A simple way to treat chronic atrial fibrillation during mitral valve surgery: the epicardial radiofrequency approach.

OBJECTIVE: We describe an original radiofrequency ablation technique to treat chronic atrial fibrillation in patients undergoing mitral valve surgery. Most of the procedure is carried out epicardially, in order to avoid an undue increase of surgical time and trauma. METHODS: The ablations are performed using a temperature-controlled multipolar radiofrequency catheter. Two encircling lesions around the ostia of the right and of the left pulmonary veins are carried out epicardially, usually before cardiopulmonary bypass. Through a conventional left atriotomy the ablation procedure is completed with two endocardial lesions connecting the two encirclings between them and to the mitral valve annulus. After the mitral valve procedure is performed, the left appendage is sutured. RESULTS: From February 1998 to May 1999, 40 patients with chronic atrial fibrillation (43. 1+/-51.9 months) underwent combined radiofrequency ablation and mitral valve surgery. Mean left atrial diameter was 56.8+/-10.7 mm. Mean cardiopulmonary bypass and aortic cross-clamp time were, respectively, 119.1+/-26.3 and 76.7+/-21.0 min. Mean postoperative blood loss was 287.2+/-186.6 ml. No reexploration for bleeding occurred. One patient died of pneumonia 12 days after operation. No patient needed permanent pacemaker implantation. Mean postoperative hospital stay was 7.3+/-5.6 days. At follow-up (mean 11.6+/-4.7 months), 30/39 (76.9%) of the patients were in stable sinus rhythm. All patients in sinus rhythm 3 months after operation recovered both left and right atrial contractility at echocardiographic control (mean 7.3+/-3.4 months). The left atrial diameter decreased significantly in patients recovering sinus rhythm. CONCLUSIONS: Epicardial radiofrequency ablation is a safe means to achieve surgical ablation of atrial fibrillation with a high success rate. The simplicity of the technique and the low procedure-related risk should dictate combined treatment virtually in all patients with atrial fibrillation undergoing open heart operations.     

Surgical ablation of atrial fibrillation with a novel bipolar radiofrequency device

OBJECTIVE: When used for epicardial ablation, unipolar devices do not predictably yield transmural scars. Bipolar radiofrequency proved highly effective on the animal model, but clinical experience is still initial. We describe acute electrophysiologic findings and follow-up results of epicardial ablation with a novel bipolar radiofrequency device. METHODS: A bipolar ablator was used to perform a simplified left atrial lesion set in 90 consecutive patients with atrial fibrillation undergoing open heart surgery. Pacing thresholds were assessed during surgery to validate 24 pulmonary vein encircling lines (12 patients). Follow-up was 100% complete. RESULTS: In 67 of 90 patients (84%), mitral valve disease was the main indication to surgery. Atrial fibrillation was continuous in 74 patients (82%) and intermittent in 16 patients (18%). Pacing threshold assessment showed a complete conduction block in 22 of 24 pulmonary vein couples (92%) after a single ablation and in all patients after doubling of the encircling lines. No complications related to the ablation procedure were recorded. The sinus rhythm restoration rate was 79% at 3 months, 87% at 6 months, and 89% (17/18 patients) at 1 year. Postablation organized arrhythmias consisted in right atrial flutter in 2 patients (2%) and left atrial flutter in 6 patients (7%). CONCLUSIONS: Epicardial ablation with bipolar radiofrequency grants acute transmurality. A simplified lesion set proved highly effective in eliminating atrial fibrillation at 1-year follow-up. Our data suggest that addition of a lesion to the mitral annulus is advisable to prevent left atrial flutter.     

Factors predicting the time until atrial fibrillation recurrence after concomitant left atrial ablation.

OBJECTIVE: Treatment of atrial fibrillation, a risk factor for morbidity and mortality, by left atrial ablation is a less complex procedure which is increasingly performed in conjunction with surgery for various heart diseases. Although restoration of sinus rhythm is effective initially, atrial fibrillation may recur. We investigated factors predicting the time until its recurrence. METHODS: Between January 2003 and December 2005, 162 consecutive patients (52.5% male, age 69+/-8.7 years) with permanent atrial fibrillation underwent concomitant left atrial ablation and isolated or combined mitral valve surgery (42.6%), isolated or combined aortic valve surgery (32.1%), and isolated or combined coronary artery bypass grafting (24.1%). Ablation was performed by microwave (n=93, 57.4%) or radiofrequency (n=69, 42.6%) technology. Follow-up was after 3, 6, 12 months and yearly thereafter. Predictive values of variables for postoperative atrial fibrillation were examined using techniques of univariate and multivariate survival analysis (proportional hazards regression). RESULTS: Eight patients died perioperatively and 13 during follow-up (not ablation related). Two patients were lost to follow-up. At last follow-up (19+/-11.3 months), 86 patients (62%) were in stable sinus rhythm, 73 (52%) without antiarrhythmic drugs, and 43 (31%) were in atrial fibrillation. Predictors for the time until recurrence of atrial fibrillation in a multivariate model were preoperative atrial fibrillation duration (hazard ratio 1.005, 95% confidence interval 1.003-1.007, p<0.001) and left atrial diameter (hazard ratio 1.056, 95% confidence interval 1.020-1.093, p=0.002). Overall, sinus rhythm conversion rate was 75% when preoperative atrial fibrillation duration was less than 2 years, but 42% in longer lasting atrial fibrillation with left atrial dilatation (>50mm). Age, gender, primary heart disease, history of thromboembolism or cardioversion, presence of concomitant diseases, EuroScore, left ventricular size and function, aortic cross-clamp time, ablation technology, and treatment with antiarrhythmic drugs did not predict rhythm outcome. CONCLUSIONS: Preoperative atrial fibrillation duration and left atrial diameter predict the time until atrial fibrillation recurrence after concomitant left atrial ablation, whereas age, type of primary cardiac surgery, ablation technology and antiarrhythmic therapy do not.     

Minimally invasive epicardial left atrial ablation and appendectomy for refractory atrial tachycardia

Surgical removal or epicardial radiofrequency ablation of the left atrial appendage (LAA) is occasionally required when endocardial ablations fail. We report a modified minimally invasive surgical approach for elimination of recurrent atrial arrhythmias arising from the LAA, including both radiofrequency ablation and appendectomy. Ablation of the LAA base was performed using the Medtronic Cardioblate bipolar radiofrequency device (Medtronic, Minneapolis, MN), and left atrial appendectomy was then completed using the EndoGIA stapling system (US Surgical, Norwalk, CT). This procedure successfully isolated and removed the tachycardia focus, and normal sinus rhythm was restored. Elimination of LAA arrhythmias using a combination of epicardial radiofrequency ablation and appendectomy ensures electrical isolation while minimizing surgical invasiveness.     

Surgical radiofrequency ablation of both atria for atrial fibrillation: results of a multicenter trial

BACKGROUND: The Cox maze procedure has shown to be effective in treating atrial fibrillation. Radiofrequency ablation, with a similar objective, has been used as an adjunct to conventional cardiac surgery for the treatment of atrial fibrillation in more than 20 centers in Australia and New Zealand since March 2000. This is a report of those results. METHODS: One hundred thirty-two patients in 20 centers underwent radiofrequency ablation as an adjunct to conventional cardiac surgery, with a standardized lesion set created with a flexible, 7-electrode, temperature-controlled probe (Cobra; EPTechnologies, San Jose, Calif). All data were entered into a central registry, with regular follow-up prompted by the registry cocoordinator. Each radiofrequency scar was made with standard parameters requiring 2 minutes of tissue coagulation at 80 degrees C to 85 degrees C. Patients undergoing mitral procedures had radiofrequency ablation performed in the left atrium endocardially. Patients undergoing aortic valve replacement or coronary artery bypass surgery underwent epicardial radiofrequency ablation of the left atrium. Epicardial radiofrequency ablation lesions on the right atrium were common to both groups of patients. Preoperatively, 75% of the patients had chronic atrial fibrillation, 21% had paroxysmal atrial fibrillation, and 4% had flutter. Surgical procedures performed included mitral valve procedure in 60%, coronary artery bypass grafting in 14%, aortic valve replacement in 7%, and coronary artery bypass grafting plus aortic valve replacement in 4%. RESULTS: There were no major complications related to the use of radiofrequency ablation. There were no soft tissue or cardiac perforations. Ten patients were defibrillated into sinus rhythm within 3 months postoperatively. The freedom from atrial fibrillation was 84% at 3 months, 90% at 6 months, and 100% at 12 months. All patients at 12 and 18 months' follow-up were in sinus rhythm. There were no thromboembolic complications. CONCLUSIONS: Surgical radiofrequency ablation can be performed safely as an adjunct to conventional cardiac surgery. A standardized lesion set created by using similar temperature settings can be adopted in multiple centers and might be effective in treating atrial fibrillation. Data collection through a central registry has helped in monitoring the effectiveness of this new technique in a scattered population.     

Atrial function after epicardial microwave ablation in patients with atrial fibrillation

OBJECTIVES: To study epicardial microwave ablation of concomitant atrial fibrillation and its effects on heart rhythm and atrial function during follow-up. DESIGN: The study included 20 open-heart surgery patients with concomitant atrial fibrillation. Transthoracic echocardiography with flow and tissue Doppler recordings was performed preoperatively and at 6 months postoperatively. Blood samples were obtained preoperatively and postoperatively for analysis of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and amino terminal precursor of brain natriuretic peptide (NT-proBNP). RESULTS: Fourteen of 19 patients (74%) were in sinus rhythm with no antiarrhythmic drugs at 12 months. All patients in sinus rhythm had preserved left and right atrial-filling waves through atrioventricular valves during atrial contraction. Tissue velocity echocardiography on patients in sinus rhythm showed preserved atrial wall velocities, atrial strain, and atrial strain rate. Levels of natriuretic peptides tended to decrease in patients with stable sinus rhythm at one year compared to patients in atrial fibrillation. CONCLUSIONS: Epicardial microwave ablation results in sinus rhythm in a majority of patients and seems to preserve atrial mechanical function.     

The radiofrequency modified maze procedure. A less invasive surgical approach to atrial fibrillation during open-heart surgery.

OBJECTIVE: Patients with mitral valve disease and suffering of atrial fibrillation of more than 1 year's duration have a low probability of remaining in sinus rhythm after valve surgery alone. Intraoperative radiofrequency ablation was used as an alternative to simplify the surgical maze procedure. METHODS: Seventy-two patients with mitral valve disease, aged 63+/-11 years ranging from 31 to 80 years, underwent valve surgery and radiofrequency energy applied endocardially, based on the maze III procedure to eliminate the arrhythmia. The right-sided maze was performed on the beating heart and the left-sided maze during aorta cross-clamping. RESULTS: Surgical procedures included mitral valve repair (n=38) or replacement (n=34) and in addition tricuspid valve repair (n=42), closure of an atrial septal defect (n=2) and correction of cor triatriatum (n=1). The left-sided maze needed 14+/-3 min extra ischemic time. There were two in-hospital deaths (2.7%) and three patients (4.2%) died during follow-up of 20+/-15 months. Among 67 surviving patients, 51 patients (76%) were in sinus rhythm, two patients (3%) had an atrial rhythm and eight patients (12%) had persistent atrial fibrillation or atrial flutter. Four patients had a pacemaker implanted, in one patient because of sinus node dysfunction. Doppler echocardiography in 64 patients demonstrated right atrial contractility in 89% and left atrial transport in 91% of patients. CONCLUSIONS: Intraoperative radiofrequency ablation of atrial fibrillation is an effective and less invasive alternative for the original maze procedure to eliminate atrial fibrillation.     

心内膜合并心外膜改良迷宫射频消融治疗心房纤颤

目的评价心内膜合并心外膜改良迷宫射频消融治疗心房纤颤的疗效。方法对295例房颤患者进行射频消融,185例进行心内膜加心外膜消融,另110例行心内膜消融。其中男124例,女171例;年龄19—77岁,平均（52±11）岁。90．8％（268／295）患者为风湿性病变。瓣膜手术289例,19例合并冠状动脉旁路移植术。结果手术死亡10例（3．4％）,其中4例死于低心排综合征,5例死于多器官功能衰竭,1例死于脑疝。随访3～47个月,平均（28±5）个月。随访每组各有1例死亡,均死于神经系统并发症。全组术后窦性心律占77．3％（228／295）,其中心内膜组70．9％（78／110）;心内膜加心外膜组81．1％（150／185）（P〈0．05）。最近随访的259例,窦性心律191例,占73．7％,其中心内膜组66．0％（64／97）,心内膜加心外膜组78．4％（127／162）（P〈0．05）。组织学可见心内膜组心肌细胞凝固性坏死灶集中在心内膜侧,近心外膜的坏死灶减少。而心内膜加心外膜组可见病灶分布组织全层,局部有炎症细胞浸润,心肌细胞网状结构破坏消失。结论心内膜合并心外膜射频消融是一种简易、安全、有效的治疗房颤的外科方法,而且效果优于心内膜消融。     

Concomitant irrigated monopolar radiofrequency ablation of atrial fibrillation in adults with congenital heart disease

Atrial fibrillation is the most frequent form of atrial arrhythmias in adults with congenital heart disease. Some serious complications are related with the presence of atrial fibrillation after surgery. Because of the complexity and the risk of bleeding, the Maze III procedure has been largely replaced by alternative energy sources. Our experience in using irrigated monopolar radiofrequency ablation to treat atrial fibrillation in adults with congenital heart disease is reported. Seven patients with congenital heart disease and atrial fibrillation underwent irrigated monopolar radiofrequency ablation. All patients were confirmed in permanent fibrillation preoperatively. Six were adult atrial septal defect patients and one was an adult patent ductus arteriosus patient. All patients survived the procedure and discharged in sinus rhythm. There were no complications related to radiofrequency ablation. The time of ablation ranged from 17 to 22 min (average 19.5 min). Follow-up ranged from 3 to 48 months. One patient with mitral valve replacement (MVR) died of cerebral hemorrhage 13 months after surgery. The last electrocardiogram showed that six patients were in sinus rhythm and one patient in junctional rhythm. Irrigated monopolar radiofrequency ablation is an easy, effective, safe and economic concomitant operation to eliminate atrial fibrillation in adult patients with congenital heart defect and atrial fibrillation.     

Cox/Maze III operation versus radiofrequency ablation for the surgical treatment of atrial fibrillation: a comparative study

BACKGROUND: The purpose of this study was to evaluate the efficacy of radiofrequency (RF) ablation in the treatment of atrial fibrillation, by comparatively analyzing the outcomes of the patients who underwent RF ablation with those of patients who underwent Cox/Maze III surgery. METHODS: Between April 1995 and June 2002, 70 patients underwent surgery for atrial fibrillation and open-heart surgery at the Department of Cardiovascular Surgery of the University of Bologna: 30 patients underwent the surgical Cox/Maze III procedure (group 1), and 40 patients underwent the RF ablation according to the Maze III configuration at least on the left atrium (group 2). There were 14 males and 56 females, with a mean age of 61.5 +/- 12.5 years (range 22 to 80 years old). RESULTS: Groups 1 and 2 did not differ in terms of baseline characteristics. The perioperative mortality rate was not significantly different between the two groups (6.6% in group 1 vs 7.5% in group 2). The overall cumulative rates of sinus rhythm were 68.9% in group 1 and 88.5% in group 2 (not statistically significant). Biatrial contraction was assessed by transthoracic echocardiography in 70.4% of the patients in group 1 and 76.5% of the patients in group 2 (p = 0.65). CONCLUSIONS: The RF ablation procedure offers as good results as the Cox/Maze III operation, allowing recovery of the sinus rhythm and atrial function in the great majority of patients with atrial fibrillation who underwent open heart surgery; it is a safe and effective means of curing atrial fibrillation with negligible technical and time requirements.     

Radiofrequency modified maze in patients with atrial fibrillation undergoing concomitant cardiac surgery

OBJECTIVE: In the majority of patients with chronic atrial fibrillation the arrhythmia will persist after correction of the underlying structural abnormality. The maze procedure is an effective surgical method to eliminate atrial fibrillation and to restore atrial contractility. METHODS: In this study we used radiofrequency energy to create lines of conduction block in both atria during cardiac surgery as a modification of the maze III procedure. One hundred twenty-two patients with atrial fibrillation for at least 1 year and structural heart disease underwent open heart operation and a radiofrequency modified maze procedure. RESULTS: In 108 (89%) of 122 patients mitral valve surgery was performed, and in this group 86 patients (80%) underwent 121 concomitant procedures. Fourteen patients (11%) underwent cardiac surgery not involving the mitral valve. The additional crossclamp time required for the left atrial part of the radiofrequency modified maze procedure was 14 +/- 3 minutes. The in-hospital mortality rate was 4.1%. The overall 39-month survival was 90%, and freedom of atrial flutter or atrial fibrillation was 78.5% +/- 5.1%. Eighty-nine survivors with sinus, atrial rhythm, or atrioventricular sequential pacemaker had Doppler echocardiography, and right atrial transport function was documented in 83% and left atrial transport function in 77% of patients. CONCLUSION: We concluded that the radiofrequency modified maze procedure as an adjunctive procedure is safe, time-sparing, and effective in eliminating atrial fibrillation and restoring atrial transport function.     

改良线路心房直视迷宫式射频消融治疗心房颤动

目的：探讨风湿性心脏病合并心房颤动（房颤）病人,在瓣膜置换同时采用改良线路经心房直视迷品式射频消融治疗房颤的可行性及疗效。方法：66例风湿性心脏病二尖瓣病变合并房颤病人,在体外循环心内直视下经心房行迷宫式射频消融,同时行二尖瓣置换术,结果：无手术死亡,57例房颤消失,其中术后窦性心律54例（81．8％）,结性心律1例（1．5％）,心房扑动2例（3％）,9例（13．6％）仍为房颤,随访2－60个月,总随访率89．6％,窦性心律稳定,无远期死亡,结论：经心房内视改良线路迷宫式射频消融治疗房颤,方法简捷,安全有效,远期疗效稳定,值得进一步研究,推广。     

Combined endocardial and epicardial radiofrequency ablation of right and left atria in the treatment of atrial fibrillation

BACKGROUND: The maze procedure and its modifications have been successful in treating atrial fibrillation (AF), at the expense of longer procedure times and increased morbidity. This study evaluated the early results of using radiofrequency ablation as a surgical adjunct in treating AF. METHODS: Twenty-six patients, with established or frequent intermittent AF, who were undergoing various cardiac surgical procedures, were enrolled. During their operations, the patients underwent intraoperative left and right atrial radiofrequency ablation lesions using a handheld flexible probe. Patients were followed up with echocardiography and Holter monitoring. RESULTS: All 26 patients were weaned off cardiopulmonary bypass in sinus rhythm. There were 2 early noncardiac deaths in high-risk patients; 23 surviving patients (95%) remained in sinus rhythm at a mean follow-up of 175 days (range 96 to 400 days). Three patients were defibrillated into sinus rhythm 30, 40, and 60 days after their operation. Test epicardial lesions on the right atrial appendage in 12 patients showed full-thickness coagulation of tissue in 10 (83%). CONCLUSIONS: A combined endocardial and epicardial set of radiofrequency lesions in both atria abolished AF in most patients at 6 months and facilitated easy conversion of recurrent AF into sinus rhythm. The transmural nature of the epicardial lesions has implications for further development.     

Endocardial and epicardial radiofrequency ablation in the treatment of atrial fibrillation with a new intra-operative device.

OBJECTIVE: Atrial fibrillation has been a difficult problem to solve in many surgical patients, especially in those with mitral valve pathology. This study evaluates the results of endocardial and epicardial radiofrequency ablation with a new intra-operative device in the treatment of atrial fibrillation. METHODS: We operated on 65 patients with atrial fibrillation, 58 of which had concomitant mitral surgery. Atrial fibrillation was chronic (over 1 year) in 46 patients (group A) and paroxysmal or recent onset in 12 (group B). Group C had lone atrial fibrillation (two), concomitant coronary artery disease (four) or a sarcoma (one). Bilateral pulmonary vein isolation with a new intra-operative device was performed through multiple dry lesions in all patients. Groups A and B had endocardial applications at 70 degrees C during 60 s and group C had epicardial applications at 75 degrees C. Three group C patients had epicardial applications off pump. Atrial wall biopsies were performed in nine patients from groups A and B. RESULTS: There were no serious post-operative complications. At 1 month follow-up 54% of all patients were out of atrial fibrillation and 34% were in normal sinus rhythm with bilateral atrial contraction (Santa Crus Score 4). At 6 months follow-up, in spite of some crossover of patients among groups, similar results were obtained. The success of the procedure was 69% (Santa Crus scores 3 and 4) in mitral patients with a left atrial volume smaller than 200 cm(3). Preliminary data on the transmurality of the lesions is presented. The patients submitted to epicardial radiofrequency ablation (group C) have satisfactory results at 1 month (six out of seven were out of AF). CONCLUSIONS: Both endocardial and epicardial RF applications are simple and quick to perform and do not pose an additional risk for most patients. Furthermore we believe that it is possible to perform bilateral epicardial radiofrequency ablation of the pulmonary veins without cardiopulmonary bypass. Further refinements of the technique are needed to assure transmurality of all lesions and better results.     

How effective is bipolar radiofrequency ablation for atrial fibrillation during concomitant cardiac surgery?

A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was whether, in patients undergoing cardiac surgery, concomitant bipolar radiofrequency ablation had an acceptable success rate to justify the additional procedure. Altogether 263 papers were found using the reported search, of which 12 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The consensus in the literature was that bipolar radiofrequency ablation was highly successful in restoring sinus rhythm. One meta-analysis of six non-randomized studies demonstrated that 76% of patients were in sinus rhythm compared with 16% in atrial fibrillation 3 months postoperatively. One randomized controlled trial found that the sinus rhythm conversion rate for any maze procedure was highly significant compared with the control group (P?=?0.001). Another found that Cardioblate radiofrequency ablation was significantly better at restoring sinus rhythm at 1 year (75 vs 39% control, P?=?0.019). Prospective studies showed a similar rate of sinus rhythm return at 1 year (89%). Notably some studies demonstrated a significant reduction in the New York Heart Association class when sinus rhythm was restored compared with those remaining in atrial fibrillation (P?相似文献   

Surgical ablation of permanent atrial fibrillation by means of maze radiofrequency: mid-term results

Abstract Background: The maze procedure can be performed surgically with radiofrequency, generating transmural ablation lines. We report our experience with a biatrial pattern of lesions based on the use of epicardial and endocardial radiofrequency ablation in an effort to minimize maze procedure. Method: In 85 patients undergoing cardiac surgery for established permanent atrial fibrillation (>3 months), a biauricular pattern of epicardic–endocardic maze lesions was performed. The main surgical procedures were diverse: 42 mitral valve surgeries, 7 mitrotricuspid valves, 18 mitroaortics, 4 mitroaortic and tricuspids, 2 aortic valves, 3 CABGs, 5 CABG and valve procedures, and 4 atrial septal defects. The mean age of the patients was 61 ± 12 (range 39–78). The mean duration of atrial fibrillation was 5.8 years (range 0.3 to 24). Results: Sixty‐two (72.9%) patients presented postoperative supraventricular arrhythmia. Hospital mortality was seen in five patients (5.8%). Two patients died after a 12‐month mean follow‐up (range 2 to 32). A total of 14.1% of patients remained with their previous atrial fibrillation and 85.9% recovered and maintained sinus rhythm, with two patients having a permanent pacemaker. A total of 56% patients have been followed‐up for a period of more than 6 months, and among them prevalence of sinus rhythm is 87.5%. Echocardiography detected biauricular contraction in 65% of them. After analyzing the data, factors involved in postoperative recurrence of atrial fibrillation after radiofrequency surgery were oldness of the atrial fibrillation (p < 0.01) and pre and postoperative left auricle volume (p < 0.04). Conclusion: Intraoperative radiofrequency has permitted us to perform the maze procedure in a simple way, with a low surgical morbid‐mortality. We have obtained an 85.9% electrographic effectiveness and a 65% recovery of atrial contraction. Postoperative incidence of arrhythmia is the main postoperative problem.     

Biatrial radiofrequency ablation for atrial fibrillation: epicardial and endocardial surgical approach

Radiofrequency energy applied by means of surgical probes permits the ablation of atrial fibrillation (AF). This study presents our initial experience on 55 consecutive cardiac patients with permanent AF with radiofrequency ablation through biatrial epicardial and endocardial surgical approach. At discharge, 8.1% of the patients had persistent AF-atrial flutter. Hospital incidence of arrhythmias were, 9% of paroxysmal atrial fibrillation, 10.9% of atrial flutter, and 34.5% of persistent atrial fibrillation. After a mean follow-up of 7 months, 83.6% patients have recovered sinus rhythm, and echocardiographic biatrial contraction was re-established in 73%. Biatrial radiofrequency ablation applied from the endocardium and the epicardium has achieved satisfactory results, without increasing the surgical risk.     

射频消融迷宫治疗心房纤颤

作者采用射频消融迷宫术治疗心房纤颤２０例,其中１９例合并风湿性二尖瓣病的患者,同时行瓣膜替换术,１例合并房间隔缺损患者进行修得。射频消融的路线采用小板井嘉夫的手术径路。术后１６例恢复窦性心律,占８０％,未恢复窦性心律的４例,２例为房颤,１例为房扑,另１例为结性心律。     

Epicardial radiofrequency ablation of both atria in the treatment of atrial fibrillation: experience in patients

BACKGROUND: Despite success with the Maze procedure and its modifications in treating atrial fibrillation, longer procedure times and increased morbidity have precluded widespread use. The operative treatment for atrial fibrillation associated with aortic valve disease and ischemic heart diseases have not been established. We report the early results of epicardial radiofrequency coagulation on both atria and discuss the availability of this procedure. METHODS: The Australasian database of radiofrequency ablation lists 130 patients with established or frequent intermittent atrial fibrillation that underwent various cardiac surgical procedures between March 2000 and March 2002. Forty patients without mitral valve disease underwent epicardial radiofrequency coagulation on both atria. Twenty-eight patients were in established chronic atrial fibrillation, 9 in paroxysmal atrial fibrillation, and 3 patients had atrial flutter. The primary surgical procedures were coronary artery bypass grafting in 19 patients, aortic valve replacement in 9, coronary artery bypass grafting plus aortic valve replacement in 8, and other procedures in 4 patients. RESULTS: The procedure increased the cross-clamp time by a mean of 10 minutes. Three patients required defibrillation postoperatively, within the first 3 months and have since stayed in sinus rhythm. One patient had late atrial flutter that was cardioverted to sinus rhythm. Sinus recovery rate was 93.7% (15 of 16 patients) at 6 months and 100% in 8 patients reviewed at 12 months. Atrial contractility was maintained. CONCLUSIONS: Epicardial radiofrequency coagulation may be a very effective way of converting patients with atrial fibrillation into sinus rhythm.     

Beating-heart surgical treatment of atrial fibrillation with microwave ablation

BACKGROUND: In this feasibility study, early results are presented of our first series of patients with microwave ablation for atrial fibrillation (AF) on the beating heart. METHODS: From June 2001 until December 2001, a total of 24 patients underwent beating-heart epicardial ablation for AF. With a microwave antenna, the left and right pulmonary veins were isolated and connected to each other followed by amputation of the left atrial appendage. Subsequently, patients underwent either off-pump coronary artery bypass graft or valve surgery on pump. The mean age of the patients was 67.4 +/- 6 years. Three patients experienced paroxysmal atrial fibrillation and all others chronic AF. Mean left atrial diameter was 5.4 +/- 0.6 cm, and mean ablation time was 13 min. RESULTS: All procedures but one were completed successfully on the beating heart. All patients were in sinus rhythm after the procedure. A total of 15 patients experienced periods with postoperative AF during hospital stay; 9 of these patients were discharged with AF. All patients received either sotalol or amiodarone. At latest follow-up (3 to 9 months), 20 of 23 patients were in sinus rhythm. CONCLUSIONS: With microwave ablation, electrical isolation of the pulmonary veins can be achieved epicardially without cardiopulmonary bypass support.