AF, thereby leading to a potentially greater need for anticoagulation at discharge. In many patients, we chose a rhythm control strategy. In a study of patients with no history of AF undergoing cardiac surgery, 523 individuals were randomly assigned to either rate or rhythm control [142]. In the rate control group, the heart rate goal was less than 100 beats per minute and in the rhythm control group, amiodarone was given with or without a rate slowing drug. If AF persisted for 24 to 48 hours, electrical cardioversion was recommended. The primary end point was the total number of days of https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 17/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate hospitalization within 60 days after randomization. There was no difference between the two groups in the primary outcome (median, 5.1 and 5 days, respectively; p = 0.76). This study had limitations, such as including heterogenous patients and lacking the power to assess effect on death or serious adverse events. Anticoagulation Patients on long-term anticoagulant For AF patients who are taking warfarin or direct oral anticoagulants, we suggest stopping this therapy at least three days before surgery. We restart oral anticoagulant therapy three to five days after surgery. The role of bridging heparin therapy for patients at high risk of an embolic complication while off oral anticoagulant, such as those with AF and a prior embolic event, is discussed elsewhere. (See "Perioperative management of patients receiving anticoagulants".) Patients not taking anticoagulant prior to cardiac surgery Patients with AF or atrial flutter, regardless of the setting, are at risk for thromboembolic events; the magnitude of that risk varies based upon a number of factors. Thromboembolic risk is primarily limited to AF or atrial flutter of more than 48 hours duration and is greater in patients with certain high risk features (eg, rheumatic mitral valve disease, previous thromboembolism, hypertension, or heart failure) ( table 2) [130]. The general recommendations for anticoagulation in patients with AF are discussed in detail elsewhere. (See "Atrial fibrillation in adults: Use of oral anticoagulants" and "Prevention of embolization prior to and after restoration of sinus rhythm in atrial fibrillation" and "Embolic risk and the role of anticoagulation in atrial flutter".) Patients who develop AF after cardiac surgery are at risk of thromboembolic events, including in- hospital stroke. However, in the individual post-surgical patient with an embolic event, the cause may be unclear, as underlying comorbidities are often responsible for such strokes, rather than the arrhythmia itself [56,64,143]. (See 'Incidence and time course' above.) Based on evidence that oral anticoagulant therapy prevents episodes of systemic embolization in the broad population of patients with atrial fibrillation, we believe that such therapy will lead to fewer embolic events in patients with postoperative AF. However, a reduction of events with anticoagulant therapy in this population has never been well studied. (See "Atrial fibrillation in adults: Use of oral anticoagulants", section on 'Summary and recommendations'.) As factors other than AF contribute to in-hospital stroke rates, it is not clear that aggressive early anticoagulation (eg, intravenous heparin as a bridge to warfarin) will reduce the incidence of stroke. In addition, the bleeding risk associated with anticoagulation in the immediate postoperative period (within the first 48 hours in most patients) makes the overall impact of this approach less certain. The potential complications associated with anticoagulation were https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 18/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate illustrated in several observational series of patients who were treated with intravenous heparin or oral anticoagulants for a variety of indications [144-146]. When closely monitored, complication rates appear to be low [144,145]. However, one report found a significant increase in large pericardial effusions and tamponade in patients treated with warfarin, particularly when the International normalized ratio (INR) was above the therapeutic target [146]. These large effusions all occurred one week or more after surgery. Thus, when anticoagulation is initiated, the patient must be monitored carefully. (See "Perioperative management of patients receiving anticoagulants".) Similarly, the optimal duration of anticoagulation after hospital discharge is unknown. Among patients with new-onset AF after cardiac surgery, many will revert to and maintain sinus rhythm [1,45-47]. Due to the inability to reverse their therapeutic effect, we do not start newer oral anticoagulants in the early postoperative period. There are limited data at present, but this is an evolving strategy that may gain support as our understanding evolves [147]. (See "Direct oral anticoagulants (DOACs) and parenteral direct-acting anticoagulants: Dosing and adverse effects".) Left atrial appendage closure Evidence is emerging that the left atrial appendage may play a major role in the development of stroke, and surgical closure may reduce this risk. Patients who have AF who are undergoing cardiac surgery for other indications may benefit from closure. Specific recommendations are provided separately. (See "Atrial fibrillation: Left atrial appendage occlusion".) Our approach to postoperative anticoagulation Among patients who develop AF following cardiac surgery, we suggest the following approach to anticoagulation: For patients with multiple episodes of AF or one episode that lasts more than 24 to 48 hours, we recommend the initiation of oral anticoagulant therapy, but only if bleeding risks are considered acceptable. As the role of direct thrombin and factor Xa inhibitors has not been established for patients with postoperative AF, we suggest that warfarin be chosen for most patients (International normalized ratio 2 to 3). We suggest continuation of anticoagulation for at least four weeks after return to sinus rhythm, particularly if the patient has risk factors for thromboembolism. Longer duration of anticoagulation is recommended by some of our experts in patients with high CHA DS - 2 2 VASc scores ( table 3), at low risk for bleeding based on the HAS-BLED score ( table 4), or at high risk of AF recurrence. https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 19/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate Long-term anticoagulation should be considered for patients who remain in AF or who have paroxysmal AF at four weeks. (See "Atrial fibrillation in adults: Use of oral anticoagulants", section on 'Summary and recommendations'.) We suggest maintaining oral anticoagulation in patients in which a concomitant Cox-Maze procedure has been performed for at least three months, regardless of no postoperative atrial arrhythmias. (See "Atrial fibrillation: Surgical ablation", section on 'Maze procedure'.) After three months with no AF recurrence, anticoagulation may be interrupted, considering the patient risk profile for stroke by the CHA DS -VASc score ( table 3) [148]. 2 2 In most cases, we do not use intravenous heparin as a bridge to full oral anticoagulation, as the risk of postoperative bleeding outweighs the small benefit from stroke prevention. For patients with prior systemic or pulmonary embolization or those with a mechanical valve, bridging anticoagulation with heparin may be reasonable. Both intravenous and oral anticoagulation should be monitored closely, as bleeding complications, including pericardial effusion and tamponade increase with excessive anticoagulation. RECOMMENDATIONS OF OTHERS Guidelines from the American College of Cardiology Foundation/American Heart Association and the European Society of Cardiology [130,148,149]. Our recommendations are generally consistent with recommendations from these groups. SOCIETY GUIDELINE LINKS Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Atrial fibrillation" and "Society guideline links: Arrhythmias in adults" and "Society guideline links: Coronary artery bypass graft surgery".) SUMMARY AND RECOMMENDATIONS Presentation Atrial fibrillation (AF) and atrial flutter occur frequently after cardiac surgery. Most episodes occur by the third postoperative day. (See 'Incidence and time course' above.) https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 20/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate Adverse outcomes Potential adverse outcomes of these atrial arrhythmias include a longer length of stay, stroke, or death. (See 'Adverse outcomes following atrial fibrillation' above.) Preventive strategies Beta blockers, sotalol, amiodarone, atrial pacing, reducing the risk of pericardial effusion, and antioxidant vitamins lower the risk of the development of AF and atrial flutter after cardiac surgery and may reduce the length of stay and lower the risk of in-hospital stroke. (See 'Prevention of atrial fibrillation and complications' above.) For patients undergoing cardiac surgery, we recommend treatment with beta blockers (Grade 1B). Beta blocker therapy should be started prior to surgery and continued at least until the first postoperative visit unless contraindicated. We prefer oral metoprolol 25 mg twice daily. For patients who cannot take beta blockers, either amiodarone or sotalol may be used, with the decision based on patient characteristics and physician familiarity. (See 'Our approach to prevention' above.) We suggest antioxidant therapy in addition to beta blocker therapy (Grade 2C). We start this therapy two days prior to surgery and continue until discharge. We prefer the regimen of vitamin C (1 gram) and vitamin E (400 international units), each given daily. (See 'Our approach to prevention' above.) Management of postoperative atrial fibrillation Ventricular rate control For hemodynamically stable patients who develop postoperative AF, the optimal ventricular rate range should be determined for each patient. In many patients, this rate will be less than 110 beats per minute. Cardioversion For patients who develop well-tolerated postoperative AF and whose rate is well controlled, we suggest not performing cardioversion within the first 24 hours of its development (Grade 2B). Cardioversion may be required within this time frame for those whose AF is poorly tolerated or whose rate is not well controlled. (See 'Rhythm control' above.) Cardioversion in asymptomatic patients may be reasonable when well-tolerated AF is present near the time of anticipated hospital discharge, or when it does not spontaneously terminate within 24 to 48 hours, so that oral anticoagulation can be avoided. https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 21/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate Anticoagulation For patients with multiple episodes of AF or one episode that lasts more than 24 to 48 hours, and if the perioperative bleeding risks are considered reasonable, we recommend oral anticoagulation (Grade 1B). (See 'Our approach to postoperative anticoagulation' above.) We suggest anticoagulation with warfarin (international normalized ratio 2 to 3) rather than either a direct thrombin or factor Xa inhibitor (Grade 2C). For patients in whom anticoagulation is started and irrespective of the rhythm status at the time of discharge from the hospital, we suggest continuation of anticoagulation for at least four weeks, rather than stopping at the time of discharge (Grade 2C). ACKNOWLEDGMENT The UpToDate editorial staff would like to thank Drs. John M. Stulak, Manuel Castell , and Arie P. Kappetein for their contributions to previous versions of this topic review. Use of UpToDate is subject to the Terms of Use. REFERENCES 1. Maisel WH, Rawn JD, Stevenson WG. Atrial fibrillation after cardiac surgery. Ann Intern Med 2001; 135:1061. 2. Cox JL. A perspective of postoperative atrial fibrillation in cardiac operations. Ann Thorac Surg 1993; 56:405. 3. Tsikouris JP, Kluger J, Song J, White CM. Changes in P-wave dispersion and P-wave duration after open heart surgery are associated with the peak incidence of atrial fibrillation. Heart Lung 2001; 30:466. 4. Dupont E, Ko Y, Rothery S, et al. The gap-junctional protein connexin40 is elevated in patients susceptible to postoperative atrial fibrillation. Circulation 2001; 103:842. 5. Karaca M, Demirbas MI, Biceroglu S, et al. Prediction of early postoperative atrial fibrillation after cardiac surgery: is it possible? Cardiovasc J Afr 2012; 23:34. 6. Mathew JP, Fontes ML, Tudor IC, et al. A multicenter risk index for atrial fibrillation after cardiac surgery. JAMA 2004; 291:1720. 7. Creswell LL, Schuessler RB, Rosenbloom M, Cox JL. Hazards of postoperative atrial arrhythmias. Ann Thorac Surg 1993; 56:539. https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 22/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate 8. Asher CR, Miller DP, Grimm RA, et al. Analysis of risk factors for development of atrial fibrillation early after cardiac valvular surgery. Am J Cardiol 1998; 82:892. 9. Zaman AG, Archbold RA, Helft G, et al. Atrial fibrillation after coronary artery bypass surgery: a model for preoperative risk stratification. Circulation 2000; 101:1403. 10. Pires LA, Wagshal AB, Lancey R, Huang SK. Arrhythmias and conduction disturbances after coronary artery bypass graft surgery: epidemiology, management, and prognosis. Am Heart J 1995; 129:799. 11. Aranki SF, Shaw DP, Adams DH, et al. Predictors of atrial fibrillation after coronary artery surgery. Current trends and impact on hospital resources. Circulation 1996; 94:390. 12. Mendes LA, Connelly GP, McKenney PA, et al. Right coronary artery stenosis: an independent predictor of atrial fibrillation after coronary artery bypass surgery. J Am Coll Cardiol 1995; 25:198. 13. Deliargyris EN, Raymond RJ, Guzzo JA, et al. Preoperative factors predisposing to early postoperative atrial fibrillation after isolated coronary artery bypass grafting. Am J Cardiol 2000; 85:763. 14. Rubin DA, Nieminski KE, Reed GE, Herman MV. Predictors, prevention, and long-term prognosis of atrial fibrillation after coronary artery bypass graft operations. J Thorac Cardiovasc Surg 1987; 94:331. 15. Wazni OM, Martin DO, Marrouche NF, et al. Plasma B-type natriuretic peptide levels predict postoperative atrial fibrillation in patients undergoing cardiac surgery. Circulation 2004; 110:124. 16. Buxton AE, Josephson ME. The role of P wave duration as a predictor of postoperative atrial arrhythmias. Chest 1981; 80:68. 17. Zacharias A, Schwann TA, Riordan CJ, et al. Obesity and risk of new-onset atrial fibrillation after cardiac surgery. Circulation 2005; 112:3247. 18. Kinoshita T, Asai T, Suzuki T, et al. Preoperative hemoglobin A1c predicts atrial fibrillation after off-pump coronary bypass surgery. Eur J Cardiothorac Surg 2012; 41:102. 19. Giaccardi M, Macchi C, Colella A, et al. Postacute rehabilitation after coronary surgery: the effect of preoperative physical activity on the incidence of paroxysmal atrial fibrillation. Am J Phys Med Rehabil 2011; 90:308. 20. Rader F, Van Wagoner DR, Ellinor PT, et al. Influence of race on atrial fibrillation after cardiac surgery. Circ Arrhythm Electrophysiol 2011; 4:644. 21. Bramer S, van Straten AH, Soliman Hamad MA, et al. Body mass index predicts new-onset atrial fibrillation after cardiac surgery. Eur J Cardiothorac Surg 2011; 40:1185. https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 23/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate 22. Argalious M, Motta P, Khandwala F, et al. "Renal dose" dopamine is associated with the risk of new-onset atrial fibrillation after cardiac surgery. Crit Care Med 2005; 33:1327. 23. Steinberg JS, Zelenkofske S, Wong SC, et al. Value of the P-wave signal-averaged ECG for predicting atrial fibrillation after cardiac surgery. Circulation 1993; 88:2618. 24. Korantzopoulos P, Kolettis TM, Galaris D, Goudevenos JA. The role of oxidative stress in the pathogenesis and perpetuation of atrial fibrillation. Int J Cardiol 2007; 115:135. 25. Bramer S, van Straten AH, Soliman Hamad MA, et al. The impact of new-onset postoperative atrial fibrillation on mortality after coronary artery bypass grafting. Ann Thorac Surg 2010; 90:443. 26. Wahr JA, Parks R, Boisvert D, et al. Preoperative serum potassium levels and perioperative outcomes in cardiac surgery patients. Multicenter Study of Perioperative Ischemia Research Group. JAMA 1999; 281:2203. 27. Zaman AG, Alamgir F, Richens T, et al. The role of signal averaged P wave duration and serum magnesium as a combined predictor of atrial fibrillation after elective coronary artery bypass surgery. Heart 1997; 77:527. 28. Aglio LS, Stanford GG, Maddi R, et al. Hypomagnesemia is common following cardiac surgery. J Cardiothorac Vasc Anesth 1991; 5:201. 29. Reinhart RA, Marx JJ Jr, Broste SK, Haas RG. Myocardial magnesium: relation to laboratory and clinical variables in patients undergoing cardiac surgery. J Am Coll Cardiol 1991; 17:651. 30. Kim YM, Kattach H, Ratnatunga C, et al. Association of atrial nicotinamide adenine dinucleotide phosphate oxidase activity with the development of atrial fibrillation after cardiac surgery. J Am Coll Cardiol 2008; 51:68. 31. Verma A, Marrouche NF, Seshadri N, et al. Importance of ablating all potential right atrial flutter circuits in postcardiac surgery patients. J Am Coll Cardiol 2004; 44:409. 32. Akar JG, Kok LC, Haines DE, et al. Coexistence of type I atrial flutter and intra-atrial re- entrant tachycardia in patients with surgically corrected congenital heart disease. J Am Coll Cardiol 2001; 38:377. 33. Seiler J, Schmid DK, Irtel TA, et al. Dual-loop circuits in postoperative atrial macro re-entrant tachycardias. Heart 2007; 93:325. 34. Wijeysundera DN, Beattie WS, Djaiani G, et al. Off-pump coronary artery surgery for reducing mortality and morbidity: meta-analysis of randomized and observational studies. J Am Coll Cardiol 2005; 46:872. 35. Athanasiou T, Aziz O, Mangoush O, et al. Do off-pump techniques reduce the incidence of postoperative atrial fibrillation in elderly patients undergoing coronary artery bypass https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 24/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate grafting? Ann Thorac Surg 2004; 77:1567. 36. Angelini GD, Taylor FC, Reeves BC, Ascione R. Early and midterm outcome after off-pump and on-pump surgery in Beating Heart Against Cardioplegic Arrest Studies (BHACAS 1 and 2): a pooled analysis of two randomised controlled trials. Lancet 2002; 359:1194. 37. Almassi GH, Pecsi SA, Collins JF, et al. Predictors and impact of postoperative atrial fibrillation on patients' outcomes: a report from the Randomized On Versus Off Bypass trial. J Thorac Cardiovasc Surg 2012; 143:93. 38. Cummings JE, Gill I, Akhrass R, et al. Preservation of the anterior fat pad paradoxically decreases the incidence of postoperative atrial fibrillation in humans. J Am Coll Cardiol 2004; 43:994. 39. White CM, Sander S, Coleman CI, et al. Impact of epicardial anterior fat pad retention on postcardiothoracic surgery atrial fibrillation incidence: the AFIST-III Study. J Am Coll Cardiol 2007; 49:298. 40. Amar D, Shi W, Hogue CW Jr, et al. Clinical prediction rule for atrial fibrillation after coronary artery bypass grafting. J Am Coll Cardiol 2004; 44:1248. 41. Villareal RP, Hariharan R, Liu BC, et al. Postoperative atrial fibrillation and mortality after coronary artery bypass surgery. J Am Coll Cardiol 2004; 43:742. 42. Mariscalco G, Klersy C, Zanobini M, et al. Atrial fibrillation after isolated coronary surgery affects late survival. Circulation 2008; 118:1612. 43. Kosmidou I, Chen S, Kappetein AP, et al. New-Onset Atrial Fibrillation After PCI or CABG for Left Main Disease: The EXCEL Trial. J Am Coll Cardiol 2018; 71:739. 44. Soucier RJ, Mirza S, Abordo MG, et al. Predictors of conversion of atrial fibrillation after cardiac operation in the absence of class I or III antiarrhythmic medications. Ann Thorac Surg 2001; 72:694. 45. Lee JK, Klein GJ, Krahn AD, et al. Rate-control versus conversion strategy in postoperative atrial fibrillation: a prospective, randomized pilot study. Am Heart J 2000; 140:871. 46. Kowey PR, Stebbins D, Igidbashian L, et al. Clinical outcome of patients who develop PAF after CABG surgery. Pacing Clin Electrophysiol 2001; 24:191. 47. Landymore RW, Howell F. Recurrent atrial arrhythmias following treatment for postoperative atrial fibrillation after coronary bypass operations. Eur J Cardiothorac Surg 1991; 5:436. 48. Ambrosetti M, Tramarin R, Griffo R, et al. Late postoperative atrial fibrillation after cardiac surgery: a national survey within the cardiac rehabilitation setting. J Cardiovasc Med (Hagerstown) 2011; 12:390. https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 25/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate 49. Ha ACT, Verma S, Mazer CD, et al. Effect of Continuous Electrocardiogram Monitoring on Detection of Undiagnosed Atrial Fibrillation After Hospitalization for Cardiac Surgery: A Randomized Clinical Trial. JAMA Netw Open 2021; 4:e2121867. 50. Stamou SC, Dangas G, Hill PC, et al. Atrial fibrillation after beating heart surgery. Am J Cardiol 2000; 86:64. 51. Almassi GH, Schowalter T, Nicolosi AC, et al. Atrial fibrillation after cardiac surgery: a major morbid event? Ann Surg 1997; 226:501. 52. Reed GL 3rd, Singer DE, Picard EH, DeSanctis RW. Stroke following coronary-artery bypass surgery. A case-control estimate of the risk from carotid bruits. N Engl J Med 1988; 319:1246. 53. Taylor GJ, Malik SA, Colliver JA, et al. Usefulness of atrial fibrillation as a predictor of stroke after isolated coronary artery bypass grafting. Am J Cardiol 1987; 60:905. 54. Lahtinen J, Biancari F, Salmela E, et al. Postoperative atrial fibrillation is a major cause of stroke after on-pump coronary artery bypass surgery. Ann Thorac Surg 2004; 77:1241. 55. Akintoye E, Sellke F, Marchioli R, et al. Factors associated with postoperative atrial fibrillation and other adverse events after cardiac surgery. J Thorac Cardiovasc Surg 2018; 155:242. 56. Hogue CW Jr, Murphy SF, Schechtman KB, D vila-Rom n VG. Risk factors for early or delayed stroke after cardiac surgery. Circulation 1999; 100:642. 57. Lotfi A, Wartak S, Sethi P, et al. Postoperative atrial fibrillation is not associated with an increase risk of stroke or the type and number of grafts: a single-center retrospective analysis. Clin Cardiol 2011; 34:787. 58. Newman MF, Wolman R, Kanchuger M, et al. Multicenter preoperative stroke risk index for patients undergoing coronary artery bypass graft surgery. Multicenter Study of Perioperative Ischemia (McSPI) Research Group. Circulation 1996; 94:II74. 59. Mickleborough LL, Walker PM, Takagi Y, et al. Risk factors for stroke in patients undergoing coronary artery bypass grafting. J Thorac Cardiovasc Surg 1996; 112:1250. 60. Butt JH, Xian Y, Peterson ED, et al. Long-term Thromboembolic Risk in Patients With Postoperative Atrial Fibrillation After Coronary Artery Bypass Graft Surgery and Patients With Nonvalvular Atrial Fibrillation. JAMA Cardiol 2018; 3:417. 61. Benedetto U, Gaudino MF, Dimagli A, et al. Postoperative Atrial Fibrillation and Long-Term Risk of Stroke After Isolated Coronary Artery Bypass Graft Surgery. Circulation 2020; 142:1320. 62. Kalavrouziotis D, Buth KJ, Ali IS. The impact of new-onset atrial fibrillation on in-hospital mortality following cardiac surgery. Chest 2007; 131:833. https://www.uptodate.com/contents/atrial-fibrillation-and-flutter-after-cardiac-surgery/print 26/43 7/5/23, 9:03 AM Atrial fibrillation and flutter after cardiac surgery - UpToDate 63. Saxena A, Dinh DT, Smith JA, et al. Usefulness of postoperative atrial fibrillation as an independent predictor for worse early and late outcomes after isolated coronary artery bypass grafting (multicenter Australian study of 19,497 patients). Am J Cardiol 2012; 109:219. 64. Crystal E, Garfinkle MS, Connolly SS, et al. Interventions for preventing post-operative atrial fibrillation in patients undergoing heart surgery. Cochrane Database Syst Rev 2004; :CD003611. 65. Kim MH, Deeb GM, Morady F, et al. Effect of postoperative atrial fibrillation on length of stay after cardiac surgery (The Postoperative Atrial Fibrillation in Cardiac Surgery study [PACS(2)]. Am J Cardiol 2001; 87:881. 66. Arsenault KA, Yusuf AM, Crystal E, et al. Interventions for preventing post-operative atrial fibrillation in patients undergoing heart surgery. Cochrane Database Syst Rev 2013; :CD003611. 67. Stephenson LW, MacVaugh H 3rd, Tomasello DN, Josephson ME. Propranolol for prevention of postoperative cardiac arrhythmias: a randomized study. Ann Thorac Surg 1980; 29:113.