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.     

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.     

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 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.     

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.     

左房顶-房隔径路二尖瓣手术与心律失常

目的：验证左房顶－房隔径路二关瓣手术的安全性。方法：１９９３年１０月至１９９７年１２月,采用此径路行二尖瓣手术５１例,其中二尖瓣替换术（ＭＶＲ）１８例,二尖瓣成形术（ＭＶＰ）１例,二尖瓣及主动脉瓣替换术（ＤＶＲ）３２例。     

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.     

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.     

Surgical treatment of permanent atrial fibrillation during heart valve surgery

A simple strategy to abolish permanent atrial fibrillation (AF) in patients undergoing heart valve surgery is described. The concept includes: (1) endocardial radiofrequency (RF) ablation creating two encircling isolation lesions around the left and the right pulmonary veins (LPV, RPV) and a connection line between both; (2) antiarrhythmic protection with amiodarone for 3 months. Between 02/01 and 02/02 29 patients underwent surgical AF ablation procedures associated with primary valve operations (mitral, n=22; aortic, n=6; aortic+mitral, n=1). Six months after surgery 87.5% (14 of 16) were in sinus rhythm (SR), particularly all patients with an LA diameter of <56 mm had SR.     

The effect of concomitant radiofrequency ablation and surgical technique (repair versus replacement) on release of cardiac biomarkers during mitral valve surgery

All patients undergoing heart surgery experience a certain amount of nonspecific myocardial injury documented by the release of cardiac biomarkers and associated with poor outcome. We investigated the role of unipolar radiofrequency ablation of atrial fibrillation on the release of cardiac biomarkers in 71 patients undergoing mitral valve surgery and concomitant left atrial ablation case-matched with 71 patients undergoing isolated mitral surgery. The study was powered to detect a 3 ng/mL difference. There was no difference between the 2 groups in terms of cardiac troponin I (10 +/- 5.3 versus 12 + 10.4 ng/mL; P = 0.7) or creatine kinase-MB (50 +/- 21.8 versus 57 +/- 62.0 ng/mL; P = 0.5) release. Postoperative peak cardiac troponin I levels had univariate associations with the duration of cardiopulmonary bypass (P = 0.002) and aortic cross-clamping (P = 0.001) and with the surgical technique (15 +/- 12 ng/mL for mitral valve replacement versus 9 +/- 4.8 for mitral valve repair; P = 0.0007) at univariate analysis. Mitral valve replacement was the only independent predictor of postoperative peak release of cardiac troponin I identified with multivariate analysis (P = 0.005). Radiofrequency ablation of atrial fibrillation does not significantly increase cardiac biomarker release compared with isolated mitral surgery; mitral valve repair is associated with less release of cardiac biomarkers compared with mitral valve replacement.     

Septal-superior exposure in mitral valve surgery with radiofrequency ablation

BACKGROUND: We review the results of surgical radiofrequency ablation of both atria in patients of mitral valve disease approached by septal-superior exposure and discuss the availability of this approach. METHODS: Eighteen patients with a mean age of 65 years were included in this study. Thirteen patients had mitral valve regurgitation predominantly and five had mitral valve stenosis. Eleven patients underwent mitral valve plasty and valve replacement was carried out in seven. All ablation lesions were created on both atria using radiofrequency energy delivered by a unipolar malleable radiofrequency ablation catheter with seven electrodes at a minimum temperature of 80-85 degrees C for a period of 2 min. RESULTS: At the time of discharge, 14 patients were showed normal sinus rhythm and one patient remained in AF. The other three patients were free from atrial fibrillation; however, they received dual-mode, dual-pacing, dual-sensing pacemaker implantation because of bradycardia during the early postoperative phase. At a mean time of 7 months after surgery, all patients were free from atrial fibrillation; 13 patients showed normal sinus rhythm and five patients received dual-mode, dual-pacing, dual-sensing pacemakers. CONCLUSION: Septal-superior exposure provides an excellent operative view both for mitral valve surgery and for radiofrequency ablation. However, this exposure has not been considered a first-line approach because of the high rate of pacemaker implantation.     

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.     

Treatment of atrial fibrillation with intraoperative radiofrequency ablation in one stage with valvular surgery

Atrial fibrillation is the most frequent chronic arrhythmia, with significant cardiovascular morbidity and mortality risk. Poor remission rate with medical treatment and the outstanding efficacy of Cox-maze procedure inspired the less invasive intraoperative radiofrequency ablation therapy in patients undergoing open heart surgery. In June 2003 the first maze procedure in Hungary with the Medtronic Cardioblate surgical ablation system, with mitral and tricuspid valvuloplasty in a patient suffering from mitral and tricuspid insufficiency with paroxysmal atrial fibrillation, was performed in our institution. After 8 months the patient is in sinus rhythm and is free of complaints.     

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.     

Pulmonary vein isolation for chronic atrial fibrillation associated with mitral valve disease: the midterm results.

OBJECTIVE: The Cox Maze procedure is widely performed for the surgical treatment of atrial fibrillation. However it requires numerous incision lines and therefore is a time-consuming operation. We report a simplified operation for chronic atrial fibrillation associated with mitral valve disease. METHODS: Pulmonary vein isolation procedure was performed on atrial fibrillation associated with mitral valve disease in thirteen patients. This simple procedure consisted of isolation of the four pulmonary veins only. Combined mitral valve surgery involved mitral valve plasty, mitral valve replacement with or without aortic valve replacement and tricuspid annuloplasty. RESULTS: Eleven patients returned to sinus rhythm (84.6%). Mean follow-up time is 32.7 +/- 11.7 months. Three patients required a DDD pacemaker implant for sick sinus syndrome but two out of these three resumed sinus rhythm most of the time recently. Left atrial contraction was detected in eight cases by trans-esophageal echo. One patient died of liver failure two months postoperatively. Eight patients had no blood transfusion. Twelve patients are classified as New York Heart Association class I. CONCLUSION: Compared with the Maze procedure, this operation was less invasive and preserved the atrial appendage and was thought to have a normal level of secretion of atrial natriuretic peptide. This study suggests that the pulmonary vein isolation procedure may be an effective and simple maneuver for atrial fibrillation associated with mitral valvular disease.     

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.     

心房纤维颤动的外科治疗

３例采用改良迷宫术探索进行心房纤颤外科治疗获成功。病人术前均为风湿性心脏病，心功能Ⅲ－Ⅳ级，心房纤颤病史３－１０年，左房直径５２－５８ｍｍ，心胸比率０．６４－０．７０。在进行改良迷宫术的同时，２例行二尖瓣替换，１例行双瓣替换及三尖瓣环缩。术后２例自动复跳，１例电击除颤复跳。３例术后早期均为窦性心律。２例术后３年恢复良好，正常心律，心功能Ｉ级；１例术后３个月死于脑血管意外。文中重点介绍了手术方法，提     

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.     

Intraoperative treatment of chronic atrial fibrillation with ultrasound

AIM: The purpose of this retrospective study is to evaluate the efficacy of intraoperative atrial compartmentalization utilizing ultrasound (US) energy in selected patients with chronic atrial fibrillation (CAF). METHODS: From March 1999 to June 2000, 27 patients with ages ranging from 15 to 69 (mean 44.62+/-15.61 years), 15 of whom were female, underwent intraoperative atrial compartmentalization with US. Mitral valve replacement was performed in 22 patients, mitral valve repair in 4 and 1 patient with paroxysmal atrial fibrillation (AF) underwent isolated atrial compartmentalization. The compartmentalization procedure was started using an ultrasonic device (UltraCision) at the level of the right atrium on cardiopulmonary bypass (CPB) and with beating heart, and then, after the mitral valve procedure, the ablation-lines were traced in an inverted U-shape, involving the 4 pulmonary veins. All patients were given verapamil or amiodarone for electrical atrial remodeling for 6 months. RESULTS: Time of surgery was 166 min on average, that is approximately 79 min of CPB, 59 min of aortic crossclamping, 12.5 min for right atrial lesion lines and 14 min for the left ones. After weaning CPB, all the patients maintained adequate cardiac output. Immediate reversion to sinus rhythm was achieved in 24 patients (88.8%). A small intraoperative left atrial wall rupture due to the ablation technique was easily repaired by a direct continuous suture. Another complication observed in 1 patient was a sternal instability, which was fixed successfully. Two patients died because of postoperative respiratory failure due to bilateral pneumonia in 1 case and low cardiac output, complicated by septicemia. The pharmacological anti-arrhythmic treatment was stopped 6 months after surgery. During 29 months of follow-up, 20 patients (74%) were still in sinus rhythm. CONCLUSIONS: The use of US during mitral valve operation in patients with CAF allowed for easy and rapid reestablishment of the sinus rhythm. This technique modifies and makes the Maze procedure easier, decreases surgical time and the incidence of postoperative complications.     

左心房折叠术在二尖瓣病变合并巨大左心房治疗中的应用

目的探讨左心房折叠术治疗二尖瓣病变合并巨大左心房的临床应用效果.方法回顾性分析23例收缩末期左心房内径为(129±37)mm (92～250 mm)、行左心房折叠术的二尖瓣手术患者的临床资料.22例选用人工机械瓣膜置换,1例为生物瓣置换,同期行左心房折叠术.术前心功能NYHA分级,Ⅲ级15例,Ⅳ级8例;术前心胸比为0.79±0.10.单纯二尖瓣置换术18例,其中行三尖瓣成形术10例;双瓣膜置换和三尖瓣成形术5例,其中二次手术2例, 术中行心房纤颤射频消融术2例.结果术后低心排出量综合征3例(13%),呼吸衰竭2例(9%).早期死亡3例(13%),其中2例为低心排出量综合征、1例为脑梗死.术后失访2例,术后1年意外死亡1例,平均随访(44±39)个月,17例生存患者心功能Ⅰ级14例、Ⅱ级3例;术后心胸比为0.68±0.11,较术前明显缩小(t=3.80,P=0.000).结论在瓣膜病手术的同时对巨大左心房症行左心房折叠术,可减少术后并发症,术后效果良好.