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Thoracoscopic Resection of the Left Atrial Appendage After Failed Focal Atrial Tachycardia Ablation Rachel D. Torok, MD, Benjamin Wei, MD, Ronald J. Kanter, MD, Robert D. B. Jaquiss, MD, and Andrew J. Lodge, MD Division of Pediatric Cardiology, Department of Pediatrics, and Division of Thoracic and Cardiovascular Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina
Background. This case series describes 3 patients with the unusual location of focal atrial tachycardia in the left atrial appendage who failed catheter ablation but were successfully treated by left atrial appendage resection by a totally thoracoscopic surgical technique. Methods. In all 3 cases, left atrial appendage resection was carried out by video-assisted thoracoscopic surgery using only 3 5- to 10-mm incisions, eliminating the need for median sternotomy or thoracotomy. An endoscopic stapler was used to resect the left atrial appendage at its base, successfully eliminating the source of the patients’ focal atrial tachycardia. Results. The mean operative time was 84 minutes. All 3 patients tolerated the procedure without any
complications and were discharged on postoperative day 3. At an average follow-up of 4.5 years, all patients remained asymptomatic and with normal ambulatory rhythm monitoring off all antiarrhythmic medications. Conclusions. Surgical resection of the left atrial appendage using a totally thoracoscopic approach is a safe and successful treatment option for patients who have failed endocardial catheter ablation. This novel approach utilizes smaller incisions and shorter operative times than the more invasive surgical techniques previously described in the literature.
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Patients and Methods
ocal atrial tachycardia (AT) most commonly arises from the crista terminalis, ostium of the coronary sinus, atrioventricular annuli, and the ostia of the pulmonary veins [1]. A focus in the left atrial appendage (LAA) is rare, accounting for only 0.6% to 3% of all focal ATs [1, 2]. Focal AT is often successfully treated using radiofrequency catheter ablation, but foci arising from the LAA at the trabeculated portion, thin-walled apex, or an epicardial site can be more difficult to treat [3–5]. When catheter ablation fails or the risk of cardiac perforation with further ablation efforts is high, surgical resection of the left atrial appendage is a suitable treatment option [3]. Exclusion or resection of the LAA by median sternotomy or thoracotomy has been reported in patients with focal AT refractory to medical and catheterbased treatments [6–8]. There has also been a single case report of a left atrial appendectomy by video-assisted thoracoscopic surgery (VATS) utilizing a minithoracotomy for focal AT [3]. Here, we present a case series of 3 patients with focal AT of the LAA who failed catheter ablation but were successfully treated by LAA resection with a completely thoracoscopic approach. Their presurgical histories follow. Accepted for publication Nov 11, 2013. Address correspondence to Dr Lodge, Division of Cardiovascular and Thoracic Surgery, Department of Surgery, Duke University Medical Center, Box 3340, Durham, NC 27710; e-mail: andrew.lodge@dm. duke.edu.
Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
(Ann Thorac Surg 2014;97:1322–7) Ó 2014 by The Society of Thoracic Surgeons
This was a retrospective review of the courses of 3 consecutive patients who underwent thoracoscopic resection of the LAA for focal AT at Duke University Medical Center. Upon discussion with one of our institution’s ethics committee chairs, the need for Institutional Review Board, and written patient consent was waived for this case series.
Patient 1 A 13-year-old, previously healthy boy presented with focal AT after an abnormal heart rhythm was discovered on a routine physical examination. Holter monitor showed nonsustained, but incessant, focal AT consisting of 4 to 6 beat runs. The focal AT had a rate between 130 and 150 beats per minute (bpm), with a borderline first degree atrioventricular block. The focal AT was suppressed by periods of sinus tachycardia and approximately 29% of his total beats were from the focal AT. Cardiac magnetic resonance imaging showed no structural abnormalities and normal ventricular function. In the subsequent 4 months the patient began to experience decreased energy, palpitations, and exacerbation of his reactive airway disease, and he was referred for electrophysiology (EP) study and possible catheter ablation. At the start of the EP study, standard catheters were placed in the coronary sinus, His bundle region, right ventricular apex, and high lateral right atrium. There 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2013.11.017
were no ectopic beats at baseline but atrial burst pacing slightly faster than the sinus rate induced short runs of atrial tachycardia, with earliest activation from the left atrium. Point-to-point mapping (NavX; Endocardial Solutions, St. Paul, MN) revealed the focal AT to originate at the anterior rim of the ostium of the left upper pulmonary vein. Radiofrequency energy accelerated and terminated this focus of tachycardia. Subsequently, intermittent boluses of phenylephrine induced a second atrial tachycardia, and point-by-point mapping showed the earliest site of activation to be at the tip of the LAA. Multiple attempts to ablate this lesion with radiofrequency energy accelerated but failed to terminate the tachycardia, suggesting an epicardial focus, inaccessible by endocardial ablation. There was a broad area of early activation and local activation times at this location never preceded the P-wave by more than 15 ms, which further suggested an epicardial focus. Due to the remaining AT focus, the patient’s symptoms from the tachycardia, and the family’s wish to avoid long-term medication, he was referred to the surgical service for resection of the left atrial appendage. On the day prior to his surgery, electroanatomic mapping was repeated, this time using the CARTO3 system (Biosense Webster, Diamond Bar, CA) in order to corroborate the AT focus location. The AT focus was clearly mapped to the midsection of the LAA, again with a diffuse region of early activation. The location of the phrenic nerve was also mapped in preparation for surgery.
Patient 2 A 34-year-old, very physically active woman with no significant past medical history presented with a 7-month history of palpitations and dyspnea. An electrocardiogram showed abnormal P-wave morphology and Holter monitor showed atrial tachycardia with a rate of 130 to 140 bpm. Echocardiogram and cardiac magnetic resonance imaging showed no abnormalities and normal ventricular function, though atrial tachycardia with abrupt termination to sinus rhythm occurred on stress testing. Treatment with calcium channel blockers failed to control her symptoms and she was referred for catheter ablation. After standard catheters were placed at the start of the EP study, spontaneous focal AT was induced by isoproterenol, suggesting automaticity as the mechanism of the tachycardia. From the coronary sinus electrograms the focal AT clearly originated from the lateral left atrium. Point-to-point mapping (NavX) showed the focal AT to originate in the LAA. Radiofrequency energy accelerated but failed to terminate the tachycardia. Attempts at cryoablation (Freezor 2; CryoCath Technologies Inc, Montreal, Canada) were also unsuccessful. An epicardial focus was felt to be most likely given that the tachycardia could be accelerated but not terminated, there was a broad area of early activation, and there was no pure QS complex on the mapping catheter. Due to concerns for cardiac perforation with further mapping and ablation attempts, the procedure was concluded. The patient was discharged home on low-dose beta blocker therapy and later changed to carvedilol. However, due to her persistent
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symptoms, inability to continue training as a runner, and a desire to avoid long-term medical therapy for an anticipated future pregnancy, she decided to pursue surgical treatment.
Patient 3 A 15-year-old previously healthy girl presented with a 1-month history of palpitations and near syncope. An echocardiogram at an outside facility demonstrated normal cardiac anatomy but low normal left ventricular function and she was placed on oral digoxin, which was ineffective in treating her symptoms. An exercise stress test demonstrated short runs of focal AT at rest and an increased rate of focal AT during exercise, up to 235 bpm. P-wave morphology suggested a single focus in the left atrium. Holter monitor showed 92 runs of atrial tachycardia, with rates as high as 250 bpm. Based on these results she was scheduled for EP study with possible ablation. After placement of standard catheters during her EP study the patient had brief runs of atrial tachycardia. Tachycardia was not inducible by programmed electrical stimulation but was facilitated by low dose isoproterenol, with sustained rates of 140 to 180 bpm, suggesting enhanced or triggered automaticity as the mechanism of the tachycardia. Point-to-point activation mapping (NavX) demonstrated the earliest site of local activation was at the anterosuperior portion of the distal LAA (Fig 1). Radiofrequency energy caused acceleration of the focal AT to rates greater than 220 bpm repeatedly but did not terminate the tachycardia. Cryoablation was applied (CryoCath Technologies), which terminated the tachycardia several times upon thawing of the catheter tip (Fig 2), after which the tachycardia promptly returned. An epicardial focus was felt to be most probable as the tachycardia could be accelerated but not fully terminated, there was a broad area of early activation, and local activation time at this location did not precede the P-wave by more than 25 ms. Given the risk of LAA perforation with repeated mapping and ablation attempts the procedure was concluded and the patient was referred for surgery.
Surgical Technique Patients undergoing thoracoscopic left atrial appendage resection had both arterial and central venous lines placed prior to the start of surgery. After being intubated with a double-lumen endotracheal tube, the patient was placed in the right lateral decubitus position. A 10-mm incision was made in the posterior axillary line at the sixth or eighth intercostal space, and the thoracoscope was inserted through this port initially. Another 10-mm port incision was made at the seventh intercostal space in the anterior axillary line, and a third port site was made at the fifth intercostal space, with a 5- to 10-mm incision in the posterior axillary line. The lung was positioned posteriorly and the phrenic nerve was visualized. The pericardium was then opened posterior to the phrenic nerve with electrocautery. An incision in the pericardium was created parallel to the phrenic nerve to expose the
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Fig 1. Earliest atrial activation site of focal atrial tachycardia during point-to-point endocardial mapping from patient 3. (A) Intracardiac mapping, with ABL-d representing the electrograms from the distal bipole of the mapping/ablation catheter at the local activation site in the distal left atrial appendage. (B) Local activation map from point-to-point bipolar recording using NavX system. Superimposed are several of the ablation sites, with brown representing radiofrequency energy and light blue representing cryoenergy. The blue circle which is encircled in yellow corresponds to the site of the ABL-d electrograms in (A). (ABL ¼ map/ ablation catheter electrograms; CS ¼ coronary sinus catheter electrograms [1 being most distal; 5 being most proximal, ie, closest to the coronary sinus ostium]; His ¼ His bundle catheter electrograms [p, proximal; m, middle; d, distal]; LAA ¼ left atrial appendage; LLPV ¼ left lower pulmonary vein; LUPV ¼ left upper pulmonary vein; MVA ¼ mitral valve annulus; RF ¼ radiofrequency.)
LAA (Fig 3). Interestingly, for all 3 patients the tachycardia terminated when the LAA was grasped. A vascular load endo-GIA stapler (Covidien, Mansfield, MA) was used to resect the LAA across its base (Fig 4). The LAA was removed from the chest and hemostasis was confirmed. A 24 to 28 French chest tube was placed through the anterior axillary port site and the remaining port sites were closed in layers with absorbable sutures. The patients were extubated in the operating room and taken to the intensive care unit for observation.
Results The mean operative time for the 3 VATS LAA resections was 84 minutes. There were no intraoperative complications. In 2 patients the chest tube was removed on postoperative day 2, and in the other it was removed on postoperative day 1. A postoperative transthoracic echocardiogram was performed only in patient 3, and which showed no residual LAA. All 3 patients were discharged on postoperative day 3. Two patients were discharged off all antiarrhythmic medications and patient 2 was discharged on her preoperative carvedilol, which was weaned off over 2 months. There were no postoperative complications. At an average follow-up of 4.5 years all patients remained symptom-free with normal ambulatory rhythm monitoring and no further need for antiarrhythmic medications.
Pathology The LAA specimen from patient 1 demonstrated benign atrial myocardium. The tissue obtained from patient 2 showed mild fatty infiltration and subendocardial fibrosis of the atrial myocardium. Evaluation of the LAA specimen from patient 3 was unrevealing.
Comment Focal atrial tachycardia is a relatively uncommon arrhythmia, accounting for 10% to 14% of all forms of supraventricular tachycardia [9, 10]. Focal AT can progress to more problematic arrhythmias such as atrial fibrillation and atrial flutter [10]. Furthermore, incessant tachycardia can result in a tachycardia-mediated cardiomyopathy, which occurs in approximately 10% of patients with focal AT [11]. Finally, and perhaps most importantly as seen in these 3 cases, patients may report intolerable symptoms of syncope, palpitations, dyspnea, and fatigue. Catheter ablation has been shown to be an effective treatment for focal AT, with success rates of 85% to 95% [12]. The LAA is an uncommon site of focal AT that often times can be successfully treated with catheter ablation, but the complex anatomy of the LAA can make this procedure difficult. Incomplete ablation of foci in thick pectinate muscle can lead to unsuccessful ablation, and the intervening thin walls of the LAA make it susceptible to perforation [7, 13]. Prior to the advent of catheter-based ablation, surgical therapy for focal AT originating from various atrial sites was more commonly performed [14–17]. Radiofrequency ablation, cryoablation, and left atrial isolation have all been described as components of surgery for focal AT, with the specific technique depending on the location and number of ectopic foci [6, 8, 18]. Although long-term success rates of up to 90% have been reported, surgical ablation of focal AT was typically performed by median sternotomy and involved the attendant inpatient hospital stay and recovery time [18]. Because of the accessibility of the LAA from the left chest, LAA resection for atrial tachycardia can be performed by minithoracotomy or thoracotomy [7, 19, 20]. To our knowledge, only a single case report by Yamada and colleagues in 2006 [3] describes a VATS approach
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Fig 2. End of cryoablation attempt in distal portion of left atrial appendage from patient 3. (A) Intracardiac electrograms demonstrating abrupt slowing of focal atrial tachycardia just after termination of energy delivery. Asterisk (*) is adjacent to the distal ablation catheter’s bipolar electrograms as the high amplitude electromagnetic noise dissipates. This represents loss of cryoadherance as the catheter “thaws.” Repeated heart rate slowing from this phenomenon indicates close proximity of the catheter tip to the anatomic origin of the tachycardia, because it never occurred at other sites. Tachycardia always resumed within seconds, however. (B) Anterior-posterior chest radiograph during cryoenergy application depicted in (A). The site of the ablation catheter (Abl) corresponds to the yellow-encircled light blue circle in Fig 1(A). (ABL ¼ map/ablation catheter electrograms; CS ¼ coronary sinus catheter electrograms [1 being most distal; 5 being most proximal, ie, closest to the coronary sinus ostium]; His ¼ His bundle catheter electrograms [p, proximal; m, middle; d, distal]; RA ¼ right atrial catheter electrograms [10 being most anatomically superior, 2 being most anatomically inferior]; RVA ¼ right ventricular apical catheter electrograms.)
to LAA resection for focal AT. However, in this case a minithoracotomy was used for access to the chest and atrium. Our case series presents 3 patients with focal AT who are the first to be successfully treated by removal of the LAA with a totally thoracoscopic approach. This was facilitated by the precise preoperative mapping of the AT focus to the mid or distal LAA in all patients in this series. In patients in whom the location of the focus is not precisely known, intraoperative mapping should be considered. All 3 patients had long-term relief of tachycardia and required only a 3-day hospital stay. Video-assisted thoracoscopic surgery was initially developed to treat lung cancer in adults and gained an increasing role among adult surgeons and later pediatric surgeons [3, 21]. Compared with thoracotomy VATS is less invasive, which leads to decreased pain, fewer pulmonary complications, shorter hospital stays, and better cosmesis [21, 22]. In the case report by Yamada and colleagues [3], a 17-year-old male with persistent focal AT of the LAA had failed medical treatment and catheter
ablation and underwent left atrial appendectomy by VATS with 2 thoracoscopic port incisions and a 50-mm minithoracotomy. Total operating time was approximately 4 hours and he had no further focal AT at 24month follow-up [3]. Our completely thoracoscopic approach further exploits the postoperative and cosmetic advantages of VATS. We used a total of 3 ports in each case, at least 2 of which were 10 mm in size, in order to provide greater versatility for applying the stapler. We believe that shorter operative time in spite of smaller incisions is feasible, as demonstrated by the fact that our cases took an average of 84 minutes with a totally thoracoscopic approach. In the future, the use of 5-mm ports for the camera and assisting instrument, with only a single 10-mm port for the stapler could further improve the cosmetic result. Another application of VATS for the treatment of focal AT in the LAA has been described using an Atriclip (Atricure Inc, West Chester, OH), which is a polyestersheathed titanium clip deployed by a thoracoscopic
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approach [23]. However, the use of this device is conceptually less appealing than LAA resection as it does not remove the focus of the tachycardia but merely isolates it. We believe complete extirpation of the arrhythmic focus is preferable to electrical isolation due to the observed establishment of conduction across suture lines after orthotopic heart transplantation and the Bj€ ork-type Fontan procedure [24, 25]. After failed endocardial catheter ablation, other nonsurgical treatment options exist. Previous reports describe epicardial mapping and ablation of focal AT, with pericardial access obtained from a percutaneous subxiphoid approach [4, 26]. Di Biase and colleagues [27] described 2 adult cases of atrioventricular reciprocating tachycardia that failed endocardial and epicardial ablation but were successfully treated with irrigated radiofrequency ablation applied to the tip of the LAA. Similarly, Hillock and colleagues [13] described 2 adult patients with focal AT who failed conventional
Fig 4. Vascular load endo-GIA applied across the base of the left atrial appendage for patient 2.
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radiofrequency catheter ablation but were successfully treated with irrigated-tip catheters. While these cases have shown favorable results, extreme caution must be taken to avoid cardiac perforation with multiple ablation attempts at the LAA, and LAA resection by VATS may be more expeditious and should be considered as an alternative treatment option. Of course the location of the AT focus must be clearly delineated prior to LAA resection. In patient 1, prior to surgery a second diagnostic EP study was performed after his initial endocardial catheter ablation attempt to clarify the location of the AT focus. In the other 2 patients the location of the focal AT in the LAA was clear during their initial EP study, and no further mapping was deemed necessary. If the location of the arrhythmia focus is ambiguous, or there is concern it may be near the left circumflex coronary artery or coronary sinus, further endocardial or epicardial mapping should be considered. The use of a cutting stapler in LAA resection has many advantages, most notably allowing a minimally invasive approach with complete resection, not just occlusion, of the appendage. However, limitations such as staple line bleeding, tears beneath the staple line, device malfunction, and inaccurate staple positioning with potential injury to nearby structures exist. Staple line failure is probably the most dangerous complication, which may prompt conversion to thoracotomy. The importance of proper patient monitoring, central venous access, and blood product availability cannot be overemphasized [28]. One option to prevent staple line failure is to use staple loads reinforced with pericardial strips or polytetrafluoroethylene, as was done for patient 2 in our case series. The decision to reinforce the staple line for this patient was made intraoperatively, based on the thickness of the tissue. Each case must be assessed independently and the decision to reinforce the staple line should be left to the discretion of the surgeon. Another safety consideration is the possible risk of thromboembolic events after LAA resection. Ligation of the LAA has been shown to significantly decrease the risk of cerebrovascular accidents among high-risk patients with postoperative atrial fibrillation [29]. As in our technique, using a cutting stapler to fully remove (not just occlude the LAA) ensures no patent communication remains to the LAA, thus further decreasing the risk of thromboembolism [30]. Finally, patients undergoing LAA resection for focal AT in the LAA remain in sinus rhythm postoperatively, making any residual LAA stump of minimal clinical significance as a risk factor for thromboembolism. Because the risk of thromboembolic events in our patients was considered to be quite low, routine follow-up echocardiography was not performed and only patient 3 had a postoperative transthoracic echocardiogram. For patients who have additional risk factors for thromboembolism, transesophageal echocardiography could be considered intraoperatively or postoperatively to assess the presence of a significant LAA stump. In conclusion, surgical resection of the LAA using a totally thoracoscopic approach is a safe and successful treatment option. Patients with focal AT located in the
LAA who have failed endocardial catheter ablation should be considered as candidates for this procedure.
References 1. Wang YL, Li XB, Quan X, et al. Focal atrial tachycardia originating from the left atrial appendage: electrocardiographic and electrophysiologic characterization and longterm outcomes of radiofrequency ablation. J Cardiovasc Electrophysiol 2007;18:459–64. 2. Kistler PM, Roberts-Thomson KC, Haqqani HM, et al. Pwave morphology in focal atrial tachycardia. J Am Coll Cardiol 2006;48:1010–7. 3. Yamada Y, Ajiro Y, Shoda M, et al. Video-assisted thoracoscopy to treat atrial tachycardia arising from left atrial appendage. J Cardiovasc Electrophysiol 2006;17:895–8. 4. Yamada T, McElderry HT, Allison JS, Kay GN. Focal atrial tachycardia originating from the epicardial left atrial appendage. Heart Rhythm 2008;5:766–7. 5. McGarvey JR, Schwartzman D, Ota T, Zenati MA. Minimally invasive epicardial left atrial ablation and appendectomy for refractory atrial tachycardia. Ann Thorac Surg 2008;86: 1375–7. 6. Mavroudis C, Deal BJ, Backer CL, Tsao S. Arrhythmia surgery in patients with and without congenital heart disease. Ann Thorac Surg 2008;86:857–68. 7. Pokushalov E, Romanov A, Artyomenko S, Arhipov A, Karaskov A. Left atrial appendectomy after failed catheter ablation of a focal atrial tachycardia originating in the left atrial appendage. Pediatr Cardiol 2010;31:908–11. 8. Bredikis J, Lekas R, Benetis R, et al. Diagnosis and surgical treatment of ectopic atrial tachycardia. Eur J Cardiothorac Surg 1991;5:199–204. 9. Ko JK, Deal BJ, Strasburger JF, Benson DW Jr. Supraventricular tachycardia mechanisms and their age distribution in pediatric patients. Am J Cardiol 1992;69:1028–32. 10. Rosso R, Kistler PM. Focal atrial tachycardia. Heart 2010;96: 181–5. 11. Medi C, Kalman JM, Haqqani H, et al. Tachycardia-mediated cardiomyopathy secondary to focal atrial tachycardia: longterm outcome after catheter ablation. J Am Coll Cardiol 2009;53:1791–7. 12. Walters TE, Kistler PM, Kalman JM. Radiofrequency ablation for atrial tachycardia and atrial flutter. Heart Lung Circ 2012;21:386–94. 13. Hillock RJ, Singarayar S, Kalman JM, Sparks PB. Tale of two tails: the tip of the atrial appendages is an unusual site for focal atrial tachycardia. Heart Rhythm 2006;3:467–9. 14. Iwa T, Ichihashi T, Hashizume Y, Ishida K, Okada R. Successful surgical treatment of left atrial tachycardia. Am Heart J 1985;109:160–2. 15. Seals AA, Lawrie GM, Margo S, et al. Surgical treatment of right atrial focal tachycardia in adults. J Am Coll Cardiol 1988;11:1111–7.
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16. Bertil Olsson S, Blomstr€ om P, Sabel KG, William-Olsson G. Incessant ectopic atrial tachycardia: successful surgical treatment with regression of dilated cardiomyopathy picture. Am J Cardiol 1984;53:1465–6. 17. Anderson KP, Stinson EB, Mason JW. Surgical exclusion of focal paroxysmal tachycardia. Am J Cardiol 1982;49:869–74. 18. Prager NA, Cox JL, Lindsay BD, Ferguson TB Jr, Osborn JL, Cain ME. Long-term effectiveness of surgical treatment of ectopic atrial tachycardia. J Am Coll Cardiol 1993;22: 85–92. 19. Frank G, Baumgart D, Klein H, Luhmer I, Kallfelz HC, Borst HG. Successful surgical treatment of focal atrial tachycardia-a case report and review of the literature. Thorac Cardiovasc Surg 1986;34:398–402. 20. Mah D, Miyake C, Clegg R, et al. Epicardial left atrial appendage and biatrial appendage accessory pathways. Heart Rhythm 2010;7:1740–5. 21. Burke RP, Wernovsky G, van der Velde M, Hansen D, Castaneda AR. Video-assisted thoracoscopic surgery for congenital heart disease. J Thorac Cardiovasc Surg 1995;109: 499–508. 22. Lawal TA, Gosemann JH, Kuebler JF, Gl€ uer S, Ure BM. Thoracoscopy versus thoracotomy improves midterm musculoskeletal status and cosmesis in infants and children. Ann Thorac Surg 2009;87:224–8. 23. Benussi S, Mazzone P, Maccabelli G, et al. Thoracoscopic appendage exclusion with an atriclip device as a solo treatment for focal atrial tachycardia. Circulation 2011;123: 1575–8. 24. Birnie D, Green MS, Veinot JP, Tang AS, Davies RA. Interatrial conduction of atrial tachycardia in heart transplant recipients: potential pathophysiology. J Heart Lung Transplant 2000;19:1007–10. 25. Peinado R, Gnoatto M, Merino JL, Oliver JM. Catheter ablation of multiple, surgically created atrioventricular connections following Fontan-Bj€ ork procedure. Europace 2007;9:848–50. 26. Phillips KP, Natale A, Sterba R, et al. Percutaneous pericardial instrumentation for catheter ablation of focal atrial tachycardias arising from the left atrial appendage. J Cardiovasc Electrophysiol 2008;19:430–3. 27. Di Biase L, Schweikert RA, Saliba WI, et al. Left atrial appendage tip: an unusual site of successful ablation after failed endocardial and epicardial mapping and ablation. J Cardiovasc Electrophysiol 2010;21:203–6. 28. Gossot D, Merlusca G, Tudor A, Boudaya MS, Radu C, Magdeleinat P. Pitfalls related to the use of endostaplers during video-assisted thoracic surgery. Surg Endosc 2009;23: 189–92. 29. Kim R, Baumgartner N, Clements J. Routine left atrial appendage ligation during cardiac surgery may prevent postoperative atrial fibrillation-related cerebrovascular accident. J Thorac Cardiovasc Surg 2013;145:582–9. 30. Gillinov AM, Pettersson G, Cosgrove DM. Stapled excision of the left atrial appendage. J Thorac Cardiovasc Surg 2005;129: 679–80.
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Thoracoscopic Resection of the Left Atrial Appendage After Failed Focal Atrial Tachycardia Ablation Rachel D. Torok, MD, Benjamin Wei, MD, Ronald J. Kanter, MD, Robert D. B. Jaquiss, MD, and Andrew J. Lodge, MD Division of Pediatric Cardiology, Department of Pediatrics, and Division of Thoracic and Cardiovascular Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina
Background. This case series describes 3 patients with the unusual location of focal atrial tachycardia in the left atrial appendage who failed catheter ablation but were successfully treated by left atrial appendage resection by a totally thoracoscopic surgical technique. Methods. In all 3 cases, left atrial appendage resection was carried out by video-assisted thoracoscopic surgery using only 3 5- to 10-mm incisions, eliminating the need for median sternotomy or thoracotomy. An endoscopic stapler was used to resect the left atrial appendage at its base, successfully eliminating the source of the patients’ focal atrial tachycardia. Results. The mean operative time was 84 minutes. All 3 patients tolerated the procedure without any
complications and were discharged on postoperative day 3. At an average follow-up of 4.5 years, all patients remained asymptomatic and with normal ambulatory rhythm monitoring off all antiarrhythmic medications. Conclusions. Surgical resection of the left atrial appendage using a totally thoracoscopic approach is a safe and successful treatment option for patients who have failed endocardial catheter ablation. This novel approach utilizes smaller incisions and shorter operative times than the more invasive surgical techniques previously described in the literature.
F
Patients and Methods
ocal atrial tachycardia (AT) most commonly arises from the crista terminalis, ostium of the coronary sinus, atrioventricular annuli, and the ostia of the pulmonary veins [1]. A focus in the left atrial appendage (LAA) is rare, accounting for only 0.6% to 3% of all focal ATs [1, 2]. Focal AT is often successfully treated using radiofrequency catheter ablation, but foci arising from the LAA at the trabeculated portion, thin-walled apex, or an epicardial site can be more difficult to treat [3–5]. When catheter ablation fails or the risk of cardiac perforation with further ablation efforts is high, surgical resection of the left atrial appendage is a suitable treatment option [3]. Exclusion or resection of the LAA by median sternotomy or thoracotomy has been reported in patients with focal AT refractory to medical and catheterbased treatments [6–8]. There has also been a single case report of a left atrial appendectomy by video-assisted thoracoscopic surgery (VATS) utilizing a minithoracotomy for focal AT [3]. Here, we present a case series of 3 patients with focal AT of the LAA who failed catheter ablation but were successfully treated by LAA resection with a completely thoracoscopic approach. Their presurgical histories follow. Accepted for publication Nov 11, 2013. Address correspondence to Dr Lodge, Division of Cardiovascular and Thoracic Surgery, Department of Surgery, Duke University Medical Center, Box 3340, Durham, NC 27710; e-mail: andrew.lodge@dm. duke.edu.
Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
(Ann Thorac Surg 2014;97:1322–7) Ó 2014 by The Society of Thoracic Surgeons
This was a retrospective review of the courses of 3 consecutive patients who underwent thoracoscopic resection of the LAA for focal AT at Duke University Medical Center. Upon discussion with one of our institution’s ethics committee chairs, the need for Institutional Review Board, and written patient consent was waived for this case series.
Patient 1 A 13-year-old, previously healthy boy presented with focal AT after an abnormal heart rhythm was discovered on a routine physical examination. Holter monitor showed nonsustained, but incessant, focal AT consisting of 4 to 6 beat runs. The focal AT had a rate between 130 and 150 beats per minute (bpm), with a borderline first degree atrioventricular block. The focal AT was suppressed by periods of sinus tachycardia and approximately 29% of his total beats were from the focal AT. Cardiac magnetic resonance imaging showed no structural abnormalities and normal ventricular function. In the subsequent 4 months the patient began to experience decreased energy, palpitations, and exacerbation of his reactive airway disease, and he was referred for electrophysiology (EP) study and possible catheter ablation. At the start of the EP study, standard catheters were placed in the coronary sinus, His bundle region, right ventricular apex, and high lateral right atrium. There 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2013.11.017
were no ectopic beats at baseline but atrial burst pacing slightly faster than the sinus rate induced short runs of atrial tachycardia, with earliest activation from the left atrium. Point-to-point mapping (NavX; Endocardial Solutions, St. Paul, MN) revealed the focal AT to originate at the anterior rim of the ostium of the left upper pulmonary vein. Radiofrequency energy accelerated and terminated this focus of tachycardia. Subsequently, intermittent boluses of phenylephrine induced a second atrial tachycardia, and point-by-point mapping showed the earliest site of activation to be at the tip of the LAA. Multiple attempts to ablate this lesion with radiofrequency energy accelerated but failed to terminate the tachycardia, suggesting an epicardial focus, inaccessible by endocardial ablation. There was a broad area of early activation and local activation times at this location never preceded the P-wave by more than 15 ms, which further suggested an epicardial focus. Due to the remaining AT focus, the patient’s symptoms from the tachycardia, and the family’s wish to avoid long-term medication, he was referred to the surgical service for resection of the left atrial appendage. On the day prior to his surgery, electroanatomic mapping was repeated, this time using the CARTO3 system (Biosense Webster, Diamond Bar, CA) in order to corroborate the AT focus location. The AT focus was clearly mapped to the midsection of the LAA, again with a diffuse region of early activation. The location of the phrenic nerve was also mapped in preparation for surgery.
Patient 2 A 34-year-old, very physically active woman with no significant past medical history presented with a 7-month history of palpitations and dyspnea. An electrocardiogram showed abnormal P-wave morphology and Holter monitor showed atrial tachycardia with a rate of 130 to 140 bpm. Echocardiogram and cardiac magnetic resonance imaging showed no abnormalities and normal ventricular function, though atrial tachycardia with abrupt termination to sinus rhythm occurred on stress testing. Treatment with calcium channel blockers failed to control her symptoms and she was referred for catheter ablation. After standard catheters were placed at the start of the EP study, spontaneous focal AT was induced by isoproterenol, suggesting automaticity as the mechanism of the tachycardia. From the coronary sinus electrograms the focal AT clearly originated from the lateral left atrium. Point-to-point mapping (NavX) showed the focal AT to originate in the LAA. Radiofrequency energy accelerated but failed to terminate the tachycardia. Attempts at cryoablation (Freezor 2; CryoCath Technologies Inc, Montreal, Canada) were also unsuccessful. An epicardial focus was felt to be most likely given that the tachycardia could be accelerated but not terminated, there was a broad area of early activation, and there was no pure QS complex on the mapping catheter. Due to concerns for cardiac perforation with further mapping and ablation attempts, the procedure was concluded. The patient was discharged home on low-dose beta blocker therapy and later changed to carvedilol. However, due to her persistent
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symptoms, inability to continue training as a runner, and a desire to avoid long-term medical therapy for an anticipated future pregnancy, she decided to pursue surgical treatment.
Patient 3 A 15-year-old previously healthy girl presented with a 1-month history of palpitations and near syncope. An echocardiogram at an outside facility demonstrated normal cardiac anatomy but low normal left ventricular function and she was placed on oral digoxin, which was ineffective in treating her symptoms. An exercise stress test demonstrated short runs of focal AT at rest and an increased rate of focal AT during exercise, up to 235 bpm. P-wave morphology suggested a single focus in the left atrium. Holter monitor showed 92 runs of atrial tachycardia, with rates as high as 250 bpm. Based on these results she was scheduled for EP study with possible ablation. After placement of standard catheters during her EP study the patient had brief runs of atrial tachycardia. Tachycardia was not inducible by programmed electrical stimulation but was facilitated by low dose isoproterenol, with sustained rates of 140 to 180 bpm, suggesting enhanced or triggered automaticity as the mechanism of the tachycardia. Point-to-point activation mapping (NavX) demonstrated the earliest site of local activation was at the anterosuperior portion of the distal LAA (Fig 1). Radiofrequency energy caused acceleration of the focal AT to rates greater than 220 bpm repeatedly but did not terminate the tachycardia. Cryoablation was applied (CryoCath Technologies), which terminated the tachycardia several times upon thawing of the catheter tip (Fig 2), after which the tachycardia promptly returned. An epicardial focus was felt to be most probable as the tachycardia could be accelerated but not fully terminated, there was a broad area of early activation, and local activation time at this location did not precede the P-wave by more than 25 ms. Given the risk of LAA perforation with repeated mapping and ablation attempts the procedure was concluded and the patient was referred for surgery.
Surgical Technique Patients undergoing thoracoscopic left atrial appendage resection had both arterial and central venous lines placed prior to the start of surgery. After being intubated with a double-lumen endotracheal tube, the patient was placed in the right lateral decubitus position. A 10-mm incision was made in the posterior axillary line at the sixth or eighth intercostal space, and the thoracoscope was inserted through this port initially. Another 10-mm port incision was made at the seventh intercostal space in the anterior axillary line, and a third port site was made at the fifth intercostal space, with a 5- to 10-mm incision in the posterior axillary line. The lung was positioned posteriorly and the phrenic nerve was visualized. The pericardium was then opened posterior to the phrenic nerve with electrocautery. An incision in the pericardium was created parallel to the phrenic nerve to expose the
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Fig 1. Earliest atrial activation site of focal atrial tachycardia during point-to-point endocardial mapping from patient 3. (A) Intracardiac mapping, with ABL-d representing the electrograms from the distal bipole of the mapping/ablation catheter at the local activation site in the distal left atrial appendage. (B) Local activation map from point-to-point bipolar recording using NavX system. Superimposed are several of the ablation sites, with brown representing radiofrequency energy and light blue representing cryoenergy. The blue circle which is encircled in yellow corresponds to the site of the ABL-d electrograms in (A). (ABL ¼ map/ ablation catheter electrograms; CS ¼ coronary sinus catheter electrograms [1 being most distal; 5 being most proximal, ie, closest to the coronary sinus ostium]; His ¼ His bundle catheter electrograms [p, proximal; m, middle; d, distal]; LAA ¼ left atrial appendage; LLPV ¼ left lower pulmonary vein; LUPV ¼ left upper pulmonary vein; MVA ¼ mitral valve annulus; RF ¼ radiofrequency.)
LAA (Fig 3). Interestingly, for all 3 patients the tachycardia terminated when the LAA was grasped. A vascular load endo-GIA stapler (Covidien, Mansfield, MA) was used to resect the LAA across its base (Fig 4). The LAA was removed from the chest and hemostasis was confirmed. A 24 to 28 French chest tube was placed through the anterior axillary port site and the remaining port sites were closed in layers with absorbable sutures. The patients were extubated in the operating room and taken to the intensive care unit for observation.
Results The mean operative time for the 3 VATS LAA resections was 84 minutes. There were no intraoperative complications. In 2 patients the chest tube was removed on postoperative day 2, and in the other it was removed on postoperative day 1. A postoperative transthoracic echocardiogram was performed only in patient 3, and which showed no residual LAA. All 3 patients were discharged on postoperative day 3. Two patients were discharged off all antiarrhythmic medications and patient 2 was discharged on her preoperative carvedilol, which was weaned off over 2 months. There were no postoperative complications. At an average follow-up of 4.5 years all patients remained symptom-free with normal ambulatory rhythm monitoring and no further need for antiarrhythmic medications.
Pathology The LAA specimen from patient 1 demonstrated benign atrial myocardium. The tissue obtained from patient 2 showed mild fatty infiltration and subendocardial fibrosis of the atrial myocardium. Evaluation of the LAA specimen from patient 3 was unrevealing.
Comment Focal atrial tachycardia is a relatively uncommon arrhythmia, accounting for 10% to 14% of all forms of supraventricular tachycardia [9, 10]. Focal AT can progress to more problematic arrhythmias such as atrial fibrillation and atrial flutter [10]. Furthermore, incessant tachycardia can result in a tachycardia-mediated cardiomyopathy, which occurs in approximately 10% of patients with focal AT [11]. Finally, and perhaps most importantly as seen in these 3 cases, patients may report intolerable symptoms of syncope, palpitations, dyspnea, and fatigue. Catheter ablation has been shown to be an effective treatment for focal AT, with success rates of 85% to 95% [12]. The LAA is an uncommon site of focal AT that often times can be successfully treated with catheter ablation, but the complex anatomy of the LAA can make this procedure difficult. Incomplete ablation of foci in thick pectinate muscle can lead to unsuccessful ablation, and the intervening thin walls of the LAA make it susceptible to perforation [7, 13]. Prior to the advent of catheter-based ablation, surgical therapy for focal AT originating from various atrial sites was more commonly performed [14–17]. Radiofrequency ablation, cryoablation, and left atrial isolation have all been described as components of surgery for focal AT, with the specific technique depending on the location and number of ectopic foci [6, 8, 18]. Although long-term success rates of up to 90% have been reported, surgical ablation of focal AT was typically performed by median sternotomy and involved the attendant inpatient hospital stay and recovery time [18]. Because of the accessibility of the LAA from the left chest, LAA resection for atrial tachycardia can be performed by minithoracotomy or thoracotomy [7, 19, 20]. To our knowledge, only a single case report by Yamada and colleagues in 2006 [3] describes a VATS approach
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Fig 2. End of cryoablation attempt in distal portion of left atrial appendage from patient 3. (A) Intracardiac electrograms demonstrating abrupt slowing of focal atrial tachycardia just after termination of energy delivery. Asterisk (*) is adjacent to the distal ablation catheter’s bipolar electrograms as the high amplitude electromagnetic noise dissipates. This represents loss of cryoadherance as the catheter “thaws.” Repeated heart rate slowing from this phenomenon indicates close proximity of the catheter tip to the anatomic origin of the tachycardia, because it never occurred at other sites. Tachycardia always resumed within seconds, however. (B) Anterior-posterior chest radiograph during cryoenergy application depicted in (A). The site of the ablation catheter (Abl) corresponds to the yellow-encircled light blue circle in Fig 1(A). (ABL ¼ map/ablation catheter electrograms; CS ¼ coronary sinus catheter electrograms [1 being most distal; 5 being most proximal, ie, closest to the coronary sinus ostium]; His ¼ His bundle catheter electrograms [p, proximal; m, middle; d, distal]; RA ¼ right atrial catheter electrograms [10 being most anatomically superior, 2 being most anatomically inferior]; RVA ¼ right ventricular apical catheter electrograms.)
to LAA resection for focal AT. However, in this case a minithoracotomy was used for access to the chest and atrium. Our case series presents 3 patients with focal AT who are the first to be successfully treated by removal of the LAA with a totally thoracoscopic approach. This was facilitated by the precise preoperative mapping of the AT focus to the mid or distal LAA in all patients in this series. In patients in whom the location of the focus is not precisely known, intraoperative mapping should be considered. All 3 patients had long-term relief of tachycardia and required only a 3-day hospital stay. Video-assisted thoracoscopic surgery was initially developed to treat lung cancer in adults and gained an increasing role among adult surgeons and later pediatric surgeons [3, 21]. Compared with thoracotomy VATS is less invasive, which leads to decreased pain, fewer pulmonary complications, shorter hospital stays, and better cosmesis [21, 22]. In the case report by Yamada and colleagues [3], a 17-year-old male with persistent focal AT of the LAA had failed medical treatment and catheter
ablation and underwent left atrial appendectomy by VATS with 2 thoracoscopic port incisions and a 50-mm minithoracotomy. Total operating time was approximately 4 hours and he had no further focal AT at 24month follow-up [3]. Our completely thoracoscopic approach further exploits the postoperative and cosmetic advantages of VATS. We used a total of 3 ports in each case, at least 2 of which were 10 mm in size, in order to provide greater versatility for applying the stapler. We believe that shorter operative time in spite of smaller incisions is feasible, as demonstrated by the fact that our cases took an average of 84 minutes with a totally thoracoscopic approach. In the future, the use of 5-mm ports for the camera and assisting instrument, with only a single 10-mm port for the stapler could further improve the cosmetic result. Another application of VATS for the treatment of focal AT in the LAA has been described using an Atriclip (Atricure Inc, West Chester, OH), which is a polyestersheathed titanium clip deployed by a thoracoscopic
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approach [23]. However, the use of this device is conceptually less appealing than LAA resection as it does not remove the focus of the tachycardia but merely isolates it. We believe complete extirpation of the arrhythmic focus is preferable to electrical isolation due to the observed establishment of conduction across suture lines after orthotopic heart transplantation and the Bj€ ork-type Fontan procedure [24, 25]. After failed endocardial catheter ablation, other nonsurgical treatment options exist. Previous reports describe epicardial mapping and ablation of focal AT, with pericardial access obtained from a percutaneous subxiphoid approach [4, 26]. Di Biase and colleagues [27] described 2 adult cases of atrioventricular reciprocating tachycardia that failed endocardial and epicardial ablation but were successfully treated with irrigated radiofrequency ablation applied to the tip of the LAA. Similarly, Hillock and colleagues [13] described 2 adult patients with focal AT who failed conventional
Fig 4. Vascular load endo-GIA applied across the base of the left atrial appendage for patient 2.
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radiofrequency catheter ablation but were successfully treated with irrigated-tip catheters. While these cases have shown favorable results, extreme caution must be taken to avoid cardiac perforation with multiple ablation attempts at the LAA, and LAA resection by VATS may be more expeditious and should be considered as an alternative treatment option. Of course the location of the AT focus must be clearly delineated prior to LAA resection. In patient 1, prior to surgery a second diagnostic EP study was performed after his initial endocardial catheter ablation attempt to clarify the location of the AT focus. In the other 2 patients the location of the focal AT in the LAA was clear during their initial EP study, and no further mapping was deemed necessary. If the location of the arrhythmia focus is ambiguous, or there is concern it may be near the left circumflex coronary artery or coronary sinus, further endocardial or epicardial mapping should be considered. The use of a cutting stapler in LAA resection has many advantages, most notably allowing a minimally invasive approach with complete resection, not just occlusion, of the appendage. However, limitations such as staple line bleeding, tears beneath the staple line, device malfunction, and inaccurate staple positioning with potential injury to nearby structures exist. Staple line failure is probably the most dangerous complication, which may prompt conversion to thoracotomy. The importance of proper patient monitoring, central venous access, and blood product availability cannot be overemphasized [28]. One option to prevent staple line failure is to use staple loads reinforced with pericardial strips or polytetrafluoroethylene, as was done for patient 2 in our case series. The decision to reinforce the staple line for this patient was made intraoperatively, based on the thickness of the tissue. Each case must be assessed independently and the decision to reinforce the staple line should be left to the discretion of the surgeon. Another safety consideration is the possible risk of thromboembolic events after LAA resection. Ligation of the LAA has been shown to significantly decrease the risk of cerebrovascular accidents among high-risk patients with postoperative atrial fibrillation [29]. As in our technique, using a cutting stapler to fully remove (not just occlude the LAA) ensures no patent communication remains to the LAA, thus further decreasing the risk of thromboembolism [30]. Finally, patients undergoing LAA resection for focal AT in the LAA remain in sinus rhythm postoperatively, making any residual LAA stump of minimal clinical significance as a risk factor for thromboembolism. Because the risk of thromboembolic events in our patients was considered to be quite low, routine follow-up echocardiography was not performed and only patient 3 had a postoperative transthoracic echocardiogram. For patients who have additional risk factors for thromboembolism, transesophageal echocardiography could be considered intraoperatively or postoperatively to assess the presence of a significant LAA stump. In conclusion, surgical resection of the LAA using a totally thoracoscopic approach is a safe and successful treatment option. Patients with focal AT located in the
LAA who have failed endocardial catheter ablation should be considered as candidates for this procedure.
References 1. Wang YL, Li XB, Quan X, et al. Focal atrial tachycardia originating from the left atrial appendage: electrocardiographic and electrophysiologic characterization and longterm outcomes of radiofrequency ablation. J Cardiovasc Electrophysiol 2007;18:459–64. 2. Kistler PM, Roberts-Thomson KC, Haqqani HM, et al. Pwave morphology in focal atrial tachycardia. J Am Coll Cardiol 2006;48:1010–7. 3. Yamada Y, Ajiro Y, Shoda M, et al. Video-assisted thoracoscopy to treat atrial tachycardia arising from left atrial appendage. J Cardiovasc Electrophysiol 2006;17:895–8. 4. Yamada T, McElderry HT, Allison JS, Kay GN. Focal atrial tachycardia originating from the epicardial left atrial appendage. Heart Rhythm 2008;5:766–7. 5. McGarvey JR, Schwartzman D, Ota T, Zenati MA. Minimally invasive epicardial left atrial ablation and appendectomy for refractory atrial tachycardia. Ann Thorac Surg 2008;86: 1375–7. 6. Mavroudis C, Deal BJ, Backer CL, Tsao S. Arrhythmia surgery in patients with and without congenital heart disease. Ann Thorac Surg 2008;86:857–68. 7. Pokushalov E, Romanov A, Artyomenko S, Arhipov A, Karaskov A. Left atrial appendectomy after failed catheter ablation of a focal atrial tachycardia originating in the left atrial appendage. Pediatr Cardiol 2010;31:908–11. 8. Bredikis J, Lekas R, Benetis R, et al. Diagnosis and surgical treatment of ectopic atrial tachycardia. Eur J Cardiothorac Surg 1991;5:199–204. 9. Ko JK, Deal BJ, Strasburger JF, Benson DW Jr. Supraventricular tachycardia mechanisms and their age distribution in pediatric patients. Am J Cardiol 1992;69:1028–32. 10. Rosso R, Kistler PM. Focal atrial tachycardia. Heart 2010;96: 181–5. 11. Medi C, Kalman JM, Haqqani H, et al. Tachycardia-mediated cardiomyopathy secondary to focal atrial tachycardia: longterm outcome after catheter ablation. J Am Coll Cardiol 2009;53:1791–7. 12. Walters TE, Kistler PM, Kalman JM. Radiofrequency ablation for atrial tachycardia and atrial flutter. Heart Lung Circ 2012;21:386–94. 13. Hillock RJ, Singarayar S, Kalman JM, Sparks PB. Tale of two tails: the tip of the atrial appendages is an unusual site for focal atrial tachycardia. Heart Rhythm 2006;3:467–9. 14. Iwa T, Ichihashi T, Hashizume Y, Ishida K, Okada R. Successful surgical treatment of left atrial tachycardia. Am Heart J 1985;109:160–2. 15. Seals AA, Lawrie GM, Margo S, et al. Surgical treatment of right atrial focal tachycardia in adults. J Am Coll Cardiol 1988;11:1111–7.
TOROK ET AL THORACOSCOPIC RESECTION OF LAA IN FOCAL AT
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16. Bertil Olsson S, Blomstr€ om P, Sabel KG, William-Olsson G. Incessant ectopic atrial tachycardia: successful surgical treatment with regression of dilated cardiomyopathy picture. Am J Cardiol 1984;53:1465–6. 17. Anderson KP, Stinson EB, Mason JW. Surgical exclusion of focal paroxysmal tachycardia. Am J Cardiol 1982;49:869–74. 18. Prager NA, Cox JL, Lindsay BD, Ferguson TB Jr, Osborn JL, Cain ME. Long-term effectiveness of surgical treatment of ectopic atrial tachycardia. J Am Coll Cardiol 1993;22: 85–92. 19. Frank G, Baumgart D, Klein H, Luhmer I, Kallfelz HC, Borst HG. Successful surgical treatment of focal atrial tachycardia-a case report and review of the literature. Thorac Cardiovasc Surg 1986;34:398–402. 20. Mah D, Miyake C, Clegg R, et al. Epicardial left atrial appendage and biatrial appendage accessory pathways. Heart Rhythm 2010;7:1740–5. 21. Burke RP, Wernovsky G, van der Velde M, Hansen D, Castaneda AR. Video-assisted thoracoscopic surgery for congenital heart disease. J Thorac Cardiovasc Surg 1995;109: 499–508. 22. Lawal TA, Gosemann JH, Kuebler JF, Gl€ uer S, Ure BM. Thoracoscopy versus thoracotomy improves midterm musculoskeletal status and cosmesis in infants and children. Ann Thorac Surg 2009;87:224–8. 23. Benussi S, Mazzone P, Maccabelli G, et al. Thoracoscopic appendage exclusion with an atriclip device as a solo treatment for focal atrial tachycardia. Circulation 2011;123: 1575–8. 24. Birnie D, Green MS, Veinot JP, Tang AS, Davies RA. Interatrial conduction of atrial tachycardia in heart transplant recipients: potential pathophysiology. J Heart Lung Transplant 2000;19:1007–10. 25. Peinado R, Gnoatto M, Merino JL, Oliver JM. Catheter ablation of multiple, surgically created atrioventricular connections following Fontan-Bj€ ork procedure. Europace 2007;9:848–50. 26. Phillips KP, Natale A, Sterba R, et al. Percutaneous pericardial instrumentation for catheter ablation of focal atrial tachycardias arising from the left atrial appendage. J Cardiovasc Electrophysiol 2008;19:430–3. 27. Di Biase L, Schweikert RA, Saliba WI, et al. Left atrial appendage tip: an unusual site of successful ablation after failed endocardial and epicardial mapping and ablation. J Cardiovasc Electrophysiol 2010;21:203–6. 28. Gossot D, Merlusca G, Tudor A, Boudaya MS, Radu C, Magdeleinat P. Pitfalls related to the use of endostaplers during video-assisted thoracic surgery. Surg Endosc 2009;23: 189–92. 29. Kim R, Baumgartner N, Clements J. Routine left atrial appendage ligation during cardiac surgery may prevent postoperative atrial fibrillation-related cerebrovascular accident. J Thorac Cardiovasc Surg 2013;145:582–9. 30. Gillinov AM, Pettersson G, Cosgrove DM. Stapled excision of the left atrial appendage. J Thorac Cardiovasc Surg 2005;129: 679–80.
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