Role of postoperative use of adrenergic drugs in occurrence of atrial fibrillation after cardiac surgery

BACKGROUND: Use of adrenergic (inotropic and vasopressor) drugs is common after cardiac surgery. HYPOTHESIS: The study was undertaken to evaluate the role of postoperative adrenergic drug use as a predictor of postoperative atrial fibrillation (AF) after cardiac surgery. METHODS: The study population consisted of 199 patients post cardiac surgery. Postoperative adrenergic drug use and the baseline and clinical variables were analyzed as possible predictors of postoperative AF. RESULTS: Of 199 patients, postoperative AF occurred in 59 patients (incidence 30%). The adrenergic drugs were used in 127 (64%) patients. Postoperative AF occurred in 49 of the 127 patients (39%) with and in 10 of the 72 patients (14%) without adrenergic drug use (p < 0.01). By univariate analyses, postoperative adrenergic drug use, age, left ventricular hypertrophy, left atrial size, valve surgery, aortic valve replacement, cross clamp time, bypass time, postoperative ventricular pacing, and hours in intensive care unit were predictors of development of postoperative AF. Atrial pacing was a predictor of freedom from developing AF. By multivariate logistic regression analysis, adrenergic drug use was an independent predictor of postoperative AF (odds ratio [OR] 3.35, 95% confidence interval [CI] 1.38-8.12, p = 0.016). Two other independent predictors were valve surgery (OR 2.88, 95% CI 1.31-6.35, p = 0.002) and age (OR 10.73, 95% CI 10.37-11.10, p = 0.0001). Adrenergic drug use, valve surgery, ventricular pacing, and age were predictors of time duration from surgery to the occurrence of AF. Drugs with predominantly beta1-adrenergic receptor affinity were associated with a higher incidence of postoperative AF (dopamine 44%, dobutamine 41% vs. phenylepherine 20%, p = 0.001). CONCLUSION: Use of adrenergic drugs is an independent predictor of postoperative AF after cardiac surgery.     

左心房容积与冠状动脉旁路移植术后心房颤动相关性的研究

目的:评价冠状动脉旁路移植术(CABG)前,二维超声心动图估测左心房容积指数(LAVI)与术后心房颤动发生的相关性。方法:入选北京同仁医院2010年1月至2012年6月期间,入院实施CABG术的冠心病患者106例进行前瞻性分析。将患者分为术后心房颤动组和术后未发生心房颤动组。采用多因素Logistic回归分析,评价术前通过二维超声心动图估测的LAVI值与术后心心房颤动动发生的相关性。结果:CABG术后发生心房颤动患者19例,术后心房颤动发生率为17.9%。术后心房颤动组的LAVI值显著高于术后未发生心房颤动组[(22.1±4.1)vs.(18.1±5.1)m L/m2,P=0.018]。多元logistic回归分析显示,年龄(OR=1.015,95%CI:1.017~1.0323,P=0.026)、高血压病史(OR=1.053,95%CI:1.019~1.087,P=0.009)、既往心房颤动病史(OR=2.273,95%CI:1.207~3.340,P=0.010)、LAV值(OR=1.784,95%CI:1.181~2.487,P=0.003)是CABG后心房颤动发生的独立危险因素。结论:CABG术前通过二维超声心动图估测的LAVI值是冠心病患者CABG术后心房颤动发生的独立危险因素,对于预测CABG术后心房颤动发生并进行危险分层具有一定参考价值。     

Predictive value of total atrial conduction time measured with tissue Doppler imaging for postoperative atrial fibrillation after coronary artery bypass surgery

Objective

Postoperative atrial fibrillation (POAF) complicating coronary artery bypass grafting surgery (CABG) increases morbidity and stroke risk. Total atrial conduction time (PA-TDI duration) has been identified as an independent predictor of new-onset atrial fibrillation (AF). We aimed to assess whether PA-TDI duration is a predictor of AF after CABG.

Methods

In 128 patients who had undergone CABG, preoperative clinical and echocardiographic data were compared between patients with and without POAF. The PA-TDI duration was assessed by measuring the time interval between the beginning of the P wave on the surface ECG and point of the peak A wave on TDI from left atrium (LA) lateral wall just over the mitral annulus.

Results

Patients with POAF (38/128, 29.6 %) were older (68.1?±?11.1 vs. 59.3?±?10.2 years; p?<?0.001), had higher LA maximum volume, had prolonged PA-TDI duration, and had lower ejection fraction compared with patients without POAF. PA-TDI duration was found to be significantly increased in POAF group (134.3?±?19.7 vs. 112.5?±?17.7 ms; p?=?0.01). On multivariate analysis, age (95 % CI?=?1.03–1.09; p?=?0.003), LA maximum volume (95 % CI?=?1.01–1.06; p?=?0.03), and prolonged PA-TDI duration (95 % CI, 1.02–1.05; p?=?0.001) were found to be the independent risk factors of POAF.

Conclusions

In this study, LA maximum volume and PA-TDI duration were found to be the independent predictors of the development of POAF after CABG. Echocardiographic predictors of left atrial electromechanical dysfunction may be useful in risk stratifying of patients in terms of POAF development after CABG.     

Association of atrial nicotinamide adenine dinucleotide phosphate oxidase activity with the development of atrial fibrillation after cardiac surgery.

OBJECTIVES: Our goal was to evaluate the role of myocardial nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and plasma markers of oxidative stress in the pathogenesis of post-operative atrial fibrillation (AF). BACKGROUND: Atrial fibrillation is a common complication of cardiac surgery, leading to increased morbidity and prolonged hospitalization. Experimental evidence suggests that oxidative stress may be involved in the pathogenesis of AF; however, the relevance of this putative mechanism in patients undergoing cardiac surgery is unclear. METHODS: We measured basal and NADPH-stimulated superoxide production in right atrial appendage samples from 170 consecutive patients undergoing conventional coronary artery bypass surgery. Plasma markers of lipid and protein oxidation (thiorbabituric acid-reactive substances, 8-isoprostane, and protein carbonyls) were also measured in blood samples drawn from a central line before surgery and after reperfusion. RESULTS: Patients who developed AF after surgery (42%) were older and had a significantly increased atrial NADPH oxidase activity than patients who remained in sinus rhythm (SR) (in relative light units/s/mug protein: 4.78 +/- 1.44 vs. 3.53 +/- 1.04 in SR patients, p < 0.0001). Plasma markers of lipid and protein oxidation increased significantly after reperfusion; however, neither pre-operative nor post-operative measurements differed between patients who developed AF and those who remained in SR after surgery. Multivariate analysis identified atrial NADPH oxidase activity as the strongest independent predictor of post-operative AF (odds ratio 2.41; 95% confidence interval 1.71 to 3.40, p < 0.0001). CONCLUSIONS: Atrial NADPH oxidase activity is independently associated with an increased risk of post-operative AF, suggesting that this oxidase system may be a key mediator of atrial oxidative stress leading to the development of AF after cardiac surgery.     

Left atrial volume: predictor of atrial fibrillation in patients with degenerative mitral regurgitation

BACKGROUND AND AIM OF THE STUDY: In patients with mitral regurgitation (MR) due to degenerative mitral valve prolapse (MVP), preoperative atrial fibrillation (AF) has been identified as an independent predictor of survival after surgery for MR. Thus, the determinants of preoperative AF may have critical implications to evaluate the timing of mitral valve repair. The study aim was to investigate the role of left atrial (LA) volume in predicting preoperative AF in patients with severe MR due to degenerative MVP. METHODS: Sixty-six patients with severe degenerative MR (regurgitant volume > or =60 ml, regurgitant fraction > or =50%, effective regurgitant orifice area > or =0.4 cm(2)) in sinus rhythm (SR) at diagnosis and conservatively managed were eligible for the study. Complete two-dimensional (2-D) echocardiographic and Doppler measurements, including the measurement of maximum LA volume, were performed in all patients. RESULTS: During follow up under conservative management (18.1+/-4.8 months), eight patients (12%) experienced conversion to AF, and 58 remained in SR. The mean LA dimension was 4.0+/-0.5 cm in patients with SR, and 5.1+/-0.8 cm in those who developed AF (p <0.0001). The mean LA volume and LA volume index (indexed to body surface area) were 95 +/-23 ml and 60+/-14 ml/m(2) respectively in patients with SR, and 166+/-66 ml and 104+/-42 ml/m(2) respectively in those who developed AF (both p <0.0001). The optimal cut-off value for LA volume to predict AF conversion was 117.5 ml (sensitivity 88%, specificity 83%), and for LA volume index was 75 ml/m(2) (sensitivity 88%, specificity 88%). CONCLUSION: LA volume measurement should be considered in patients with degenerative severe MR diagnosed in SR. A LA volume index > or =75 ml/m(2) reflects the risk of subsequent AF, and patients should be closely monitored.     

Left atrial reservoir function as a potent marker for first atrial fibrillation or flutter in persons > or = 65 years of age

The aim of this prospective study was to evaluate the incremental value of left atrial (LA) function for the prediction of risk for first atrial fibrillation (AF) or atrial flutter. Maximum and minimum LA volumes were quantitated by echocardiography in 574 adults (mean age 74 +/- 6 years, 52% men) without a history or evidence of atrial arrhythmia. During a mean follow-up period of 1.9 +/- 1.2 years, 30 subjects (5.2%) developed electrocardiographically confirmed AF or atrial flutter. Subjects with new AF or atrial flutter had lower LA reservoir function, as measured by total LA emptying fraction (38% vs 49%, p <0.0001) and higher maximum LA volumes (47 vs 40 ml/m(2), p = 0.005). An increase in age-adjusted risk for AF or atrial flutter was evident when the cohort was stratified according to medians of LA emptying fraction (< or =49%: hazard ratio 6.5, p = 0.001) and LA volume (> or =38 ml/m(2): hazard ratio 2.0, p = 0.07), with the risk being highest for subjects with concomitant LA emptying fractions < or =49% and LA volume > or =38 ml/m(2) (hazard ratio 9.3, p = 0.003). LA emptying fraction (p = 0.002) was associated with risk for first AF or atrial flutter after adjusting for baseline clinical risk factors for AF or atrial flutter, left ventricular ejection fraction, diastolic function grade, and LA volume. In conclusion, reduced LA reservoir function markedly increases the propensity for first AF or atrial flutter, independent of LA volume, left ventricular function, and clinical risk factors.     

Left atrial dysfunction is a predictor of postcoronary artery bypass atrial fibrillation: association of left atrial strain and strain rate assessed by speckle tracking

Background: Even though atrial fibrillation (AF) is the most common arrhythmia after coronary artery bypass grafting (CABG), its etiology remains poorly understood. Several factors are linked to postoperative AF (POAF), including advanced age and systemic inflammation. However, left atrial (LA) contractile dysfunction has not been evaluated in the perioperative scenario. Aim: To evaluate LA function through strain and strain rate in patients with coronary artery disease undergoing CABG and its correlation with POAF. Methods: We studied 70 patients undergoing CABG in sinus rhythm at the time of surgery. Preoperative echocardiography with evaluation of LA strain and strain rate by speckle tracking was performed. The occurrence of POAF was evaluated by continuous monitoring. Baseline and postoperative C‐reactive protein (CRP) levels were measured to evaluate systemic inflammation. Results: After 1‐week follow‐up 26% of subjects developed AF. LA strain s wave (LASs) and LA strain rate s (LASRs) and a wave (LASRa) were significantly decreased in patients who developed POAF: LASs (10 ± 1% vs. 24 ± 1%, P < 0.001), LASRs (0.6 ± 0.1 sec^–1 vs. 1.2 ± 0.1 sec^?1, P < 0.001), LASRa (?0.6 ± 0.1 sec^–1 vs. –1.8 ± 0.1 sec^?1, P < 0.001). LASRs, LASRa, age, and LA volume were independent predictors of POAF. CRP at baseline was similar irrespective of POAF development. Conclusions: LA dysfunction, evaluated by strain and strain rate is an independent predictor of POAF and contributes to classic risk factors like age and atrial volume. (Echocardiography 2011;28:1104‐1108)     

Impact of atrial fibrillation on clinical status, atrial size and hemodynamics in patients after mitral valve replacement.

BACKGROUND AND AIM OF THE STUDY: The association between mitral valve disease and atrial fibrillation (AF) is well known, but few data exist regarding the impact of AF after mitral valve replacement (MVR) on NYHA functional class, atrial size and hemodynamic parameters. The present study was conducted to evaluate these issues. METHODS: Eighty-six patients (26 men, 60 women) who underwent MVR were evaluated by transthoracic echocardiography. Fifty-nine patients had chronic AF (AF group), and 27 were in sinus rhythm (sinus group). Variables analyzed included end-systolic left atrial and right atrial areas, tricuspid regurgitation, and presence and duration of AF. Peak and mean transprosthetic mitral valve gradients and pulmonary pressure were estimated by Doppler echocardiography. RESULTS: Groups were matched for age, sex and time from MVR (mean 6.6 years). Sixty-four patients (77%) had rheumatic heart disease, 18 (21%) had mitral valve disease, and two (2%) had mitral valve prolapse. Mean duration of AF was 11+/-12 years (range: 8-50 years). Preoperatively, AF patients had a worse NYHA class than sinus patients (2.8+/-0.8 versus 1.1+/-0.7, p = 0.001), but both had similar fractional shortening of the left ventricle and preserved prosthetic mitral valve function. Multivariate analysis identified AF as a single predictor of NYHA class after MVR. Although left and right atrial areas were larger in AF patients (47+/-25 versus 27+/-7 cm2, p = 0.0001 and 30+/-12 versus 17+/-5 cm2, p = 0.0001, respectively), the left:right atrial size ratio was not significantly different between groups. Multivariate analysis identified mean transmitral gradient and duration of AF as independent predictors of left atrial size after MVR (p = 0.01 and p = 0.0001, respectively). Tricuspid regurgitation and duration of AF were independent predictors of right atrial size (p = 0.003 and p = 0.0001, respectively). CONCLUSION: The presence of AF after MVR is associated with a worse NYHA functional class, increased transmitral gradients, and larger areas of both atria, when compared with sinus rhythm. Hence, a special effort should be made to correct arrhythmia during surgery, and in case of paroxysmal arrhythmia, earlier surgery should be considered before the condition becomes chronic.     

Left Volume Atrial Index and P-wave Dispersion as Predictors of Postoperative Atrial Fibrillation After Coronary Artery Bypass Graft: A Retrospective Cohort Study

Preoperative left atrial remodeling as Postoperative atrial fibrillation (POAF) predisposing factors could be measured by left atrial volume index (LAVI) and P-wave dispersion. This study aimed to assess P-wave dispersion and LAVI as preoperative predictors of POAF among patients who underwent Coronary Artery Bypass Graft (CABG). An analytical retrospective cohort study was performed on patients who underwent CABG. The P-wave dispersion and POAF were evaluated based on documented ECG results. LAVI size was collected from echocardiographic reports. Hazard ratios of P-wave dispersion and LAVI for POAF were analyzed using Cox proportional hazard model. A total of 42 subjects (57 ± 1 years) were included in this study. POAF occurred in 28.6% of patients at a median of 2 days after CABG. P-wave dispersion was significantly longer in patients in whom AF was developed (53.03 ± 3.82 ms vs 44.01 ± 1.98ms, p:0.028), while LAVI difference was not significant. The Cox proportional hazard model showed a significant association between P-wave dispersion and risk of POAF (HR 1.05, CI95%, 1.001-1.103; P = 0.048). There was no association between LAVI and risk of POAF (HR 1.003, CI 95%, 0.965-1.044; P = 0.864). P-wave dispersion is a predictor of POAF in patients who underwent CABG. Risk stratification using P-wave dispersion enables clinicians to identify high-risk patients before CABG surgery.     

Plasma concentration of atrial natriuretic peptide is related to the duration of atrial fibrillation in patients with advanced heart failure

BACKGROUND: Plasma concentration of atrial natriuretic peptide (ANP) is elevated in patients with atrial fibrillation (AF) and in patients with chronic heart failure (CHF).Aim. To assess ANP level in patients with permanent AF and advanced CHF. METHODS: The study group consisted of 41 patients (27 males, mean age 62+/-8 years) with AF of a mean duration of 8.8 months. Twenty six (63%) patients were in NYHA class II, and 15 (37%) - in NYHA class III or IV. All patients underwent clinical and echocardiographic evaluation as well as ANP plasma concentration assessment. Multiple regression analysis was used to identify factors which determine ANP plasma concentration. RESULTS: Mean ANP plasma concentration was 52.4+/-22.7 pg/ml in the whole study group; 38.6+/-10.8 pg/ml in NYHA class II patients and 74.9+/-18.7 pg/ml in NYHA class III-IV subjects (p<0.0001). Among echocardiographic parameters, patients with NYHA class III or IV had significantly lower left ventricular ejection fraction and greater left atrial volume than patients with NYHA class II (32% versus 56%, p<0.0001 and 101.0+/-23.8 cm(3) versus 83.4+/-16.1 cm(3), p<0.006, respectively). Multiple regression analysis revealed a significant negative correlation between AF duration and ANP level (p=0.0013) in a group of patients with NYHA class III or IV and identified AF duration as an independent predictor of ANP plasma concentration in this group of patients. CONCLUSIONS: ANP plasma concentration in patients with persistent AF and advanced CHF is determined by AF duration - the longer the AF duration the lower the ANP level.     

Diastolic function and new-onset atrial fibrillation following cardiac surgery

Background:

Numerous studies have reported predictors of new-onset postoperative atrial fibrillation (POAF) following cardiac surgery, which is associated with increased length of stay, cost of care, morbidity, and mortality. The purpose of this study was to examine the association between preoperative diastolic function and occurrence of new-onset POAF in patients undergoing a variety of cardiac surgeries at a single institution.

Methods:

Using data from a prospective study from November 2007 to January 2010, a retrospective review was conducted. The diastolic function of each patient was determined from preoperative transthoracic echocardiograms. Occurrence of new-onset POAF was prospectively noted for each patient in the original study. Demographic and operative characteristics of the study population were analyzed to determine predictors of POAF.

Results:

Of 223 patients, 91 (40.8%) experienced new-onset POAF. Univariate predictors of POAF included increasing age, male gender, operations involving mitral valve repair/replacement, nonsmoking, hypertension, increased intraoperative pulmonary artery pressure, grade I diastolic dysfunction, abnormal diastolic function of any grade, decreased medial e’, elevated medial E/e’, and increased left atrial volume. Multivariate predictors of POAF included increasing age, increased left atrial volume, and elevated initial intraoperative pulmonary artery pressure. Even after exclusion of patients with hypertrophic obstructive cardiomyopathy or those undergoing mitral valve operations, diastolic dysfunction was not a multivariate predictor of POAF.

Conclusions:

In the patient population studied here, preoperative diastolic dysfunction was not predictive of POAF. In addition to increasing age, initial intraoperative pulmonary artery systolic pressure and left atrial volume were both significant multivariate predictors of POAF.     

Predisposing conditions for atrial fibrillation in atrial septal defect with and without operative closure.

The aims of this study were to determine the prevalence and predisposing conditions for atrial fibrillation (AF) in adults with atrial septal defect (ASD) and to evaluate the influence of age at surgical repair. The study population consisted of 286 adults with ASD (mean age 39.5 +/- 19 years). All patients had >or = 1 follow-up visit and a Doppler echocardiographic study. One hundred ninety-two of the patients underwent surgical closure 1 to 34 years before the study. Analyzed variables were entered into univariate (Mann-Whitney U) and multivariate (stepwise logistic regression) models to assess independent predictors for AF. The prevalence of AF was similar in surgically treated patients (15.6%) and in the nonsurgical group (13.8%) (p = 0.69). Multivariate analysis showed that current age (RR 1.9 per each decade of age, 95% confidence interval [CI] 1.3 to 2.7, p = 0.001), mitral regurgitation (RR 3.0 per each degree of regurgitation, 95% CI 1.6 to 5.8, p = 0.001), left atrial enlargement (RR 2.8 per each 10 mm increase in size, 95% CI 1.5 to 5.2, p = 0.001), and tricuspid regurgitation (RR 1.9 per each degree of regurgitation, 95% CI 1.0 to 3.7, p = 0.04) were independent predictors of AF; however, gender, anatomic type, defect size, Qp:Qs, pulmonary artery pressure, right ventricular dimension, left ventricular shortening fraction, and prior surgical repair were not related to late AF development. In the surgical group, age >25 years at the time of surgery was the only predictor for AF independent of age at the time of the study (p = 0.02).     

Histologic assessment of right atrial appendage myocardium in patients with atrial fibrillation after coronary artery bypass graft surgery

Atrial fibrillation (AF) is a common complication after coronary artery bypass graft (CABG) surgery. Despite the prevalence of AF occurring after cardiac surgery, its pathophysiology is incompletely understood. Our previous study demonstrated that age and left atrial enlargement were independent predictors of postoperative AF. Accordingly, the purpose of this study was to determine whether cellular changes such as fibrosis and/or hypertrophy occurred in the atrium in patients who subsequently developed postoperative AF. Right atrial appendage tissue was obtained during atriotomy in patients undergoing elective CABG surgery. Quantitative assessment of atrial fibrosis was performed with Sirius red stain, and atrial cell diameter was measured with the HE stain. Linear regression, t test, chi2 test or Fisher exact test were used for statistical analysis. Sixty-one patients (mean age 71 +/- 8 years) were studied. Increasing age was significantly associated with fibrosis (beta 0.3, 95% CI: 0.06-0.55, p = 0.017). The amount of right atrial fibrosis tended to correlate with the incidence of postoperative AF (p = 0.08). Cell diameter was not significantly different between patients with versus without postoperative AF (p = 0.85). These results suggest that the age-related atrial fibrosis rather than cellular hypertrophy may be important in the pathogenesis of AF after CABG surgery and should be further investigated.     

Value of preoperative echocardiography in the prediction of postoperative atrial fibrillation following isolated coronary artery bypass grafting

The value of echocardiography, especially tissue Doppler imaging (TDI), in the assessment of risk of postoperative atrial fibrillation (AF) after coronary artery bypass grafting (CABG) is not clear. One hundred two consecutive patients (80 men; mean age 61 +/- 10 years) who underwent elective isolated CABG were included in the study. All patients underwent conventional transthoracic echocardiography and TDI of the left and right heart before surgery. Also, 24-hour Holter recordings were obtained for all patients. The study end point was the development of postoperative AF. The surgical mortality rate was 2%. Postoperative AF occurred in 18 patients (18%). Patients with postoperative AF have been significantly older than patients without postoperative AF (73 +/- 7 vs 58 +/- 9 years, respectively; p <0.001). Compared with patients without postoperative AF, a significantly higher proportion of patients with postoperative AF experienced paroxysmal AF before surgery (6% vs 33%, respectively; p = 0.001). Patients with postoperative AF had a significantly larger mean left atrial diameter compared with patients without postoperative AF (37 +/- 3 vs 35 +/- 3 mm, respectively; p = 0.012). Multivariate logistic regression analysis identified age as the most significant predictor of postoperative AF (odds ratio 1.254, 95% confidence interval 1.127 to 1.396; p <0.001). Of the echocardiographic variables, only left atrial diameter was identified as a significant predictor of postoperative AF (odds ratio 1.250, 95% confidence interval 1.055 to 1.562; p = 0.047). In conclusion, in the prediction of postoperative AF after isolated CABG, preoperative transthoracic echocardiography, including both conventional echocardiography and TDI, is of little value.     

Echocardiographic factors predictive of restoration and maintenance of sinus rhythm after reduction of atrial fibrillation

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia. While the arrhythmia was initially thought to be little more than a nuisance, it is now clear that AF has a significant negative impact on quality of life and a corresponding increase in both morbidity and mortality. OBJECTIVE: The aim of this study was to identify Doppler echographic patterns that allow prediction of atrial fibrillation reduction and maintenance of sinus rhythm within 12 months. PATIENTS AND METHODS: One hundred and thirty patients having permanent atrial fibrillation, recent (51) or chronic (79) are included in the study, excepting those with valvular heart disease or thyroid dysfunction. The mean age was 63.5 +/- 11.3 years. Both transthoracic and transoesophageal echocardiography was performed using a Philips SONOS 5500 Echograph, before cardioversion. Were studied: end diastolic and systolic left ventricular diameters, left ventricular ejectionnal fraction, left atrial area (LAA), left atrial diameter, left atrial appendage area and peak emptying velocities of the left atrial appendage (PeV). Sinus rhythm was re-established in 102 patients (44 having recent and 58 chronic atrial fibrillation). Sinus rhythm was maintained for 12 months in 79 patients. RESULTS: Within the echographic parameters studied, the left atrial area (LAA) and peak emptying velocities of left atrial appendage (PeV) before cardioversion were the best predictors of restoration of sinus rhythm. On monovariate analysis, SOG is significantly lower and PicV is significantly higher in patients whose sinus rhythm had been restored in comparison with those with permanent atrial fibrillation. (Mean SOG: 27.7 +/- 7.62 vs. 34 +/- 7,6 cm2, p<0.0001; Mean PicV: 44 +/- 15.8 vs. 31.4 +/- 13,7 cm/s, p<0.0001). This difference was maintained on multivariate analysis (p=0.002 for SOG and p=0.005 for PicV). In patients with recent atrial fibrillation, only left atrial area can predict on mono and multivariate analysis (p=0.05, OR=0.5, IC=0.36 à 3.56), re-establishing of sinus rhythm whereas in patients with chronic atrial fibrillation, peak emptying velocity of left atrial appendage predict better re-establishing of sinus rhythm (p=0.04, OR=1.29, IC=0.12 à 4.23). The threshold values of LAA and PeV for conversion of atrial fibrillation into sinus rhythm are respectively 25 cm2 and 20 cm/sec. In patients who converted into sinus rhythm; LAA predict maintenance of sinus rhythm at the end of 12 months of survey (p=0.04) with a threshold value of 25 cm2. In the subgroup of patients admitted with chronic atrial fibrillation, PeV predicts better the maintenance of sinus rhythm (p=0.05) with a threshold value of 60 cm/sec, p=0.06; whereas LAA remains better in patients with a recent atrial fibrillation. (p=0.02). CONCLUSION: In addition to the anatomic study of cardiac structure and the search of intracavitary thromboses before reduction of atrial fibrillation, echocardiography allows prediction of cardioversion success (LAA and PeV) and maintenance of sinus rhythm within 12 months.     

左心瓣膜术后心房颤动与三尖瓣反流的关系

目的:研究左心瓣膜术后三尖瓣反流与术后心房颤动(房颤)的关系。方法:随访2002年3月至2008年11月接受主动脉瓣置换术或二尖瓣置换术,且未行三尖瓣成形术或三尖瓣置换术的患者374例,其中男性151例,女性223例,年龄23～79岁,平均(52±11)岁。所有患者均经过术前和术后彩色多普勒超声心动检查及心电图检查。单因素分析组间使用χ2检验。危险因素采用Logistic回归模型分析。结果:左心瓣膜术后房颤是术后发生三尖瓣反流的独立危险因素。Logistic多因素分析结果为:术后房颤、女性及术后左心房扩大,是术后三尖瓣反流的独立危险因素;术时年龄、术后左心室大小、术后右心室大小及术后射血分数这4项不是三尖瓣反流的危险因素。结论:左心瓣膜术后房颤是术后发生三尖瓣反流的独立危险因素。对于术后房颤应该引起重视,积极治疗。     

Effect of mitral valve repair/replacement surgery on atrial arrhythmia behavior

BACKGROUND AND AIMS OF THE STUDY: Few data have been published on the effects of mitral valve surgery on atrial rhythm. The study aims were to determine the effects of surgery on: (i) persistence of atrial fibrillation (AF); (ii) measures of left atrial and ventricular dimensions; and (iii) ECG P-wave duration. METHODS: A retrospective case-note review of 92 patients with chronic mitral regurgitation was undertaken. Variables determined included prevalence and duration of AF; incidence of new-onset or persistence of AF after surgery; rhythm changes in relation to age, gender, left atrial and ventricular dimensions and function, anti-arrhythmic drug usage and ECG P-wave duration in sinus rhythm prior to surgery. RESULTS: Only 4/47 (8.5%) patients with any history of AF before surgery were in sinus rhythm at six months after surgery. All 28 patients with persistent AF for >12 months and 41/45 (91%) in sinus rhythm before surgery retained these rhythms after surgery. The left atrial dimension was decreased after surgery, in the whole group (51.3 +/- 9.0 versus 48.4 +/- 9.5 mm; p = 0.011) and in the subgroup in sinus rhythm, but not in the subgroup in AF. The left ventricular end-diastolic dimension decreased in the group as a whole (60.6 +/- 6.2 versus 53.0 +/- 8.7 mm; p = 0.0001) and in both subgroups after surgery. In 24 patients with 12- lead ECGs in sinus rhythm before and three months after surgery, P-wave duration remained unchanged. However, this measure decreased in the 18 patients in sinus rhythm consistently, but increased in the six patients continuing to have paroxysmal AF after surgery. CONCLUSION: Mitral valve surgery alone restored sinus rhythm in only 8.5% of patients with any previous history of AF. Concomitant anti-arrhythmic procedures should be considered for all patients with AF who undergo mitral valve surgery.     

Left atrial volume predicts cardiovascular events in patients originally diagnosed with lone atrial fibrillation: three-decade follow-up.

AIMS: The objectives of this study were to determine the long-term outcome and the predictors of adverse events in patients originally diagnosed with lone atrial fibrillation (AF). METHODS AND RESULTS: This population-based historical cohort study comprised 46 residents of Olmsted County, MN, USA, with well-documented, clinically defined lone AF and a complete two-dimensional echocardiographic examination. The original echocardiographic videotape recordings were analysed in a blinded fashion for left atrial volume (LAV) and left ventricular ejection fraction. With 1296 person-years of follow-up, the median duration of AF was 27 (first quartile=24, third quartile=33) years. Twenty-three (50%) patients developed events. Cerebral infarction occurred in seven patients, myocardial infarction in 11, and congestive heart failure in 16. In a multivariable analysis, patients with indexed LAV >or=32 mL/m(2) had a significantly worse event-free survival (adjusted HR, 4.46; 95% CI, 1.56-12.74; P=0.005). All cerebral infarctions occurred in patients with an indexed LAV >32 mL/m(2). CONCLUSION: Patients originally diagnosed with benign lone AF follow divergent courses based on LAV. Those originally diagnosed with lone AF and normal sized atria had a benign clinical course throughout the long-term follow-up. Patients with increased LAV at diagnosis or later during the follow-up experienced adverse events.     

Association between serum C-reactive protein elevation and atrial fibrillation after first anterior myocardial infarction

BACKGROUND: Elevated inflammatory markers have been found to correlate with higher risk for cardiac events in patients with acute myocardial infarction (AMI). It has been suggested that C-reactive protein (CRP) may be involved in the initiation process of atrial fibrillation (AF). However, the role of CRP levels in the occurence of AF in patients with AMI has not been studied. This study investigated whether CRP is a risk factor for AF in patients with acute anterior MI. METHODS: We prospectively evaluated 92 consecutive patients (25 women and 67 men; aged 58 +/- 11 y) with a first acute anterior wall MI. Blood samples were obtained at the time of admission to the hospital, and serum CRP levels were measured by an ultrasensitive immunonephelometry method. All patients were evaluated by echocardiography to measure the left ventricular (LV) diameter and functions. All patients were monitored continuously for the detection of AF in the coronary care unit. RESULTS: Atrial fibrillation occured in 19 (20%) of 92 patients. Univariate analysis showed that patients with AF had an advanced age (63 +/- 9.9 versus 56.7 +/- 11.7 y, p = 0.034), higher serum CRP level (2.95 +/- 2.5 versus 1.71 +/- 2.12 mg/dL, p = 0.034), larger LV end-systolic volume (74 +/- 15 versus 63 +/- 19, mL p = 0.02), higher LV ejection fraction (31.1 +/- 6.2 versus 38.4 +/- 10%, p = 0.001), and larger left atrial (LA) diameter (37.1 +/- 4.2 versus 34.7 +/- 3.3 mm, p = 0.01). In multivariate analysis, only age (odds ratio [OR]: 1.05, 95% confidence interval [CI]: 1-1.11, p = 0.036) and CRP levels (OR: 1.27, 95% CI: 1-1.59, p = 0.039) were independent predictors of AF. CONCLUSION: These results suggest that CRP may be a risk factor for AF in patients with acute anterior wall MI.     

Effective prevention of atrial fibrillation by continuous atrial overdrive pacing after coronary artery bypass surgery

OBJECTIVES: The present study was aimed to evaluate the efficacy of a specific algorithm with continuous atrial dynamic overdrive pacing to prevent atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery. BACKGROUND: Atrial fibrillation occurs in 30% to 40% of patients after cardiac surgery with a peak incidence on the second day. It still represents a challenge for postoperative prevention and treatment and may have medical and cost implications. METHODS: Ninety-six consecutive patients undergoing CABG for severe coronary artery disease and in sinus rhythm without antiarrhythmic therapy on the second postoperative day were randomized to have or not 24 h of atrial pacing through temporary epicardial wires using a permanent dynamic overdrive algorithm. Holter ECGs recorded the same day in both groups were analyzed to detect AF occurrence. RESULTS: No difference was observed in baseline data between the two study groups, particularly for age, male gender, history of AF, ventricular function, severity of coronary artery disease, preoperative beta-adrenergic blocking agent therapy or P-wave duration. The incidence of AF was significantly lower (p = 0.036) in the paced group (10%) compared with control subjects (27%). Multivariate analysis showed AF incidence to increase with age (p = 0.051) but not in patients with pacing (p = 0.078). It decreased with a better left ventricular ejection fraction only in conjunction with atrial pacing (p = 0.018). CONCLUSIONS: We conclude that continuous atrial pacing with an algorithm for dynamic overdrive reduces significantly incidence of AF the second day after CABG surgery, particularly in patients with preserved left ventricular function.