|
|
||||||||
Ann Thorac Surg 2000;69:446-450
© 2000 The Society of Thoracic Surgeons
a Department of Cardiovascular Surgery, Ebina General Higashi Hospital, Kanagawa, Japan
b Department of Cardiovascular Surgery, Yokohama Rosai Hospital, Kanagawa, Japan
Address reprint requests to Dr Harada, Department of Cardiovascular Surgery, Ebina General Higashi Hospital, 1519 Kawaraguchi, Ebina-City, Kanagawa 243-0433, Japan
| Abstract |
|---|
|
|
|---|
Methods. Surgical treatment guided by intraoperative electrophysiologic mapping was performed in 12 patients with chronic atrial fibrillation associated with isolated mitral valve disease. In 10 of 12 patients, regular and repetitive activation (cycle length ranged from 118 to 210 msec) originated in the left atrial appendage and/or orifice of the left pulmonary vein. In the remaining 2 patients, dominant repetitive activation and sporadic complex activation were alternately observed in the left atrium. However, the activation sequence of the right atrium was extremely complex and chaotic.
Results. On the basis of intraoperative mapping, surgical procedures, including resection of the left atrial appendage and/or cryoablation of the orifice of the left pulmonary vein, were applied on the breakthrough site of the repetitive activation. No surgical procedure was performed on the right atrium in 11 patients. Ten of 12 patients (83%) have maintained sinus rhythm for 6 to 40 months (average 24.8 months) after operation.
Conclusions. In the majority of the patients with isolated mitral valve disease, the left atrium acts as an electrical driving chamber for chronic atrial fibrillation. Computerized intraoperative mapping should guide surgeons in determining the appropriate surgical procedure for chronic atrial fibrillation.
| Introduction |
|---|
|
|
|---|
| Material and methods |
|---|
|
|
|---|
Before the institution of cardiopulmonary bypass, intraoperative mapping was performed. The card type electrode was attached to the right epicardial surface to record 30 unipolar local electrograms simultaneously. Then the electrode was switched and similarly attached to the left atrial epicardial electrograms. All unipolar electrograms were recorded at a frequency response of 100 to 1,000 Hz. A computer stored the digitalized unipolar data and displayed the wave forms. A computer program determined local activation times from unipolar tracings. The peak negative derivative of the major deflection of the unipolar complex was defined as the time of local activation. Within 30 seconds after acquisition of the atrial epicardial electrograms, atrial activation maps for a 100-millisecond window were automatically produced from the computer analysis and displayed sequentially. Total time spent atrial mapping was less than 20 minutes. The detailed methods for electrophysiologic mapping were reported previously [11]. We routinely used an intraoperative transesophageal echocardiography (TEE) to evaluate the thrombus of the left atrial appendage. In patients with mural thrombus, cardiac mapping was performed very carefully, using an electrode which makes only very superficial contact with the left atrium. However, in patients with pedunculated thrombus, cardiac mapping should not be performed to avoid a thromboembolic complication. In the present study there were no patients with pedunculated thrombus.
After the institution of cardiopulmonary bypass, the ascending aorta was cross-clamped and the heart was arrested with cold cardioplegic solution. Depending on surgeon preference, either superior-transseptal incision (10 patients) or standard left atriotomy (2 patients) was performed to expose the mitral valve. Mitral valve replacement in 6 patients, mitral valve plasty in 5 patients, and open mitral commissurotomy in 1 patient, were performed. After the mitral valve operations, procedures to ablate chronic AF were performed. According to the results of the atrial activation maps in each patient, different procedures including resection of the left atrial appendage and/or cryoablation were selected intraoperatively.
Both electrophysiologic mapping and operations were performed after informed consent had been obtained from each patient.
| Results |
|---|
|
|
|---|
|
Figures 1 and 2 demonstrate representative epicardial electrograms and sequential activation maps of the left atrium in patient 8. As shown in Figure 1, the left atrium was activated regularly at a cycle length of 148 millisec-onds. Atrial activation maps, constructed from the electrograms of Figure 1, demonstrated that there was a breakthrough of the regular activation in the middle portion of the posterior wall of the left atrial appendage (Fig 2). Activation spread coaxially from the site of the breakthrough to the body of the left atrium. On the basis of the activation pattern, the presence of either microreentry or automaticity was suspected. There was no evidence of macroreentry. The activation of the right atrium was complex and chaotic. No identical patterns of activation were observed and there were no evidence of macroreentry, microreentry, and automaticity in the right atrium. In this patient, we performed mitral valve replacement through standard left atriotomy. Then, using a cryoprobe, 3-mm in diameter, only 1 cryoablation (-60°C for 3 minutes) was applied on the breakthrough site of the repetitive activation. The patient has maintained normal sinus rhythm for 24 months after operation.
|
|
In patient 4, regular activation was mainly in the left atrial appendage but did not perpetuate. Existence of arrhythmogenecities in parts of the left atrium other than the left atrial appendage were suspected. Therefore, cryoablation on the orifice of the left pulmonary vein were added to the resection of the left atrial appendage.
In patients 5 and 6, the origin of the repetitive activation was identified in the orifice of the left pulmonary vein on which cryoablation was performed. However, additional resection of the left atrial appendage was performed due to the macroscopic finding that the left atrial appendage was remarkably dilated and the endocardium of it was thickened. There were no major complications including thromboembolism and postoperative bleeding.
Ten of 12 patients (83%) have maintained sinus rhythm, without any antiarrhythmic agent to control supraventricular arrhythmias, for 6 to 40 months (average 24.8 months) after the operation. However, AF was present even after operation in patient 3 and 4.
| Comment |
|---|
|
|
|---|
On the basis of this previous study, we hypothesized that chronic AF associated with isolated mitral valve disease, may be caused by electrical discharges in the left atrium in the majority of patients. Then, surgical procedures including exclusion and/or cryoablation were applied to the parts of the left atrium in which repetitive activations originated. As a result, chronic AF was successfully converted to sinus rhythm in 10 of 12 patients (83%). The results supported our hypothesis.
Graffigna and associates [4] reported the electrophysiologic effects of left atrial isolation for AF associated with mitral valve operations, in which the left atrium was electrically isolated from the remainder of the heart, and reentrant circuit and/or ectopic focus were confined to the left atrium [12]. They performed left atrial isolation in 100 patients with chronic AF complicated by mitral valve disease, and sinus rhythm was successfully restored in 79 (81.4%) of 97 survivors.
Sueda and colleagues [9] also devised a simple left atrial procedure to eliminate chronic AF during mitral valve operations. The procedure consisted of surgical incisions and cryolesion was performed only on the left atrium, while the right atrium was spared. The procedure was performed in 11 patients with chronic AF associated with mitral valve disease, and 10 patients continued to have a sinus rhythm (AF free rate, 91%).
The clinical reports of Graffigna, Sueda, and our study suggest that in more than 80% of chronic AF cases complicated by mitral valve disease, the left atrium plays an important role in maintaining AF but the right atrium does not.
AF recurred in patients 3 and 4, which is probably explained by the fact that the focus of AF could reach regions where mapping was unavailable. With current mapping systems, the electrode cannot be inserted into the posterior side of the left atrium or interatrial septum, so that no information is available from these areas. The right atrium may also play an important role in maintaining chronic AF in a few patients (those in whom the procedures failed to ablate AF), but detailed activation sequence of the right atrium has not been analyzed to present because of chaotic activation patterns. Therefore, we are making efforts to improve the mapping system and software in order to analyze the AF activation sequence.
A historical study of AF atrial activation has been reported by Cox and associates [10]. Based on the atrial activation sequence of electrically induced AF in experimental models and patients with WPW syndrome, they demonstrated the presence of macroreentrant circuits and the absence of both microreentrant circuits and evidence of atrial automaticity. Although various concepts of reentry and ectopic focus for the mechanism of AF have been proposed [10, 11, 1316], the mechanism or activation sequence of chronic AF associated with mitral valve disease is still unknown.
Both our previous and present studies on atrial activation during chronic AF, in patients with isolated mitral valve disease, demonstrated regular and repetitive activation in the left atrium and intricate activation in the right atrium. Since our mapping system was limited to a 32-channel system, and simultaneous right and left atrial mapping was not performed, detailed mechanisms, whether ectopic or reentrant, were not determined. A more sophisticated mapping system, capable of simultaneous mapping of both right and left atria, is required to analyze the detailed mechanism of AF. Our electrophysiologic studies indicated the absence of macroreentry in both the right and left atria, and the presence of either microreentry or ectopic focus, mainly in the left atrium rather than the right atrium. As shown in Figure 2, regular and repetitive activation sequence spread coaxially from the sites of origin, and the presence of either microreentry or ectopic focus was strongly suspected from the activation pattern. The activation patterns of repetitive activation in the other patients were the same as in Figure 2. However, we do not think that all chronic AF occurs by the same mechanism, and intend to investigate chronic AF with other diseases as well.
The procedures, including surgical resection of the atrial tissue and/or cryoablation, were applied on the origins of repetitive activation. As shown in Table 1, depending on the activation pattern, a different procedure was performed for each patient. The advantage of intraoperative map guided operation is that it simplifies the procedure and does not require much time [17, 18]. All procedures to ablate chronic AF required less than 30 minutes (minimum 5 minutes in patient 8) and were acceptable as concomitant procedures for mitral valve operation.
Although AF is an extremely complex and intricate arrhythmia, we advocate performing intraoperative atrial mapping to investigate its detailed mechanism. We concluded that intraoperative mapping should guide surgeons in determining the appropriate surgical procedure, and facilitate operations to treat AF.
| References |
|---|
|
|
|---|
Related Article
Ann. Thorac. Surg. 2000 69: 450-451.
This article has been cited by other articles:
![]() |
J. Sirak, D. Jones, B. Sun, C. Sai-Sudhakar, J. Crestanello, and M. Firstenberg Toward a Definitive, Totally Thoracoscopic Procedure for Atrial Fibrillation Ann. Thorac. Surg., December 1, 2008; 86(6): 1960 - 1964. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Q. Cui, L. B. Sun, Y. Li, C. L. Xu, J. Han, H. Li, and X. Meng Intraoperative Modified Cox Mini-Maze Procedure for Long-Standing Persistent Atrial Fibrillation Ann. Thorac. Surg., April 1, 2008; 85(4): 1283 - 1289. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Hornero, I. Rodriguez, V. Estevez, O. Gil, S. Canovas, R. Garcia, and J. M. Leon Analysis of the postoperative epicardial auriculogram after surgical ablation of atrial fibrillation: Risk stratification of late recurrences J. Thorac. Cardiovasc. Surg., June 1, 2007; 133(6): 1493 - 1498. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Grandmougin and O. Tiffet Video-assisted thoracoscopic epicardial ablation of left pulmonary veins for lone permanent atrial fibrillation Interactive CardioVascular and Thoracic Surgery, February 1, 2007; 6(1): 136 - 138. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Takahashi, M. Hocini, M. D. O'Neill, P. Sanders, M. Rotter, T. Rostock, A. Jonsson, F. Sacher, J. Clementy, P. Jais, et al. Sites of Focal Atrial Activity Characterized by Endocardial Mapping During Atrial Fibrillation J. Am. Coll. Cardiol., May 16, 2006; 47(10): 2005 - 2012. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Haissaguerre, M. Hocini, P. Sanders, Y. Takahashi, M. Rotter, F. Sacher, T. Rostock, L.-F. Hsu, A. Jonsson, M. D. O'Neill, et al. Localized Sources Maintaining Atrial Fibrillation Organized by Prior Ablation Circulation, February 7, 2006; 113(5): 616 - 625. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Gillinov, F. Bakaeen, P. M. McCarthy, E. H. Blackstone, J. Rajeswaran, G. Pettersson, J. F. Sabik III, F. Najam, K. M. Hill, L. G. Svensson, et al. Surgery for Paroxysmal Atrial Fibrillation in the Setting of Mitral Valve Disease: A Role for Pulmonary Vein Isolation? Ann. Thorac. Surg., January 1, 2006; 81(1): 19 - 28. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Khargi, B. Lemke, and T. Deneke Concomitant anti-arrhythmic procedures to treat permanent atrial fibrillation in CABG and AVR patients are as effective as in mitral valve patients Eur. J. Cardiothorac. Surg., May 1, 2005; 27(5): 841 - 846. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Nitta, H. Ohmori, S.-i. Sakamoto, Y. Miyagi, S. Kanno, and K. Shimizu Map-guided surgery for atrial fibrillation J. Thorac. Cardiovasc. Surg., February 1, 2005; 129(2): 291 - 299. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Sahadevan, K. Ryu, L. Peltz, C. M. Khrestian, R. W. Stewart, A. H. Markowitz, and A. L. Waldo Epicardial Mapping of Chronic Atrial Fibrillation in Patients: Preliminary Observations Circulation, November 23, 2004; 110(21): 3293 - 3299. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Khargi, B. Lemke, H. Haardt, K.-M. Muller, A. Mugge, A. Laczkovics, and T. Deneke Concomitant anti-arrhythmic surgery, using irrigated cooled-tip radiofrequency ablation, to treat permanent atrial fibrillation in CABG patients: expansion of the indication? Eur. J. Cardiothorac. Surg., June 1, 2004; 25(6): 1018 - 1024. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Park, C.-C. Chou, P. C. Drury, Y. Okuyama, A. Peter, A. Hamabe, Y. Miyauchi, R. M. Kass, H. S. Karagueuzian, M. C. Fishbein, et al. Thoracic vein ablation terminates chronic atrial fibrillation in dogs Am J Physiol Heart Circ Physiol, June 1, 2004; 286(6): H2072 - H2077. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. L. Cox Atrial fibrillation II: rationale for surgical treatment J. Thorac. Cardiovasc. Surg., December 1, 2003; 126(6): 1693 - 1699. [Full Text] [PDF] |
||||
![]() |
E. R. Jessurun, J. M. T. de Bakker, N. M. van Hemel, T. Opthof, A. C. Linnenbank, P. F. H. M. van Dessel, J. J. A. M. T. Defauw, and A. B. de la Riviere Right atrial modification of maze surgery does not affect refractoriness and conduction patterns of human lone atrial fibrillation Europace, January 1, 2003; 5(1): 39 - 46. [Abstract] [PDF] |
||||
![]() |
J. L. Cox Surgical treatment of atrial fibrillation: a review Europace, January 1, 2003; 5(s1): S20 - S29. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Benussi, S. Nascimbene, E. Agricola, G. Calori, S. Calvi, A. Caldarola, M. Oppizzi, V. Casati, C. Pappone, and O. Alfieri Surgical ablation of atrial fibrillation using the epicardial radiofrequency approach: mid-term results and risk analysis Ann. Thorac. Surg., October 1, 2002; 74(4): 1050 - 1057. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Zhou, C.-M. Chang, T.-J. Wu, Y. Miyauchi, Y. Okuyama, A. M. Park, A. Hamabe, C. Omichi, H. Hayashi, L. A. Brodsky, et al. Nonreentrant focal activations in pulmonary veins in canine model of sustained atrial fibrillation Am J Physiol Heart Circ Physiol, September 1, 2002; 283(3): H1244 - H1252. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Deneke, K. Khargi, P. H. Grewe, S. von Dryander, F. Kuschkowitz, T. Lawo, K.-M. Muller, A. Laczkovics, and B. Lemke Left atrial versus bi-atrial maze operation using intraoperatively cooled-tip radiofrequency ablation in patients undergoing open-heart surgery: Safety and efficacy J. Am. Coll. Cardiol., May 15, 2002; 39(10): 1644 - 1650. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Jalife, O. Berenfeld, and M. Mansour Mother rotors and fibrillatory conduction: a mechanism of atrial fibrillation Cardiovasc Res, May 1, 2002; 54(2): 204 - 216. [Abstract] [Full Text] [PDF] |
||||
![]() |
P.-S. Chen, T.-J. Wu, C. Hwang, S. Zhou, Y. Okuyama, A. Hamabe, Y. Miyauchi, C.-M. Chang, L. S. Chen, M. C. Fishbein, et al. Thoracic veins and the mechanisms of non-paroxysmal atrial fibrillation Cardiovasc Res, May 1, 2002; 54(2): 295 - 301. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. C. Kress, D. Krum, V. Chekanov, J. Hare, N. Michaud, M. Akhtar, and J. Sra Validation of a left atrial lesion pattern for intraoperative ablation of atrial fibrillation Ann. Thorac. Surg., April 1, 2002; 73(4): 1160 - 1168. [Abstract] [Full Text] [PDF] |
||||
![]() |
T.-J. Wu, J. J. C. Ong, C.-M. Chang, R. N. Doshi, M. Yashima, H.-L. A. Huang, M. C. Fishbein, C.-T. Ting, H. S. Karagueuzian, and P.-S. Chen Pulmonary Veins and Ligament of Marshall as Sources of Rapid Activations in a Canine Model of Sustained Atrial Fibrillation Circulation, February 27, 2001; 103(8): 1157 - 1163. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Li, L. Zhang, J. Kneller, and S. Nattel Potential Ionic Mechanism for Repolarization Differences Between Canine Right and Left Atrium Circ. Res., June 8, 2001; 88(11): 1168 - 1175. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |