Sinus rhythm heart rate increase after atrial fibrillation ablation is associated with lower risk of arrhythmia recurrence.

Background: Pulmonary vein isolation (PVI) with autonomic modulation may be more successful than PVI alone for atrial fibrillation (AF) ablation and may be signaled by changes in sinus rhythm heart rate (HR) post ablation. We sought to determine if a change in sinus rhythm HR predicted AF recurrence post PVI.

Methods: Patients who underwent AF ablation from 2000 to 2011 were included if sinus rhythm was noted on ECG within 90 days pre and 7 days post ablation.

Efficacy of medical and ablation therapy for inappropriate sinus tachycardia: A single-center experience.

Background: Effective therapy for inappropriate sinus tachycardia (IST) remains challenging with high rates of treatment failure and symptom recurrence. It is uncertain how effective pharmacotherapy and procedural therapy are long-term, with poor response to medical therapy in general.

Methods: We retrospectively reviewed all patients with the diagnosis of IST at a tertiary academic medical center from 1998 to 2018.

Incremental benefit of a novel signal recording system during mapping and ablation.

Aims: Current electrophysiology signal recording and mapping systems have limited dynamic range (DR) and bandwidth, which causes loss of valuable information during acquisition of cardiac signals. We evaluated a novel advanced signal processing platform with the objective to obtain and assess additional information of clinical importance.

Methods And Results: Over 10 canines, we compared intracardiac recordings within all cardiac chambers, in various rhythms, in pacing and during radiofrequency (RF) ablation across two platforms; a conventional system and the PURE EP™ [(PEP); Bio Sig Technologies, Inc.

Left Bundle Branch Block: Current and Future Perspectives.

Left bundle branch block may be due to conduction system degeneration or a reflection of myocardial pathology. Left bundle branch block may also develop following aortic valve disease or cardiac procedures. Patients with heart failure with reduced ejection fraction and left bundle branch block may respond positively to cardiac resynchronization therapy.

Natural history and clinical outcomes of inappropriate sinus tachycardia.

Background: Limited data are available regarding the demographics, disease associations, and long-term prognosis of patients with inappropriate sinus tachycardia (IST).

Objective: To establish epidemiologic data for patients with IST, including symptom onset, comorbid disease, and long-term outcomes.

Methods: We retrospectively reviewed all patients with an IST diagnosis at the Mayo Clinic (Rochester, MN) during a 20-year period (1998-2018).

Association between the Charlson comorbidity index and outcomes after implantable cardioverter defibrillator generator replacement.

Background: Recipients of implantable cardioverter defibrillator (ICD) generator replacement with multiple medical comorbidities may be at higher risk of adverse outcomes that attenuate the benefit of ICD replacement. The aim of this investigation was to study the association between the Charlson comorbidity index (CCI) and outcomes after ICD generator replacement.

Methods: All patients undergoing first ICD generator replacement at Mayo Clinic, Rochester and Beth Israel Deaconess Medical Center, Boston between 2001 and 2011 were identified.

Irreversible electroporation for catheter-based cardiac ablation: a systematic review of the preclinical experience.

Introduction: Irreversible electroporation (IRE) utilizing high voltage pulses is an emerging strategy for catheter-based cardiac ablation with considerable growth in the preclinical arena.

Methods: A systematic search for articles was performed from three sources (PubMed, EMBASE, and Google Scholar). The primary outcome was the efficacy of tissue ablation with characteristics of lesion formation evaluated by histologic analysis.

Paced QRS morphology predicts incident left ventricular systolic dysfunction and atrial fibrillation.

Background: The prognostic significance of paced QRS complex morphology on surface ECG remains unclear. This study aimed to assess long-term outcomes associated with variations in the paced QRS complex.

Methods: Adult patients who underwent dual-chamber pacemaker implantation with 20% or more ventricular pacing and a 12-lead ECG showing a paced complex were included.

Cardiac Resynchronization Therapy in Preserved to Mildly Reduced Systolic Function.

Cardiac resynchronization therapy has been proven to be clearly beneficial for patients with heart failure, a prolonged QRS duration, and a left ventricular ejection fraction ≤35%. Ejection fraction cutoff, however, is arbitrary and very likely excludes many patients who could benefit from cardiac resynchronization. This article describes the major detrimental effects of left bundle branch block and summarizes the data regarding the potential beneficial effects of cardiac resynchronization in patients with a left ventricular ejection fraction greater than 35%.

Electroporation of epicardial autonomic ganglia: Safety and efficacy in medium-term canine models.

Background: Endocardial radiofrequency ablation of epicardial ganglionic plexus (GP) for atrial fibrillation (AF) is complicated by myocardial damage.

Objectives: We hypothesized that an epicardial approach with a novel nitinol catheter system capable of causing irreversible electroporation (IRE) with direct current (DC) could selectively and permanently destroy GP without collateral myocardial injury.

Methods: Acute studies and medium-term terminal studies (mean survival, 1137 days) were performed with seven dogs.

Diagnostic Accuracy of Echocardiography and Intraoperative Surgical Inspection of the Unicuspid Aortic Valve.

Unicuspid aortic valve (UAV) is a rare malformation that is often difficult to distinguish from a bicuspid aortic valve (BAV) with commissural fusion by echocardiography or intraoperative surgical inspection. This study assessed the accuracy of intraoperative surgical inspection and two-dimensional echocardiography in diagnosing UAV compared to a gold standard of pathological diagnosis. The Mayo Clinic echocardiographic database, tissue registry database and electronic medical record were searched for all patients assigned a diagnosis of UAV by any technique.

Pulsed electric fields for cardiac ablation and beyond: A state-of-the-art review.

Irreversible electroporation (IRE) occurs when a strong, pulsed electric field (PEF) causes permeabilization of the cell membrane, leading to cellular homeostasis disruption and cell death. IRE is a Food and Drug Administration-approved treatment of tumor ablation and has been gaining attention in cardiology as an ablation modality. Applications of PEF in cardiology are vast and include atrial fibrillation, ventricular fibrillation, septal ablation, and targeting vascular structures.

Risk of Appropriate Therapy and Death Before Therapy After Implantable Cardioverter-Defibrillator Generator Replacement.

Background The decision to initially implant an implantable cardioverter-defibrillator (ICD) is informed by robust randomized controlled trials, but no such data exist to guide the decision to replace an ICD generator. In this study, we aimed to determine outcomes after ICD generator replacement. Methods All patients with ischemic or nonischemic cardiomyopathy who underwent ICD generator replacement from 2001 to 2011 at Mayo Clinic, MN, or Beth Israel Deaconess Medical Center, MA, were included.

Termination of Atrial Fibrillation With Epicardial Cooling in the Oblique Sinus.

Objectives: This study aimed to determine if epicardial cooling could repeatedly terminate induced atrial fibrillation (AF) in a canine heart.

Background: Rapid termination of AF could control symptoms and prevent atrial remodeling; however, defibrillation by internal electrical cardioversion is not tolerable to most patients. Cooling of the epicardium slows atrial conduction and may provide a less painful method to quickly terminate AF.

Three Cases of Rare Retroaortic Coronary Anomalies Diagnosed With Angiography and Cardiac CTA.

Coronary artery anomalies are relatively rare (approximately 1% on CTA). We present two exceedingly rare cases, as well as the first reported case of anomalous retro-aortic coronary arteries diagnosed with cardiac CTA and angiography.

Preprocedural Utility of the Echocardiographic Retroaortic Anomalous Coronary Sign.

Imaging series highlighting echocardiographic findings associated with the retroaortic anomalous coronary sign and its utility as a non-invasive modality to recognize technically complex and high-risk retroaortic coronary anomalies prior to intervention.

Feasibility of directional percutaneous epicardial ablation with a partially insulated catheter.

Purpose: To demonstrate the feasibility of directional percutaneous epicardial ablation using a partially insulated catheter.

Methods: Partially insulated catheter prototypes were tested in 12 (6 canine, 6 porcine) animal studies in two centers. Prototypes had interspersed windows to enable visualization of epicardial structures with ultrasound.

Intrapulmonary Vein Ablation Without Stenosis: A Novel Balloon-Based Direct Current Electroporation Approach.

Background: Current thermal ablation methods for atrial fibrillation, including radiofrequency and cryoablation, have a suboptimal success rate. To avoid pulmonary vein (PV) stenosis, ablation is performed outside of the PV, despite the importance of triggers inside the vein. We previously reported on the acute effects of a novel direct current electroporation approach with a balloon catheter to create lesions the PVs in addition to the antrum.

Irreversible electroporation for the treatment of cardiac arrhythmias.

Cardiac ablation is an established treatment modality for the management of patients with cardiac arrhythmias. Current approaches to cardiac ablation employ thermal based energy to achieve lesions (damage) within the heart. There are many shortcomings and limitations of thermal based approaches.