Mulpuru, Siva K.

AbstractBackgroundWhile ventricular tachycardia (VT) in the setting of postmyocardial infarction left ventricular aneurysms (LVA) is not uncommonly encountered, there is a scarcity of data regarding the safety, efficacy, and outcomes of ablation of VT in this subset of patients.MethodsOur study included consecutive patients aged 18 years or older with postmyocardial infarction LVA who presented to Mayo Clinic for catheter ablation of VT between 2002 and 2018.ResultsOf 34 patients, the mean age was 70.4 ± 9.1 years; 91% were male. Mean LVEF was 29 ± 9.7% and left ventricular end‐diastolic dimension was 64.9 ± 6.6 mm. The site of the LVA was apical in 21 patients (62%). Fifteen patients (44%) presented with electrical storm or incessant VT. Nine patients (26%) had a history of intracardiac thrombus. All except for one patient had at least one VT originating from the aneurysm. The mean number of VTs was 2.9 ± 1.7. All patients underwent ablation at the site of the aneurysm. Ablation outside the aneurysm was performed in 13 patients (38%). Low‐voltage fractionated potentials and/or late potentials at the aneurysmal site were present in all cases. Complete elimination of all VTs was achieved in 18 (53%), while the elimination of the clinical VT with continued inducibility of nonclinical VTs was achieved in a further 11 patients (32%). Two patients developed cardiac tamponade requiring pericardiocentesis. During a mean follow‐up period of 2.3 ± 2.4 years, 11 patients (32%) experienced VT recurrence. Freedom from all‐cause mortality at 1‐year follow‐up was 94%.ConclusionRadiofrequency catheter ablation targeting the aneurysmal site is a feasible and reasonably effective management strategy for clinical VTs in patients with postinfarction LVA.

Abstract Background The aim of the Subcutaneous ICD Combined with Ventricular Tachycardia Ablation (SICD-VTAbl) Study is to provide preliminary data on the safety and efficacy of a management strategy that incorporates S-ICD implantation and VT ablation among patients with a secondary prevention indication for an ICD. We hypothesize that VT ablation for the prevention of monomorphic VT recurrence combined with S-ICD implantation for termination of life-threatening VT/VF is safe, while reducing the need for device interventions and systemic complications associated with conventional transvenous ICD implantation for secondary prevention. Methods SICD-VTAbl is an uncontrolled, prospective, multinational observational study, conducted in France, Germany, US (Rochester NY, and Rochester MN) and coordinated in Israel. We aim to prospectively enroll 30 patients presenting with scar-related VT/VF who will undergo VT ablation/substrate modification followed by S-ICD implantation. The primary endpoint is the first occurrence of S-ICD therapy (appropriate and inappropriate). Secondary endpoints include separate occurrence of appropriate and inappropriate ICD therapies, peri-procedural complications, and adverse clinical outcomes. Results We provide clinical, arrhythmia, and outcome data on the first 15 patients enrolled in the SICD-VTAbl Study through February 2021. Mean age was 59±12 years, 78% were males, 60% had New York Heart Association (NYHA) Class ≥II symptoms, 20% had renal insufficiency, and 33% were treated with an antiarrhythmic medication (all amiodarone). Periprocedural, arrhythmia, and long-term outcome data are provided in Table 1. There were no major complications associated with the VT ablation and the S-ICD implantation procedures. During a median follow-up of 6 months (interquartile range: 2–12 months), 2 patients (13%) received S-ICD therapy: one patient (7%) experienced VF terminated by the S-ICD and one patient experienced a single episode of inappropriate S-ICD therapy. Adverse events during follow-up, unrelated to study procedures, occurred in 3 patients (20%): hospitalization for heart failure exacerbation (N=1) and non-cardiovascular hospitalizations (N=2). None of the patients died during follow-up (Table 1). Conclusions Our preliminary data from the SICD-VTAbl Study suggest that a management approach that incorporates VT ablation followed by S-ICD implantation is safe and may lead to improved arrhythmia and clinical outcomes in patients presenting with a secondary prevention indication for an ICD. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): Research grant to Sheba Medical Center from Boston Scientific

Introduction: Although the vast majority of mitral valve prolapse (MVP) is benign, women with bileaflet MVP (biMVP), complex ventricular ectopy (VE), and abnormal T waves may comprise the recently described malignant biMVP syndrome. The mechanism of ventricular arrhythmia is unknown. To further characterize the arrhythmic substrate, we reviewed our center’s ablation experience in 6 biMVP patients with prior cardiac arrest and recurrent ICD shocks for drug refractory ventricular fibrillation (VF). Methods and Results: Six women with biMVP (median age 31.5 [range 24.2 - 58.7] years, EF 65 [45 - 67]%, all ≤moderate mitral regurgitation) experienced 6 (3 - 25) appropriate ICD shocks over 4.8 (2.8 - 10.7) years and underwent index ablation between 2/2007 - 10/2013. All had multiple VE morphologies (median 7 [3 - 24]) with variable coupling intervals but with a predominant VE trigger for the VF. A median 2 (1 - 4) VE foci were ablated. Sites of successful ablation of VF-triggering and other dominant VE were left ventricular papillary muscles [PM] (1 anterior, 1 posterior, 1 both), fascicles (1 anterior, 1 posterior), or both (1 both PM and posterior fascicle). Outflow tract VE was also present and targeted (1 left, 1 right)i. Two underwent repeat ablation (288 and 312 days) for recurrent complex VE without shocks, with different foci to the index ablation (1 posterior fascicle, 1 both fascicles). The VF-triggering VE in all patients was confirmed as originating from within the left fascicular system, which in 3/6 was at a papillary muscle. Acute procedural success was seen in all with no complications to date. A VF storm occurred within 24 hours of ablation in a single patient. At follow-up of a mean 662 (47 - 2099) days, 1 patient received a single shock (p=0.03 vs. preablation). Symptomatic VE was reduced in all; while 3/6 continue Class 1c antiarrhythmics and 5/6 have beta blockade. Conclusion: Malignant biMVP syndrome is characterized by fascicular and papillary muscle PVCs that trigger ventricular fibrillation, yet in all patients, the VE is multifocal. Ablation of at least one focus appears to improve symptoms and reduce shocks.

Introduction: Prior cardiac surgery, especially the presence of coronary bypass grafts, is thought to preclude percutaneous epicardial access (EpiAcc) and, due to limited catheter maneuverability, mapping and ablation. The objective of our study was to evaluate the feasibility and safety of EpiAcc in patients with prior cardiac surgery. Methods: We retrospectively analyzed all patients who underwent EpiAcc as part of an ablation procedure between 01/01/2004-06/30/2013 at Mayo Clinic, Rochester, MN. All had documented VT or recurring, symptomatic PVCs. Baseline clinical characteristics and procedural characteristics were collected. Results: Of 162 patients that underwent EpiAcc, 18 had prior cardiac surgery (mean age 61 years, all male). This included 10 CABG, 2 epicardial ICD placement, 5 valve surgery (3 aortic valve, 2 mitral valve), 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 patients (66.7%); the inferior approach was utilized in 78%. Of patients with prior CABG, successful access was attained in 6 (60%). The average procedural time was 441.6 ± 141.3 minutes. Adhesiolysis was required in 10 patients with the sheath, access wire, pigtail catheter or ablation catheter. Intra-procedural coronary angiography was performed in 8 patients. There were a total of 45 VTs/PVCs ablated in 18 patients (average 2.5 ± 1.7), mean cycle length 463.6 ± 95.9ms. Ultimately, 12 patients (66.7%) underwent endocardial only ablation, 1 (5.5%) had epicardial only ablation while 5 (27.8%) had endocardial/epicardial ablation. The procedure was deemed successful in 13 patients (72.2%). Four patients had bleeding complications (pericardial effusion, pericardial hematoma, hemoperitoneum and pericardial tamponade [the latter required repair of the RV wall]). In patients with coronary grafts, there was no evidence of acute graft disruption. Conclusions: Percutaneous epicardial access is feasible in patients with previous cardiac surgery, including CABG. However, adhesiolysis is frequently required. Although the risk of coronary graft injury is low, life-threatening complications may occur.

Introduction: The availability, national scope and perceived unbiased nature of administrative claims data makes it an attractive choice by health care policy makers for evaluating quality and outcomes. We calculated Ventricular tachycardia (VT) ablation complication rates from national administrative data and compared them with data from randomized trials and prospective studies. Methods: A PUBMED database search was done to identify existing studies of VT ablation. Studies were divided into clinical (randomized controlled trials (RCTs) and prospective studies). Pooled rates of vascular, cardiac, neurological complications and procedure related mortality were computed and compared to reported complication rates from administrative database studies Results: We identified two administrative database studies of VT ablation that included a total of 14,352 procedures and 18 clinical studies with a total of 1,705 procedure. Overall complication rate in administrative studies was higher than in clinical studies (9.39% vs. 7.97%). Rates of cardiac/pericardial (4.47% vs. 2.29%) and vascular access complications (6.9% vs. 3.0%) were higher in real world studies. Neurological complications (1.17% vs. 0.45%) and procedure related mortality (1.53% vs. 1.29%) were higher in clinical studies. Among clinical studies, RCTs had the lowest reported complication rate. Conclusion: Despite substantial improvement, “real-world” complication rates from administrative data remain higher than those reported in RCTs. The discrepancy may be attributable to differences in operator skills, selection bias and variation in data quality. Use of large databases provides an important analytical resource as we embark on improving national health care efficacy and safety in the current challenging environment.

Introduction: As the US population ages and indications for cardiac device implantation expand, there is a concomitant increase in patients undergoing lead removal/extraction (LR/E).. We sought to examine trends in outcomes and complications associated with LR/E. Methods: We conducted a retrospective analysis using data from a large U.S. commercial insurance database (privately insured and Medicare Advantage patients) identifying all patients undergoing LR/E between 2004 and 2013 with at least one year continuous medical plan enrollment prior to LR/E (to identify baseline comorbidities). Using ICD9 codes and CPT codes, major complications (hemorrhage requiring transfusion, vascular injury, pericardial complications, respiratory complications, cerebrovascular complications, and requirement for cardiac surgery) associated with LR/E and 30-day readmission rates were evaluated. Results: Among 42,878 patients who underwent LR/E (median age of 62 ( 54, 72) years, 70% male); approximately 1 in 40 experienced a major adverse event (2.4%) during the study period. Respiratory complications were the most common complication and 311 patients required cardiac surgery. 30-day readmission occurred in 11.1% of the total population. The most common reasons for readmission were heart failure exacerbation (18.7%) and device related complications (13.2%). Conclusion: The observed complication rates after LE/R in clinical practice are similar to those seen in recent clinical trials and have been relatively stable over the past 10 years.

Introduction: Percutaneous epicardial access (EAc) is increasingly performed as part of VT/PVC ablation, especially in those that have failed prior ablation. We aimed to delineate the outcomes of EAc. Methods: We retrospectively analyzed individuals undergoing EAc for arrhythmia ablation between June 2004 and July 2014. Acute procedural success was defined as elimination/non-inducibility of the clinical arrhythmia after ablation; clinical success was defined as absence of symptoms/arrhythmia. Results: Of 175 patients, 126 (72%) were male with a mean age of 52.8±15.7 years. Eighty-three (47.4%) patients had NICM, 25 (14.3%) had ICM and 34 (19.4%) had normal hearts. Baseline EF was 44±16%. Patients had failed an average of 1.7±1.2 antiarrhythmic drugs; 139 patients (79%) had failed prior endocardial (endo) ablation (average 1.3±1.1). Six (3.4%) had prior EAc and 18 (10.3%) prior cardiac surgery. The indication for ablation was VT or PVC in 113 (64.6%) and 60 (34.3%) patients, respectively. Successful access was obtained in 168 (98%) patients. Anterior access, inferior access, or both, was utilized in 89 (52.7%), 77 (45.6%) and 2 (1.2%) patients, respectively. There were an average of 2.7±2.2 VT/PVCs identified, and 1.6±1.1 ablated. Endo, epicardial (epi) or combined ablation was performed in 58 (33.1%), 14 (8%), and 100 (57.1%) patients, respectively; 3 did not undergo ablation. Procedural success was obtained in 158 of 173 (91.3%) patients for whom data was available. At 12 months, clinical success was maintained in 62% with no difference between endo, epi or combined ablation (figure). Cardiac tamponade requiring repeat EAc occurred in 12 (6.9%) patients. There were no procedural related deaths. Conclusion: Epicardial access is feasible in almost all patients with no prior cardiac surgery, and permits acute procedural success in 91.3% of patients, most of whom had failed previous ablation. Furthermore, complications are relatively infrequent in this complex cohort.

Background: Data regarding ventricular tachycardia (VT) or premature ventricular complex (PVC) ablation following MVS is limited.) CA can be challenging given perivalvular substrate in the setting of mitral annuloplasty or prosthetic valves. Objective: To investigate the characteristics, safety, and outcomes of radiofrequency catheter ablation (CA) in patients with prior mitral valve surgery (MVS) and ventricular arrhythmias (VA). Methods: We identified consecutive patients with prior MVS who underwent CA for VT or PVC between January 2013- December 2018. We investigated the mechanism of arrhythmia, ablation approach, peri-operative complications, and outcomes. Results: In our cohort of 31 patients (77% men, mean age 62.3±10.8 years, left ventricular ejection fraction 39.2±13.9%) with prior MVS underwent CA (16 VT; 15 PVC). Access to the left ventricle was via transseptal approach in 17 patients, and a retrograde aortic approach was used in 13 patients. A combined transseptal and retrograde aortic approach was used in one patient, and a percutaneous epicardial approach was combined with trans-septal approach in 1patient. Heterogenous scar regions were present in 94% of VT patients and scar-related reentry was the dominant mechanism of VT. Clinical VA substrates involved the peri-mitral area in 6 patients with VT and 5 patients with PVC ablation. No procedure-related complications were reported. The overall recurrence-free rate at 1-year was 72.2%; 67% in the VT group and 78% in the PVC group. No arrhythmia-related death was documented on long-term follow-up. Conclusion: CA of VAs can be performed safely and effectively in patients with MVS

AbstractBackgroundMany advanced heart failure patients have both a left ventricular assist device (LVAD) and an implantable cardioverter‐defibrillator (ICD). This study examines incidence, clinical impact, and management of LVAD‐related EMI.MethodsWe performed a three‐center retrospective analysis of transvenous ICD implanted patients with LVAD implanted between January 1, 2005 and December 31, 2020. The primary outcome was EMI after LVAD implantation, categorized as LVAD‐related noise or telemetry interference.ResultsThe rate of LVAD‐related EMI among the 737 patients (mean age 58.6 ± 12.8 years) studied was 5.0%. Telemetry interference (1.5%) compromised ICD interrogation in all patients. This was resolved successfully with use of a metal shield, encased wand, radiofrequency tower, different ICD programmer or by increasing distance between ICD programmer and LVAD (n = 6). ICD replacement was required to reestablish successful communication in three patients. LVAD‐related noise (3.5%) led to oversensing (n = 4), inappropriate mode switches (n = 4), noise reversion (n = 3), inhibition of pacing (n = 2), inappropriate detection as atrial fibrillation (AF) (n = 2) and inappropriate detection as ventricular tachycardia (VT) and/or ventricular fibrillation (VF) (n = 2). This noise interference persisted (n = 3), resolved spontaneously (n = 16), resolved with programming change (n = 6) or required lead revision (n = 1).ConclusionsEMI from LVAD impacts ICD function, although, the incidence rate is low. Physicians implanting both, LVAD in patients with ICD (more common) or ICD in patients with LVAD, should be aware of possible interferences. Telemetry failure not resolved by metal shielding was overcome by ICD generator replacement to a different manufacturer. In most cases, LVAD‐related noise resolves spontaneously.

AbstractBackgroundCatheter ablation is associated with limited success rates in patients with persistent atrial fibrillation (AF). Currently, existing mapping systems fail to identify critical target sites for ablation. Recently, we proposed and validated several techniques (multiscale frequency [MSF], Shannon entropy [SE], kurtosis [Kt], and multiscale entropy [MSE]) to identify pivot point of rotors using ex‐vivo optical mapping animal experiments. However, the performance of these techniques is unclear for the clinically recorded intracardiac electrograms (EGMs), due to the different nature of the signals.ObjectiveThis study aims to evaluate the performance of MSF, MSE, SE, and Kt techniques to identify the pivot point of the rotor using unipolar and bipolar EGMs obtained from numerical simulations.MethodsStationary and meandering rotors were simulated in a 2D human atria. The performances of new approaches were quantified by comparing the “true” core of the rotor with the core identified by the techniques. Also, the performances of all techniques were evaluated in the presence of noise, scar, and for the case of the multielectrode multispline and grid catheters.ResultsOur results demonstrate that all the approaches are able to accurately identify the pivot point of both stationary and meandering rotors from both unipolar and bipolar EGMs. The presence of noise and scar tissue did not significantly affect the performance of the techniques. Finally, the core of the rotors was correctly identified for the case of multielectrode multispline and grid catheter simulations.ConclusionThe core of rotors can be successfully identified from EGMs using novel techniques; thus, providing motivation for future clinical implementations.