Surgery for atrial fibrillation using radiofrequency catheter ablation

OBJECTIVE: We present the results obtained in 40 patients with chronic atrial fibrillation using direct intraoperative radiofrequency to perform atrial fibrillation surgery. METHODS: Between April 2001 and June 2002, 40 patients underwent surgery for atrial fibrillation using radiofrequency ablation and cardiac surgery at the Department of Cardiovascular Surgery of the University of Bologna [corrected]. There were 8 men and 32 women with a mean age of 62 +/- 11.6 years (range: 20 to 80 years). RESULTS: Concomitant surgical procedures were: mitral valve replacement (n = 13), mitral valve replacement plus tricuspid valvuloplasty (n = 11), combined mitral and aortic valve replacement (n = 8), and combined mitral and aortic valve replacement plus tricuspid valvuloplasty (n = 5). Moreover, 1 patient underwent tricuspid valvuloplasty plus atrial septal defect repair, another required aortic valve replacement plus coronary artery bypass graft, and a third underwent aortic valve replacement. After the mean follow-up time of 16.5 +/- 2.5 months survival was 92.8% and the overall cumulative rate of sinus rhythm was 88.5%. CONCLUSIONS: We conclude that the radiofrequency ablation procedure is a safe and effective means of curing atrial fibrillation with negligible technical and time requirements, allowing recovery of the sinus rhythm and atrial function in the great majority of patients with atrial fibrillation who underwent cardiac surgery (88.5% of our study population).     

Evaluation of clinical treatment of atrial fibrillation associated with rheumatic mitral valve disease by radiofrequency ablation.

OBJECTIVES: The aim of this clinical study was to evaluate the effectiveness and advantages of the radiofrequency ablation maze procedure in the treatment of atrial fibrillation associated with rheumatic mitral valve disease. METHODS: We developed one kind of modified Cox III maze procedure with the use of radiofrequency ablation in the treatment of atrial fibrillation associated with rheumatic mitral valve disease and compared the outcome of 96 patients of atrial fibrillation associated rheumatic mitral valve disease who underwent radiofrequency ablation maze procedure plus mitral valve replacement with that of 87 patients with atrial fibrillation associated rheumatic mitral valve disease who had mitral valve replacement during the same interval by the same surgeon. The patients in the two groups were similar in age, gender, preoperative New York Heart Association class and duration of preoperative atrial fibrillation. RESULTS: No operative deaths occurred in the study group and the control group. Duration of cardiopulmonary bypass (137.63 +/- 10.82 vs. 90.95 +/- 7.65 min, P<0.01) and duration of aortic crossclamping (56.96 +/- 6.19 vs. 32.66 +/- 3.55 min, P<0.01) were prolonged in the study group. Blood loss from chest tubes was similar in the two groups (494.06 +/- 100.44 vs. 476.09 +/- 115.84 ml, P=0.263). Freedom from atrial fibrillation in the study group was 77% 3 years after the operation compared with 25% in the control group (P<0.01). CONCLUSIONS: The addition of the radiofrequency ablation maze procedure to mitral valve replacement is safe and effective in the treatment of atrial fibrillation associated with rheumatic mitral valve disease.     

Curative treatment of atrial fibrillation with intraoperative radiofrequency ablation: short-term and midterm results

OBJECTIVE: This report describes the early and midterm results after intraoperative radiofrequency ablation of atrial fibrillation for patients with isolated chronic atrial fibrillation or atrial fibrillation in combination with additional valvular and nonvalvular cardiac diseases. METHODS: From August 1998 to March 2001, a total of 234 patients with chronic atrial fibrillation underwent isolated intraoperative radiofrequency ablation alone (n = 74, 31.6%) or in combination with other cardiac procedures, such as mitral valve reconstruction (n = 57, 24.4%), mitral valve replacement (n = 38, 16.2%), aortic valve replacement (n = 11, 5.1%), coronary artery bypass grafting (n = 8, 5.0%), or a combination of the last with other cardiac procedures (n = 46, 19.7%). In all cases anatomic reentrant circuits confined within the left atrium were eliminated by placing contiguous lesion lines involving the mitral anulus and the orifices of the pulmonary veins through the use of radiofrequency energy application (exposure time, 20 seconds). A median sternotomy was used in 101 cases (43.2%), and video assistance through a right lateral minithoracotomy was used in 133 cases (56.8%). RESULTS: A total of 188 patients (83.9%) were discharged in sinus rhythm, 17 patients (7.6%) had atrial fibrillation, and 19 patients (8.5%) had atypical flutter. Pacemakers were implanted in 23 patients (9.8%). There were 10 in-hospital deaths (4.2%), and 30-day mortality was 5 patients (2.1%). In 3 cases (1.3%) an atrioesophageal fistula developed, necessitating surgical repair. Six months' follow-up was complete for 122 (61.0%) of 200 patients, with 99 patients still in stable sinus rhythm (81.1%, 95% confidence interval 73.1%-89.9%). Twelve months' follow-up was complete for 80 (90.9%) of 88 patients, with 58 patients still in sinus rhythm (72.5%, 95% confidence interval 61.3%-83.2%). CONCLUSIONS: Intraoperative radiofrequency ablation is a curative procedure for chronic atrial fibrillation. It is technically less challenging than the maze procedure and can be applied through a minimally invasive approach. Protection of the esophagus seems mandatory to avoid the deleterious complication of a left atrioesophageal fistula, such as was observed in 3 cases.     

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.     

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 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.     

Long-term results of irrigated radiofrequency modified maze procedure in 200 patients with concomitant cardiac surgery: six years experience

BACKGROUND: The Cox maze procedure is considered an effective surgical treatment of atrial fibrillation in patients with and without organic heart disease. Radiofrequency energy offers an alternative to the complex surgical maze procedure. We used the radiofrequency modified maze III procedure in patients with atrial fibrillation undergoing elective concomitant cardiac surgery. This study evaluated the long-term results of the irrigated radiofrequency ablation to create linear lines of conduction block endocardially. METHODS: Between November 1995 and June 2001, 200 patients with mainly structural heart disease and chronic atrial fibrillation underwent intraoperative radiofrequency linear ablation in both atria with concomitant cardiac surgery. RESULTS: The in-hospital mortality rate was 3.5% (7 patients) and during the mean follow-up of 40 months (range, 12 to 80) 27 patients (13.5%) died. Eight patients (4%) were lost from follow-up and complete data were available in 158 survivors. Sinus or atrial rhythm was present in 116 patients (73.4%) and an atrial driven rhythm in 10 patients (6.3%) with an atrioventricular pacemaker. Atrial fibrillation or flutter was documented in 32 patients (20.3%). Antiarrhythmic drugs were used in 49% of survivors who were free of atrial fibrillation or flutter. CONCLUSIONS: Intraoperative radiofrequency endocardial ablation is an effective technique to eliminate atrial fibrillation with promising long-term results.     

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.     

Combined atrial fibrillation and mitral valve surgery using microwave technology

Atrial fibrillation is associated with a significant morbidity and mortality and is typically related to patients with mitral valve disease. Microwave ablation is a new option for surgical treatment of chronic atrial fibrillation. We present our experience with surgical treatment of mitral valve disease and microwave ablation in patients with chronic atrial fibrillation. In 105 patients (73 women, 32 men, 68.6 +/- 8 years of age from 45 to 83 years, ejection fraction 28% to 80%, left atrial diameter 56 +/- 9.1 mm from 35 to 97 mm) with mitral valve disease, chronic atrial fibrillation was documented for 8.6 +/- 6.8 years. Microwave ablation was performed using a continuous ablation line starting at the posterior mitral valve annulus and incorporating the interior of all pulmonary veins. In 33 patients, mitral valve reconstruction was performed. Ten patients received biologic valve replacement; 3 of them got a stentless quattro mitral valve prosthesis. Survival rate was 99.1% (n = 104). In the 6-month follow-up, 42 of 69 patients were in sinus rhythm (61%); in the 1-year follow-up, 37 of 64 patients were in sinus rhythm (57.8%). Microwave ablation is a safe and efficient method for surgical treatment of chronic atrial fibrillation in patients with mitral valve disease.     

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.     

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。     

Surgical treatment of chronic atrial fibrillation combined with rheumatic mitral valve disease: Effects of the cryo-maze procedure and predictors for late recurrence.

OBJECTIVE: The aim of this study was to evaluate the effects of the modified maze procedure using cryoablation for treating chronic atrial fibrillation (AF) associated with rheumatic mitral valve disease and to assess the risk factors for late failure of sinus rhythm restoration. METHODS: Between March 2000 and June 2004, 170 consecutive patients, who underwent the modified maze procedure using cryoablation concomitant with mitral valve surgery for atrial fibrillation associated with rheumatic mitral valve disease, were divided into two groups based on the type of right-sided maze: the modified Cox-maze III (CM group, n=93) and modified Kosakai-maze (KM group, n = 77) procedures. The postoperative and mid-term follow-up results were analyzed and compared between the two groups. Both univariate and multivariate analyses were used to assess the risk factors for late recurrence of atrial fibrillation. RESULTS: There were three in-hospital deaths, including two in the CM group (2.2%) and one in the KM group (1.3%), and there were no significant differences in the incidence of postoperative complications between the two groups. The cardiopulmonary bypass and aortic cross-clamp times were significantly shorter in the KM group than the CM group. At discharge, the sinus rhythm rate was 70% in the CM group and 74% in the KM group (p = 0.55). Follow-up was completed in 97% of the patients, with a mean time of 26.6+/-15.2 months. At the latest follow-up, one death occurred in the CM group (0.6%). Sinus rhythm was documented in 141 (84%) out of all the patients, including 76 (84%) in the CM group and 65 (86%) in the KM group (p=0.72). The 4-year actuarial survival free from stroke was 90.3+/-5.9% for the CM group and 96.4+/-3.5% for the KM group (p = 0.68), and 4-year event-free survival was 81.2+/-7.4% for the CM group and 96.4+/-3.5% for the KM group (p = 0.078). Using a multivariate analysis, a left atrial dimension >65 mm (p = 0.011) and repair for rheumatic mitral valve disease (p = 0.038) were independent risk factors for a late recurrence of AF. CONCLUSIONS: The modified maze procedures using cryoablation are safe and effective in treating chronic atrial fibrillation associated with rheumatic mitral valve disease.     

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.     

Survival and sinus rhythm maintenance after modified Cox/maze procedure and mitral valve operation in patients with chronic atrial fibrillation

OBJECTIVE: Sinus rhythm gained after the Cox/maze procedure concomitant with mitral valve operation has demonstrated long-term attrition during the follow-up, no information exists on whether the type of mitral valve operation--(repair vs. replacement)--affects this sinus rhythm maintenance rate. We retrospectively studied patients undergoing concomitant mitral valve operation and Cox/maze procedure to answer this question. METHODS: Between April 1993 and August 1995, 87 consecutive patients--35 men and 52 women (mean age: 59.3 years)--with chronic atrial fibrillation and mitral valve disease underwent the modified Cox/maze procedure and concomitant mitral valve operation, with 56 having mitral valve repair (repair group) and 31 mitral valve replacement (replacement group). Patients were followed up and changes in rhythm studied retrospectively. RESULTS: Follow-up for a mean 51.3 +/- 11.6 months was completed in 82 of 83 long-term survivors (99%). Repair group surgery survival was 98.1 +/- 1.9% at 1 year and 94.2 +/- 3.2% at 5 based on the Kaplan-Meier method. Replacement group surgery survival was 85.7 +/- 5.9% at 1 year and 82.9 +/- 6.4% at 5. Probability in sinus rhythm maintenance for the repair group at 1 year was 88.6 +/- 5.4% and at 5 years was 67.6 +/- 9.1%. Probability in sinus rhythm maintenance for the replacement group at 1 year was 95.7 +/- 4.3% and at 5 years was 65.0 +/- 11.1%. CONCLUSIONS: Medium-term results after the Cox/maze III procedure concomitant with mitral valve operation are good. The attrition of sinus rhythm maintenance appears similar by the completion of 5-year follow-up.     

Outcome of valve repair and the Cox maze procedure for mitral regurgitation and associated atrial fibrillation.

OBJECTIVE: The objective was to determine whether the Cox maze procedure provides adjunctive benefit in patients with atrial fibrillation undergoing mitral valve repair. METHODS: We compared the outcome of 39 patients who had the Cox maze procedure plus mitral valve repair between January 1993 and December 1996 (maze group) with that of 58 patients with preoperative atrial fibrillation who had mitral valve repair during the same interval by the same surgeons (control group). Patients in the 2 cohorts were similar for age, gender, preoperative New York Heart Association class III or IV, and duration of preoperative atrial fibrillation. The control group had a higher incidence of previous heart surgery and coronary artery disease. RESULTS: No operative deaths occurred, and 1 patient in each group required pacemaker implantation after the operation. Duration of cardiopulmonary bypass (122 +/- 40 minutes vs 58 +/- 27 minutes, P <.0001) and hospitalization (12.6 +/- 6.4 vs 9.3 +/- 3.4 days, P <.0025) were prolonged in patients having the Cox maze procedure. Overall, 2-year survival was similar (92% +/- 5% for maze patients and 96% +/- 3% for controls). Freedom from atrial fibrillation in the maze group was 74% +/- 8% 2 years after the operation compared with 27% +/- 7% for the control group (P <.0001). Freedom from stroke or anticoagulant-associated bleeding in the maze group was 100% 2 years after the operation compared with 90% +/- 8% in the control group (P =.04). At most recent follow-up, 82% of maze patients were in normal sinus rhythm (53% in control group). CONCLUSION: The addition of the Cox maze procedure to mitral valve repair is safe and effective for selected patients, and elimination of atrial fibrillation decreased late complications.     

Intraoperative radiofrequency maze ablation for atrial fibrillation: the Berlin modification.

BACKGROUND: The Cox-maze procedure combined with an operation for organic heart disease is highly successful in the elimination of chronic atrial fibrillation. However, it prolongs significantly the aortic cross-clamp and operating time. In this study, a simplified left atrial maze procedure, which is a short procedure performed using a surgical radiofrequency ablation probe, is added to elective open heart procedures in patients with atrial fibrillation. METHODS: Forty-eight adults with atrial fibrillation (duration, 6 months to 36 years) underwent elective open heart operations (isolated valve procedures or coronary artery bypass grafting, n = 27 patients; combined procedures, n = 21 patients) combined with intraoperative radiofrequency ablation of the left atrium. The postoperative follow-up period ranged from 1 to 11 months (mean, 4 months). Possible predictors for persistent postoperative atrial fibrillation were determined among 40 variables by univariate and multivariate analyses. RESULTS: Intraoperative radiofrequency ablation prolonged the aortic cross-clamp time for 6 to 14 minutes (mean, 11 minutes). Freedom from atrial fibrillation was 100% intraoperatively, 25% at 1 week after operation (12 of 48 patients), 59% at 1 month postoperatively (16 of 27 patients), 64% at 3 months postoperatively (16 of 25 patients), and 92% at 6 months postoperatively (12 of 13 patients). The only predictor of postoperative atrial fibrillation was the presence of coronary artery disease (odds ratio, 7.5; 80% confidence interval, 2.24-25.13). CONCLUSIONS: Intraoperative radiofrequency ablation of the left atrium combined with an operation for organic heart disease effectively eliminates atrial fibrillation without significant prolongation of the aortic cross-clamp and operative time. The presence of coronary artery disease decreases the success rate during the first 6 postoperative months.     

心脏直视手术中双极射频消融治疗心房颤动91例分析

目的 探讨心脏直视手术同期采用双极射频消融技术治疗心房颤动的方法和早、中期疗效.方法 2005年3月至2007年1月共91例心房颤动患者于心脏直视手术同期接受了双极射频消融手术治疗.阵发性心房颤动5例,持续性/永久性心房颤动86例.37例采用AtricureTM干式双极射频消融系统,54例采用CardioblateTM冲洗式双极射频消融系统.消融径线包括标准Cox-mazeⅢ手术、改良Cox Mini.maze手术和单纯左心房迷宫手术.结果 平均射频消融时间(14.1±6.7)min,未发生与消融有关的并发症.围手术期死亡3例.术后2例患者安装永久起搏器,1例患者发生脑卒中及下肢动脉栓塞.随访6～29个月,双极射频消融组在术后6、12及12个月以上的成功率均高于单极射频消融组.截至末次随访,阵发性心房颤动组的非心房颤动心律为100%,持续性/永久性心房颤动组为75.3%.AtricureTM组与CardioblateTM组间,以及3种射频消融路径组间的成功率无差异.结论 双极射频消融技术实施简便、安全,耗时短,疗效满意,是一种更为先进的手术方法.     

Predictive factors for persistence of atrial fibrillation after mitral valve operation

BACKGROUND: The majority of patients operated on for mitral valve disease with chronic atrial fibrillation (AF) do not recover sinus rhythm with conventional postoperative treatment. The maze procedure may be used in these circumstances. To define the precise indications for the maze procedure, it would be necessary to identify those patients based on preoperative factors. METHODS: A retrospective study was undertaken on 100 consecutive patients operated on for mitral valve disease in chronic AF. The return to sinus rhythm was analyzed with relation to age, gender, AF duration, left atrial size, left ventricular ejection fraction, lesion type, valve procedure, associated procedures, and reoperation. RESULTS: At late follow-up (more than 1 year) 26 (26%) patients presented sinus rhythm and 74 (74%) remained in AF. Statistical single parametric analysis demonstrated that mitral stenosis was a risk factor for maintaining AF, whereas regurgitation was more associated to sinus rhythm recovery. There was no relation with the other parameters with return to sinus rhythm. It should be noted, however, that 96% of this series had AF for more than 6 months preoperatively. CONCLUSIONS: The majority of patients with mitral valve disease remain in AF and this may justify the association of maze procedure. Pure regurgitation may be a single predictor for return to sinus rhythm after mitral valve operation in chronic AF.     

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。     

Prevention of atrial fibrillation during the acute postoperative period following open-heart surgery by pulmonary vein antrum isolation using bipolar radiofrequency ablation

We evaluated the effectiveness of pulmonary vein isolation (PVI) with bipolar radiofrequency ablation in prevention of atrial fibrillation during the acute postoperative period following open-heart surgery. Twenty-six patients with paroxysmal atrial fibrillation (PAF) underwent elective open-heart surgery combined with PVI using bipolar radiofrequency ablation from October 2004 to January 2006. They consisted of 17 male and 9 female with the mean age of 64.2 +/- 8.6 years. Their structural heart disease included coronary artery disease, aortic valve disease, and mitral valve disease. PVI was performed on the bilateral pulmonary vein antra under beating heart using cardiopulmonary bypass. The bipolar radiofrequency system included Atricure (n = 19) and Cardioblate (n = 7). There was no operative death nor complication related to bipolar radiofrequency ablation. In principle, no anti-arrhythmic drugs except beta-blockades were administered postoperatively. In 24 of 26 (92.3%) patients, the sinus rhythms were restored without PAF during the 2 week postoperative period. Even in cases with preoperative PAF, PVI was effective in preventing atrial fibrillation during the acute phase following open-heart surgery. We suggest that bipolar radiofrequency ablation is an alternative procedure to prevent atrial fibrillation in open-heart surgery.