Surgical Ablation of Atrial Fibrillation in Patients Undergoing Bioprosthetic Valve Replacement / 대한흉부외과학회지

BACKGROUND: Scarce data have been reported on the efficacy of concomitant atrial fibrillation (AF) ablation in patients undergoing bioprosthetic valve replacement. METHODS: From 2001 and 2014, 146 consecutive patients (69.3±9.4 years, 84 females) who underwent bioprosthetic heart valve replacement concomitant with AF ablation were assessed. We evaluated long-term rhythm and valve-related outcomes. RESULTS: During 49.1 months of follow-up (interquartile range, 22.5–96.8 months), 7 in-hospital and 49 (6.7% per person-year) post-discharge deaths occurred. The thromboembolic event-free survival rate at 5 years was 79.2%±3.5%. The freedom from AF recurrence rate at 5 years was 59.8%±4.9%. Multivariate analysis showed that old age (hazard ratio [HR], 1.06; 95% confidence interval [CI], 1.02–1.11; p=0.002), previous cardiac operation (HR, 3.01; 95% CI, 1.22–7.43; p=0.02), and a large left atrial (LA) dimension (HR, 1.02; 95% CI, 1.00–1.05; p=0.045) were significantly associated with AF recurrence. CONCLUSION: The overall long-term clinical outcomes in these predominantly elderly patients undergoing AF ablation concomitantly with bioprosthetic valve replacement were satisfactory; however, AF recurrence was frequent. Older age, a history of prior cardiac surgery, and large LA size were associated with an increased risk of AF recurrence.

Outcome of Concomitant Cox Maze Procedure with Narrow Mazes and Left Atrial Volume Reduction

BACKGROUND: To improve sinus rhythm conversion, the Cox maze III procedure with narrow mazes (width: < or =3.0 cm) was performed in combination with left atrial volume reduction. METHODS: From October 2007 to April 2013, 87 patients with atrial fibrillation (paroxysmal in 3, persistent in 14, and permanent in 70) underwent the Cox maze procedure concomitant with another cardiac procedure. They were followed-up with serial electrocardiographic and echocardiographic studies. We used 24-hour Holter monitoring tests to evaluate postoperatively symptomatic patients. RESULTS: At the mean follow-up time of 36.4 months, 81 patients (94.2%) had sinus rhythm and two were on anti-arrhythmic medication (one on a beta-blocker and the other on amiodarone). Five patients (5.8%) with postoperative recurrent and persistent atrial fibrillation never experienced sinus rhythm conversion; however, they did not require any medication for rate control. On postoperative echocardiography, the left atrial A waves were more frequently observed after concomitant mitral valve repair than after concomitant mitral valve replacement (82.4% vs. 40.4%, respectively; p<0.001). CONCLUSION: For the Cox maze procedure, narrow mazes and atrial volume reduction resulted in excellent sinus rhythm conversion without the preventive use of anti-arrhythmic drugs, and they did not affect the presence of the left atrial A waves on echocardiography.

Efficacy of Cox Maze IV Procedure Using Argon-Based Cryoablation: A Comparative Study with N2O-Based Cryoablation

BACKGROUND: We compared the mid-term results of the Cox maze IV procedure using argon-based cryoablation with a procedure using N2O-based cryoablation. METHODS: From May 2006 to June 2012, 138 patients (mean age, 58.2+/-11.0 years) underwent the Cox maze IV procedure. Eighty-five patients underwent the maze procedure using an N2O-based cryoprobe (group N), and 53 patients underwent the maze procedure using an argon-based cryoprobe (group A). Bipolar radiofrequency ablation was concomitantly used in 131 patients. The presence of atrial fibrillation immediately, 6 months, 1 year, and 2 years after surgery was compared. RESULTS: Early mortality occurred in 6 patients (4.3%). There were no differences in early mortality or postoperative complications between the two groups. Nineteen of 115 patients (16.5%) remained in atrial fibrillation at postoperative 12 months (14 of 80 patients (17.5%) in group N and 5 of 35 patients (14.3%) in group A, p=0.669). There were no differences in the number of patients who remained in atrial fibrillation at any of the time periods except in the immediate postoperative period. A multivariable analysis revealed that the energy source of cryoablation was not associated with the presence of atrial fibrillation at 1 year (p=0.862) and that a fine F wave (<0.1 mV) was the only risk factor predicting the presence of atrial fibrillation at 1 year (p<0.001, odds ratio=20.287). CONCLUSION: The Cox maze IV procedure using an argon-based cryoprobe was safe and effective compared with the maze procedure using an N2O-based cryoprobe in terms of operative outcomes and the restoration of sinus rhythm for up to 2 years after surgery.

Modern Treatment of Atrial Fibrillation

Atrial fibrillation (AF) is the most common type of arrhythmia and has a large global burden. In general, treatment of AF is based on medication and consists of rate and rhythm control together with anticoagulation. However, surgical treatment may be required in patients with AF combined with organic valvular heart diseases or who experience recurrence despite medication. In addition, surgical treatment plays a role in the treatment of lone AF. This article reviews the various surgical treatment options for AF.

Efficacy of the Maze Procedure for Atrial Fibrillation Associated with Atrial Septal Defect

BACKGROUND: Atrial fibrillation (AF) is a common complication in elderly patients with atrial septal defect (ASD). The purpose of this study was to examine the efficacy of the maze procedure in these patients. MATERIALS AND METHODS: Between February 2000 and May 2011, 46 patients underwent the maze procedure as a concomitant operation with ASD closure. Three patients who underwent a right-sided maze were excluded, and one patient was lost to follow-up. The mean follow-up duration was 3.2+/-2.5 years. Electrocardiography was performed 1 month, 3 months, 6 months, and 1 year after surgery, and checked annually after that. RESULTS: AF persisted in 4 patients after surgery. One year after surgery, among 38 patients, 55.3% remained in sinus rhythm without antiarrhythmic drugs. However, when including the patients who took antiarrhythmic drugs, 92.1% were in sinus rhythm. Freedom from AF recurrence at 3 months, 6 months, 1 year, 2 years, 3 years, and 5 years after surgery were 97.4+/-2.6, 94.4+/-3.8, 91.2+/-4.9, 87.8+/-5.8, 79.5+/-7.6, and 68.2+/-12.4, respectively. There was no early mortality after operation. CONCLUSION: Concomitant treatment with the maze procedure and ASD closure is safe and effective for restoring the sinus rhythm.

Predictive Factors of Sustained Sinus Rhythm and Recurrent Atrial Fibrillation after the Maze Procedure

BACKGROUND: We examined perioperative predictors of sustained sinus rhythm (SR) in patients undergoing the Cox maze operation and concomitant cardiac surgery for structural heart disease. MATERIALS AND METHODS: From October 1999 to December 2008, 90 patients with atrial fibrillation (AF) underwent the Cox maze operation and other concomitant cardiac surgery. Eighty-nine patients, all except for one postoperative death, were followed-up with serial electrocardiographic studies, 24-hour Holter monitoring tests, and regular echocardiographic studies. RESULTS: Eighty-nine patients undergoing the maze operation were divided into two groups according to the presence of SR. At the time of last follow-up (mean follow-up period, 51.0+/-30.8 months), 79 patients (88.8%) showed SR (SR group) and 10 patients (11.2%) had recurrent AF (AF group). Factors predictive of sustained SR were the immediate postoperative conversion to SR (odds ratio, 97.2; p=0.001) and the presence of SR at the 6th month postoperatively (odds ratio, 155.7; p=0.002). Duration of AF, mitral valve surgery, number of valves undergoing surgery, left atrial dimension, and perioperative left ventricular dimensions and ejection fractions were not predictors of postoperative maintenance of SR. CONCLUSION: Immediate postoperative SR conversion and the presence of SR at the 6th postoperative month were independent predictors of sustained SR after the maze operation.

Outcomes of Surgical Atrial Fibrillation Ablation: The Port Access Approach vs. Median Sternotomy

BACKGROUND: The aim of this study is to evaluate the clinical and rhythm outcomes of atrial fibrillation (AF) ablation through a port access approach compared with sternotomy in patients with AF associated with mitral valve diseases. MATERIALS AND METHODS: From February 2006 through December 2009, 135 patients underwent biatrial AF ablation with a mitral operation via either a port-access approach (n=78, minimally invasive cardiac surgery [MICS] group) or a conventional sternotomy (n=57, sternotomy group). To adjust for the differences in the two groups' baseline characteristics, a propensity score analysis was performed. RESULTS: After adjustment, there were no significant differences in the two groups' baseline profiles. The cardiopulmonary bypass time was significantly longer (p=0.045) in the MICS group (176.0+/-49.5 minutes) than the sternotomy group (150.0+/-51.9 minutes). There were no significant differences (p=0.31) in the two groups' rate of reoperation for bleeding (MICS=6 vs. sternotomy= 2, p=0.47) or the requirement for permanent pacing (MICS=1 vs. sternotomy=3). The major event-free survival rates at two years were 87.4+/-8.1% in the MICS group and 89.6+/-5.8% in the sternotomy group (p=0.92). Freedom from late AF at 2 years was 86.8+/-6.2% in the MICS group and 85.0+/-6.9% in the sternotomy group (p=0.86). CONCLUSION: Both the port-access approach and sternotomy showed tolerable clinical outcomes following biatrial AF ablation with mitral valve surgery.

Surgical Outcomes of Cox-maze IV Procedure Using Bipolar Irrigated Radiofrequency Ablation and Cryothermy in Valvular Heart Disease

BACKGROUND: We evaluated the efficacy of Cox-maze IV procedure using bipolar irrigated radiofrequency ablation and cryothermy in chronic atrial fibrillation associated with valvular heart disease. MATERIAL AND METHODS: From November 2005 to June 2009, ninety four patients have undergone valvular heart surgery with Cox-maze IV procedure. Preoperative duration of atrial fibrillation was 7.6+/-6.5 years and follow-up duration was 22.7+/-12.3 months. RESULTS: There were two (2.1%) postoperative deaths not related to maze procedure. Two cerebrovascular accidents, five low cardiac output syndromes and two permanent pacemaker implantations have occurred after surgery. Preoperative ejection fraction on echocardiography was 55.3+/-8.1% and ejection fraction of postoperative six month was 54.7+/-6.5%. Left atrial size of preoperative and postoperative were 61.5+/-11.6 mm and 53.1+/-8.4 mm at each. Freedom from atrial fibrillation rate at postoperative six-month was 80.7% and the cases of recurrence of atrial fibrillation after six months were three (3.3%). Risk factors for failure or recurrence of maze procedure were old age (p=.010) and preoperative moderate or severe tricuspid regurgitation (p=.033). CONCLUSION: The Cox-maze IV procedure using RFBP2 and cryothermy is quite safe and freedom from atrial fibrillation at postoperative 6 month was 82.5%. Risk factors for failure or recurrence of atrial fibrillation after Cox-maze IV were old age and preoperative over moderate tricuspid regurgitation.

Change of the Left Atrial Dimension and Transport Function after the Cox-Maze Procedure for Treating Atrial Fibrillation Associated with Mitral Valve Disease: the Short-term and Mid-Term Results / 대한흉부외과학회지

BACKGROUND: Although the high efficiency of conversion into sinus rhythm has been demonstrated after performing the Cox-Maze procedure in patients with atrial fibrillation associated with mitral valve disease, the changes in the mechanical function and size of the left atrium have not been determined. The aim of this study was to evaluate the effect of the Maze procedure on the left atrial size and contractile transport function. MATERIAL AND METHOD: From July 1997 to July 2008, 647 consecutive patients were operated on for chronic atrial fibrillation associated with mitral valve disease. Among these, 211 patients that (1) were able to be followed up for 2 years after surgery, (2) had sustained normal sinus rhythm, regardless of whether they were taking anti-arrhythmic medications and (3) did not have valvular regurgitation greater than grade III or they did not have moderate grade valvular stenosis were selected for evaluation. The left atrial size and contractile transport function were assessed by transthoracic echocardiography at the postoperative base line (1 year) and at regular follow-up periods (2 years, 3 years, 4 years and 6 year). RESULT: The left atrial dimension was increased and the contractile transport function was decreased during the follow-up period. The longer the follow-up period, the greater was the statistical significance of the left atrial size increase and contractile transport function decrease. CONCLUSION: In patients who sustain normal sinus rhythm conversion after a Maze III procedure with a mitral valve operation, there is a gradual increase of the left atrial dimensions and a decrease of contractile transport function during the follow-up period. Therefore, scrupulous follow-up is needed for these patients.

Result of Cox Maze Procedure with Bipolar Radiofrequency Electrode and Cryoablator for Persistent Atrial Fibrillation: Compared with Cut-sew Technique / 대한흉부외과학회지

BACKGROUND: The Cox maze procedure has been used as a standard surgical treatment for atrial fibrillation for about 20 years. Recently, the creators have used a bipolar radiofrequency electrode (Cox maze IV procedure) instead of the incision and suture (cut-sew) technique to make atrial ablation lesions for persistent atrial fibrillation. We investigated clinical outcomes for the Cox maze procedure with a bipolar radiofrequency electrode and cryoablator in patients with persistent atrial fibrillation, and compared results with clinical outcomes of the cut-sew procedure. MATERIAL AND METHOD: Between April 2005 and July 2007, 40 patients with persistent atrial fibrillation underwent Cox maze IV procedure with a bipolar radiofrequency electrode and cryoablator (bipolar radiofrequency group). Surgical outcomes were compared with those of 35 patients who had the cut-sew technique for the Cox maze III procedure. All patients had concomitant cardiac surgery. Postoperatively, the patients were followed up every 1 to 2 months. RESULT: At 6 months postoperatively, the conversion rate to regular sinus rhythm was not significantly different between the two groups: 95.0% for the bipolar radiofrequency ablation group; 97.1% for the cut-sew technique (p=1.0). At the end of the follow-up period, the conversion rate to regular sinus rhythm was also not significantly different (92.5% vs. 91.6%, p=1.0). In multivariate analysis using a Cox-regression model, the postoperative atrial dimension was an independent determinant of sinus conversion in the bipolar radiofrequency ablation group (hazard ratio 31, p=0.005). In the Cox-regression model for both groups, atrial fibrillation at 6 months postoperatively (hazard ratio 92.24, p=0.003) and the postoperative left atrial dimension (hazard ratio 16.05, p=0.019) were independent risk factors of continuance or recurrence of atrial fibrillation after Cox maze procedures. Aortic cross-clamp time and cardiopulmonary bypass time were significantly shorter in the radiofrequency group than in the cut-sew group. CONCLUSION: In the Cox maze procedure for patients with persistent atrial fibrillation, the use of bipolar radiofrequency ablation and a cryoablator is as good as the cut-sew technique for conversion to sinus rhythm. The postoperative left atrial dimension is an independent determinant of postoperative continuance and recurrence of atrial fibrillation.

The Influence of Simplified Surgical Procedures on the Surgical Treatment for Atrial Fibrillation with using the Cut-and-Sew Technique / 대한흉부외과학회지

BACKGROUND: The Cox maze-III procedure is considered as the most effective surgical treatment for atrial fibrillation. Because this procedure takes a long time and it complicates the concomitant cardiac surgery, some surgeons perform a left atrial maze procedure or pulmonary vein isolation only to reduce the operation time. This study was performed to evaluate how the modified procedures, with using cut-and-sew techniques, can influence the treatment of atrial fibrillation. MATERIAL AND METHOD: Between Feb 1999 and June 2005, 40 patients (17 males and 23 females) with organic heart disease and atrial fibrillation underwent the Cox maze-III procedure (23), the left atrial maze procedure (10) or pulmonary vein isolation (7). The cut-an-sew technique was used to ablate the atrial wall, but cryoablation was used instead of the cut-and-sew technique for the coronary sinus and the inferior wall between the pulmonary vein and the mitral annulus. RESULT: After a mean follow-up period of 50.0+/-21.6 months, all (100%) of the 23 patients who underwent the Cox maze-III procedure had regular sinus or atrial rhythm conversion, and 7 (70%) of 10 with a left atrial maze procedure and 4 (57.1%) of 7 with pulmonary vein isolation had regular sinus or atrial rhythm conversion (p=0.002). CONCLUSION: To obtain a high conversion rate from atrial fibrillation to a regular sinus rhythm or a regular atrial rhythm, the standard Cox maze-III procedure should be performed in both atria. The limited modified procedures like the left atrial maze procedure or pulmonary vein isolation may reduce the cure rate of atrial fibrillation.

The Long-term Results of a Modified Maze Procedure with Using Cryoablation / 대한흉부외과학회지

BACKGROUND: Atrial fibrillation is associated with several complications such as cerebro-vascular accidents and peripheral arterial embolism. Most of the patients who have this arrhythmia chronically feel their heart beating and so they are frightened; therefore, the quality of a patient's life is decreased. The purpose of this article is to determine the long term results of a modified Maze procedure and the factors that influence the success of the procedure. MATERIAL AND METHOD: This study enrolled 88 patients who underwent the modified Maze with using cryoablation between June, 2001 and February, 2007. The 88 consecutive patients were divided into two groups according to how the pulmonary veins were isolated, that is, with or without cryoablation. There were 58 patients who were isolated by cutting and sewing in the right pulmonary veins and by cyroablation in the left pulmonary veins in group 1 (group 1, n=58), and 30 patients who underwent isolation by cryoablation in the right & left pulmonary veins were placed in group 2 (group 2, n=30). The ECG was checked at discharge to determine the sinus conversion rate and we followed up the patients to determine whether or not the patients maintained sinus rhythm. We also checked the ECG at the last visit to determine the patients' heart rhythm. RESULT: The mean follow up time was 44.3+/-19.2 months. At discharge, 72.4% of the patients in group 1 were in proper sinus rhythm and 66.7% of the patients in group 2 were in proper sinus rhythm. At the last follow up, 81% of the patients in group 1 were in normal sinus rhythm and 60% of the patients in group 2 were in normal sinus rhythm. When we analyzed the data via the Kaplan-Meier method, 86.5% of the patients were free from atrial fibrillation (% free from AF) at 1 year, 80% of the patients were free from atrial fibrillation at 5 year in group 1 and 70% of the patients were free from atrial fibrillation at 1 year and 51% of the patients in group 2 were free from atrial fibrillation at 5 year. CONCLUSION: The modified Maze technique using cryoablation was a simple and effective procedure. But the success rate of the Maze technique using cryoblation is lower than that of the standard Maze III. The method using cryoablation shorten the operation time, but we must conduct more studies to get a better result of the modified Maze technique with using cryoablation.

Surgical Treatment of Arrhythmias Associated with Congenital Heart Disease / 대한흉부외과학회지

BACKGROUND: We analyzed our experience of arrhythmia surgery in patients with congenital heart disease. MATERIAL AND METHOD: A retrospective review was performed on 43 consecutive patients with congenital heart disease, who underwent arrhythmia surgery between June 1998 and June 2006. RESULT: The median age at surgery was 52 years (4~75 years). The most frequent cardiac anomaly was an atrial septal defect (23/43, 53.5%). The types of arrhythmias were atrial flutter-fibrillation, intermittent non-sustainable ventricular tachycardia and others in 37, 2 and 4, respectively. Arrhythmia surgery consisted of a bi-atrial maze operation in 18 patients (modified cox maze III procedure in 5 patients, and a right side maze plus pulmonary vein cryo-isolation in 13), right side maze operation in 18 patients, cavo-tricuspid isthmus cryoablation for benign atrial flutter in 4 patients, right ventricular endocardial cryoablation in 2 patients and extranodal cryoablation for atrioventricular node re-entry tachycardia in 1 patient. The median follow-up was 23.8 months (1~95.2 months). There was no early mortality, and one late non-cardiac related death. The overall rates of restored sinus rhythm before discharge and 3~6 months after surgery were 79% and 81%, respectively (bi-atrial maze group: 72% and 83%, right-side maze group: 77%, 77%). CONCLUSION: Arrhythmias associated with congenital heart disease can be safely treated surgically with an excellent intermediate-term outcome.

Outcomes of the Modified Maze Procedure for Chronic Atrial Fibrillation Combined with Rheumatic Mitral Valve Disease / 대한흉부외과학회지

BACKGROUNG: The aim of this study was to investigate the mid-term outcomes of our modifications to the maze procedure using cryoablation for treating atrial fibrillation associated with rheumatic mitral valve disease. MATERIAL AND METHOD: Between March 2000 and February 2004, 177 consecutive patients underwent the modified maze procedure with the use of cryoablation concomitant with mitral valve surgery for atrial fibrillation associated with rheumatic mitral valve disease, and were divided into three groups: (1) modified Cox-maze III (CM group, n=88); (2) modified Kosakai-maze (KM group, n=63); and (3) left atrial maze procedure (LA group, n=26). The postoperative and follow- up results were analyzed and compared between the groups. RESULT: There were three hospital deaths (1.7%) and no significant differences in the incidence of postoperative complications between the three groups. The operative time, such as the cardiopulmonary bypass and aortic crossclamp time, were significantly longer in the CM group than in the KM and LA groups, respectively (p<0.0001). The mean follow-up was 22.4+/-15.1 months (1~52.6 months) for all patients. One late death developed in the CM group (0.6%). At last follow-up, 139 patients exhibited sinus rhythm (79.9%), which was also regained in 67 patients (77.9%) in the CM group, 50 (80.7%) in the KM group and 22 (84.6%) in the LA group (p=0.743). The actuarial freedom from stroke at 4 years was 84.6+/-9.4% in the CM group, 95.0+/-4.9% in the KM group, and 92.9+/-6.9% in the LA group (p=0.916). CONCLUSION: The modified maze procedure using cryoablation is safe and effective in treating chronic atrial fibrillation associated with rheumatic mitral valve disease.

Effect of Left Atrial Volume Reduction with Maze Operation on Sinus Conversion and Recovery of Left Atrial Transport Function / 대한흉부외과학회지

BACKGROUND: The Maze procedure considered the most effective method of treatment for atrial fibrillation. However, the sinus conversion rates decreased due to several factors, especially enlarged left atrium. The purpose of this study was to investigate the effects of Maze procedure with left atrial volume reduction plasty on rheumatic mitral valve disease. MATERIAL AND METHOD: From December of 2001 to July of 2004, 45 patients received mitral valve and Maze operation. The patients were placed in either group 1 or group 2, based on the left atrial volume reduction plasty. The presence and onset of sinus rhythm and the incidence of trans mitral A waves were monitored during the postoperative 7 days and throughout the follow up period of 3 and 6 months. Mean follow up periods were 15.8 10.1 months in group 1 and 6.1+/-2.7 months in group 2. RESULT: The sinus onset were 9.88+/-12.2 days in group 1, and 1+/-3.6 days in group 2 (p<0.01). The sinus conversion rates in the group 1 and 2 were 65%, 75% (p=0.07) in the postoperative 7 days, 70.5%, 100% (p<0.01) at postoperative 3 months, and 93%, 100% (p<0.01) at postoperative 6 months, respectively. The wave detection rates in the postoperative 7 days were 31.2% and 63.6%, and continued to improve over time to 83.3% and 100% by 6months, respectively. CONCLUSION: The results suggest that Maze procedure with left atrial volume reduction plasty is effective for inducing sinus rhythm and for restoring left atrial contractile function after concomitant rheumatic mitral valve surgery. However further follow up of this patients for long time is necessary.

Arrhythmia Surgery in Fontan Operation / 대한흉부외과학회지

BACKGROUND: Refractory atrial arrhythmias in patients late after the Fontan operation result in significant morbidity and mortality. We reviewed our experience with arrhythmia surgery in patients who had Fontan operation. MATERIAL AND METHOD: Between July 1986 and December 2003, 275 early survivors after Fontan operation were reviewed. Fourteen patients underwent arrhythmia surgery at reoperation after Fontan operation, and mean age at reoperation was 16.8+/-7.1 (range: 4.5~30.6) years. Mechanisms of arrhythmia included atrial flutter in 8 patients, and atrial fibrillation in 2. Arrhythmia surgery has evolved from isthmus cryoablation in 12 patients to right-sided maze in 2 patients. Thirty-two patients underwent prophylactic isthmus cryoablation concomitantly at initial Fontan operation. RESULT: Postoperative arrhythmias occurred in 68 patients (24.7%) among 275. There was no early and late mortality after the arrhythmia surgery. After redo Fontan operation, all patients maintained normal sinus rhythm. Atrial flutter recurred in 3 patients who had sinus conversion with medication and 7 required permanent pacemakers with a mean follow-up of 26.5+/-29.1 (range: 2~73) months. All patients have improved to NYHA class I or II. After prophylactic cryoablation at initial Fontan operation, 29 patients (90.6%) had sinus rhythm, 1 patient had junctional tachycardia, 1 patient had sinus nodal dysfunction, and 1 patient had AV block with a mean follow-up of 51.3+/-19.8 (range: 4~80) months. CONCLUSION: Redo Fontan operation, and concomitant arrhythmia surgery reduced atrial arrhythmias and improved NYHA functional classification.

Epicardial Microwave Ablation of Atrial Fibrillation / 대한흉부외과학회지

Even though the Cox-Maze III procedure is the gold standard in the therapy for atrial fibrillation (AF) and its outcome is excellent, the complexity of the operation, longer cardiopulmonary bypass time and the risk of bleeding have tended to dissuade cardiac surgeons from its application. The recent data of the pathogenesis of AF and the development of alternative energy sources have facilitated the development of the modified Cox-Maze procedure rapidly. We reported that atrial fibrillation was conversed to sinus rhythm by the epicardial microwave ablation without cardiopulmonary bypass and the normal sinus rhythm was observed during 33 months of follow-up period.

Development of New Device to Improve Sucess Rate of Maze Procedure with Radiofrequency Energy / 대한흉부외과학회지

BACKGROUND: The sinus conversion rate after the maze procedure in chronic atrial fibrillation using radiofrequency energy is lower than with either conventional 'cut and saw' technique or cryothermia. The creation of incomplete transmural lesions due to poor tissue-catheter contact is thought to be the main cause. To address this problem, the current study was aimed to evaluate the effectiveness of a specially constructed compression device designed to enhance tissue catheter contact during unipolar radiofrequency catheter ablation. MATERIAL AND METHOD: Circumferential right auricular epicardial lesions were created with a linear radiofrequency catheter in 10 anesthetized pigs. A device specially designed to increase contact by compression of the catheter to the atrial wall was used in 5 pigs (study group). This device was not used in the control group (5 pigs). Conduction block across the right auricular lesion was assessed by pacing, and the transmurality of the lesions were confirmed by microscopic examination. RESULT: Conduction block was observed in a total of 8 pigs; 5 in study group and 3 in control group. Transmural injury was confirmed microscopically by the accumulation of acute inflammatory cells and loss of elastic fibers in the endocardium. In two pigs with failed conduction block, microscopic examination of the endocardium appeared normal. CONCLUSION: Failed radiofrequency ablation is strongly related to non-transmural energy delivery. The specially constructed compression device in the current study was successful in creating firm tissue-catheter contact and thereby generating transmural lesions during unipolar radiofrequency ablation.

Fontan Conversion with Arrhythmia Surgery in a Jehovah's Witnesses / 대한흉부외과학회지

The conversion of failing Fontan circuit to total cavopulmonary connection(TCPC) is recommended as a therapeutic option in patients with late Fontan complications such as atrial arrhythmia, atrial enlargement, pulmonary venous obstruction, and ventricular dysfunction. Combined TCPC with extracardiac conduit and cryoablation of arrhythmia circuit is preferred for treatment of failing Fontan connection with atrial tachyarrhythmia. We report a case of conversion of atriopulmonary connection to extracardiac conduit Fontan and cryoablation of atrial arrhythmia circuit in a patient with tricuspid atresia, who also had ectopic atrial tachycardia, right atrial thrombi, pulmonary venous obstruction, and ventricular dysfunction. This patient and the parents were Jehovah's Witnesses; therefore, the patient underwent the procedure without blood transfusion.

The Mid-term Results of Pulmonary VeinIsolation for Atrial Fibrillation associated with Mitral Valvular Heart Disease / 대한흉부외과학회지

BACKGROUND: Maze procedure, as an antiarrhythmic surgery, results in a favorable sinus conversion rate, however , the complexity and relatively longer operative time made its application difficult for all patients having atrial fibrillation. Therefore, pulmonary vein isolation(PVI) can be done for selected patients. We performed the risk factor analysis associated with sinus conversion for patients who underwent PVI procedure. MATERIAL AND METHOD: Retrospective study was done for 96 patients who received concomitant PVI procedure from October 1995 to February 1999. There were 37 males(38.5%) and 59 females(61.5%), with mean age of 46.9+/-11.6 years. Underlying valvular heart diseases were as cases of mitral stenosis(52.1%), 24 cases of mitral regurgitation(25%), and 22 cases of mitral stenoinsufficiency(22.9%). Left atrial auricle was resected and pulmonary venous encircling incision was performed after valvular procedure. Electrocardiogram and echocardiogram was performed between 6 months and 1 year after the operation. Mean follow up duration was 25.9+/-11.5 months. Analysis was done between sinus conversion group and non-conversion group. RESULT: There were 3 early deaths and 2 follow-up losses within postoperative 6 months. Early postoperative complications include 4 cases of reoperation for bleeding, 1 required ventricular assistant device, 1 stroke, 1 perioperative MI and so on. Late complications include 1 case of permanent pacemaker implantation due to sick sinus syndrome, and 1 case of transient ischemic attack. There was no valve-related complication. 75 patients(82%) converted to sinus rhythm after operation. Risk factors associated with difficulty for sinus conversion were age over 50 years(p=0.03), left atrial size more than 65 mm(p=0.03), and accompanying right heart procedure(p=0.02). CONCLUSION: PVI can be done for selected patients with acceptable sinus conversion rate.