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.     

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.     

应用射频迷宫术治疗心房纤颤

１９９４年１０月于１９９５年８月采用射频迷宫术先天性继发孔房缺合并心房纤颤１例，瓣膜替换术的治疗风湿性二尖瓣病变合并心房纤颤９例。术后房颤全部消失，呈窦性心律６例，结性心律３例，心房扩动１例。作者认为，此方法操作简单易行，效果确实，手术时间短，避免了心脏多处切口，渗血少，术后平顺，无近期并发症。     

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.     

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。     

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.     

A prospective, single-center clinical trial of a modified Cox maze procedure with bipolar radiofrequency ablation

OBJECTIVE: The Cox maze III procedure has excellent long-term efficacy in curing atrial fibrillation. It has not been widely practiced because it is technically challenging and requires prolonged cardiopulmonary bypass. The aim of this study was to examine a simplified Cox maze III procedure that uses bipolar radiofrequency energy as an ablative source. METHODS: Beginning January 2002, a total of 40 consecutive patients underwent a modified Cox maze III procedure with bipolar radiofrequency energy. Nineteen had a lone maze procedure and 21 had a maze procedure plus a concomitant operation. One month after the operation, the first 8 patients were investigated with high-resolution magnetic resonance imaging. Patients were followed up monthly with clinical examination and electrocardiography. RESULTS: There was no operative deaths. The crossclamp times were 47 +/- 26 minutes for the modified lone Cox maze III procedure and 92 +/- 37 minutes for the Cox maze III procedure plus concomitant procedures. These were significantly shorter than our previous times for the traditional Cox maze III procedure (93 +/- 34 minutes and 122 +/- 37 minutes, respectively, P <.05). Follow-up magnetic resonance imaging showed no evidence of pulmonary vein stenosis, and atrial contractility was preserved in all patients. There were no late strokes. At 6-month follow-up, 91% of patients (21/23) were in sinus rhythm. CONCLUSIONS: Bipolar radiofrequency ablation can be used to replace the surgical incisions of the Cox maze procedure. This energy source did not result in pulmonary vein stenosis. The modification of the Cox maze III procedure to use bipolar radiofrequency ablation simplified and shortened this procedure without sacrificing short-term efficacy.     

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.     

A technique for off-pump ablation of atrial fibrillation on beating heart using the epicardial radiofrequency approach

Recently ablation surgery for atrial fibrillation, so-called maze procedure, has become popular. However, this procedure usually needs cardiopulmonary bypass. Here we describe 3 patients for whom the simple, new procedure in which epicardial radiofrequency ablation is sucessfully done without cardiopulmonary bypass prior to concomitant cardiac operation. Our modified maze procedure consists of isolation of pulmonary veins using the FLEX 7 radiofrequency ablation device (COBRA). Following the surgery, all patients quickly attained regular sinus rhythm. We believe our procedure would be especially useful for patients for whom concomitant cardiac procedure can be done on beating heart.     

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 atrial fibrillation: predictors of late recurrence

OBJECTIVE: The Cox maze procedure was introduced in 1987 for the treatment of atrial fibrillation. This study evaluated the predictors of late atrial fibrillation recurrence in 276 consecutive patients who underwent this procedure at our institution. METHODS: From 1987 through June 2003, 276 patients (79 female and 197 male patients; mean age, 55 +/- 11 years) underwent the Cox maze procedure. Thirty-three patients had Cox maze procedure I, 16 patients had Cox maze procedure II, and 197 patients had Cox maze procedure III. The last 30 patients underwent a modified procedure (Cox maze procedure IV) with bipolar radiofrequency ablation. There were 113 (41%) patients who had a concomitant operation, most commonly either a mitral valve procedure (19%) or coronary artery bypass grafting (20%). Data were analyzed by means of univariate analysis, with preoperative and perioperative variables used as covariates. Patient follow-up was conducted by means of questionnaire, physician examination, and electrocardiographic documentation. All patients had a minimum of 6 months of follow-up. RESULTS: Patient follow-up was achieved in 92.8% of cases, with a mean follow-up time of 5.8 +/- 3.6 years. Risk factors for late atrial fibrillation recurrence were duration of preoperative atrial fibrillation (P = .01) and Cox maze procedure version (P = .001). There was no difference in actuarial 10-year survival between the Cox maze procedure versions. CONCLUSION: The Cox maze procedure remains the gold standard for the treatment of atrial fibrillation and has excellent long-term efficacy. The most significant predictor of late recurrence was duration of preoperative atrial fibrillation, suggesting that earlier surgical intervention would further increase efficacy.     

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.     

Ablation for atrial fibrillation during mitral valve surgery: 1-year results through continuous subcutaneous monitoring

Continuous monitoring of cardiac rhythm may play an important role in measuring the true symptomatic/asymptomatic atrial fibrillation (AF) burden and improve the management of anti-arrhythmic and anti-thrombotic therapies. Forty-seven patients with mitral valve disease and longstanding persistent AF (LSPAF) underwent a left atrial maze procedure with bipolar radiofrequency and valve surgery. The follow-up data recorded by an implanted loop recorder were analysed after 3, 6 and 12 months. On discharge, 40 (85.1%) patients were in stable sinus rhythm, as documented by in-office electrocardiography (ECG), 4 (8.5%) were in pacemaker rhythm and 3 (6.4%) were in AF. One (2.1%) patient died after 7 months. On 12-month follow-up examination, 30 (65.2%) patients had an AF burden <0.5% and were classified as responders. Three (6.5%) of the 16 non-responders had atrial flutter and 13 (27.7%) had documented AF recurrences with an AF burden >0.5%. Two (4.3%) patients with AF recurrences were completely asymptomatic. Among the symptomatic events stored by the patients, only 27.6% was confirmed as genuine AF recurrences according to the concomitant ECG recorded by the implanted loop recorder. A concomitant bipolar maze procedure during mitral valve surgery is effective in treating AF, as proved by detailed 1-year continuous monitoring.     

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.     

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。     

Surgical ablation of atrial fibrillation with off-pump, epicardial, high-intensity focused ultrasound: results of a multicenter trial

BACKGROUND: A simplified alternative to the Cox maze procedure to treat atrial fibrillation with epicardial high-intensity focused ultrasound was evaluated clinically, and the initial clinical results were assessed at the 6-month follow-up visit. METHODS: From September 2002 through February 2004, 103 patients were prospectively enrolled in a multicenter study. Atrial fibrillation duration ranged from 6 to 240 months (mean, 44 months) and was permanent in 76 (74%) patients, paroxysmal in 22 (21%) patients, and persistent in 5 (5%) patients. All patients had concomitant operations, and ablation was performed epicardially on the beating heart before the concomitant procedure. The device automatically created a circumferential left atrial ablation around the pulmonary veins in an average of 10 minutes, and an additional mitral line was created epicardially in 35 (34%) patients with a handheld device by using the same technology. RESULTS: No complications or deaths were device or procedure related. There were 4 (3.8%) early deaths and 2 late extracardiac deaths. The 6-month follow-up was complete in all survivors. At the 6-month visit, freedom from atrial fibrillation was 85% in the entire study group (80% in patients with permanent atrial fibrillation, 88% in the 35 patients who had the additional mitral line, and 100% in patients with paroxysmal atrial fibrillation). A pacemaker was implanted in 8 patients. Only the duration and type of atrial fibrillation significantly increased the risk of recurrence. CONCLUSION: Epicardial, off-pump, beating-heart ablation with acoustic energy is safe and cures 80% of patients with permanent atrial fibrillation associated with long-standing structural heart disease.     

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   

Restoring sinus rhythm in patients with previous pacemaker implantation submitted to cardiac surgery and concomitant surgical ablation of atrial fibrillation

OBJECTIVE: Some patients submitted to cardiac surgery have concomitant atrial fibrillation and a previously implanted pacemaker. Because it is unknown if there is any potential for these patients to reassume a regular rate sinus rhythm after ablation of atrial fibrillation, we reviewed the results of all patients with pacemaker enrolled in the Registry of Atrial Fibrillation. MATERIALS: Thirty-six patients were included in this study. Twenty-six had valve disease, seven had coronary disease and three had congenital heart disease. They were submitted concomitantly to ablation of atrial fibrillation using biatrial approaches (seven patients), left sided (27), or right sided (three patients). Thirty-three hospital survivors had a mean follow-up of 18 months, and a maximum of 25 months. RESULTS: At 1 year (n=21), patients' rhythm was sinus non-pacing dependent (52%), sinus pacing-dependent (14%), and atrial fibrillation (14%). At 2 years (n=14), patients' rhythm was sinus non-pacing dependent (57%) and atrial fibrillation (43%). The only factor that may have had impact on the recovery of sinus rhythm at 1 year was the small size of the left atrium (p=0.05). CONCLUSIONS: We conclude that in a significant number of patients, having a pacemaker before surgery does not preclude sinus rhythm recovery after a cardiac operation and ablation for concomitant atrial fibrillation.     

Repetitive atrial flutter as a complication of the left-sided simple maze procedure

BACKGROUND: Of 41 patients who had undergone a left-sided simple maze procedure, 4 (9.8%) developed repetitive tachycardia due to atrial flutter, and required radiofrequency catheter ablation. Linear ablation of the right atrial isthmus was effective to treat atrial flutter. METHODS: We conducted an electrophysiologic study of atrial flutter and determined its reentry circuit on the atrium. We consider how to reduce atrial flutter after the left-sided simple maze procedure. RESULTS: Common atrial flutter through the right atrial isthmus was induced in all 4 patients, and linear ablation on the right atrial isthmus was effective in 3 of these. An incisional atrial flutter around the right atriotomy was also induced in 2 of 4 patients; both were successfully treated by linear ablation between the right atriotomy and the inferior vena cava. CONCLUSIONS: Common atrial flutter through the right atrial isthmus is a risk after the left-sided simple maze procedure. When a left-sided simple maze procedure is performed, sufficient cryoablation on the right atrial isthmus of the arrested heart should be administered to prevent postoperative atrial flutter.     

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.