Anterior pericardial access to facilitate electrophysiology study and catheter ablation of ventricular arrhythmias: A single tertiary center experience

Epicardial ventricular tachycardia ablation: safety and efficacy of access and ablation using low-iodine content

BACKGROUND

Epicardial ablation has become an integral part of the treatment of ventricular tachycardias (VT). This study reports the safety of epicardial access as well as the efficacy of epicardial ablation of structural heart disease in a tertiary single-center experience.

METHODS

Between January 2016 and February 2022, consecutive patients undergoing an epicardial access for VT ablation were included. Different puncture techniques and occurrence of epicardial access-related complications as well as the safety of ablation using non-ionic 5% dextrose in water (D5W) compared to standard 0.9% normal saline (NS) irrigation were analyzed. VT recurrence rates during a mean follow-up of 37 ± 23 months were reported.

RESULTS

In total, 197 patients undergoing a total of 239 procedures were included (59.8 ± 15.3 years, 86% males). A total of 154 patients (78%) had non-ischemic cardiomyopathies with a mean LVEF of 37 ± 14. Anterior-oriented epicardial access was aimed for in all cases and was successful in 217 (91%) of all procedures, whereas access was achieved in 19 procedures (8%) only using an inferior oriented access and in three procedures (1%) using surgical access due to severe adhesions or anatomical requirements. Overall epicardial puncture-related complications occurred in 18 (8%) of all procedures with minor pericardial bleeding in nine, pericardial tamponade in one, pneumothorax in five, pneumopericardium in one, and abdominal puncture in two cases. Presence of adhesions could be identified as the only independent predictor of epicardial access-related complications. D5W was used in 79 cases and regular 0.9% saline in 117 procedures. No differences were seen regarding acute ablation success or complications. During follow-up, 47% of all patients were free from any VTs (56% D5W vs. 40% NS; log-rank p = 0.747) and 92% of clinical VTs (98% D5W vs. 91% NS; log-rank p = 0.139).

CONCLUSIONS

In this large single-centre experience, epicardial access and ablation were safe and feasible. Although long-term clinical VT recurrence rates were low, overall VT recurrences as well as mortality were high advocating for a highly experienced, interdisciplinary approach including intense management of underlying cardiac disease/heart failure. Routine usage of D5W was safe and associated with comparable short- or long-term clinical or overall VT freedom.

Dry suction water seal system for management of pericardial fluid during epicardial ablation

INTRODUCTION

Epicardial ablation is an important approach in the management of patients with complex ventricular arrhythmias. Irrigated ablation catheters present a challenge in this potential space due to fluid accumulation that can cause hemodynamic compromise, requiring frequent manual fluid aspiration. In this series, we report our initial experience with the use of a dry suction water seal system for pericardial fluid management during epicardial ablation.

METHODS

Consecutive patients undergoing epicardial ventricular tachycardia (VT) ablation at a single center were included. All patients underwent epicardial access via a subxiphoid approach with a single operator. A deflectable sheath was advanced into the pericardial space, and the side port was attached to a dry suction water seal system attached to wall suction at -20 mmHg. Procedural information including patient characteristics, outcomes, and adverse events. After a period of initial experience, pericardial fluid infusion and aspiration volumes were recorded.

RESULTS

Eleven patients were included in this series. All patients underwent epicardial ablation with complete success achieved in 8 of the 11 patients and partial success in the remaining patients. Pericardial fluid intake ranging from 485 to 3050 mL with aspiration of 350-3050 mL using the dry suction water seal system. No adverse events occurred.

CONCLUSION

Dry suction water seal drainage systems can provide a safe strategy for efficient pericardial fluid management during epicardial VT ablation, potentially shortening procedure duration.

Sustained Apnea for Epicardial Access With Right Ventriculography: The SAFER Epicardial Approach

BACKGROUND

Epicardial access (EA) has emerged as an increasingly important approach for the treatment of ventricular arrhythmias and to perform other interventional cardiology procedures. EA is frequently underutilized because the current approach is challenging and carries a high risk of life-threatening complications.

OBJECTIVE

The purpose of this study was to determine the efficacy and safety of the SAFER (Sustained Apnea for Epicardial Access With Right Ventriculography) epicardial approach.

METHODS

Consecutive patients who underwent EA with the SAFER technique were included in this multicenter study. The primary efficacy outcome was the successful achievement of EA. The primary safety outcomes included right ventricular (RV) perforation, major hemorrhagic pericardial effusion (HPE), and bleeding requiring surgical intervention. Secondary outcomes included procedural characteristics and any complications. Our results were compared with those from previous studies describing other EA techniques to assess differences in outcomes.

RESULTS

A total of 105 patients undergoing EA with the SAFER approach from June 2021 to February 2023 were included. EA was used for ventricular tachycardia ablation in 98 patients (93.4%), left atrial appendage closure in 6 patients (5.7%), and phrenic nerve displacement in 1 patient (0.9%). EA was successful in all subjects (100%). The median time to EA was 7 minutes (IQR: 5-14 minutes). No cases of RV perforation, HPE, or need of surgical intervention were observed in this cohort. Comparing our results with previous studies about EA, the SAFER epicardial approach resulted in a significant reduction in major pericardial bleeding.

CONCLUSIONS

The SAFER epicardial approach is a simple, efficient, effective, and low-cost technique easily reproducible across multiple centers. It is associated with lower complication rates than previously reported techniques for EA.

Association of Sinus Wavefront Activation and Ventricular Extrastimuli Mapping With Ventricular Tachycardia Re-Entrant Circuits

BACKGROUND

Substrate-based ablation targets areas of delayed and fractionated electrograms during sinus rhythm, which are sensitive for identifying the ventricular tachycardia (VT) isthmus but is influenced by the activation wavefront direction and decremental pacing.

OBJECTIVES

The aim of this study was to correlate the areas of latest activation during varying wavefront activation mapping and decremental pacing mapping with sites critical to the VT isthmus.

METHODS

Three high-density electroanatomical substrate maps were created in patients presenting for ablation of monomorphic VT: 1) native sinus rhythm; 2) right ventricular (RV) apical pacing; and 3) an RV apical S2 map following the S1 drive train at 20 ms above the ventricular effective refractory period. Areas corresponding to the latest activation were compared with the VT isthmus identified by conventional mapping.

RESULTS

Twenty patients with structural heart disease with a mean age of 55.6 ± 16.9 years were included. The majority of the cohort consisted of patients with ischemic heart disease (50%) and arrhythmogenic RV cardiomyopathy (35%). Epicardial ablation was performed in 45% of patients. The concordance of the site of latest activation in sinus rhythm with the VT isthmus was 75%. The location of the latest activation during RV apical pacing corresponded with the VT isthmus in 85% of cases. However, in 95% of cases, the site of the latest activation following the S2 stimulus colocalized to the VT isthmus.

CONCLUSIONS

In a mix of underlying myocardial substrates, regions of conduction slowing during decremental pacing colocalize with the VT isthmus more frequently than sinus rhythm activation mapping and may have a role in substrate-based ablation where VT induction is undesirable.

Cardioneuroablation Using Epicardial Pulsed Field Ablation for the Treatment of Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting millions of people worldwide. The cardiac autonomic nervous system (ANS) is widely recognized as playing a key role in both the initiation and propagation of AF. This paper reviews the background and development of a unique cardioneuroablation technique for the modulation of the cardiac ANS as a potential treatment for AF. The treatment uses pulsed electric field energy to selectively electroporate ANS structures on the epicardial surface of the heart. Insights from in vitro studies and electric field models are presented as well as data from both pre-clinical and early clinical studies.

Contemporary approach to catheter ablation of ventricular tachycardia in nonischemic cardiomyopathy

Nonischemic cardiomyopathy (NICM) comprises a heterogenous group of disorders with myocardial dysfunction unrelated to significant coronary disease. As the use of implantable defibrillators has increased in this patient population, catheter ablation is being utilized more frequently to treat NICM patients with ventricular tachycardia (VT). Progress has been made in identifying multiple subtypes of NICM with variable scar patterns. The distribution of scar is often mid-myocardial and subepicardial, and identifying and ablating this substrate can be challenging. Here, we will review the current understanding of NICM subtypes and the outcomes of VT ablation in this population. We will discuss the use of cardiac imaging, electrocardiography, and electroanatomic mapping to define the VT substrate and the ablation techniques required to successfully prevent VT recurrence.

Safety and Efficacy of a Novel Blunt-Tip Concealed-Needle Epicardial Access Device: First-in-Human Feasibility Study

Epicardial access is becoming increasingly important for various cardiovascular interventions. Access to dry pericardial space can be challenging and is often associated with significant complications. A novel concealed-needle blunt-tip device is designed to capture the parietal pericardium layer and retract it into the distal end of the device, which houses a fixated concealed needle, in a bid to minimize the likelihood of lacerating the visceral layer of the pericardium. This prospective single-arm study evaluated the feasibility of use of this device in 11 human subjects with successful access attained in 91% (10 of 11) of cases without adverse events. (Pericardial Access With ViaOne Device; NCT05006157).

Assessment of an ECG-Based System for Localizing Ventricular Arrhythmias in Patients With Structural Heart Disease

Background

We have previously developed an intraprocedural automatic arrhythmia‐origin localization (AAOL) system to identify idiopathic ventricular arrhythmia origins in real time using a 3‐lead ECG. The objective was to assess the localization accuracy of ventricular tachycardia (VT) exit and premature ventricular contraction (PVC) origin sites in patients with structural heart disease using the AAOL system.

Methods and Results

In retrospective and prospective case series studies, a total of 42 patients who underwent VT/PVC ablation in the setting of structural heart disease were recruited at 2 different centers. The AAOL system combines 120‐ms QRS integrals of 3 leads (III, V2, V6) with pace mapping to predict VT exit/PVC origin site and projects that site onto the patient‐specific electroanatomic mapping surface. VT exit/PVC origin sites were clinically identified by activation mapping and/or pace mapping. The localization error of the VT exit/PVC origin site was assessed by the distance between the clinically identified site and the estimated site. In the retrospective study of 19 patients with structural heart disease, the AAOL system achieved a mean localization accuracy of 6.5±2.6 mm for 25 induced VTs. In the prospective study with 23 patients, mean localization accuracy was 5.9±2.6 mm for 26 VT exit and PVC origin sites. There was no difference in mean localization error in epicardial sites compared with endocardial sites using the AAOL system (6.0 versus 5.8 mm, P=0.895).

Conclusions

The AAOL system achieved accurate localization of VT exit/PVC origin sites in patients with structural heart disease; its performance is superior to current systems, and thus, it promises to have potential clinical utility.

CT-guided percutaneous epicardial access for ventricular tachycardia ablation: A proof-of-concept study

INTRODUCTION

The objective of this study was to evaluate the safety and efficacy of preprocedural computed tomography (CT) to guide percutaneous epicardial puncture for catheter ablation of ventricular tachycardia.

METHODS AND RESULTS

A preprocedural CT was used to plan the site, angle, and depth of needle insertion during epicardial access in 10 consecutive patients undergoing ventricular tachycardia (VT) ablation. Adjacent structures (right ventricle, diaphragm, liver, colon, internal mammary artery) were visualized and the course of the needle was planned avoiding these structures. During epicardial access, a protractor was used to guide the angle of needle entry into the subxiphoid space. Postprocedural CT was performed to calculate the deviation between the planned and executed access and to assess for any collateral damage. Percutaneous epicardial access was obtained successfully in all the patients using anterior (n = 4) and inferior (n = 6) approaches. The planned site and angle of puncture was more caudal (2.9 ± 0.9 vs. 3.7 ± 0.7 cm, p = .021) and acute (61.7 ± 5.8 vs. 49.0 ± 5.4°, p = .011) for an anterior approach compared to an inferior approach, respectively. Postprocedure CT revealed minimal deviation of the puncture site (5.4 ± 1.0 mm), angle (5.4 ± 1.2°), and length of needle insertion (0.5 ± 0.2 cm). With regard to the site of entry in the pericardial space, there was a deviation of 5.9 ± 1.1, 6.1 ± 1.1, and 5.8 ± 1.4 mm in the x, y, and z dimensions, respectively. In eight patients with minimal deviation between planned and executed access, there was no collateral injury to adjacent viscera or vessels. In two patients with increased deviation of angle and length of needle insertion, there was entry through the diaphragm during inferior access.

CONCLUSIONS

Utilizing pre-procedural CT planning may aid in the success and safety of percutaneous epicardial access during VT ablation.

Impaired Right Ventricular Calcium Cycling Is an Early Risk Factor in R14del-Phospholamban Arrhythmias

The inherited mutation (R14del) in the calcium regulatory protein phospholamban (PLN) is linked to malignant ventricular arrhythmia with poor prognosis starting at adolescence. However, the underlying early mechanisms that may serve as prognostic factors remain elusive. This study generated humanized mice in which the endogenous gene was replaced with either human wild type or R14del-PLN and addressed the early molecular and cellular pathogenic mechanisms. R14del-PLN mice exhibited stress-induced impairment of atrioventricular conduction, and prolongation of both ventricular activation and repolarization times in association with ventricular tachyarrhythmia, originating from the right ventricle (RV). Most of these distinct electrocardiographic features were remarkably similar to those in R14del-PLN patients. Studies in isolated cardiomyocytes revealed RV-specific calcium defects, including prolonged action potential duration, depressed calcium kinetics and contractile parameters, and elevated diastolic Ca-levels. Ca-sparks were also higher although SR Ca-load was reduced. Accordingly, stress conditions induced after contractions, and inclusion of the CaMKII inhibitor KN93 reversed this proarrhythmic parameter. Compensatory responses included altered expression of key genes associated with Ca-cycling. These data suggest that R14del-PLN cardiomyopathy originates with RV-specific impairment of Ca-cycling and point to the urgent need to improve risk stratification in asymptomatic carriers to prevent fatal arrhythmias and delay cardiomyopathy onset.

Epicardial access complications during electrophysiology procedures

INTRODUCTION

Percutaneous epicardial access (EA) was first described more than two decades ago. Since its initial introduction, indications for its utilization in the field of electrophysiology have expanded dramatically.

DISCUSSION

Epicardial mapping and ablation in patients with ventricular tachycardia is routinely performed in tertiary electrophysiology centers around the world. Although limited by lack of randomized controlled trials, epicardial ablation for atrial fibrillation has been suggested as a conjunctive strategy in patients who have failed an initial endocardial catheter ablation attempt, and it is necessary for placement of some left atrial appendage occlusion devices as well. An accurate understanding of the cardiac anatomy is crucial to avoid complications such as inadvertent right ventricular puncture, injury to the coronary arteries, abdominal viscera, phrenic nerves, and esophagus during both EA and catheter ablation.

CONCLUSION

The aim of this review is to provide a comprehensive overview of the cardiac anatomy, technical aspects to optimize the safety of epicardial puncture, recognize and avoid potential complications.

Efficacy of catheter ablation for premature ventricular contractions in arrhythmogenic right ventricular cardiomyopathy

BACKGROUND

Premature ventricular contractions (PVCs) may be found in any stage of arrhythmogenic right ventricular cardiomyopathy (ARVC) and have been associated with the risk of sustained ventricular tachycardia (VT).

OBJECTIVE

To investigate the role of PVC ablation in ARVC patients.

METHODS

We studied consecutive ARVC patients who underwent PVC ablation due to symptomatic high PVC burden. Mean daily PVC burden and antiarrhythmic drug (AAD) use were assessed before and after the procedure. Complete long-term success was defined as more than 80% reduction in PVC burden off of membrane-active AADs.

RESULTS

Eight patients (37 ± 15 years; 4 males) underwent PVC ablation. The mean daily PVC burden before ablation ranged from 5.4% to 24.8%. A total of 7 (87.5%) patients underwent epicardial ablation. Complete acute elimination of PVCs was achieved in 4 (50%) patients (no complications). The mean daily PVC burden variation ranged from an 87% reduction to a 26% increase after the procedure. Over a median follow-up of 345 days (range: 182-3004 days), only one (12.5%) patient presented complete long-term success, and 6 (75%) patients either maintained or increased the need for Class I or Class III AADs. A total of 2 (25%) patients experienced sustained VT for the first time following the ablation procedure, requiring repeat ablation. No death or heart transplantation occurred.

CONCLUSION

PVC ablation was not associated with a consistent reduction of the PVC burden in ARVC patients with symptomatic, frequent PVCs. PVC ablation may be reserved for highly symptomatic patients who failed AADs. Additional investigation is required to improve the efficacy of PVC ablation in ARVC patients.

Epicardial Ablation Complications

The percutaneous epicardial approach has become an adjunctive tool for electrophysiologists to treat disparate cardiac arrhythmias, including accessory pathways, atrial tachycardia, and particularly ventricular tachycardia. This novel technique prompted a strong impulse to perform epicardial access as an alternative strategy for pacing and defibrillation, left atrial appendage exclusion, heart failure with preserved ejection fraction, and genetically engineered tissue delivery. However, because of the incremental risk of major complications compared with stand-alone endocardial ablation, it is still practiced in a limited number of highly experienced centers across the world.

Epicardial Ablation of Ventricular Tachycardia in Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart muscle disease characterized by progressive fibrofatty replacement of the myocardium, right ventricular enlargement, and malignant ventricular arrhythmias. Ventricular tachycardia (VT) may be seen in all stages of the disease and is associated with sudden cardiac death. In patients who failed anti-arrhythmic medical therapy, catheter ablation has become an attractive therapeutic option to reduce VT burden and implantable cardioverter-defibrillator interventions. In this article, the authors aim to address the overall concepts of epicardial catheter ablation in ARVC, focusing on substrate characterization and ablation strategies.

Techniques for Percutaneous Access

Percutaneous epicardial access continues to have a growing role within cardiac electrophysiology. The classic approach has typically been with a Tuohy needle via a subxiphoid approach guided by fluoroscopic landmarks and tactile feedback. Recent developments have highlighted the role of the micropuncture needle, electroanatomic mapping, and real-time pressure sensors to reduce complications. Further, different access sites, such as the right atrial appendage, have been described and may offer a novel approach to percutaneous epicardial access. In addition, future directions of percutaneous access may involve direct visualization, near-field impedance monitoring, and real-time virtual imaging.

Epicardial access for VT ablation: analysis of two different puncture techniques, incidence of adhesions and complication management

Introduction

Pericardial access for ablation of ventricular arrhythmias (VA) can be gained either by an anterior-oriented or inferior-oriented epicardial puncture under fluoroscopical guidance. We retrospectively sought to assess the safety of these two puncture techniques and the incidence of epicardial adhesions and introduce our algorithm for management of pericardial tamponade.

Methods and results

In 211 patients (61.4 ± 15.6 years, 179 males; 84.8%) 271 epicardial ablation procedures of VA were performed using either an anterior- or inferior-oriented approach for epicardial access. Puncture-related complications were systematically analyzed. Furthermore, the incidence of adhesions was evaluated during first and repeated procedures.

A total of 34/271 (12.5%) major complications occurred and 23/271 (8.5%) were directly related to epicardial puncture. The incidence of puncture-related major complications in the anterior and inferior group was 4/82 (4.9%) and 19/189 (10.1%), respectively. Pericardial tamponade was the most common major complication (15/271; 5.5%). Collateral damages of adjacent structures such as liver, colon, gastric vessels and coronary arteries occurred in 6/189 (3.2%) patients and only within the inferior epicardial access group. Adhesions were documented in 19/211 (9%) patients during the first procedure and in 47.1% if patients had 2 or more procedures involving epicardial access.

Conclusion

Anterior-oriented epicardial puncture shows an observed association to a reduced incidence of pericardial tamponades and overall puncture-related complications in epicardial ablation of VA. In cases of repeated epicardial access adhesions increase significantly and may lead to ablation failure.

Percutaneous Pericardiocentesis With the Anterior Approach: Demonstration of the Precise Course With Computed Tomography

OBJECTIVES

This study aimed to confirm the precise course of a pericardiocentesis with the anterior approach using post-procedural computed tomography (CT).

BACKGROUND

Percutaneous epicardial ventricular tachycardia (VT) ablation has been increasingly performed. Although the inferior approach has been the common method, the feasibility of the anterior approach has subsequently been reported. However, the precise course of the anterior approach has not been presented.

METHODS

An epicardial ablation with the anterior approach was performed in 15 patients. At the end of the procedure, the epicardial sheath was exchanged for a drainage tube to monitor bleeding. Of those patients, in 9 procedures in 8 patients a CT scan was performed just after the procedure to confirm the course of the drainage tube and to rule out any complications. Epicardial ablation was indicated for a failed endocardial VT ablation in 7 patients and epicardial substrate modification in 1 patient with Brugada syndrome.

RESULTS

Volume-rendered images reconstructed from CT demonstrated each course of the drainage tubes and their relation to the surrounding organs. These images revealed that the tube had a curved trace, and did not penetrate the diaphragm or pass through the abdominal cavity. No injury to the surrounding organs was detected in any of the cases.

CONCLUSIONS

The precise course of the drainage tube placed along the trajectory of the anterior approach was able to be confirmed using post-procedural CT images. These images support the safety and feasibility of the anterior approach from the anatomic standpoint with a low incidence of abdominal viscera injury.

Initial validation of a novel ECGI system for localization of premature ventricular contractions and ventricular tachycardia in structurally normal and abnormal hearts

BACKGROUND

View into Ventricular Onset (VIVO) is a novel ECGI system that uses 3D body surface imaging, myocardial CT/MRI, and 12‑lead ECG to localize earliest ventricular activation through analysis of simulated and clinical vector cardiograms.

OBJECTIVE

To evaluate the accuracy of VIVO for the localization of ventricular arrhythmias (VA).

METHODS

In twenty patients presenting for catheter ablation of VT [8] or PVC [12], VIVO was used to predict the site earliest activation using 12‑lead ECG of the VA. Results were compared to invasive electroanatomic mapping (EAM).

RESULTS

A total of 22 PVC/VT morphologies were analyzed using VIVO. VIVO accurately predicted the location of the VA in 11/13 PVC cases and 8/9 VT cases. VIVO correctly predicted right vs left ventricular foci in 20/22 cases.

CONCLUSION

View into Ventricular Onset (VIVO) can accurately predict earliest activation of VA, which could aid in catheter ablation, and should be studied further.