Thoracoscopic stand-alone appendectomy for atrial tachycardia originating from the left atrial appendage in a patient with severe left ventricular dysfunction

Published:September 25, 2020DOI:https://doi.org/10.1016/j.jccase.2020.08.011

      Abstract

      Focal atrial tachycardia (AT) originating from the left atrial appendage (LAA) is one of the rare supraventricular tachycardias and is likely to cause arrhythmia-induced heart failure. Surgical treatment could be an alternative therapy because antiarrhythmic drugs and catheter ablation therapy to focal AT originating from the distal portion of the LAA is still challenging. We report a case of successful operation of minimally invasive thoracoscopic appendectomy in a patient with poor left ventricular (LV) function due to drug-resistant AT originating from the LAA for the first time. A 51-year-old female who had AT with a poor LV function suffered from congestive heart failure. We diagnosed the ongoing AT as focal AT that originated from the distal portion of LAA by electrophysiological examination. Total thoracoscopic stand-alone appendectomy was performed safely. AT was terminated and restored to sinus rhythm immediately after appendectomy.
      <Learning objective: Although catheter ablation has become a first-line treatment for almost all cardiac arrhythmias, it is difficult to achieve complete cure of atrial tachycardia (AT) originating from the distal portion of left atrial appendage (LAA) because there is AT recurrence and risk of cardiac perforation and ischemic stroke. Minimally invasive thoracoscopic appendectomy is curative and can be applied safely even in patients who have poor left ventricular function due to focal AT originating from the LAA.>

      Keywords

      Introduction

      Atrial tachycardia (AT) arises from various parts of the atrium (coronary sinus ostium, crista terminalis, atrioventricular annulus, and pulmonary veins), but focal AT from the left atrial appendage (LAA) is rare, accounting for approximately 1%–3% of all ATs [
      • Wang Y.L.
      • Li X.B.
      • Quan X.
      • Ma J.X.
      • Zhang P.
      • Xu Y.
      • et al.
      Focal atrial tachycardia originating from the left atrial appendage: electrocardiographic and electrophysiologic characterization and long-term outcomes of radiofrequency ablation.
      ]. Catheter ablation has become a first-line treatment for almost all cardiac arrhythmias because ablation systems and techniques have evolved in the past several decades. However, ablation therapy in the case of arrhythmia originating from the distal portion of the LAA is still challenging because there is the risk of cardiac perforation and AT recurrence [
      • Di Biase L.
      • Burkhardt J.D.
      • Mohanty P.
      • Sanchez J.
      • Mohanty S.
      • Horton R.
      • et al.
      Left atrial appendage: an underrecognized trigger site of atrial fibrillation.
      ]. In these cases, surgical treatment could be an alternative therapy.
      Thoracoscopic stand-alone appendectomy was established for preventing thromboembolism due to atrial fibrillation (AF) and has been applied to patients with non-valvular AF [
      • Ohtsuka T.
      • Ninomiya M.
      • Nonaka T.
      • Hisagi M.
      • Ota T.
      • Mizutani T.
      Thoracoscopic stand-alone left atrial appendectomy for thromboembolism prevention in nonvalvular atrial fibrillation.
      ]. We report a case of successful operation of total thoracoscopic stand-alone appendectomy in a patient with severe left ventricular (LV) dysfunction due to drug-resistant AT originating from the LAA for the first time. 

      Case report

      A 51-year-old female who had supraventricular tachycardia with poor LV function suffered from congestive heart failure. She had no history of pulmonary and cardiac diseases. The 12-lead electrocardiogram revealed ongoing AT with a cycle length of 437 ms. The P wave was negative in leads I and aVL and positive in leads II, III, aVF, and V1 (Fig. 1A). Echocardiography revealed a LV ejection fraction (LVEF) of 31%, LV end-diastolic diameter within the normal limit, and mild mitral valve regurgitation. There were no signs of myocyte necrosis associated with mononuclear cell infiltration, interstitial fibrosis, and edema in the histopathological findings by endomyocardial biopsy. The late gadolinium enhancement as the evidence of severe myocardial fibrotic change was not observed in the cardiac magnetic resonance imaging. She had no coronary artery disease and metabolic disorders causing heart failure. Thus, the cause of heart failure with poor LV function was thought to be persistent AT. The persistent AT did not respond to drug therapy including bisoprolol (oral, 5.0 mg daily) and verapamil (oral, 120 mg daily). The patient underwent electrophysiological examination after cessation of all antiarrhythmic drugs.
      Fig. 1
      Fig. 1The electrocardiogram (ECG) before (A) and after (B) thoracoscopic appendectomy. (A) ECG at the time of admission showed atrial tachycardia (AT) with a cycle length of 437 ms. The P wave was negative in leads I and aVL and positive in leads II, III, aVF, and V1. (B) ECG after thoracoscopic appendectomy showed normal sinus rhythm.
      The earliest activation site (EAS) of AT was observed at the distal portion of the LAA (Fig. 2B and C). Intracardiac electrogram at the EAS showed a local activation preceding body-surface electrocardiographic P onset by 59 ms (Fig. 2A). We diagnosed the ongoing AT as focal AT that originated from the distal portion of the LAA. We decided to perform atrial appendectomy using the thoracoscopic approach to avoid cardiac perforation due to catheter ablation.
      Fig. 2
      Fig. 2(A) Intracardiac electrogram at the earliest activation site (EAS) of the atrial tachycardia (AT) revealed a local activation preceding body-surface electrocardiographic P onset by 59 ms (the red line indicates the timing of the EAS). (B) A high-density activation map of the left atrium was created using a multielectrode mapping catheter (7Fr Inquiry™ AFocus II™ EB Catheter, St. Jude Medical, St. Paul, MN, USA; now Abbott, Abbott Park, IL, USA) and 3D mapping system (EnSite™ NavX™, St. Jude Medical).
      The EAS of AT was observed at the distal portion of the left atrial appendage (LAA).
      (C) The X-ray fluoroscopic image showed a multielectrode catheter was placed in the distal portion of the LAA.
      LAA, left atrial appendage; RV, right ventricle; CS, coronary sinus.
      The patient was anesthetized with a double-lumen endotracheal tube and placed in the right lateral position. After the left lung was deflated, four endoscopic ports were made in the left lateral thorax. Pericardiotomy was performed just above the LAA and posterior to the left phrenic nerve to approach the LAA. The incision on the pericardium was made at least a centimeter away from the phrenic nerve due to avoid complication of phrenic nerve injury. The endoscopic cutter (EZ45G Endoscopic Linear Cutter, Ethicon Endo-Surgery, Cincinnati, OH, USA) was used to resect the LAA across its base (Fig. 3A and B). Immediately after appendectomy, AT was terminated and restored to sinus rhythm (Figs. 1B, 3 C, and 3 D). The operative time for appendectomy was 24 min. No intraoperative complications were noted. The LVEF increased from 31% to 56% within 2 weeks. After the procedure, the patient was free from an AT episode and hospital admission due to heart failure during the 12-month follow-up period, without administration of any antiarrhythmic agents.
      Fig. 3
      Fig. 3(A) and (B) Thoracoscopic views of left atrial appendectomy. The endoscopic cutter (EZ45G Endoscopic Linear Cutter, Ethicon Endo-Surgery, Cincinnati, OH, USA) was used to resect the left atrial appendage (LAA) across its base. (C) Transesophageal echocardiography showed the LAA and left atrium (LA) before left atrial appendectomy. (D) Immediately after appendectomy, atrial tachycardia was terminated and restored to sinus rhythm.

      Discussion

      Arrhythmia-induced cardiomyopathy (AIC) is a reversible cardiomyopathy in which poor LV function is induced by atrial or ventricular arrhythmias. The greatest hallmark of AIC is that the cardiac function promptly improves by conversion to sinus rhythm. Our previous study showed that rhythm control with ablation was better at improving the cardiac function and complete cure of AIC than rate control with drugs [
      • Sairaku A.
      • Nakano Y.
      • Oda N.
      • Uchimura Y.
      • Tokuyama T.
      • Kawazoe H.
      • et al.
      Incomplete cure of tachycardia-induced cardiomyopathy secondary to rapid atrial fibrillation by heart rate control without sinus conversion.
      ].
      Focal AT originating from the LAA is one of the rare supraventricular arrhythmias, accounting for only 1–3% of all focal ATs, and is likely to become persistent [
      • Wang Y.L.
      • Li X.B.
      • Quan X.
      • Ma J.X.
      • Zhang P.
      • Xu Y.
      • et al.
      Focal atrial tachycardia originating from the left atrial appendage: electrocardiographic and electrophysiologic characterization and long-term outcomes of radiofrequency ablation.
      ]. Thus, patients with AT originating from the LAA often have an initial presentation of AIC due to persistent tachycardia. However, catheter ablation for AT originating from the LAA was still challenging because of high rates of recurrence and cardiac tamponade.
      Di Biase et al. reported that the rate of AT recurrence after the first ablation procedure was 36% and the rate of cardiac tamponade was 1.8%, which were approximately two times higher than those in the cases of AF ablation [
      • Di Biase L.
      • Burkhardt J.D.
      • Mohanty P.
      • Sanchez J.
      • Mohanty S.
      • Horton R.
      • et al.
      Left atrial appendage: an underrecognized trigger site of atrial fibrillation.
      ]. Moreover, Guo et al. demonstrated that the greatest predictor of unsuccessful ablation for AT was origin at the distal portion of the LAA [
      • Guo X.G.
      • Zhang J.L.
      • Ma J.
      • Jia Y.-H.
      • Zheng Z.
      • Wang H.-Y.
      • et al.
      Management of focal atrial tachycardias originating from the atrial appendage with the combination of radiofrequency catheter ablation and minimally invasive atrial appendectomy.
      ]. Furthermore, if cardiac perforation occurred in patients with a poor cardiac function, it has a greater negative impact for prognosis than that in patients with a normal LV function. We also considered other therapeutic options, such as LAA isolation by encircling ablation of the ostium of the LAA in this case. However, electrical isolation of the LAA increases the risk of ischemic stroke or TIA [
      • Kim Yun Gi
      • Shim Jaemin
      • Oh Suk-Kyu
      • Lee K.-N.
      • Choi J.-I.
      • Kim Y.-H.
      Electrical isolation of the left atrial appendage increases the risk of ischemic stroke and transient ischemic attack regardless of postisolation flow velocity.
      ]. Thus, we chose the surgical treatment from the beginning without trying catheter ablation.
      There are several surgical techniques used to close LAAs, and they mainly divided into two types: excising or exclusion LAAs. Excision is performed by elimination of LAAs, either by scissors or stapling devices. Exclusion is performed by suture, clipping, or stapling devices. In this case, excision of the LAA was recommended based on the following reason. Excision of the LAA, which removes the focus of the AT completely, could eliminate the AT. On the other hand, LAA exclusion by surgical suture is not enough to achieve electrical isolation. Moreover, a previous study reported that rate of residual LAA patency was higher in patients undergoing suture or staple exclusion of LAAs than LAA excisions [
      • Cullen M.W.
      • Stulak J.M.
      • Li Z.
      • Powell B.D.
      • White R.D.
      • Ammash N.M.
      • et al.
      Left atrial appendage patency at cardioversion after surgical left atrial appendage intervention.
      ]. The residual LAA patency was associated with occurrence of LAA thrombus, and these patients cannot discontinue anticoagulation after such procedures.
      Total thoracoscopic stand-alone appendectomy, a minimally invasive surgery combined with the surgical ablation of AF and resection of the LAA, has clinical advantages such as maintenance of sinus rhythm and prevention of thromboembolism even after discontinuation of anticoagulation. Ohtsuka et al. reported that their thoracoscopic LAA resection in patients with non-valvular AF could completely eliminate LAAs safely, and provide acceptable prevention of thromboembolism without anticoagulation [
      • Ohtuska T.
      • Nonaka T.
      • Hisagi M.
      • Ninomiya M.
      • Masukawa A.
      • Ota T.
      Thoracoscopic stapler-and-loop technique for left atrial appendage closure in nonvalvular atrial fibrillation: mid-term outcomes in 201 patients.
      ]. Thus, the thoracoscopic stand-alone appendectomy, has been widely used as an alternative therapy to prevent cardiogenic thromboembolism. Moreover, it has been reported that minimally invasive thoracoscopic appendectomy was performed in patients with unsuccessful catheter ablation for AT originating from the LAA [
      • Guo X.G.
      • Zhang J.L.
      • Ma J.
      • Jia Y.-H.
      • Zheng Z.
      • Wang H.-Y.
      • et al.
      Management of focal atrial tachycardias originating from the atrial appendage with the combination of radiofrequency catheter ablation and minimally invasive atrial appendectomy.
      ]. However, their detailed cardiac function was not explicitly mentioned. To our knowledge, this is the first report to describe minimally invasive thoracoscopic appendectomy performed in a patient with severe LV dysfunction due to focal AT originating from the LAA.

      Conclusion

      Minimally invasive thoracoscopic appendectomy can be applied safely even in patients who have poor LV function due to focal AT originating from the LAA. 

      Conflict of interest statement

      Authors declare no conflict of interests for this article.

      Acknowledgments

      We are grateful to Dr Toshiya Ohtsuka (Department of Cardiovascular Surgery, Tokyo Metropolitan Tama Medical Center, Tokyo, Japan) for his technical support. We thank the members of the clerical and medical staff at Hiroshima University Hospital for their assistance. We thank ENAGO Group (English editing system) for editing a draft of this manuscript.

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