Patterns of Atrial Fibrillation After Coronary Artery Bypass Surgery

Background: Atrial fibrillation (AF) is the most common arrhythmia occurring in patients after coronary artery bypass surgery (CABG). The purpose of this study was to determine whether AF characteristics were independently associated with postoperative length of stay (LOS). Methods: Two hundred ninety consecutive post‐CABG patients were examined through a detailed chart review. Baseline, intraoperative, and postoperative variables and the characteristics of AF were recorded. AF episodes were divided into single episodes lasting less than 24 hours (short‐lived AF) and recurrent or prolonged ≥24 hours of AF (recurrent/prolonged AF). Results: AF occurred in 94 (32.4%) patients. Twenty‐six (27.7%) of AF patients had short‐lived AF, and 68 (72.3%) of AF patients had recurrent/prolonged AF. Patients with recurrent/prolonged AF were older (P < 0.001) and more likely to have a history of prior AF (P < 0.001) relative to the other groups. Short‐lived AF did not prolong LOS (7.2 ± 2.1 days) relative to patients without AF (7.5 ± 3.9 days), whereas recurrent/prolonged AF significantly prolonged LOS (10.4 ± 6.1 days, P < 0.001). Multivariate analysis identified postoperative complications, recurrent/prolonged AF, age, and digoxin use as independent predictors of LOS. Recurrent/prolonged AF contributed an additional 1.1 days to LOS after adjusting for baseline clinical differences. Conclusions: There are heterogenous patterns of AF after cardiac surgery. A substantial minority of AF is short‐lived and isolated with no impact on LOS; however, recurrent or prolonged AF significantly affects LOS.     

冠状动脉旁路移植术后发生心房颤动的相关因素分析

目的：分析国人冠状动脉旁路移植（ＣＡＢＧ）术后心房颤动（ＡＦ）的高危因素。　　方法：回顾我院近３ 年在体外循环下进行ＣＡＢＧ术患者６８６ 例,对可能与术后ＡＦ发生有关的诸因素进行卡方检验和Ｌｏｇｉｓｔｉｃ多因素回归分析,以找出与ＣＡＢＧ术后ＡＦ发生相关的高危因素。　　结果：６８６例患者中,１４０ 例（２０．４％ ）并发了ＣＡＢＧ术后ＡＦ。ＡＦ的发生与年龄,术前ＡＦ史及术前心房早搏关系密切（Ｌｏｇｉｓｔｉｃ回归Ｐ＝ ０．００３,０．００１,０．０４６）。而与性别,心肌梗塞,体外循环时间,阻断时间,术前术后射血分数等诸因素无关（卡方检验及Ｌｏｇｉｓｔｉｃ Ｐ＞ ０．０５）。　　结论：ＡＦ同样是国人ＣＡＢＧ术后常见并发症。高龄、术前ＡＦ史及术前心房早搏是其高危因素     

冠状动脉旁路移植术后心房颤动及治疗

为探讨冠状动脉旁路移植 (CABG)术后早期心房颤动 (AF)的易患危险因素 ,回顾分析 81例单纯CABG病人的年龄、合并症、左房和左室大小、术前心功能、手术方式、血管桥数目及术后并发症等因素与术后AF发生的关系 ,并总结药物及电复律转复AF的效果。结果 :术后早期AF发生率为 2 3.5 % ,AF病人术后ICU监护时间延长 ;单因素分析表明高龄 (≥ 6 5岁 )、移植血管桥数目及术后并发症与AF发生密切相关 (P =0 .0 1,0 .0 0 2 ,0 .0 0 1)。Logistic回归表明术后并发症是AF发生的独立危险因素。 (P =0 .0 0 9,B =1.73,OR值为 5 .6 5 )AF总转复率为 81.3% ,电转复 2例 ,药物转复 11例 (78.6 % )。结论 :增龄、移植血管桥数目增多及出现术后并发症是CABG术后早期AF的易患危险因素 ,药物及电复律能有效转复术后AF。     

Combination Therapy for Prevention of Atrial Fibrillation after Coronary Artery Bypass Surgery: A Randomized Trial of Sotalol and Magnesium

Objective: Atrial Fibrillation (AF) is a common complication of coronary artery bypass surgery reported to occur in 20–40% of patients. Sotalol alone and magnesium alone have been shown to decrease the incidence of AF. The aim of this study was to evaluate the efficacy of these two agents, alone or in combination, to reduce postoperative AF. Methods: Two hundreds and seven consecutive coronary artery bypass patients were randomized to receive sotalol alone (80 mg two times daily for five days starting from the morning of the first postoperative day), magnesium alone (1.5 g daily for six days starting in the operating room just before cardiopulmonary bypass), both pharmacological agents at the same dosages or no antiarrhythmic agents (Control group). Patients with an ejection fraction <40% were excluded. Results: The incidence of postoperative AF was 11.8% (6/51) in the sotalol group, 14.8% (8/54) in the magnesium group, 1.9% (1/52) in sotalol+magnesium group and 38% (19/50) in the control group. The differences were significant between the control group and the other three groups (sotalol, magnesium and sotalol + magnesium groups: p = 0.002, p = 0.007 and p < 0.0001 respectively), and between the sotalol + magnesium group and single drug groups (sotalol and magnesium groups: p = 0.04 and p = 0.01, respectively. Conclusion: The incidence of AF after coronary surgery was significantly reduced by the administration of sotalol alone and magnesium alone. The incidence of postoperative AF was further reduced by combining the two pharmacological agents.     

影响老龄冠状动脉旁路移植术后新发心房颤动的危险因素

目的:目前尚缺乏针对老龄患者冠状动脉旁路移植术(Coroanry artery bypass grafting,CABG)后新发心房颤动(房颤)的风险因素分析.本研究以老龄CABG患者为研究对象,考察了影响老龄CABG后新发房颤的独立危险因素.方法:1999年至2005年间,有1 756例老龄患者(大于65岁)在我院接...     

Effect of Intravenous Diltiazem and Digoxin on Atrial Fibrillation After On-Pump Coronary Artery Bypass Surgery

Atrial fibrillation (AF) occurs in 10–40% of patients undergoing coronary artery bypass surgery (CABG). The purpose of this study is to determine predictors of the time to occurrence of AF after CABG and the impact of intravenous diltiazem and digoxin on acutely (<6 hours) controlling heart rate ( 100/minute) and converting AF to normal sinus rhythm (NSR). We performed a retrospective review of 151 consecutive patients who had undergone CABG during a four-month period at our institution. Patients who developed AF postoperatively were treated at the discretion of the attending physician with the combination of IV diltiazem and digoxin, as per an approved protocol by a hospital committee. Univariate analysis using chi-square and Students t-test was performed. Cox Proportional Hazards Model was performed to determine variables that predicted the time to occurrence of AF. Time to achieve rate control ( 100/minute) was recorded in patients who did not convert to NSR. Arrhythmia control was defined as either conversion to NSR or rate control within six hours of initiation of treatment. AF occurred in 59 patients (39%) at a mean of 2.17 days following surgery, and 29 patients received immediate IV diltiazem (bolus 0.25 mg/kg followed by 5 mg/hr incremental drip) and digoxin (0.75 mg IV load). Acute conversion to NSR occurred in 21/29 (72%) patients. Arrhythmia control was achieved in 24/29 (83%) patients. Patients who developed AF and were on beta-blockers (BB) derived no incremental benefit from the addition of IV diltiazem and digexin in converting to NSR (p=NS). Using Cox Proportional Hazards Model, history of AF (p < 0.0001), age (p < 0.001), and chronic obstructive pulmonary disease (COPD) (p=0.028) were significant variables in predicting the time to occurrence of AF. AF occurs frequently after CABG, and the combination of IV diltiazem and digoxin appears to be effective in rate control and was associated with a high conversion rate to NSR. History of AF, age, and COPD predicted the time to occurrence of AF.     

Does Totally Endoscopic Access for Off-pump Cardiac Surgery Influence the Incidence of Postoperative Atrial Fibrillation in Coronary Artery Bypass Grafting? A Preliminary Report

Background The occurrence rate of atrial fibrillation (AF) after coronary artery bypass grafting, quoted in the literature, is wide ranging from 5% to over 40%. It is speculated that, off-pump coronary artery bypass grafting (OPCAB) and also minimally invasive cardiac surgery reduces the incidence of postoperative AF due to reduced trauma, ischemia, and inflammation. Current data, however, do not clearly answer the question, whether the incidence of postoperative AF is reduced in using minimally invasive techniques, ideally resulting in the combination of both small access and off-pump surgery. The aim of this study was to evaluate the incidence of postoperative AF in patients undergoing totally endoscopic off-pump coronary artery bypass grafting (TECAB).Methods A retrospective analysis of 72 patients undergoing myocardial revascularization was performed. Early postoperative incidence of AF was compared between three groups of patients: 24 after conventional coronary artery bypass grafting (CABG), 24 after OPCAB, and 24 after totally endoscopic off-pump CABG. Clinical profile of the patients, including factors having potential influence on postoperative AF was matched for groups.Results Postoperative AF occurred in 25% of the patients in the CABG group, in 16% of the patients in the OPCAB group, and in 16% of the patients in the TECAB group. This difference has no statistical significance. Risk factors and incidence of postoperative complications were comparable in all groups excepting the number of distal anastomoses. There was a statistical significance between CABG group and TECAB group.Conclusion Avoiding cardiopulmonary bypass and minimizing surgical trauma did not reduce the incidence of postoperative AF in this patient collective. It remains an attractive hypothesis that postoperative AF is reduced by off-pump myocardial revascularisation and minimizing surgical trauma but more robust data are required.     

Obstructive Sleep Apnea as a Predictor of Atrial Fibrillation After Coronary Artery Bypass Grafting: A Systematic Review and Meta-analysis

BackgroundPost–coronary artery bypass grafting atrial fibrillation (PCAF) is associated with increased morbidity, mortality, and system costs. Few studies have explored obstructive sleep apnea (OSA) as a risk factor for PCAF. We aimed to systematically review and synthesize the evidence associating OSA with PCAF.MethodsWe conducted a search of MEDLINE, EMBASE, Google Scholar, and Web of Science, as well as abstracts, conference proceedings, and reference lists until June 2014. Eligible studies were in English, were conducted in humans, and assessed OSA with polysomnography (PSG) or a validated questionnaire. Two reviewers independently selected studies, with disagreement resolved by consensus. Piloted forms were used to extract data and assess risk of bias.ResultsFive prospective cohort studies were included (n = 642). There was agreement in study selection (κ statistic, 0.89; 95% confidence interval [CI], 0.75-1.00). OSA was associated with a higher risk of PCAF (odds ratio [OR], 1.86; 95% CI 1.24-2.80; P = 0.003; I² = 35%). We conducted 3 subgroup analyses. The associations increased for data that used PSG to assess OSA (OR, 2.34; 95% CI, 1.48-3.70), when severe OSA was included from 1 study (OR, 2.59; 95% CI, 1.63-4.11), and when adjusted analyses were pooled (OR, 2.38; 95% CI, 1.57-3.62; P < 0.001 in all), with no heterogeneity detected in any subgroup analysis (I² < 0.01% in all).ConclusionsOSA was shown to be a strong predictor of PCAF.     

Left Atrial Strain Assessed by Speckle Tracking Imaging Is Related to New-Onset Atrial Fibrillation After Coronary Artery Bypass Grafting

Background

Left atrial (LA) dysfunction was recently proposed as an important factor in the development of postoperative atrial fibrillation (POAF). LA strain analysis by 2-dimensional (2D) speckle tracking imaging is emerging as a new tool to evaluate LA function. We aimed to evaluate the correlation of LA dysfunction assessed by 2D speckle tracking imaging with the occurrence of POAF after coronary artery bypass grafting (CABG).

Methods

In this study, 53 patients (mean age 66 ± 9 years) undergoing elective isolated CABG were enrolled. Conventional transthoracic echocardiography and 2D speckle tracking strain analysis were performed before surgery. POAF was detected with continuous electrocardiography monitoring throughout hospitalization (mean duration 17 ± 10 days).

Results

POAF occurred in 13 of 53 patients (24%). Patients with POAF were significantly older than patients with normal sinus rhythm after surgery (71 ± 5 vs 64 ± 10 years, P = 0.026). Compared with patients with normal sinus rhythm, patients with POAF had a significantly larger LA volume index (32.6 ± 5.1 vs 27.3 ± 7.2 mL/m², P = 0.018), lower value of LA global strain (25.4 ± 10.4 vs 36.8 ± 7.6%, P = 0.001), and strain rate (1.2 ± 0.6 vs 1.6 ± 0.8 seconds, P = 0.024). By multivariate logistic regression analysis, only LA global strain (odds ratio, 1.12; 95% confidence interval, 1.00-1.24; P = 0.040) was an independent predictor of POAF after CABG.

Conclusions

Preoperative LA global strain measured by 2D speckle tracking strain analysis is associated with the development of POAF after CABG.     

P‐Wave Signal‐Averaged Electrocardiogram Predicts Atrial Fibrillation After Coronary Artery Bypass Grafting

Background: AF is one of the most common complications after CABG. The aim of the study was to identify the risk factors for postoperative AF. Methods: Between June and December 2000, 129 consecutive patients (72 men, 47 women; mean age 67 ± 6 years) underwent preoperative signal‐averaged electrocardiogram (SAECG) with assessment of filtered P‐wave duration (fPWD) and of the root mean square voltage of the last 10 and 20 ms of atrial depolarization (RMSV10 and RMSV20, respectively) before CABG. Results: Fifty‐six (43%) patients developed one episode of AF lasting > 30 seconds at a mean distance of 2.6 ± 1.8 days after surgery (group A), while 73 patients remained in sinus rhythm (group B). No differences between the two groups were found in terms of age, sex, P‐wave duration on the standard ECG, left atrial dimensions, and operative characteristics. In contrast, group A patients showed a significantly longer fPWD (138 ± 10 vs 111 ± 9 ms; P < 0.001) and smaller RMSV10 and RMSV20 (2.8 ± 1.0 vs 4.3 ± 1.1 μV, P < 0.001; 4.2 ± 2.1 vs 6.2 ± 2.0 μV, P < 0.001). Multivariate analysis indicated only fPWD as an independent predictor of AF (P = 0.009). With a cut‐off value of 135 ms for fPWD, the occurrence of AF could be predicted with a sensitivity of 84%, a specificity of 73%, a negative predictive value of 85%, and a positive predictive value of 70%. Conclusion: Preoperative SAECG is a simple exam that correctly identifies patients at higher risk of AF after CABG. A more widespread use of this technique can be suggested. A.N.E. 2002;7(3):198–203     

The Value of P Dispersion on Predicting Atrial Fibrillation After Coronary Artery Bypass Surgery: Effect of Magnesium on P Dispersion

Background: AF is a frequent arrhythmia complicating CABG, and it is well known that dispersion and prolongation of P wave increases the risk of AF. The aim of this study was to investigate the effect of magnesium (Mg) treatment on P‐wave duration and dispersion in patients undergoing CABG. Method: The study included 148 consecutive patients (33 women, 115 men; mean age 62.1 ± 7.0 years) undergoing CABG who were randomly allocated to two groups. Group A consisted of 93 patients to whom 1.5 g daily MgSO₄ infusion was applied the day before surgery, just after operation, and 4 days following surgery, and group B consisted of 55 control patients. From the preoperative and postoperative fourth day, 12‐lead ECG recordings, duration of the P waves, and P‐wave dispersions were calculated. Results: There were no differences between the two groups with regard to age, sex, and blood Mg level. Comparison of the baseline and day 4 ECG measurements showed no difference as far as heart rates, duration of PQ, and QRS intervals were concerned. AF developed in 2 (2%) cases in group A and in 20 (36%) cases in group B (P < 0.001). There was no difference between the two groups when average basal P max, P min, P dispersion, and day 4 P min values were compared. In group A, fourth day P max (94.3 ± 11.8 vs 101.0 ± 13.2 ms; P = 0.0025) and P dispersion (38.2 ± 9.2 vs 44.9 ± 10.9 ms; P = 0.0002) were significantly lower as compared to group B. Comparing the patients who developed AF, and who did not, no difference was detected with regard to baseline P max, P min, P dispersion, and day 4 P min. Day 4 P max (95.1 ± 11.8 vs 106.4 ± 14.0 ms, P = 0.0015) and P dispersion (38.9 ± 8.8 vs 50.7 ± 13.0 ms, P = 0.001) of patients who developed AF were significantly higher. Baseline Mg levels were similar in patients who developed AF, and who did not, but the day 4 Mg level was significantly lower in AF group (2.0 ± 0.23 vs 2.15 ± 0.26 mg/dL, P < 0.001). Conclusion: Perioperative Mg treatment reduces P dispersion and the risk of developing AF in patients undergoing CABG. A.N.E. 2002;7(3):211–218