Prophylaxis Of Postoperative Atrial Fibrillation Research Articles

Effect of green tea on amiodarone-induced lung injury in albino rats

Introduction Amiodarone (AM) is an antiarrhythmic agent used in the treatment and prophylaxis of postoperative atrial fibrillation. It has some serious side effects, including pulmonary toxicity. Green tea is among the most popular beverages. It is characterized by the presence of catechins, a subgroup of polyphenols, known as a powerful antioxidant. Aim The aim of the study was to determine the toxic effects of AM as an animal model on lung injury and evaluate the possible role of green tea extract against these effects in albino rats. Materials and methods The study included 21 adult male albino rats weighing 180–200 g. They were divided into three equal groups, comprising seven rats each. Group I was considered the control group. Group II rats were given AM orally at 30 mg/kg daily for 2 weeks. Group III rats were given green tea extract orally at 150 mg/kg daily for 2 weeks concomitantly with AM as in group II. The lungs were dissected out and processed for histological and immunohistochemical study. Morphometric and statistical studies were also carried out. Results Administration of AM in group II resulted in obvious distortion to the lung architecture. Collapsed alveoli, vacuolar degeneration of pneumocytes type II, thickening of interalveolar septa, and significant increase in collagen deposition were observed. Significantly increased number of macrophages was observed in group II. However coadministration of green tea extract with AM in group III showed obvious preservation of the lung architecture. Conclusion Administration of AM in rats induced severe lung damage, whereas concomitant administration of green tea extract effectively ameliorated lung tissue damage.

Postoperative Atrial Fibrillation in Liver Transplantation

Postoperative atrial fibrillation (POAF) is common after major surgeries and is associated with increased morbidity and mortality. POAF after liver transplantation (LT) has not been reported. This study was undertaken to investigate the incidence, impact, and risk factors of POAF in LT patients. After IRB approval, LT between January 2006 and August 2013 at our center were retrospectively reviewed. POAF that occurred within 30 days after LT was included. Patients with and without POAF were compared and independent risk factors were identified by logistic regression. Of 1387 adults LT patients, 102 (7.4%) developed POAF during the study period. POAF was associated with significantly increased mortality, graft failure, acute kidney injury and prolonged hospital stay. Independent risk factors included age, body weight, MELD score, presence of previous history of AF, the vasopressors use prior to LT and pulmonary artery diastolic pressure at the end of LT surgery (odds ratios 2.0-7.2, all p < 0.05). A risk index of POAF was developed and patients with the high-risk index had more than 60% chance of developing POAF. These findings may be used to stratify patients and to guide prophylaxis for POAF in the posttransplant period.

Carvedilol for Prevention of Atrial Fibrillation after Cardiac Surgery: A Meta-Analysis

BackgroundPostoperative atrial fibrillation (POAF) remains the most common complication after cardiac surgery. Current guidelines recommend β-blockers to prevent POAF. Carvedilol is a non-selective β-adrenergic blocker with anti-inflammatory, antioxidant, and multiple cationic channel blocking properties. These unique properties of carvedilol have generated interest in its use as a prophylaxis for POAF.ObjectiveTo investigate the efficacy of carvedilol in preventing POAF.MethodsPubMed from the inception to September 2013 was searched for studies assessing the effect of carvedilol on POAF occurrence. Pooled relative risk (RR) with 95% confidence interval (CI) was calculated using random- or fixed-effect models when appropriate. Six comparative trials (three randomized controlled trials and three nonrandomized controlled trials) including 765 participants met the inclusion criteria.ResultsCarvedilol was associated with a significant reduction in POAF (relative risk [RR] 0.49, 95% confidence interval [CI] 0.37 to 0.64, p<0.001). Subgroup analyses yielded similar results. In a subgroup analysis, carvedilol appeared to be superior to metoprolol for the prevention of POAF (RR 0.51, 95% CI 0.37 to 0.70, p<0.001). No evidence of heterogeneity was observed.ConclusionsIn conclusion, carvedilol may effectively reduce the incidence of POAF in patients undergoing cardiac surgery. It appeared to be superior to metoprolol. A large-scale, well-designed randomized controlled trial is needed to conclusively answer the question regarding the utility of carvedilol in the prevention of POAF.

Atrial fibrillation after coronary artery bypass grafting

Atrial fibrillation after coronary artery bypass grafting

Pre-Operative Left Atrial Mechanical Function Predicts Risk of Atrial Fibrillation Following Cardiac Surgery

The purpose of this study was to examine whether left atrial (LA) mechanical function, as measured by LA total emptying fraction (TEF), is a predictor for the development of post-operative atrial fibrillation (POAF) following cardiac surgery. POAF is an important and frequent complication of cardiac surgery. LA enlargement has been reported to be a risk factor for POAF, but the relationship between LA mechanical function and POAF is not well understood. We examined the relationship between pre-operative LA function and POAF in patients without a history of atrial fibrillation. A total of 101 subjects (mean age 64 ± 13 years) underwent pre-operative transthoracic echocardiograms and were followed for occurrence of POAF during the hospitalization for cardiac surgery. The left atrial maximum volume (LAVmax) and left atrial minimum volume (LAVmin) were measured and indexed to body surface area (LAVmaxI and LAVminI, respectively). LA TEF was calculated as: {[(LAVmax - LAVmin)/LAVmax] × 100%}. Univariate and multivariate analyses examined clinical and echocardiographic predictors of POAF. POAF occurred in 41% of subjects. Mean LA TEF was 49 ± 15%, mean LAVmaxI was 38 ± 15 ml/m(2), and mean LAVminI was 20 ± 13 ml/m(2). Age, LA TEF, and LAVminI were independent predictors of POAF. LA TEF was lower in patients with POAF compared with those without POAF (43 ± 15% vs. 55 ± 13%, p < 0.001), and patients with a LA TEF <50% had a high risk of POAF (odds ratio: 7.94, 95% confidence interval: 3.23 to 19.54, p < 0.001). Compared with LAVmaxI >32 ml/m(2), LA TEF <50% had higher discriminatory power for POAF, which remained significantly higher when adjusted for age (p = 0.04). LA TEF is an independent predictor of POAF and is a stronger predictor of POAF than LAVmaxI is. Impaired LA mechanical function may help to identify patients who are most likely to benefit from prophylaxis for POAF.

P-07 Incidence, prophylaxis and treatment of postoperative atrial fibrillation following cardiac surgery: a survey from the European Workgroup of Cardiothoracic Intensivists (EWCI)

Postoperative atrial fibrillation (POAF) is still a major complication following cardiac surgery. It is responsible for an increased risk of stroke, mortality, ICU and hospital stay, and costs. Guidelines for POAF prophylaxis have been presented by several Cardiothoracic Surgical Societies [1]. A survey is presented on the incidence, prophylaxis and treatment of POAF in EWCI centres.

Pharmacologic Prophylaxis of Postoperative Atrial Fibrillation in Patients Undergoing Cardiac Surgery: Beyond β‐Blockers

Postoperative atrial fibrillation (POAF) is a frequent complication of cardiac surgery that increases patient morbidity, length of stay, and hospital costs. A substantial body of evidence exists evaluating various pharmacologic and nonpharmacologic methods to decrease the occurrence of POAF in an effort to decrease its burden on the health care system. Evidence-based guidelines support the use of beta-blockers as standard prophylaxis of POAF in patients undergoing cardiac surgery. Traditional prophylactic therapy for POAF targets the sympathetic nervous system, refractory period, and atrial conduction. However, associations between the development of POAF and the inflammatory process, oxidative stress, and atrial remodeling have prompted the investigation of novel therapies targeting these processes. To evaluate the role of pharmacologic strategies beyond beta-blockers in the prevention of POAF, we conducted a search of the PubMed database to identify studies published from 1950-February 2009. Emphasis was placed on how these therapies could be used in patients intolerant to beta-blockers or as additive therapy in high-risk patients. We found that sufficient evidence exists to recommend the use of amiodarone, sotalol, and possibly magnesium as monotherapy in patients unable to take beta-blockers or as add-on therapy for the prevention of POAF. Currently, available evidence does not support the use of propafenone, procainamide, digoxin, thiazolidinediones, triiodothyronine, or calcium channel blockers in the prevention of POAF. Preliminary evidence suggests that dofetilide, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), nonsteroidal antiinflammatory drugs, corticosteroids, omega-3 fatty acids, ascorbic acid, N-acetylcysteine, and sodium nitroprusside may be effective in preventing POAF. Additional large-scale, adequately powered clinical studies are needed to determine the benefit of these agents before they can be considered for routine use.

The Changing Face of Postoperative Atrial Fibrillation Prevention

Atrial fibrillation is the most common postoperative arrhythmia with significant consequences on patient health. Postoperative atrial fibrillation (POAF) complicates up to 8% of all noncardiac surgeries, between 3% and 30% of noncardiac thoracic surgeries, and between 16% and 46% of cardiac surgeries. POAF has been associated with increased morbidity, mortality, and longer, more costly hospital stays. The risk of POAF after cardiac and noncardiac surgery may be affected by several epidemiologic and intraoperative factors, as well as by the presence of preexisting cardiovascular and pulmonary disorders. POAF is typically a transient, reversible phenomenon that may develop in patients who possess an electrophysiologic substrate for the arrhythmia that is present before or as a result of surgery. Numerous studies support the efficacy of beta-blockers in POAF prevention; they are currently the most common medication used in POAF prophylaxis. Perioperative amiodarone, sotalol, nondihydropyridine calcium channel blockers, and magnesium sulfate have been associated with a reduction in the occurrence of POAF. Biatrial pacing is a nonpharmacologic method that has been associated with a reduced risk of POAF. Additionally, recent studies have demonstrated that hydroxymethylglutaryl-CoA reductase inhibitors may decrease the risk of POAF. Finally, based on recent evidence that angiotensin converting enzyme inhibitors and angiotensin receptor blockers reduce the risk of permanent atrial fibrillation, these medications may also hold promise in POAF prophylaxis. However, there is a need for further large-scale investigations that incorporate standard methodologies and diagnostic criteria, which have been lacking in past trials.

Letter by Shroff and Orlandi Regarding Article, “Randomized Trial of Atorvastatin for Reduction of Postoperative Atrial Fibrillation in Patients Undergoing Cardiac Surgery: Results of the ARMYDA-3 (Atorvastatin for Reduction of Myocardial Dysrhythmia After Cardiac Surgery) Study”

HomeCirculationVol. 115, No. 15Letter by Shroff and Orlandi Regarding Article, “Randomized Trial of Atorvastatin for Reduction of Postoperative Atrial Fibrillation in Patients Undergoing Cardiac Surgery: Results of the ARMYDA-3 (Atorvastatin for Reduction of Myocardial Dysrhythmia After Cardiac Surgery) Study” Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBLetter by Shroff and Orlandi Regarding Article, “Randomized Trial of Atorvastatin for Reduction of Postoperative Atrial Fibrillation in Patients Undergoing Cardiac Surgery: Results of the ARMYDA-3 (Atorvastatin for Reduction of Myocardial Dysrhythmia After Cardiac Surgery) Study” Gautam R. Shroff, MD and Quirino G. Orlandi, MD Gautam R. ShroffGautam R. Shroff University of Minnesota,, Minneapolis Heart Institute, Minneapolis, Minn. Search for more papers by this author and Quirino G. OrlandiQuirino G. Orlandi University of Minnesota,, Minneapolis Heart Institute, Minneapolis, Minn. Search for more papers by this author Originally published17 Apr 2007https://doi.org/10.1161/CIRCULATIONAHA.106.677708Circulation. 2007;115:e404To the Editor:We read with great interest the study by Patti and colleagues1 that suggests a beneficial effect of atorvastatin in preventing postoperative atrial fibrillation in cardiac surgery patients.The placebo arm in this study had fewer patients on β-blockers (60% versus 72%, P=0.08), more patients with left atrial enlargement (46% versus 36%, P=0.16), more patients with mitral valve disease (7% versus 2%, P=0.10) and more patients undergoing valve surgery (25% versus 16%). All these variables are known to have a strong association with atrial fibrillation.2 Although these individual differences were not statistically significant, the combination of these variables likely contributed to the magnitude of the treatment effect.It would be helpful for clinicians to know the incremental benefit of atorvastatin in patients already receiving β-blocker therapy. We also invite the authors to comment on the difference in the clinical outcome after adjusting for the magnitude of left atrial enlargement. Recent data demonstrate that left atrial volume is a strong predictor of atrial fibrillation after cardiac surgery.3 Therefore, it would be relevant to know how left atrial enlargement was measured in the study.Lastly, 75% patients in the placebo arm of this study and 83% patients in the atorvastatin arm underwent elective coronary bypass surgery. In modern cardiology practice, it would be unusual for patients with established coronary disease to undergo elective bypass surgery without any prior statin therapy. This study, however, highlights the potential benefit of even a short course of statin therapy prior to surgery in preventing atrial fibrillation.DisclosuresNone.1 Patti G, Chello M, Candura D, Pasceri V, D’Ambrosio A, Covino E, Di Sciascio G. Randomized trial of atorvastatin for reduction of postoperative atrial fibrillation in patients undergoing cardiac surgery: results of the ARMYDA-3 (Atorvastatin for Reduction of MYocardial Dysrhythmia After cardiac surgery) study. Circulation. 2006; 114: 1455–1461.LinkGoogle Scholar2 Hogue CW Jr., Creswell LL, Gutterman DD, Fleisher LA; American College of Chest Physicians. Epidemiology, mechanisms, and risks: American College of Chest Physicians guidelines for the prevention and management of postoperative atrial fibrillation after cardiac surgery. Chest. 2005; 128 (2 Suppl): 9S–16S.CrossrefMedlineGoogle Scholar3 Osranek M, Fatema K, Qaddoura F, Al-Saileek A, Barnes ME, Bailey KR, Gersh BJ, Tsang TS, Zehr KJ, Seward JB. Left atrial volume predicts the risk of atrial fibrillation after cardiac surgery: a prospective study. J Am Coll Cardiol. 2006; 48: 779—786.CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Mio M and Goldstein B (2021) Bipolar disorder and cardiovascular dysfunction: Mechanisms and implications Neurobiology of Bipolar Disorder, 10.1016/B978-0-12-819182-8.00019-3, (223-233), . Carrascal Y, Arnold R, De la Fuente L, Revilla A, Sevilla T, Arce N, Laguna G, Pareja P and Blanco M (2016) Efficacy of atorvastatin in prevention of atrial fibrillation after heart valve surgery in the PROFACE trial (PROphylaxis of postoperative atrial Fibrillation After Cardiac surgEry), Journal of Arrhythmia, 10.1016/j.joa.2016.01.010, 32:3, (191-197), Online publication date: 1-Jun-2016. Moro C, Hernández-Madrid A and Matía R (2010) Non-Antiarrhythmic Drugs to Prevent Atrial Fibrillation, American Journal Cardiovascular Drugs, 10.2165/11537270-000000000-00000, 10:3, (165-173), Online publication date: 1-Jun-2010. Yin L, Wang Z, Wang Y, Ji G and Xu Z (2010) Effect of Statins in Preventing Postoperative Atrial Fibrillation Following Cardiac Surgery, Heart, Lung and Circulation, 10.1016/j.hlc.2010.06.664, 19:10, (579-583), Online publication date: 1-Oct-2010. April 17, 2007Vol 115, Issue 15 Advertisement Article InformationMetrics https://doi.org/10.1161/CIRCULATIONAHA.106.677708PMID: 17438159 Originally publishedApril 17, 2007 PDF download Advertisement SubjectsArrhythmiasCardiovascular Surgery

Amiodarone Prophylaxis for Atrial Fibrillation After Cardiac Surgery: Meta‐Analysis of Dose Response and Timing of Initiation

To investigate a possible dose-response relationship between amiodarone and reduction in incidence of postoperative atrial fibrillation, and to determine whether pre- or postoperative initiation of amiodarone is superior. Meta-analysis of randomized controlled trials. MEDLINE and EMBASE databases and the Cochrane Central Register of Controlled Trials for English-language reports published between 1966 and December 2005. Of 23 identified randomized controlled trials of amiodarone prophylaxis of postoperative atrial fibrillation, 14 were included in the final analysis. These studies enrolled a total of 2864 patients. For each study, the total administered amiodarone dose--categorized as low (< 3000 mg), medium (3000-5000 mg), or high (> 5000 mg)--and preoperative versus postoperative initiation were aggregated by using meta-analytic techniques. The incidence of postoperative atrial fibrillation was significantly reduced by amiodarone compared with placebo (p<0.001). Although the odds of developing atrial fibrillation appeared to be somewhat higher in the low-dose group, no significant differences were noted in the odds ratios (ORs) of developing atrial fibrillation among the low-, medium-, and high-dose groups: OR 0.58, 95% confidence interval (CI) 0.44-0.77; OR 0.45, 95% CI 0.30-0.69; and OR 0.44, 95% CI 0.33-0.58; respectively (p=0.238). In addition, the ORs for atrial fibrillation development associated with preoperative and postoperative initiation of amiodarone were not significantly different (OR 0.50, 95% CI 0.39-0.63; and OR 0.48, 95% CI 0.37-0.63; respectively, p=0.862). Total amiodarone doses of 3000 mg or higher may be more effective than lower doses in reducing the rate of postoperative atrial fibrillation after cardiac surgery. Preoperative initiation of amiodarone appears to be unnecessary. These findings require confirmation in prospective, randomized trials.

Carvedilol versus Metoprolol for the Prevention of Atrial Fibrillation After Off-Pump Coronary Bypass Surgery: Rationale and Design of the Carvedilol or Metoprolol Post-Revascularization Atrial Fibrillation Controlled Trial (COMPACT)

Postoperative new-onset atrial fibrillation (AF) remains the most common complication of coronary artery bypass graft surgery. Postoperative AF carries the risk of hemodynamic instability, increases the risk of thromboembolic events, and has a significant economic impact. Current guidelines recommend treatment with beta-blockers to prevent AF; information, however, is limited regarding the relative efficacy of beta-blocking agents. Carvedilol is a non-selective adrenergic blocker with anti-inflammatory, antioxidant, and multiple cationic channel blocking properties. These unique properties of carvedilol have generated interest in its use as a prophylaxis for postoperative AF. We hypothesize that carvedilol will be more effective than metoprolol, a conventional beta(1)-selective antagonist, in suppressing newly developed AF following off-pump coronary artery bypass (OPCAB) surgery. We have designed the Carvedilol or Metoprolol Post-Revascularization Atrial Fibrillation Controlled Trial (COMPACT) to test our hypothesis in a multi-center, open-label, randomized, and controlled trial. A total of at least 650 patients will be randomized to receive an initial oral dose of either 5 mg of carvedilol twice per day or 20 mg of metoprolol tartrate three times per day following surgery. The dose of each beta-blocker will be increased to the maximum tolerated dose. The primary endpoint is the incidence of new-onset AF during the first 7 days after surgery. The COMPACT is the first multi-center, randomized, controlled trial to directly compare two different beta-blockers in patients following surgical coronary revascularization. Results of this trial will help to guide physicians in choosing appropriate medications following OPCAB surgery.

Safety of amiodarone in the prevention of postoperative atrial fibrillation: A meta-analysis

A meta-analysis was conducted to assess the safety of amiodarone in the prevention of postoperative atrial fibrillation. A search of the medical literature was conducted to identify randomized controlled trials of prophylactic amiodarone use in cardiothoracic surgery. Studies were independently reviewed by three investigators and selected for inclusion if they met the following three criteria: (1) randomized controlled trial of amiodarone versus placebo or routine treatment, (2) patients underwent coronary artery bypass graft or valvular surgery, and (3) reported data on the frequency of at least one of the following safety endpoints: bradycardia, hypotension, heart block, nausea, cerebral vascular accident, myocardial infarction, and death. Both random- and fixed-effects models were used to determine any significant associations between amiodarone and safety endpoints. Eighteen trials were analyzed. A total of 3408 patients were enrolled in these trials (1736 received amiodarone and 1672 received placebo). Amiodarone increased the odds of developing bradycardia (odds ratio [OR], 1.70; 95% confidence interval [CI], 1.05-2.74) and hypotension (OR, 1.62; 95% CI, 1.04-2.54). The administration of i.v. amiodarone, an average daily dose exceeding 1 g, and postoperative amiodarone administration were each associated with a greater likelihood of hemodynamic adverse effects. Amiodarone did not appear to affect other safety endpoints. Meta-analysis showed amiodarone to be associated with an increased risk of developing bradycardia and hypotension when used for the prophylaxis of postoperative atrial fibrillation. The greatest risk in the occurrence of these adverse events arose when using regimens containing i.v. amiodarone, initiating prophylaxis during the postoperative period, and using regimens with average daily doses exceeding 1 g.

Introduction: American College of Chest Physicians Guidelines for the Prevention and Management of Postoperative Atrial Fibrillation After Cardiac Surgery

Atrial fibrillation (AF) and atrial flutter (AFL) are arrhythmias that commonly occur following cardiac surgery. The precipitating events are not always obvious, although predisposing factors including age have been defined. Postoperative AF and AFL add significantly to both the cost and morbidity of cardiac surgery. This guideline report, which was created under the auspices of the American College of Chest Physicians (ACCP), critically reviews evidence-based literature defining optimal treatment and prophylaxis for postoperative AF. Specific issues addressed include the following: (1) controlling the ventricular response rate in the patient with postoperative AF and AFL; (2) preventing thromboembolism in the setting of AF and AFL including the appropriate role of anticoagulation therapy; (3) pharmacologic approaches to converting AF or AFL to normal sinus rhythm, and maintaining normal sinus rhythm postoperatively; and (4) pharmacologic and surgical prophylaxis against postoperative AF and AFL. The resulting clinical practice guidelines represent the best-supported treatments, based on a rational scientific approach formulated from randomized clinical trials and systematic reviews. The panel convened by the Health and Sciences Policy Committee of the ACCP reviewed the currently available evidence to provide a basis for making specific recommendations for patient care.

Three-Day Magnesium Administration Prevents Atrial Fibrillation After Coronary Artery Bypass Grafting

The efficacy of magnesium administration in preventing the occurrence of atrial fibrillation after coronary artery bypass grafting surgery remains controversial. Optimal dose and timing of the administration also await clarification. The purpose of this study was to assess the effect of 3-day postoperative infusion of magnesium on postoperative atrial fibrillation and to find factors that can influence the efficacy of this treatment. After institutional review board approval, a retrospective study was conducted reviewing 200 consecutive patients who underwent isolated, initial coronary artery bypass grafting operation. The first 100 patients did not receive the prophylactic treatment, whereas the next 100 patients were treated with magnesium postoperatively. Patients in the magnesium-treated group received 10 mmol (2.47 g) of magnesium sulfate (MgSO4 * 7H2O) infused daily for 3 days after surgery. The incidence of postoperative atrial fibrillation was 35% in the untreated group compared with 16% in the magnesium-treated group (p = 0.002). Multivariate logistic regression analysis revealed that advanced age, decreased left ventricular ejection fraction, and absence of magnesium therapy were independent predictors of postoperative atrial fibrillation. For patients receiving the magnesium therapy, advanced age and decreased ejection fraction were the independent factors that predicted the arrhythmia. Postoperative 3-day magnesium infusion is effective in reducing the incidence of atrial fibrillation occurring after coronary artery bypass grafting surgery. However, in older patients or in patients with reduced left ventricular function, magnesium treatment alone is insufficient for prophylaxis of postoperative atrial fibrillation.

Temporary atrial epicardial pacing as prophylaxis against atrial fibrillation after heart surgery: a meta-analysis.

Recent studies have reported the use of temporary epicardial atrial pacing as prophylaxis for postoperative atrial fibrillation (AF). The aim of this study was to assess the effect of pacing therapies for prevention of postoperative AF using meta-analysis. Using a computerized MEDLINE search, eight pacing prophylaxis trials with 776 patients were included in the meta-analysis. Trials compared control patients to patients randomized to right atrial, left atrial, or biatrial pacing used in conjunction with either fixed high-rate pacing or overdrive pacing. Overdrive biatrial pacing (OR 2.6, CI 1.4-4.8), overdrive right atrial pacing (OR 1.8, CI 1.1-2.7), and fixed high-rate biatrial pacing (OR 2.5, CI 1.3-5.1) demonstrated a significant antiarrhythmic effect for prevention of AF after open heart surgery. Furthermore, studies investigating overdrive left atrial pacing and fixed high-rate right atrial pacing have been underpowered to assess efficacy. Biatrial overdrive and fixed high-rate pacing and right atrial fixed high-rate pacing reduced the risk of new-onset AF after open heart surgery, and the relative risk reduction is approximately 2.5-fold. These results imply that various pacing algorithms are useful as a nonpharmacologic method to prevent postoperative AF.

Magnesium infusion dramatically decreases the incidence of atrial fibrillation after coronary artery bypass grafting

Background. Atrial fibrillation (AF) is one of the most common complications of cardiac surgery. Magnesium, like several other pharmacologic agents, has been used in the prophylaxis of postoperative AF with varying degrees of success. However, the dose and the timing of magnesium prophylaxis need to be clarified. The purpose of this study was to assess the effect of intermittent magnesium infusion on postoperative AF. Methods. A total of 200 consecutive patients who had elective, isolated, first-time coronary artery bypass grafting were prospectively randomized to two groups. Patients in the magnesium group (n = 100) received 6 mmol MgSO 4 infusion in 100 mL 0.9% NaCl solution (25 mL/h) the day before surgery, just after cardiopulmonary bypass, and once daily for 4 days after surgery. Patients in the control group (n = 100) received only 100 mL 0.9% NaCl solution (25 mL/h) at the same time points. Results. Postoperative AF occurred in 2 (2%) patients in the magnesium group and in 21 (21%) patients in the control group ( p < 0.001). Atrial fibrillation started, on average, 49.4 ± 16.8 hours postoperatively. The postoperative length of hospital stay was not significantly different in patients with AF (7.4 ± 8.0 days) compared with patients without AF (5.4 ± 1.1 days; p = 0.236). Conclusions. The use of magnesium in the preoperative and early postoperative periods is highly effective in reducing the incidence of AF after coronary artery bypass grafting.