Atrial fibrillation (AF) occurs in one quarter to one third of patients after coronary artery bypass graft surgery (CABG). Conventional CABG uses cardiopulmonary bypass, a process that is itself associated with a systemic vascular inflammatory response that contributes to postoperative morbidity. The avoidance of cardiopulmonary bypass is associated with a significant reduction in the inflammatory response and in the release of markers of myocardial necrosis when compared with conventional CABG. There is speculation that off-pump CABG may reduce the incidence of postoperative AF through reduced trauma, ischaemia, and inflammation. Current data, however, do not emphatically answer the question of whether the incidence of post-CABG AF is reduced by off-pump surgery. The evidence from both observational and randomised studies is conflicting and many studies have weaknesses in design, conduct, or interpretation. It remains an attractive hypothesis that postoperative AF is reduced by off-pump CABG but more robust data are required.
atrial fibrillation; off-pump coronary artery bypass surgery
Atrial fibrillation (AF) occurs in about 27% to 40% of post cardiac surgery patients. AF following coronary artery bypass graft surgery (CABG) is associated with a two-fold increase in morbidity and mortality. Various demographic risk factors and medications have been studied to predict the occurrence of this arrhythmia. The role of angiotensin related medications on the occurrence of AF in CABG patients is not determined.
Retrospective clinical and statistical analysis was made of all the patients who had undergone CABG surgery at Lehigh Valley Hospital during the years 2005 and 2006. Patients with chronic AF and those undergoing valvular surgery with CABG were excluded. Statistic analysis included chi-square test for categorical and student t-test for continuous variables.
757 patients (560 males and 197 females) were studied. AF occurred in 19% of the patients. Age (70.5 vs. 65.1, p < 0.005. OR per year of age: 1.02, 95%CI: 1.018-1.023) and presence of hypertension (OR: 1.92, 95%CI: 1.086-3.140, p = 0.025) were significantly associated with occurrence of AF. Neither ARBs (OR: 0.78, 95%CI: 0.431-1.410, p = 0.41) nor ACE inhibitors (OR: 1.01, 95%CI: 0.753-1.608, p = 0.63) reduced the occurrence of post operative AF. Patients with post operative AF had a significantly longer hospital stay (9.5 +/- 5.4 days vs. 6.9 +/- 4.3 days, p = 0.001).
Advanced age and presence of hypertension were independent predictors of post-CABG AF. Patients with post operative AF had significantly longer hospital stay. Neither ARBs nor ACE inhibitors were associated with reduction of post-surgical AF. Further studies are needed to better delineate the role of angiotensin related medications on reduction of post-surgical AF.
Atrial fibrillation (AF) is the most common complication of coronary artery bypass graft surgery (CABG). The reported incidence of AF after CABG varies from 20% to 40%. Postoperative AF (POAF) is associated with increased incidence of hemodynamic instability, thromboembolic events, longer hospital stays, and increased health care costs. A variety of pharmacological and nonpharmacological strategies have been employed to prevent AF after CABG. Preoperative and postoperative beta blockers are recommended in all cardiac surgery patients as the first-line medication to prevent POAF. Sotalol and amiodarone are also effective and can be regarded as appropriate alternatives in high-risk patients. Corticosteroids and biatrial pacing may be considered in selected CABG patients but are associated with risk. Magnesium supplementation should be considered in patients with hypomagnesemia. There are no definitive data to support the treatment with nonsteroidal anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, procainamide, and propafenone, or anterior fat pad preservation to reduce POAF.
Atrial fibrillation; Coronary artery bypass; Drug therapy; Cardiac pacing, artificial
Atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery is a common problem. In this study, we sought to evaluate the safety and tolerance of continuous atrial pacing after CABG. We hypothesized that a strategy of temporary atrial pacing after CABG would reduce the incidence of postoperative AF.
During 2012, CABG candidates over 18 years of age at Sina Hospital (Isfahan, Iran) were recruited. Before surgery, the participants were randomly assigned to two groups of ventricular pacing and left atrial ventricular pacing (atrial pacing). The primary end point of the study was the initial occurrence of AF or atrial flutter with a ventricular rate greater than 100 beats per minute for 10 consecutive minutes or completion of the 48-hour monitoring period.
We evaluated 64 consecutive CABG candidates with sinus rhythm. They were allocated to two groups of ventricular pacing and atrial ventricular pacing (n = 32 in each group). Three patients in the ventricular pacing group (10%) and six in the atrial ventricular pacing group (22%) had sustained AF during the first 48 hours after CABG (P = 0.18 according to Fisher’s exact test).
Continuous atrial pacing in the postoperative setting is safe and well-tolerated. In this study, we found that temporary atrial pacing increased the frequency of postoperative AF. Since the difference between the two groups was not significant, larger studies are required to determine the exact relation between pacing method and AF.
Atrial Fibrillation; Coronary Artery Bypass Graft; Atrial Pacing
OBJECTIVE: To define the clinical value of the signal averaged P wave (SAPW) and to compare it with the standard electrocardiogram (ECG), echocardiogram, and clinical assessment for the prediction of atrial fibrillation after coronary bypass grafting (CABG). DESIGN: Prospective validation cohort study. SETTING: Regional cardiothoracic centre. PATIENTS: 201 unselected patients undergoing first elective CABG were recruited over six months. Patients requiring concomitant valve surgery were excluded. MAIN OUTCOME MEASURES: Age, sex, cardiothoracic ratio, and cardioactive drugs were noted. P wave specific SAPW recordings, ECG, and M mode echocardiograms from which left atrial diameter was measured were performed within 24 hours of surgery. Filtered P wave duration (SAPWD), spatial velocity, and energy were calculated from the SAPW. From the ECG, lead II P wave duration, P terminal force in lead V1, total P wave duration, and isoelectric interval were measured. Patients had Holter monitoring for 48 hours postoperatively and daily ECGs until discharge. RESULTS: Two patients died (1%) and 10 were unsuitable for analysis (5%). Of the remaining 189, 51 (27%) had atrial fibrillation (AF) lasting > 1 hour at a mean of 2 (0.5 to 7) days after CABG. Of the variables examined, only SAPWD (AF group 148 (SD 12), v 142 (14) ms, P = 0.008) and male sex (AF group 96%, v 78%, P < 0.01) were significantly different. A prospectively defined SAPWD of > 141 ms predicted atrial fibrillation with positive and negative predictive accuracies of 34% and 83%. Logistic regression analysis identified both male sex and SAPWD as significant independent predictors of postoperative atrial fibrillation. CONCLUSIONS: Signal averaged P wave duration was a better predictor of atrial fibrillation after coronary bypass grafting than standard electrocardiographic or echocardiographic criteria. The predictive value of this test is such that it is likely to be useful in the design of prospective trials of prophylactic antiarrhythmic treatment but is of limited use using current techniques in the clinical management of individual patients.
We sought to evaluate retrospectively the outcomes of patients at our hospital who had moderate ischemic mitral regurgitation and who underwent coronary artery bypass grafting (CABG) alone or with concomitant mitral valve repair (CABG+MVr).
A total of 83 patients had a reduced left ventricular ejection fraction and moderate mitral regurgitation: 28 patients underwent CABG+MVr, and 55 underwent CABG alone. Changes in mitral regurgitation, functional class, and left ventricular ejection fraction were compared in both groups.
The mean follow-up was 5.1 ± 3.6 years (range, 0.1–15.1 yr). Reduction of 2 mitral-regurgitation grades was found in 85% of CABG+MVr patients versus 14% of CABG-only patients (P < 0.0001) at 1 year, and in 56% versus 14% at 5 years, respectively (P = 0.1), as well as improvements in left ventricular ejection fraction and functional class. One- and 5-year survival rates were similar in the CABG+MVr and CABG-only groups: 96% ± 3% versus 96% ± 4%, and 87% ± 5% versus 81% ± 8%, respectively (P = NS). Propensity analysis showed similar results. Recurrent (3+ or 4+) mitral regurgitation was found in 22% and 47% at late follow-up, respectively.
In patients with moderate ischemic mitral regurgitation, either surgical approach led to an improvement in functional class. Early and intermediate-term mortality rates were low with either CABG or CABG+MVr. However, an increased rate of late recurrent mitral regurgitation in the CABG+MVr group was observed.
Cardiac surgical procedures; coronary artery bypass; coronary disease/complications/surgery; disease-free survival/trends; matched-pair analysis; mitral valve insufficiency/physiopathology/surgery; multivariate analysis; myocardial ischemia/complications/surgery; myocardial revascularization/methods/statistics & numerical data; postoperative period; recurrence; risk assessment
OBJECTIVE: To investigate the role of low serum magnesium as a trigger for atrial fibrillation in patients with a substrate for the arrhythmia (assessed by signal averaged P wave duration). DESIGN: A case-control study. SETTING: A regional referral cardiac centre. PATIENTS AND INTERVENTIONS: 105 consecutive patients undergoing elective coronary artery bypass surgery had signal averaged P wave recordings before operation. Serum electrolytes were analysed preoperatively and on days 1, 2, and 5 after surgery. MAIN OUTCOME MEASURES: Any episode of electrocardiographically recorded atrial fibrillation was taken as a study end point. RESULTS: Of 102 patients discharged, 27 (26%) had documented episodes of atrial fibrillation at a mean of 2.7 days after surgery. A combination of P wave duration > 155 ms and serum magnesium on the first postoperative day of < 0.7 mmol/l had a sensitivity of 75% and specificity of 80% for predicting atrial fibrillation. Duration of hospital stay (7.9 v 6.8 days) was longer in the atrial fibrillation group (P < 0.01). Stepwise regression showed age, serum magnesium < 0.7 mmol/l on the first postoperative day (both P < 0.001), angiotensin converting enzyme inhibitor withdrawal (P < 0.02), and signal averaged P wave duration (P = 0.04) to be independent predictors. CONCLUSIONS: The combination of signal averaged P wave duration and low serum magnesium on the first postoperative day identified the majority of patients with atrial fibrillation after coronary artery bypass surgery. Early identification and pharmacological treatment for selected patients may reduce the incidence of postoperative atrial fibrillation.
Atrial fibrillation (AF) occurs in 20–40% of patients after coronary artery bypass graft surgery (CABG) and contributes to increased morbidity and expenditure after CABG. The limited efficacy of pharmacological treatment to prevent post-CABG AF has stimulated research into alternative prophylactic strategies for the arrhythmia. This article critically reviews the trial evidence in the literature regarding the efficacy of epicardial atrial pacing to prevent post-CABG AF. Thirteen randomised controlled trials of either right, left, or biatrial pacing to prevent post-CABG AF were identified. Overall, prophylactic biatrial epicardial pacing appears to be effective prophylaxis against post-CABG AF and to reduce postoperative hospital stay. The efficacy of single site right or left atrial pacing is less clear. Further data are required to determine both the efficacy of single site atrial pacing and the cost effectiveness of pacing strategies to prevent AF after CABG.
atrial pacing; atrial fibrillation; coronary artery bypass graft
Coronary artery bypass grafting (CABG) with cardiac vale repair is an uncommon surgery in infants. CABG is technically demanding in infants due to the small size not only of the coronary arteries but also the potential graft arteries. The short and long-term outcome of surgery is not known and thus has largely been avoided.
We report the case histories of two infants in whom CABG was undertaken successfully as a life-saving measure. Case 1: This infant needed an arterial switch operation after which the right coronary artery (RCA) was stenosed resulting in low cardiac output. After the right internal mammary artery (RIMA) was used to anastamose the RCA, the hemodynamic status improved drastically. Case 2: This infant underwent surgical correction for Anomalous Left Coronary Artery from Pulmonary Artery (ALCAPA). Postoperatively, she was in low cardiac output. She was found to have an occluded left coronary artery and mitral regurgitation (MR). After she underwent left internal mammary artery (LIMA) to Left Anterior Descending (LAD) anastamosis and mitral valve repair, the clinical condition improved dramatically.
CABG is an uncommon operation in infants. This surgery is technically difficult. The long term results are not known and there are very few reports for the same. Though such an operation is best avoided, it can be used as a desperate life saving measure.
Atrial fibrillation (AF) is the most common type of arrhythmia following elective off-pump coronary bypass graft (CABG) surgery, occurring on the 2nd or 3rd postoperative day. Postoperative atrial fibrillation and early complications may be the cause of long term morbidity and mortality after hospital discharge. High sensitive C-reactive protein (hsCRP) seems to be most significantly associated with cardiovascular disorders. This study was designed to evaluate whether preoperative hsCRP (≥3 mg/dl) can predict post-elective off-pump CABG, AF, and early complications in patients with severe left ventricle dysfunction (Ejection Fraction (EF)<30%).
This study was conducted on 104 patients with severe left ventriclar dysfunction (EF < 30%), undergoing elective off-pump CABG surgery during April to September 2011 at the Afshar Cardiovascular Center in Yazd, Iran. Patients undergoing emergency surgery and those with unstable angina, creatinine higher than 2.0 mg/dl, malignancy, or immunosuppressive disease were excluded from the study. The subjects were divided into two groups: Group I with preoperative increased hsCRP (>3 mg/dl) (n=51) and group N with preoperative normal hsCRP (<3 mg/dl) (n=53). We evaluated post-CABG variables including incidence, duration, and frequency of AF, early morbidity (bleeding, infection, vomiting, renal and respiratory dysfunctions), ICU or hospital stay and early mortality. Data were then analyzed by Analysis of Variance (ANOVA), Chi-square and Fisher exact test for quantitative and qualitative variables.
The average age of the patients was 62.5 years, 75 cases (72.1%) were male, and 39 (37.5%) were female. Postoperative AF occurred in 19 cases (18.2%); 17 cases (33.3%) had hsCRP≥3 mg/dl and 2 cases (3.8%) had hsCRP≤3 mg/dl (P=0.03). Postoperative midsternotomy infection, respiratory dysfunction, and hospital stay were significantly higher in group I compared with group N (P<0.05). No statistical significant differences were identified between the two groups concerning other postoperative complications (bleeding, vomiting, renal dysfunction and ICU stay) (P>0.05).
Preoperative hsCRP ≥3 mg/dl can predict incidence of postoperative atrial fibrillation and early complications such as midsternotomy infection, respiratory dysfunction, and hospital stay following elective off-pump CABG.
Atrial fibrillation; C-reactive protein; early complications; elective off-pump CABG
To examine whether or not off-pump CABG (Coronary Artery Bypass Reduce) reduces the incidence of AF after cardiac surgery.
The study was carried out in 939 consecutive coronary artery disease patients with sinus rhythm from which 383 patients underwent off-pump CABG, and 556 patients were operated through on-pump CABG. All patients were monitored postoperatively during intensive care unit (ICU) stay. Then, the incidence and predictive risk factors of post operative AF (POAF) in two groups were determined and compared with each other.
Overall, the mean age of the patients was 56.0±12.8 years with 234 patients (24.9%) being older than 65 years. POAF developed in 38 patients (9.9%) of the off-pump and in 93 patients (16.7%) of the on-pump CABG. There was significant difference between two groups when considering the incidence of POAF (P=0.002). Among preoperative risk factors, age>65 years had a significant association with the incidence of AF in both groups. This study also showed that most of the POAF cases converted to sinus rhythm after treatment. Moreover, these finding demonstrated that conversion to sinus rhythm is significantly more probable in off-pump group (P=0.006).
A reduced prevalence of POAF could be observed in patients with off-pump as compared with on-pump techniques. Furthermore, conversion to sinus rhythm in off-pump group was significantly more probable than on-pump group.
Off-pump CABG; On-pump CABG; Postoperative Atrial Fibrillation; Risk Factor
Postoperative atrial fibrillation occurs in 20 % to 40 % of patients undergoing coronary artery bypass grafting ( CABG ) and contributes to increasing length of stay and hospital cost . The purpose of our study was to compare the length of hospital stay between patients of postoperative atrial fibrillation treated with amiodarone (experimental) and those with normal sinus rhythm ( NSR ) (Control ) after CABG.
From October of 2008 to October 2010, our experimental group including 26 patients was treated with amiodarone in Tabriz Madani Heart Center. The background variables, length of atrial fibrillation, and length of hospital stay were recorded. The experimental group was compared with a control group of 50 patients. The two groups were the same in terms of age, gender, ejection fraction, vascular diseases and risk factors.
The hospital stay duration was 8.0 ±1.6 and 7.4 ±1.4 days (p = 0.08) for experimental, and control groups respectively. Atrial fibrillation occurred mainly (60%) on the second postoperative day.
25 patients out of 26 patients (96 %) returned to NSR after starting the amiodarone protocol and the length of hospital stay in the experimental group was not significantly different from that of the control group. Thus, treating with Amiodarone in postoperative atrial fibrillation can reduce hospital stay duration compared to that of normal sinus patients.
Heart Surgery; Atrial Fibrillation; Amiodarone; Length of hospital stay
To assess the effects of intraoperative left atrial epicardial cryoablation on rhythm and atrial and ventricular function.
Thirty five patients with coronary artery disease and documented atrial fibrillation underwent coronary artery bypass surgery and concomitant cryoablation. An age and gender matched control group of 35 patients with atrial fibrillation underwent bypass surgery alone. Echocardiography was performed 9 ± 32 days before and 22 ± 6 months after surgery.
The proportion of patients in sinus rhythm at follow-up was 63% and 34% (p = 0.04) in the cryoablation and control groups, respectively. In patients with sinus rhythm both before surgery and at follow-up, the left atrial area increased (p = 0.002) and the mitral annular excursion during atrial contraction decreased (p = 0.01) after cryoablation. The mitral flow velocity during atrial systole decreased after cryoablation (p = 0.002). The LV diameter increased (p = 0.03) and the left ventricular ejection fraction (LVEF) decreased (p = 0.03) in cryoablated but not in control patients. Continued deterioration was seen in patients with atrial fibrillation both pre- and postoperatively.
At long-term follow-up, a significantly higher proportion of patients was in sinus rhythm in the cryoablation than in the control group. The atrial and ventricular function had decreased at follow-up two years after surgery. This decrease was small and occurred within or close to the reference values in patients with sinus rhythm at follow-up, while patients remaining in atrial fibrillation showed a significant continued deterioration. Some subgroups were small, and the findings, although statistically significant, should be interpreted with caution.
atrial fibrillation; echocardiography; intraoperative ablation
Atrial fibrillation (AF) remains a frequent complication after coronary artery bypass graft surgery (CABG). We evaluate the association of AF occurrence and serum cardiac troponin I (cTnI) levels in the early postoperative period after CABG. Between April 2009 and January 2010, 95 consecutive patients with sinus rhythm who underwent CABG were evaluated. The patients were divided into two groups according to their postoperative rhythms: sinus rhythm group (SR) and AF group (AF). Demographic, clinical variables, and troponin I were evaluated at the pre- and postoperative times. There were no clinical or demographic differences between the two groups. The postoperative troponin I in the SR group was lower than that in the AF group (0.66 ± 1.62 vs. 2.07 ± 5.01 ng/ml; P = 0.029). Using the receiver operating characteristic curves was found as the best cut-off value to predict AF occurrence at the value of 0.901 ng/ml. Using this value of cTnI, a sensitivity of 60% and a specificity of 87% for AF onset prediction were observed. The cTnI serum levels at the postoperative period after CABG were higher in patients who subsequently developed AF. The cut-off value of 0.901 ng/ml is useful for prediction and preventive therapeutic actions.
Atrial fibrillation; Troponin I; Coronary artery bypass
Although rare, bloodstream infections caused by Aeromonas tend to be very severe and progress rapidly.
We report a case of an 81-year-old man with fetal septicemia and endotoxin shock caused by Aeromonas hydrophila. The patient had dilated cardiomyopathy, paroxysmal atrial fibrillation, interstitial pneumonitis and renal dysfunction was admitted to our hospital with chest pain and dyspnea. Transthoracic echocardiography demonstrated impaired left ventricular wall motion and severe mitral regurgitation due to tethering. Cardiac catheterization revealed severe stenotic lesions in the left anterior descending artery and the right coronary artery. Surgery for coronary artery bypass grafts and mitral annuloplasty were performed. However, 2 days after surgery, he suddenly developed a high-grade fever and his hemodynamics deteriorated rapidly. His blood cultures revealed gram-negative Bacillus and the endotoxin concentration in the blood was elevated. Despite intensive support efforts, the patient died 1 day after the sudden change. His blood culture revealed A. hydrophila.
Whenever Aeromonas is found in a patient’s bloodstream, clinicians should start appropriate and intensive treatment immediately.
Aeromonas hydrophila; septicemia; endotoxin
Atrial fibrillation (AF) is a frequent and serious complication of coronary artery bypass graft (CABG) surgery.
We undertook a retrospective review of the records of patients undergoing CABG at Imam Ali Hospital between February 1, 2003 and February 1, 2006. The patients were divided in two groups, ie, Group A (AF) and Group B (no AF). The association between the occurrence of AF following CABG and other variables was compared with respect to continuous or categorical variables by t-test and χ2-test.
Multivariate logistic regression analysis of potentially predictive factors in univariate analysis showed that opium use, type of operation, and crossclamp time were predictors of AF following CABG.
This study identifies some new predictors of postoperative AF, control of which could lead to a lower incidence of AF and reduced morbidity, mortality, and resource utilization for patients undergoing cardiac surgery.
atrial fibrillation; coronary artery bypass grafting; cardiac surgery; predictors
The present study was aimed to identify the preoperative, intraoperative, and postoperative predictors of AF in a pure cohort of the patients with coronary artery disease who underwent CABG surgery.
Between November 2005 and May 2006, 302 consecutive patients were included in this prospective study. All the relevant clinical, electrocardiographic, echocardiographic, and laboratory data were gathered in the included patients and they were also monitored for development of post-CABG AF.
Postoperative AF occurred in 46 (15%) of patients. By univariate analysis, older age, P-wave abnormality in ECG, presence of mitral regurgitation, larger left atrium (LA), left main coronary artery involvement, failure to graft right coronary artery (RCA), and adrenergic use in ICU were significantly associated with occurrence of post-CABG AF (all P< 0.05). However, in the logistic regression model, age (OR: 1.067, 95%CI: 1.02-1.116, P=0.005), LA dimension (OR: 1.102, 95%CI: 1.017-1.1936, P=0.017), P-wave morphology (OR: 12.07, 95%CI: 3.35-48.22, P=0.0001), failure to graft RCA (OR: 3.57, 95%CI: 1.20-10.64, P=0.022), and postoperative adrenergic use (OR: 0.35, 95%CI: 0.13-0.93, P=0.036) remained independently predictive of postoperative AF.
The present study suggested that age, P-wave morphology, LA dimension, failure to graft right coronary artery, and postoperative adrenergic use were independent predictors of post-CABG AF. Therefore, clinical data, ECG and echocardiography may be useful in preoperative risk stratification of the surgical patients for the occurrence of post-CABG AF.
atrial fibrillation; predictor; coronary artery bypass graft
Omega-3 polyunsaturated fatty acids (n3-PUFAs) might have antiarrhythmic properties, but data conflict on whether n3-PUFAs reduce rates of atrial fibrillation (AF) after coronary artery bypass graft surgery (CABG). We hypothesized that n3-PUFAs would reduce post-CABG AF, and we tested this hypothesis in a well-powered, randomized, double-blind, placebo-controlled, multicenter clinical trial.
Methods and Results
Patients undergoing CABG were randomized to pharmaceutical-grade n3-PUFAs 2 g orally twice daily (minimum of 6 g) or a matched placebo ≥24 hours before surgery. Gas chromatography was used to assess plasma fatty acid composition of samples collected on the day of screening, day of surgery, and postoperative day 4. Treatment continued either until the primary end point, clinically significant AF requiring treatment, occurred or for a maximum of 2 weeks after surgery. Two hundred sixty patients were enrolled and randomized. Before surgery, n3-PUFA dosing increased plasma n3-PUFA levels from 2.9% to 4% and reduced the n6:n3-PUFA ratio from 9.1 to 6.4 (both P<0.001). Similar changes were noted on postoperative day 4. There were no lipid changes in the placebo group. The rate of post-CABG AF was similar in both groups (30% n3-PUFAs versus 33% placebo, P=0.67). The post-CABG AF odds ratio for n3-PUFAs relative to placebo was 0.89 (95% confidence interval 0.52–1.53). There were no differences in any secondary end points.
Oral n3-PUFA supplementation begun 2 days before CABG did not reduce AF or other complications after surgery.
Clinical Trial Registration
url: http://www.clinicaltrials.gov Unique identifier: NCT00446966. (J Am Heart Assoc. 2012;1:e000547 doi: 10.1161/JAHA.111.000547.)
fatty acids; coronary artery bypass graft surgery; atrial fibrillation
The risk of developing conduction disturbances after coronary bypass grafting (CABG) or valvular surgery has been well established in previous studies, leading to permanent pacemaker implantation in about 2% to 3% of patients, and in 10% of patients undergoing repeat cardiac surgery.
We sought to determine the incidence, features and predictors of conduction disorders in the immediate post-operative period of patients subjected to open-heart surgery, and the need for permanent pacemaker implantation.
Material and Method
We prospectively studied 374 consecutive patients who underwent open-heart surgery in our institution: coronary artery bypass (CABG) (n=128), Mitral valve replacement(MVR)(n=18), aortic valve replacement(AVR) (n=21), MVR and AVR(n=56), repair of ventricular septal defect (VSD) (n=51), repair of tetralogy of Fallot (TOF) (n=57),CABG and valvular surgery (n=6), others (n=37).
Among 374 patients included in our study (mean age 34.46±25.68; 146 males), 192 developed new conduction disorders: symptomatic sinus bradycardia in 8%, atrial fibrillation with slow ventricular response (AF) in 4.5%, first-degree atrioventricular block (AVB)in 6.4%, second-degree AVB in 0.3%, third-degree AVB in 7%, new right bundle branch block (RBBB) in 33%, and new left bundle branch block (LBBB) in 2.1%. In 5.6% patients, a permanent pacemaker was implanted, 47.6% of them underwent valvular surgery. In 44.1% of patients the conduction defects occurred in the first 48 hr. after surgery. In CABG group, 29.7% of patients developed new conduction disturbances; the most common of them was symptomatic sinus bradycardia. After valvular surgery 44.2% of patients developed conduction disturbances, of those the most common was atrial fibrillation with slow ventricular response . After VSD and TOF repair, the most common conduction disturbance was new RBBB. Perioperative myocardial infarction (MI) occurred in 1.9% of patients. The occurrence conduction disturbance was compared with patient age, sex, occurrence of perioperative MI, ejection fraction (EF), postoperative use of ß-adernergic receptor blocking agents and digitalis and type of cardiac surgery. By regression analysis there was a correlation between type of surgery and new conduction defects, being significant for CABG and TOF repair. Only the occurrence of perioperative MI was related to PPM implantation.
Irreversible AVB requiring a PPM is an uncommon complication after open-heart surgery. Peri-operative MI is a risk factor.
Post operative conduction disturbances; permanent pacemaker
Mitral reguritation is a relatively common finding in coronary heart disease. In this series of 127 patients, selected with a view to coronary or left ventricular surgery on the basis of severity of symptoms, the incidence was 39 (31%). Mitral regurgitation is significantly more common in patients with a history or electrocardiographic evidence of previous myocardial infarction. Clinically it may present as a pan- or late systolic or even a mid-systolic, ejection type murmur at the apex or at the left sternal edge; but in 39 per cent of the patients with angiographic mitral regurgitation no murmur was present. Angiographically important mitral regurgitation (grades 2-4/4) was usually associated with a systolic murmur; this finding was independent of ejection fractions. Left ventricular enlargement clinically or radiographically is likely to accompany mitral regurgitation but left atrial enlargement (electrocardiographically or on chest x-ray) is a more reliable pointer to mitral regurgitation and pulmonary venous hypertension is even more strongly suggestive of its presence. The electrocardiographic signs of papillary muscle infarction were rare in this series (15%) and were not related to angiographic mitral regurgitation. There was no difference in the incidence of mitral regurgitation in association with anterior or inferior myocardial infarction or in distribution of coronary artery disease. There is, however, a higher incidence of mitral regurgitation in more severe coronary arterial disease (P less than 0-05). The incidence of mitral regurgitation is significantly higher with reduction in left ventricular ejection fraction (P less than 0-001), with rise in the left ventricular end-diastolic pressure (P less than 0-02), and with abnormal contraction patterns, but the severity of mitral regurgitation is not significantly related to these findings.
Atrial fibrillation (AF) after coronary artery bypass graft surgery (CABG) constitutes the most common sustained arrhythmia and results in prolonged hospitalization. The purpose of this study was to assess simultaneous right and left atrial pacing as prophylaxis for postoperative atrial fibrillation.
Methods and Results
From July 2003 to May 2004, 120 patients without structural heart disease and who underwent CABG were randomly classified into one of the following 3 groups: biatrial pacing (BAP), left atrial pacing (LAP), and no pacing (control). Atrial pacing was performed for 4 days. Post-CABG AF was significantly reduced in BAP group compared to single-site and control group (BAP, 17.5%; LAP, 30%; control, 45%; p=0.02). The mean length of hospital stay was significantly reduced in BAP group. Hospital charges were not significantly different between three groups. The mean length of hospital stay was most significantly reduced in BAP group (6.1±1.2 versus 9.0±4.1 days in the control groups; p=0.002, and 8.7±1.3 days in LAP groups; p=0.01). The mean length of stay in the intensive care unit was also significantly reduced in the BAP group (2.8±0.7 versus 4.6±4.5 days in control group; p=0.04, and 4.2±3.2 days in LAP group; p=0.01).
Simultaneous right and left atrial pacing is well tolerated and is more effective in preventing post-CABG AF than single-site pacing, and, results in a shortened hospital stay. Identifying patients at risk for developing postoperative AF and using this prophylactic method may be the optimal effective strategy.
fibrillation; pacing; arrhythmia; coronary bypass
Previous studies on the effects of Statins in preventing atrial fibrillation (AF) after cardiac surgery have shown conflicting results. Whether statins prevent AF in patients treated with postoperative beta blockers and whether the statin-effect is dose related are unknown.
We retrospectively studied 1936 consecutive patients who underwent coronary artery bypass graft (CABG) (n = 1493) or valve surgery (n = 443) at the Minneapolis Veterans Affairs Medical Center. All patients were in sinus rhythm before the surgery. Postoperative beta blockers were administered routinely (92% within 24 hours postoperatively).
Mean age was 66+10 years and 68% of the patients were taking Statins. Postoperative AF occurred in 588 (30%) patients and led to longer length of stay in the intensive care unit versus those without AF (5.1+7.6 days versus 2.5+2.3 days, p < 0.0001). Patients with a past history of AF had a 5 times higher risk of postoperative AF (odds ratio 5.1; 95% confidence interval 3.4 to 7.7; p < 0.0001). AF occurred in 31% of patients taking statins versus 29% of the others (p = 0.49). In multivariable analysis, statins were not associated with AF (odds ratio (OR) 0.93, 95% confidence interval (CI) 0.7 to 1.2; p = 0.59). However, in a subgroup analysis, the patients treated with Simvastatin >20 mg daily had a 36% reduction in the risk of postoperative AF (OR 0.64, 95% CI 0.43 to 0.6; p = 0.03) in comparison to those taking lower dosages.
Among cardiac surgery patients treated with postoperative beta blockers Statin treatment reduces the incidence of postoperative AF when used at higher dosages
Whether mitral valve repair (MVRep) during coronary artery bypass grafting (CABG) improves survival in patients with ischemic mitral regurgitation (MR) remains unknown.
Methods and Results
Patients with ejection fraction ≤ 35% and coronary artery disease amenable to CABG were randomized at 99 sites worldwide to medical therapy (MED) with or without CABG. The decision to treat the mitral valve during CABG was left to the surgeon. The primary endpoint was mortality. Of 1212 randomized patients, 435 (36%) had none/trace, 554 (46%) mild, 181 (15%) moderate, and 39 (3%) severe MR. In the medical arm, 70 deaths (32%) occurred in patients with none/trace, 114 (44%) with mild and 58 (50%) in moderate-severe MR. In patients with moderate-severe MR, there were 29 deaths (53%) among 55 patients randomized to CABG who did not receive mitral surgery (HR vs. MED 1.20, 95% CI 0.77–1.87) and 21 deaths (43%) among 49 patients who received mitral surgery (HR vs. MED 0.62, 95% CI 0.35–1.08). After adjustment for baseline prognostic variables, the HR for CABG with mitral surgery vs. CABG alone was 0.41 (95%CI 0.22–0.77; p=0.006).
While these observational data suggest that adding MVRep to CABG in patients with LV dysfunction and moderate-severe MR may improve survival compared with CABG alone or MED alone, a prospective randomized trial would be necessary to confirm the validity of these observations.
cardiomyopathy; coronary disease; mitral valve; surgery; trials
Low levels of antithrombin (AT) have been independently associated with prolonged intensive care unit stay and an increased incidence of neurologic and thromboembolic events after cardiac surgery. We hypothesized that perioperative AT activity is independently associated with postoperative major adverse cardiac events (MACEs) in patients undergoing coronary artery bypass graft (CABG) surgery.
We prospectively studied 1403 patients undergoing primary CABG surgery with cardio-pulmonary bypass (CPB) (http://clinicaltrials.gov/show/NCT00281164). The primary clinical end point was occurrence of MACE, defined as a composite outcome of any one or more of the following: postoperative death, reoperation for coronary graft occlusion, myocardial infarction, stroke, pulmonary embolism, or cardiac arrest until first hospital discharge. Plasma AT activity was measured before surgery, after post-CPB protamine, and on postoperative days (PODs) 1–5. Multivariate logistic regression modeling was performed to estimate the independent effect of perioperative AT activity upon MACE.
MACE occurred in 146 patients (10.4%), consisting of postoperative mortality (n = 12), myocardial infarction (n = 108), stroke (n = 17), pulmonary embolism (n = 8), cardiac arrest (n = 16), or a subsequent postoperative or catheter-based treatment for graft occlusion (n = 6). AT activity at baseline did not differ between patients with (0.91 ± 0.13 IU/mL; n = 146) and without (0.92 ± 0.13 IU/mL; n = 1257) (P = 0.18) MACE. AT activity in both groups was markedly reduced immediately after CPB and recovered to baseline values over the ensuing 5 PODs. Postoperative AT activity was significantly lower in patients with MACE than those without MACE. After adjustment for clinical predictors of MACE, AT activity on PODs 2 and 3 was associated with MACE.
Preoperative AT activity is not associated with MACE after CABG surgery. MACE is independently associated with postoperative AT activity but only at time points occurring predominantly after the MACE.
Patients undergoing coronary artery bypass grafting (CABG) experience a reduction in right ventricular long axis velocities post surgery.
We tested whether the phenomenon of right ventricular (RV) long axis velocity decline depends on the chest being opened fully by mid-line sternotomy, pericardial incision, or on the type of operation performed.
By intraoperative transoesophageal echocardiography (TEE) we recorded serial right ventricular (RV) systolic pulse-wave tissue Doppler velocities during 6 types of elective procedure: 53 CABG surgery, 15 robotic-assisted minimally-invasive CABG (RCABG), 28 aortic valve replacement (AVR), 8 minimally-invasive aortic valve replacement (mini-AVR), 5 mediastinal mass excision, and 1 left atrial myxoma excision. Pre and post operative transthoracic echocardiography (TTE) were also conducted.
Surgery without substantial opening of the pericardium did not significantly reduce RV systolic velocities (RCABG 13 ± 1.8 versus 12.4 ± 2.7 cm/s post; mini-AVR 11.9 ± 2.3 versus 11.1 ± 2.3 cm/s; mediastinal mass excision 13.9 ± 3.1 versus 13.8 ± 4 cm/s). In contrast, within 5 min of pericardial incision those whose surgery involved full opening of the pericardium had large reductions in RV velocities: 54 ± 11% decline with CABG (11.3 ± 1.9 to 5.1 ± 1.6 cm/s, p < 0.0001), 54 ± 5% with AVR (12.6 ± 1.4 to 5.7 ± 0.6 cm/s, p < 0.001) and 49% with left atrial myxoma excision (11.3 to 15.8 cm/s). This persisted immediately after pericardial opening to the end of surgery (61 ± 11%, p < 0.0001; 58 ± 7%, p < 0.0001; 59% respectively).
It is full opening of the pericardium, and not cardiac surgery in general, which causes RV long axis decline following cardiac surgery. The impact is immediate (within 5 min) and persistent.
RV function; Pericardium; Cardiac surgery; Pulsed-wave tissue Doppler echocardiography