Double Puncture of an Atrial Septal Patch to Perform Catheter Ablation of Atrial Tachyarrhythmia

ABSTRACT: Objective. Atrial tachyarrhythmias are often located in the pulmonary veins or antrum of the left atrium, and successful catheter ablation of this arrhythmia often necessitates needle puncture of the fossa ovalis. Occasionally, in order to access the left atrium, the cardiologist is confronted with the need to puncture artificial barriers such as patches or baffles. Knowledge of the natural history of the defects created in these barriers after transseptal puncture is limited. It is unclear whether spontaneous closure occurs, especially in the setting of chronic anticoagulation. We report a case demonstrating the feasibility of transseptal puncture of a pericardial patch in order to perform catheter ablation. Methods and Results. In a patient with a prior patch closure of an ostium secundum atrial septal defect, two transseptal punctures of a pericardial patch were performed successfully in order to perform catheter ablation of a left atrial arrhythmia. No immediate or delayed complications were seen and repeat echocardiography four months after the procedure showed no evidence of a septal defect or shunt. Conclusion. Transseptal puncture of a pericardial patch can be performed safely without creating an iatrogenic persistent atrial septal defect despite chronic anticoagulation.

Introduction

Catheter ablation of atrial fibrillation (AF) that includes electrical isolation of the pulmonary veins has been demonstrated to be feasible and effective in treating symptomatic AF when compared to antiarrhythmic drug therapy.¹ Most often the arrhythmogenic sites are thought to be located in the pulmonary veins or antrum of the left atrium (LA), necessitating needle puncture of the interatrial septum and specifically, the valve of the fossa ovalis (septum primum), in order to perform catheter ablation of AF. On occasion, the electrophysiologist or interventional cardiologist is confronted with artificial barriers such as baffles or patches. There are few data on whether transseptal puncture (TSP) can be performed safely and whether spontaneous closure of the subsequent defect occurs. Experience performing TSP across artificial barriers is lacking, and so is our understanding of the natural history of what happens after puncture (i.e., whether spontaneous closure of the defect occurs, especially in the setting of chronic anticoagulation). Thus, there is considerable trepidation regarding puncturing these structures and possibly creating persistent iatrogenic defects. A literature review evaluating multiple studies shows mixed results.^2-7 This case presentation reports the feasibility of TSP across a pericardial patch to perform catheter ablation of symptomatic atrial tachyarrhythmia and the subsequent spontaneous closure of the patch with no residual defect.

Case Presentation

A 59-year-old male with a history of hypertension and depression initially presented with symptoms that were attributed to a large ostium secundum atrial septal defect (ASD) and AF. The ASD was treated surgically with an autologous pericardial patch closure. His AF was treated with microwave ablation. Of note, the secundum ASD measured 25 x 35 mm intraoperatively and was comparable in size to the tricuspid annulus. Microwave catheter ablation (FLEXView catheter, Boston Scientific, Natick, MA) was performed with lesion applications for a “Modified Maze” procedure. The patient tolerated the procedure well and subsequent imaging studies, including transesophageal echocardiography and multislice CT scan shown in Figure 1, show no evidence of a residual ASD. A few months after surgery, he presented to the arrhythmia service with progressively worsening symptomatic palpitations, lethargy, fatigue, dyspnea, and a chronically rapid heart rate. A diagnosis of atrial flutter was made and medical therapy in the form of beta-blockers was initiated (Figure 2). Additional agents which were started and had to be stopped due to side effects, include diltiazem and amiodarone. He continued to have persistent symptomatic atrial arrhythmia with multiple recurrent hospitalizations. After considerable thought, and due to the absence of other options, a decision was made to offer the patient percutaneous catheter ablation.

Methods

The electrophysiology study and ablation procedure was performed in the electrophysiology laboratory under general anesthesia. The intravascular sheaths inserted include a 5 French (Fr) sheath in the right internal jugular vein, an 11, 6 and 5 Fr sheath in the left femoral vein, and two 8 Fr sheaths in the right femoral vein. A 5 Fr decapolar catheter (Supreme 5 Fr Decapolar CSL curve, St. Jude Medical, Minneapolis, MN) was advanced into the coronary sinus, a 5 Fr quadripolar catheter (Supreme 5 Fr Quadripolar CRD-2 curve, St. Jude Medical) was advanced across the anteroseptal tricuspid annulus to record a His-bundle electrogram. Using the 11 Fr sheath in the left femoral vein, a 10 Fr intracardiac echocardiography catheter (ACUSON AcuNav 10 Fr ultrasound catheter, Siemens Medical Solutions, Mountain View, CA) was advanced to the right atrium. Using the 8 Fr sheath in the right femoral vein, a 7 Fr ablation catheter (ThermoCool F curve, Biosense Webster, Inc., a Johnson & Johnson company, Diamond Bar, CA) was advanced to the right atrium for mapping and an electroanatomical map of this chamber was created. The initial rhythm in the laboratory was atrial tachycardia [cycle length (CL) 430 msec] with 2:1 AV conduction, and was similar to ECGs obtained during his recurrent hospitalizations (Figure 2). An activation sequence map performed in the right atrium using the Carto system (Biosense Webster, Inc.) showed data consistent with an LA arrhythmogenic focus, and a decision was made to proceed with TSP. The two, short 8 Fr sheaths in the right femoral vein were exchanged for two, SL1 long sheaths (8.5 Fr SL1 Fast-Cath Guiding Introducer, St. Jude Medical). Initially, a BRK needle was used unsuccessfully. This was then exchanged for a BRK-1 needle with subsequent successful TSP of the pericardial patch. This process was repeated using the same needle and the second SL-1 long sheath, and the two sheaths were advanced into the LA under fluoroscopic guidance. In addition to intracardiac echocardiography, the procedure was also guided by biplane fluoroscopy, pressure manometry and contrast infusion. One of the SL1 sheaths was then exchanged for an Agilis sheath with an 8.5 Fr inner diameter and 11.5 Fr outer diameter (Agilis NxT Steerable Introducer Small Curl, St. Jude Medical). Figure 3 demonstrates still radiographic images of the sheaths in the right and left anterior oblique views in the LA. Heparin was infused to maintain an ACT of greater then 350s. A 20-electrode multipolar catheter (Lasso, Biosense Webster, Inc.) was then advanced through the remaining SL1 sheath and placed in the LA and the pulmonary veins. The 7 Fr Biosense Webster ThermoCool F curve catheter was then advanced through the Agilis sheath into the LA. Electroanatomical mapping of the atrial tachycardia revealed earliest activation to be in the region of the antrum of the right pulmonary veins. Catheter ablation then proceeded in the region of the pulmonary vein ostia with subsequent termination of the arrhythmia. Catheter ablation was continued and lesions were delivered in a circumferential manner around each ostia of the pulmonary veins until complete electrical isolation was achieved. Post-ablation, electrophysiology testing was performed; including both aggressive programmed electrical and pharmacologic stimulation with no evidence of induced atrial tachyarrhythmia.

Results

The patient tolerated the procedure well and there were no complications. After normalization in the ACT below 150, the venous sheaths were removed safely with no significant bleeding or hematoma noted. After discharge, the patient had routine follow-up. He was maintained on coumadin anticoagulation. The patient had no recurrence of his prior symptoms, including no dyspnea with exertion or palpitations. He also did not have any repeat hospitalizations. A repeat transthoracic echocardiogram, performed four months after the procedure, showed no evidence of a septal defect or intracardiac shunt. Infusion of agitated saline and concomitant Valsalva showed no evidence of septal defect or shunt indicating that spontaneous closure of the TSP of the pericardial patch had occurred.

Discussion

We demonstrate that TSP through a pericardial patch in order to perform radiofrequency catheter ablation and pulmonary vein isolation of an arrhythmogenic focus located in the pulmonary veins can be done safely without complication. Our report also shows that despite creating two separate defects using catheters with 8.5 Fr and 11.5 Fr outer diameters across a pericardial patch and maintaining coumadin anticoagulation, there was no subsequent evidence of an interatrial septal defect or shunt on transthoracic echocardiography four months after the procedure. Spontaneous closure after multiple large sheaths across a native interatrial septum has been reported; however, there is minimal literature regarding transseptal puncture through pericardial patches. Experience has been limited and there has been mixed results after transseptal puncture through artificial interatrial barriers. Cardiologists may often experience difficulties with TSP of the interatrial septum, especially in the setting of altered anatomy. For example, fibrosis of the interatrial septum after prior transseptal puncture; a thickened lipomatous or aneurysmal interatrial septum; or, as described in our case, an artificial barrier in the form of a patch or baffle can complicate the puncture procedure. In fact, in situations such as an aneurysmal atrial septum, transseptal catheterization of the interatrial septum may be difficult and sometimes impossible with needle puncture alone. In an elegant use of available technology, the use of radiofrequency current delivery (using a standard electrocautery device) applied to the shaft of a transseptal needle to cross the interatrial septum has been described in a patient with interatrial septal fibrosis and inability to perform LA catheterization with traditional needle puncture.⁸ A TSP apparatus that incorporates radiofrequency energy has been developed to obtain percutaneous transseptal left heart access.^9-11 The acute radiofrequency injury is similar to that seen in conventional needle puncture; however, the characteristics of tissue insult are different.¹¹ Both needle puncture and radiofrequency energy techniques show well-developed healing after a short duration. In retrospect, this technology could possibly have proven useful in our patient (i.e., puncturing an artificial barrier). Conflict of interest: Subramaniam Krishnan, MD has commercialized intellectual property relating to transseptal puncture technology to St. Jude Medical. Ahmad Edris, MD has no disclosures to report.

References

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———————————————————— Editor’s Note: This article underwent peer review by one or more members of EP Lab Digest’s editorial board.