Intravenous amiodarone for prevention of atrial fibrillation after coronary artery bypass grafting

BACKGROUND: Atrial fibrillation occurs in 10% to 40% of patients who undergo coronary artery bypass grafting. This prospective study assesses the safety and efficacy of low-dose intravenous amiodarone in the prevention of atrial fibrillation after coronary artery bypass grafting. METHODS: One hundred forty patients were randomly divided into two groups: an amiodarone group (n = 74) receiving intravenous amiadarone in a loading dose of 150 mg and maintenance dose of 0.4 mg x kg(-1) x h(-1) for 3 days before and 5 days after operation and a control group (n = 76) receiving matching infusions of 5% glucose solution. RESULTS: Atrial fibrillation occurred in 9 (12%) of the amiodarone group patients and in 26 (34%) of the control group patients during hospitalization (p < 0.01). The maximum ventricular rate during atrial fibrillation was significantly slower in the amiodarone group (107 +/- 21) than in the control group (138 +/- 24 beats per minute, p < 0.01). The duration of atrial fibrillation in the amiodarone group (1.1 +/- 1.2 hours) was significantly shorter than that in the control group (3.2 +/- 1.3 hours, p = 0.01). The two groups had no significant differences in incidence of major morbidity (8 of 74 versus 8 of 76 in amiodarone and control groups, respectively) or mortality (4 of 74 versus 5 of 76). However, the control group had significantly longer intensive care unit stays (132 +/- 24 versus 111 +/- 19 hours, p < 0.01). CONCLUSIONS: Perioperative low-dose intravenous amiodarone significantly reduces the incidence, ventricular rate, and duration of atrial fibrillation after coronary artery bypass grafting. Furthermore, low-dose intravenous amiodarone is well tolerated and does not increase the risk of intraoperative or postoperative complications.     

小剂量胺碘酮预防冠状动脉旁路移植术后心房纤颤

目的 评价小剂量胺碘酮对冠状动脉旁路移植术后心房纤颤的预防效果、耐受性和安全性。方法 对1998至1999年235例冠状动脉旁路移植术后病人进行回顾性研究分析，其中对照组155例予常规药物，试验组80例合用小剂量胺碘酮。结果 常规药物治疗组21．93％出现心房纤颤，而小剂量胺碘酮预防用药组10％出现心房纤颤(P=0．024)。小剂量胺碘酮致心律失常3例，无甲状腺及肺部并发症发生。结论 预防应用小剂量胺碘酮能明显降低术后心室率，减少心房纤颤发生率，延迟发作，缩短持续时间，促进心房纤颤转复，同时改善心功能。小剂量胺碘酮毒副作用低于大剂量胺碘酮，尤其适用于缺血性心脏病合并心肌梗死及左心功能不全者。     

Atrial fibrillation after coronary artery bypass grafting

The increase in atrial high-frequency activity has been reported as a marker of the risk of paroxysmal atrial fibrillation. The presence of proximal right coronary artery disease is a predictor of atrial fibrillation after bypass surgery, however, the potential mechanism remains controversial. In this study, high-frequency atrial activity to clarify the electrophysiologic background for the predisposition to have proximal right coronary artery disease leading to atrial fibrillation after coronary revascularization was investigated. Before and soon after coronary revascularization, frequency analyses were performed on the 100 ms segment at the end of signal-averaged P waves in 22 patients with right coronary artery disease as opposed to the 23 patients without disease. Under the spectrum curve, area ratio (AR₅₀) and magnitude ratios (MR) were calculated as follows; AR₅₀ = (area 20–50 Hz/0–20 Hz)×100, and MR = (magnitude at 20, 30, 40 and 50 Hz, respectively/maximal magnitude)×100. In patients with proximal right coronary artery disease, high-frequency atrial components increased significantly in the 20 to 50 Hz range after coronary revascularization, and the incidence of postoperative atrial fibrillation was higher than in those without disease. In patients without right coronary artery disease, the frequency distribution of P waves was unchanged. Postoperatively, the two groups showed the same atrial frequency distribution. This data suggests that the increase in high-frequency atrial activity after right coronary artery revascularization might be associated with the pathogenesis of postoperative atrial fibrillation.     

Prophylaxis of atrial fibrillation with magnesium sulfate after coronary artery bypass grafting

Ninety-nine consecutive consenting patients were prospectively entered into a randomized, double-blind, placebo-controlled trial to determine the efficacy of postoperative magnesium therapy on the incidence of cardiac arrhythmias after elective coronary artery bypass grafting. No patient had documented or suspected arrhythmias preoperatively. Forty-nine patients received 178 mEq of magnesium given over the first 4 postoperative days, and 50 patients received only placebo. The clinical characteristics of both groups were similar. The preoperative mean serum magnesium concentration was similar in both study (1.90 mEq/L) and placebo (1.90 mEq/L) groups. The mean postoperative serum magnesium concentration in study patients was significantly elevated over postoperative days 1 through 4 when compared with preoperative levels (p less than 0.001). The postoperative mean serum magnesium concentration in control patients declined and remained significantly depressed through postoperative day 3 (p less than 0.001), but increased to preoperative levels by postoperative day 4. The mean serum magnesium concentration was significantly greater in the study patients as compared with the control patients over postoperative days 1 through 4 (p less than 0.001). Although there was no significant difference between groups with respect to episodes of ventricular arrhythmias, there was a significant decrease in the number of episodes of atrial fibrillation in the group receiving magnesium therapy (p less than 0.02). There were no recognized adverse effects of magnesium therapy. Prophylactic magnesium administration seems to lessen the incidence and severity of atrial fibrillation after coronary artery bypass grafting.     

Hemodynamic predictors of atrial fibrillation or flutter after coronary artery bypass grafting

The cumulated incidence of atrial fibrillation or flutter after coronary artery bypass grafting is 30%. The causes of these arrhythmias have not yet been sufficiently identified. We therefore undertook the present study to analyze the possible association of hemodynamic function during the various phases of coronary artery bypass grafting and the later development of atrial fibrillation/flutter.
Hemodynamic function was measured with a pulmonary artery catheter in 120 consecutive patients undergoing elective coronary artery bypass surgery.
Thirty-five (29%) of the patients developed atrial fibrillation/flutter. Logistic regression analysis identified independent predictors of atrial fibrillation/flutter: After induction of general anesthesia, the relative risk (95% confidence interval) of older age was 1.09/year (1.03–1.16), and the reduction in relative risk by an increase in left ventricular stroke work was 0.96/gm (0.93–0.99). After weaning from the extracorporeal circulation the independent significant predictors were age, relative risk 1.07/year (1.01–1.13), and increased central venous pressure, relative risk 1.12/mm Hg (1.00–1.26). At the time of admission to the intensive care unit, the relative risk of age was 1.10/year (1.03–1.18), and the relative risk of an increased central venous pressure was 1.26/mm Hg (1.06–1.49). However, the best prediction model (prediction after induction of general anesthesia) only provided a median predicted probability of atrial fibrillation/flutter of 0.37 for the patients who had atrial fibrillation/flutter, and a median predicted probability of atrial fibrillation/nutter of 0.20 for the patients without these arrhythmias. We identified possible hemodynamic predictors of atrial fibrillation/flutter after coronary bypass surgery, but the use of a risk stratification for development of atrial fibrillation/flutter based on hemodynamic function cannot be recommended.     

Amiodarone reduces the incidence of atrial fibrillation after coronary artery bypass grafting

OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of postoperative administration of prophylactic amiodarone in the prevention of new-onset postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting. METHODS: In this prospective study 157 patients were randomly divided into two groups: 77 patients (amiodarone group) received intravenous amiodarone in a dose of 10 mg/kg/d for postoperative 48 hours. On postoperative day 2 oral amiodarone was started with a dose of 600 mg/d for 5 days, 400 mg/d for the following 5 days, and 200 mg/d for 20 days, and 80 patients received placebo (control group). RESULTS: Preoperative patient characteristics and operative variables were similar in the two groups. Postoperative atrial fibrillation occurred in 8 patients (10.4%) receiving amiodarone and in 20 (25.0%) patients receiving placebo (P =.017). Duration of atrial fibrillation was 12.8 +/- 4.8 hours for the amiodarone group compared with 34.7 +/- 28.7 hours for the control group (P =.003). The maximum ventricular rate during atrial fibrillation was slower in the amiodarone group than in the control group (105.9 +/- 19.1 beats per minute and 126.0 +/- 18.5 beats per minute, respectively, P =.016). The two groups had a similar incidence of complication other than rhythm disturbances (20.8% vs 20.0%, P =.904). Amiodarone group patients had shorter hospital stays than that of control group patients (6.8 +/- 1.7 days vs 7.8 +/- 2.9 days, P =.014). The in-hospital mortality was not different between two groups (1.3% vs 3.8, P =.620). CONCLUSIONS: Postoperative intravenous amiodarone, followed by oral amiodarone, appears to be effective in the prevention of new-onset postoperative atrial fibrillation. It also reduces ventricular rate and duration of atrial fibrillation after coronary artery bypass grafting. It is well tolerated and decreases the length of hospital stay.     

Diltiazem prophylaxis reduces incidence of atrial fibrillation after coronary artery bypass grafting

AIM: To evaluate the prophylactic effect of diltiazem on the incidence of atrial arrhythmia (fibrillation and/or flutter) following coronary artery bypass grafting (CABG). Data were retrospectively gathered. METHODS: Patients undergoing elective CABG by one surgeon at one institution over a three-year period were considered for inclusion. Those selected were divided into 3 groups: A (patients placed on intravenous diltiazem intraoperatively, then converted to oral diltiazem upon initiation of oral intake); B (patients started on oral diltiazem upon initiation of oral intake without prior intravenous diltiazem); and C (patients receiving no diltiazem). A comparison of postoperative rates of atrial fibrillation was made between the 3 (demographically balanced) groups using logistic regression. RESULTS: Two hundred and eighty seven patients met inclusion criteria. The incidence of postoperative atrial fibrillation in the entire sample was 19.9% (57/287). Incidence of postoperative atrial fibrillation within each group was: A = 16.3% (22/135); B = 12.7% (7/55); C = 28.9% (28/97). Statistical significance was demonstrated for the following comparisons: A versus C (p = 0.0451) and B versus C (p = 0.0065). In an alternate model groups A and B were combined and compared to C (p = 0.0181). CONCLUSIONS: A lower incidence of atrial fibrillation following CABG was observed in patients treated prophylactically with diltiazem. Differences were statistically significant whether the drug was administered intravenously and orally (A) or only orally (B). Diltiazem, which has an established role in the management of atrial fibrillation, may prove to be well suited for prophylaxis due to low cost and relative safety.     

Combination of sotalol and magnesium prevents atrial fibrillation after coronary artery bypass grafting

BACKGROUND: Atrial fibrillation (AF) is a common complication reported in 20% to 40% of patients after coronary operations. Sotalol alone and magnesium alone have been shown to partially decrease the incidence of AF. The goal of this study was to evaluate the efficacy of these two pharmacological agents, used alone or in combination, to reduce postoperative AF. METHODS: Two hundred seven consecutive coronary artery bypass patients (mean age 62 +/- 11 years) were randomized to receive sotalol alone (80 mg twice daily for 5 days starting from the morning of the first postoperative day) (group S), magnesium alone (1.5 g daily for 6 days starting in the operating room just before cardiopulmonary bypass) (group M), both pharmacologic agents at the same dosages (group S+M), or no antiarrhythmic agents (group CTR). All patients with an ejection fraction less than 0.40 were excluded. RESULTS: The incidence of postoperative AF was 11.8% (6/51) in the S group, 14.8% (8/54) in the M group, 1.9% (1/52) in the S+M group, and 38% (19/50) in the CTR group. The following differences were significant: group CTR versus groups S, M, and S+M with values of p = 0.002, p = 0.007 and p < 0.0001, respectively; and group S+M versus groups S and M with p = 0.04 and p = 0.01, respectively. CONCLUSIONS: Incidence of AF after coronary operation was significantly reduced by the administration of sotalol alone and magnesium alone; more importantly, the incidence was further reduced by combining these agents.     

Effect of Sotalol in the prevention of atrial fibrillation following coronary artery bypass grafting

OBJECTIVE: We assessed the efficacy of postoperatively administered oral Sotalol in preventing the occurrence of postoperative atrial fibrillation. METHODS: Subjects were 80 consecutive patients undergoing coronary artery bypass grafting (CABG) randomized alternately into a Sotalol group (40 patients) administered 80 mg of oral Sotalol daily starting on the postoperative day 1 and continued for 14 days, and a control group (40 patients) matched for age and gender. RESULTS: The incidence of postoperative atrial fibrillation (21 patients) was significantly lower in the Sotalol group (6/40 patients; 15%) than in controls (15/40; 37.5%) (p < 0.05). Significant bradycardia or hypotension, necessitating drug withdrawal, occurred in 3 of 40 (7.5%) patients in the Sotalol group. None in the Sotalol group developed Torsardes de Pointes or sustained ventricular arrhythmias or other severe side effects. The sinus heart rate increased in both groups but less in the Sotalol group. QT, QRS, and QTc durations did not differ between groups. Postoperative hospital stay did not differ between groups. CONCLUSIONS: Oral Sotalol administration of 80 mg daily was associated with a significant decrease in postoperative atrial fibrillation in patients undergoing CABG without appreciable side effects. Sotalol should thus be considered in preventing postoperative atrial fibrillation in patients undergoing CABG in the absence of heart failure and significant left ventricular dysfunction.     

冠状动脉旁路移植术后早期新发心房颤动的临床特征及影响因素分析

目的 探讨冠状动脉旁路移植术后新发心房颤动(房颤)的临床特征及影响因素.方法 回顾性分析2012年1月至2019年1月在我院行冠状动脉旁路移植术的339例患者的临床资料,其中男267例、女72例,年龄37～83(58.03±8.90)岁.分析术后新发房颤的临床特征及影响因素.结果 不停跳冠状动脉旁路移植(off-pum...     

Red cell distribution width predicts new-onset atrial fibrillation after coronary artery bypass grafting

Abstract

Objectives. The AHA/ACC/ESC Guidelines for management of atrial fibrillation (AF) patients suggest criteria for adequate rate control. We hypothesized that AF patients fulfilling these criteria would have better quality of life (QoL) and exercise capacity compared to the ones not fulfilling the criteria. Design. Heart rate at rest, during moderate exercise and over 24 hours, and peak oxygen uptake (VO₂ peak) were measured in patients with permanent AF, all aged 75 years, recruited from two Norwegian municipalities. SF-36 Physical component summary (PCS) and Mental component summary (MCS) QoL scores were assessed. The similar program was also applied to 71 age-matched subjects in sinus rhythm. Results. Twenty-seven AF patients participated. Six (22%) of the AF patients satisfied the Guidelines’ criteria for rate control; their VO₂ peak (mean ± SD) was 23.0 ± 6.5 versus 22.6 ± 5.3 ml/kg/min in AF patients not satisfying the criteria, PCS score had median (25^th, 75^th percentile) 44 (30, 57) versus 41 (31, 47), and MCS score had median 52 (40, 62) versus 56 (43, 60), all p-values > 0.500. When the rate criteria were applied to the group in sinus rhythm, only 45% had heart rates within the ranges recommended by the Guidelines for AF patients. Conclusion. AF patients satisfying the Guidelines' criteria for adequate rate control did not have higher oxygen uptake or report better QoL than AF patients not satisfying the criteria.     

Intraoperative high-rate atrial pacing test as a predictor of atrial fibrillation after coronary artery bypass surgery

BACKGROUND: Atrial fibrillation (AF) is a common complication after coronary artery bypass grafting (CABG) operations. The aim of this prospective trial was to test the hypothesis that intraoperative high-rate atrial pacing may induce AF by mimicking rapid atrial tachycardia and can identify the patients at risk for postoperative AF. METHODS; Eighty patients having on-pump CABG without additional procedures were included in the study. After cannulation but before initiation of cardiopulmonary bypass two pacing wires were placed on the lateral surface of the right atrium. The right atrium was paced with the rate of 200 beats per minute for 10 seconds. If the patient was in sinus rhythm after the high-rate pacing, the pacing test was repeated with the rate of 250 and finally 300 beats per minute. RESULTS: Postoperatively AF developed in 28 patients (35%). The high-rate atrial pacing test induced AF in 27 patients (33.7%). Of the 28 patients who experienced AF during the postoperative period, 17 patients were inducible in the atrial-pacing test (sensitivity 0.61). Of the 52 patients who did not develop AF postoperatively, 42 patients were not inducible in the atrial-pacing test (specificity of the test was 0.81). Positive and negative predictive values of the test were 0.63 and 0.79, respectively. CONCLUSIONS: The intraoperative high-rate atrial pacing test turned out to be a simple, safe, and fast way to identify the patients at risk for AF after CABG. The diagnostic accuracy of this test is sufficient to identify a group of patients to whom prophylactic treatment could be directed.     

Relationship between left atrial volume and atrial fibrillation following coronary artery bypass grafting

Abstract Background: Atrial fibrillation (AF) is a common complication of coronary artery bypass grafting (CABG). However, limited information is available about the role of preoperative echocardiographic left atrial evaluation to predict AF occurrence after CABG. Thus, we prospectively compared the ability of echocardiographic measurements of left atrial volume to predict AF in this setting. Methods: From January to December 2009, 220 patients (75% males, 66.8 ± 10.0 years) met the inclusion criteria of our study (isolated and elective CABG, no valve surgery, no permanent AF, or other chronic atrial arrhythmias). The day before CABG a complete echocardiographic evaluation was performed with left atrial volume measurements. The primary endpoint of the study was postoperative AF (POAF) lasting >30 seconds. Results: POAF was observed in 61 patients (27.7%). POAF patients showed increased left atrial M‐mode anteroposterior dimension (41.2 ± 6.4 mm vs. 43.6 ± 7.3 mm; p = 0.020) and increased left atrial volume (59.0 ± 18.3 mL vs. 70.6 ± 28.1 mL; p = 0.0004). Left atrial volume was an independent risk factor for POAF (OR 10.03; 95% CI 10.01 to 10.05; p = 0.01), along with postoperative bleeding with hemoglobin levels below 8 g/dL (OR 20.84; 95% CI 10.12 to 70.19; p = 0.03) and preoperative left ventricular ejection fraction below 40% (OR 10.08; 95% CI 10.01 to 10.15; p = 0.02). Conversely, preoperative statin therapy exerted a protective role (OR 0.30; 95% CI 0.12 to 0.74; p = 0.009). Conclusion: Preoperative echocardiographic evaluation of patients with isolated CABG demonstrated that left atrium volume measurements were independently correlated to the occurrence of POAF. Further investigations should focus on the opportunity to target prophylactic antiarrhythmic treatments to patients with large left atrial volumes. (J Card Surg 2012;27:128–135)     

Relation of inflammatory cytokines to atrial fibrillation after off-pump coronary artery bypass grafting.

OBJECTIVE: It has been observed that a systemic inflammatory response after on-pump coronary artery bypass grafting (CABG) participates in the pathogenesis of postoperative atrial fibrillation (AF). In patients undergoing off-pump CABG, it is plausible that inflammation is associated with the development of postoperative AF. The present study examined relation of proinflammatory cytokines, which play an important role in the upstream of inflammatory cascade, to the development of AF after off-pump CABG. METHODS: The present study included 39 patients undergoing off-pump CABG. Tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, and IL-8, were measured by enzyme-linked immunosorbent assay, on anesthetic induction, after sternotomy before anastomoses, at the completion of anastomoses, 3 and 6h thereafter, and on postoperative days (POD) 1-4. C-reactive protein (CRP) was also measured by turbidimetric immunoassay, preoperatively, and on POD 1, 2, 3, 6, 9, and 13. RESULTS: Eleven patients (28%) developed postoperative AF. Patients with postoperative AF were older (70+/-6.4 years vs 60+/-8.8 years, P=0.001); however, there was no difference in other pre- and perioperative variables. TNF-alpha level did not change during the study period. However, IL-8 and CRP levels significantly increased after the surgery, although there was no significant difference between the two groups. IL-6 level also increased after the surgery with its peak at 6h after the completion of anastomoses. IL-6 levels of 3 and 6h after anastomoses were significantly higher in patients with postoperative AF (360+/-143 pg/ml vs 230+/-94 pg/ml, P=0.0047, 435+/-175 pg/ml vs 247+/-102 pg/ml, P=0.0005, respectively). Logistic regression analysis indicated that the highest quartile of IL-6 level immediately after the surgery (odds ratio 7.63; 95% CI, 1.06-54.9; P=0.04) and age (odds ratio 1.18; 95% CI, 1.01-1.39; P=0.04) independently predict postoperative AF. Furthermore, the maximum level of IL-6 immediately after the surgery significantly correlated to age and intraoperative blood loss (r=0.04, P=0.01, and r=0.47, P=0.04, respectively). CONCLUSIONS: Advanced age was a major risk factor for postoperative AF. Furthermore, inflammatory response induced by surgical trauma was also associated with the development of AF after off-pump CABG.