Epicardial catheter ablation of idiopathic ventricular arrhythmias originating from uncommon epicardial sites.

PURPOSE: Idiopathic epicardial ventricular arrhythmias (VAs) are clustered in the areas of the summit and crux. This study was to report a group of idiopathic epicardial VAs remote from the summit and crux areas. METHODS: In total, 9 patients (6 males, mean age 32 ± 13 years) were enrolled. The locations were identified by epicardial mapping and ablation. The electrocardiographic and electrophysiological characteristics were compared to those of 9 patients who had VAs ablated at the opposite endocardial site. RESULTS: VAs were identified at the epicardium, with 4 patients had VAs located at the inferior wall, one at the anterior wall, one at the apex and 3 patients had VAs at the lateral wall. A "QS" type at the location-related leads was the only identified surface electrocardiogram indication suggesting epicardial origin (compared to that of the controls, 100% vs 0%, p<0.001). Endocardial and epicardial mapping revealed pre-maturities of -11 ± 4 ms and -25 ± 8 ms, respectively (VS. -28 ± 8 ms revealed by endocardial mapping in control patients, p<0.001 and p=0.389, respectively). All of the study cases demonstrated an "rS" pattern in the endocardial unipolar electrogram. Acute and long-term successful ablation (a median of 11 months of follow-up) was achieved in all patients without complications. CONCLUSIONS: A distinct group of idiopathic VAs remote from the summit and crux areas warranting ablation by a subxiphoid approach were identified. Morphological ECG features of a "QS" type among the location-related grouped leads combined with the mapping findings helped in the identification of the epicardial site of origin.

Patient Selection, Techniques, and Complication Mitigation for Epicardial Ventricular Tachycardia Ablation.

Percutaneous epicardial ventricular tachycardia ablation can decrease implanted cardioverter defibrillator shocks and hospitalizations; proper patient selection and procedural technique are imperative to maximize the benefit-risk ratio. The best candidates for epicardial ventricular tachycardia will depend on history of prior ablation, type of cardiomyopathy, and specific electrocardiogram and cardiac imaging findings. Complications include hemopericardium, hemoperitoneum, coronary vessel injury, and phrenic nerve injury. Modern epicardial mapping techniques provide new understandings of the 3-dimensional nature of reentrant ventricular tachycardia circuits across cardiomyopathy etiologies. Where epicardial access is not feasible, alternative techniques to reach epicardial ventricular tachycardia sources may be necessary.

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.

Percutaneous Epicardial Approach to Catheter Ablation of Cardiac Arrhythmias.

Since their introduction >2 decades ago, percutaneous catheter-based epicardial mapping and ablation have become widely adopted by cardiac electrophysiologists around the world. Although epicardial mapping has been used for catheter ablation of a wide variety of cardiac arrhythmias, its most common use is for ablation of intramural and subepicardial substrates that give rise to ventricular tachycardia, particularly in patients with nonischemic cardiomyopathy. As such, the subxiphoid percutaneous epicardial approach has emerged as an important adjunct, and, in some cases, is the preferred strategy in this regard. This review discusses the rationale and indications for epicardial catheter mapping and/or ablation. This paper also reviews the prevalence of epicardial arrhythmias and their electrocardiographic criteria. In addition, it examines the anatomy of the pericardium and commonly used epicardial access techniques, as well as the optimal methodologies for epicardial mapping and ablation and the impact of epicardial fat. Finally, this review discusses the potential of the various complications associated with the percutaneous epicardial approach, in addition to patient-specific risk factors, and potential strategies to mitigate the risk of complications.

Pericardial access via wire-guided puncture without contrast: The feasibility and safety of a modified approach.

OBJECTIVE: To investigate the feasibility and safety of wire-guided pericardial access without contrast. METHODS: From January 2014 to February 2019, patients who received epicardial mapping and ablation of ventricular tachycardia in the Beijing Anzhen Hospital were entered into the current study. They were divided into contrast-guided access group or wire-guided access group according to the pericardial puncture technique used. The baseline variables, procedure parameters, complications were collected and compared. RESULTS: During the study period, a consecutive of 73 patients received epicardial access. The initial 32 patients received contrast-guided puncture with success achieved in 30 patients, the remaining 41 patients underwent wire-guided puncture with success achieved in 40 patients (30/32 and 40/41, P = .581). Fluoroscopy time (4.45 ± 0.52 and 4.38 ± 0.46 minutes, P = .891) and access time (5.14 ± 0.58 and 5.34 ± 0.50 minutes, P = .657) were comparable between the two groups. Inadvertent right ventricular puncture occurred more commonly in the contrast-guided group (5/32 and 1/41, P = .038). Though more pericardial effusions (2/32 and 1/41, P = .575), tamponade (2/32 and 1/41, P = .575), and surgical repair (1/32 and 0/41, P = .432) occurred in the contrast-guided group, they reached no statistical difference. CONCLUSION: Wire-guided pericardial puncture exhibits better safety and similar success rates to contrast-guided technique with a trend towards less complications.

Feasibility and safety of percutaneous epicardial access for mapping and ablation for ventricular arrhythmias in patients on oral anticoagulants.

PURPOSE: This study aimed to assess the risk of procedure-related complications of percutaneous epicardial access (EpiAcc) for radiofrequency catheter ablation (RFA) of ventricular arrhythmias (VAs) in patients chronically treated oral anticoagulants (OACs) with warfarin compared to those not on OACs. METHODS: We analyzed 205 patients (53 ± 16 years, 155 males) undergoing percutaneous EpiAcc as part of an RFA for VAs, and compared the outcome between patients chronically on OACs with warfarin (OAC group) and those without (non-OAC group). RESULTS: Forty-seven patients (23%) were chronically treated on OACs before their procedure. EpiAcc in patients on OAC (OAC group) was not associated with an increased risk of cardiac tamponade (11% vs. 6%, p = 0.238) compared to non-OAC group, but a higher risk of need for blood transfusion (17% vs. 6%; p = 0.013). With respect to the OAC group, the international normalized ratio (INR) on the day of the RFA was ≥ 2.0 in 9 patients (19%) and < 2.0 in the remaining 38 patients (81%). The rate of all complication and blood transfusion were similar between them (11% vs. 21%; p = 0.496, 11% vs. 18%; p = 0.600). CONCLUSION: Percutaneous EpiAcc in patients on chronic OAC with warfarin did not significantly increase the risk of cardiac tamponade, but was associated with a higher risk of need for blood transfusion. EpiACC in patients with an INR > 2.0 is reasonable in experienced hands when clinical indications are strong.

Calm Before the Storm: An Uncomplicated Epicardial Lead Extraction Resulting in DIC and Patient Demise.

A previously stable 77-year-old man with significant cardiac history underwent an uneventful extraction of a Citrobacter-infected and eroded pacemaker lead. His postoperative course was acutely complicated by respiratory failure and quickly progressed into disseminated intravascular coagulation, acute renal failure, shock liver, and ventricular tachycardic arrest. I believe that this is the first case report of such a drastic turn of events after a routine pacemaker lead extraction.

Safety and Feasibility of Open Chest Epicardial Mapping and Ablation of Ventricular Tachycardia During the Period of Left Ventricular Assist Device Implantation.

INTRODUCTION: Patients undergoing catheter ablation for ventricular tachycardia (VT) may require epicardial mapping. In patients with end-stage heart failure, hybrid surgical epicardial mapping and ablation during the period of left ventricular assist device (LVAD) implantation may be considered in select patients to reduce post-LVAD ventricular tachycardia. METHODS AND RESULTS: From March 2009 to October 2012, 5 patients (4 men and 1 woman, age range 52-73 years) underwent open chest electrophysiology study and epicardial mapping for recurrent ventricular tachycardia while the heart was exposed during the period of LVAD implantation. Epicardial mapping was considered if patients had recurrent VT despite failed prior endocardial ablation and/or electrocardiogram (EKG) features of an epicardial exit. Activation and/or a substrate mapping approach were employed during all procedures. Three of 5 patients (60%) had acute procedural success. In all patients, VT was either eliminated or significantly reduced with epicardial ablation. One patient had mediastinal bleeding delaying sternal closure. During a follow-up period of 363 ± 368 days, 4 patients died due to nonarrhythmic causes. CONCLUSIONS: Open-chest hybrid epicardial mapping and ablation for recurrent VT is feasible and can be considered in select patients during the period of LVAD implantation.

Percutaneous epicardial access for mapping and ablation is feasible in patients with prior cardiac surgery, including coronary bypass surgery.

BACKGROUND: Prior cardiac surgery, especially the presence of coronary artery bypass grafts, is thought to preclude percutaneous epicardial access (EpiAcc) and, therefore, mapping and ablation. We evaluated the feasibility and safety of EpiAcc in patients with a prior cardiac operation. METHODS AND RESULTS: We retrospectively analyzed all patients who underwent EpiAcc for ablation for ventricular tachycardia or symptomatic premature ventricular complexes between 2004 and 2013 at Mayo Clinic, Rochester, MN. Of 162 patients who underwent EpiAcc, 18 had prior cardiac surgery (median age, 64 years, all men). This included 10 coronary artery bypass grafts, 2 epicardial implantable cardioverter defibrillator placement, 5 valve surgery, 2 septal myectomy, 1 aortic arch replacement, 1 myocardial bridge unroofing, and 1 myocardial perforation repair (3 patients had multiple procedures). Access was successful in 12 of 18; the inferior approach was used in 78%. Successful access was achieved in 6 of 10 patients with prior coronary artery bypass grafts. Adhesiolysis was required in 10 patients with the sheath, access wire, and pigtail or ablation catheter. Intraprocedural coronary angiography was performed in 8 patients. A total of 45 ventricular tachycardias/premature ventricular complexes were ablated. Thirteen patients underwent endocardial-only ablation, 2 had epicardial-only ablation, whereas 3 had endocardial-epicardial ablation. Ablation was deemed successful in 13 of 18 patients. Four patients had bleeding complications (pericardial effusion, pericardial hematoma, hemoperitoneum, and pericardial tamponade). In patients with coronary grafts, there was no evidence of acute graft disruption. CONCLUSIONS: Percutaneous EpiAcc is feasible in patients with previous cardiac surgery, including coronary artery bypass grafts. However, adhesiolysis is frequently required. Although the risk of coronary graft injury is low, life-threatening complications may occur.

Influence of steroid therapy on the incidence of pericarditis and atrial fibrillation after percutaneous epicardial mapping and ablation for ventricular tachycardia.

BACKGROUND: This study evaluates the influence of 3 therapeutic approaches on the incidence of pericarditis and atrial fibrillation (AF) after percutaneous epicardial mapping and ablation for ventricular tachycardia. METHODS AND RESULTS: Eighty-five consecutive procedures (2006-2011) were retrospectively reviewed. After the first 17 procedures (20.0%), no steroids were administered. For the subsequent 30 procedures (35.3%), systemic steroids were administered intravenously or orally, whereas the last 38 procedures (44.7%) were followed by intrapericardial steroid injection. Compared with no steroids, the incidence of pericarditic chest pain was significantly reduced by intrapericardial steroids (58.8% versus 21.1%; P=0.006) but not by intravenous or oral steroids (58.8% versus 43.4%; P=0.31). There was no significant difference in the incidence of pericarditic ECG with steroids (36.8%, 30.0%, and 41.2% for intrapericardial, intravenous or oral, and none, respectively). There was a nonsignificant reduced incidence of chest pain with ECG changes with steroids (13.2%, 10.0%, and 29.4% for intrapericardial, intravenous or oral, and none, respectively). Radiofrequency applications (65.9% of procedures) did not affect the incidence of pericarditic ECG changes, pericarditic chest pain, or pericarditis (all P>0.05). In 7 (8.3%) patients with no prior history of AF, AF was documented a median 36 hours after procedure. Patients with pericarditic ECG tended to be at greater risk of AF (16.7 versus 3.6%; P=0.091). CONCLUSIONS: There is a high incidence of pericarditic chest pain and ECG changes after epicardial ventricular tachycardia mapping and ablation. Pericarditic chest pain is significantly decreased by intrapericardial steroids. Procedure-related AF is relatively frequent and tends to occur more commonly with pericarditic ECG changes.