Early Impact of Proton Beam Therapy on Electrophysiological Characteristics in a Porcine Model.

Background: Particle therapy is a noninvasive, catheter-free modality for cardiac ablation. We previously demonstrated the efficacy for creating ablation lesions in the porcine heart. Despite several earlier studies, the exact mechanism of early biophysical effects of proton and photon beam delivery on the myocardium remain incompletely resolved.

Construction and Validation of a Benchtop Model for Testing of Mechanical Thrombectomy Devices for Pulmonary Embolism.

Purpose: This study aims to define the process of designing and manufacturing 3D printed and glass models of the pulmonary artery (PA) and utilizing them in a test bed for evaluation of devices for mechanical thrombectomy of pulmonary embolism (PE).

Materials And Methods: Patient derived computed tomography angiography (CTA) images of the PA were digitally converted into a hollowed-out structure and translated into clear 3D printed and glass models. A test bed was created using a peristaltic pump and silicone tubing connected to the models.

Effects of Pulsed Electric Fields on the Coronary Arteries in Swine.

Background: Previous animal studies have shown no significant vascular injury from pulsed electrical field (PEF) ablation. We sought to assess the effect of PEF on swine coronary arteries.

Methods: We performed intracoronary and epicardial (near the coronary artery) PEF ablations in swine pretreated with dual antiplatelet and antiarrhythmic therapy.

Bipolar Electroporation Across the Interventricular Septum: Electrophysiological, Imaging, and Histopathological Characteristics.

Background: Pulsed electric field (PEF) ablation is an emerging modality for the treatment of cardiac arrhythmias. Data regarding effects on the interventricular septum are limited, and the optimal delivery protocol and electrode configuration remain undefined.

Objectives: This study sought to evaluate the electrophysiological, imaging, and histological characteristics of bipolar direct-current PEF delivered across the interventricular septum.

Open-chest Pulsed Electric Field Ablation of Cardiac Ganglionated Plexi in Acute Canine Models.

This study aimed to evaluate the safety and acute effect on markers of cardiac autonomic tone following pulsed electric fields (PEFs) delivered to epicardial ganglionated plexi (GP) during a cardiac surgical procedure. Ablation of GP as a treatment for atrial fibrillation (AF) has shown promise, but thermal ablation energy sources are limited by the risk of inadvertent collateral tissue injury. In acute canine experiments, median sternotomy was performed to facilitate the identification of 5 epicardial GP regions using an anatomy-guided approach.

Ventricular nanosecond pulsed electric field delivery using active fixation leads: a proof-of-concept preclinical study.

Background: Mid-myocardial ventricular arrhythmias are challenging to treat. Cardiac electroporation via pulsed electric fields (PEFs) offers significant promise. We therefore tested PEF delivery using screw-in pacemaker leads as proof-of-concept.

Injectable Flexible Subcutaneous Electrode Array Technology for Electrocardiogram Monitoring Device.

Implantable cardiac monitors have undergone considerable miniaturization. However, they continue to be associated with complications such as infection, bleeding/bruising, and device extrusion or migration. In this paper, we demonstrate the feasibility of using a small, flexible, injectable, subcutaneous microelectrode-based device to record electrocardiograms (ECGs).

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.

Fibroplasty (venoplasty) to facilitate transvenous lead placement: A single-center experience.

Introduction: Venous stenosis is a well-recognized complication of transvenous leads (TVLs) that is encountered during lead revisions or device upgrades. We here report the outcomes of TVL placement facilitated by fibroplasty or tunneling (TUN) procedure.

Methods: We conducted a single-center retrospective cohort study of all patients undergoing TVL implantation requiring fibroplasty or TUN from 2005 to 2017.

Development of a novel ablation hood to prevent systemic embolization of microbubbles and particulate emboli.

Background: Atrial fibrillation ablation results in microbubbles and particulate emboli formation. We aimed to develop and test the early feasibility of a novel ablation hood to contain microbubbles and particulate emboli with the ultimate goal of preventing systemic embolization.

Methods: In seven canines, we developed, iterated, and tested a novel retractable hood that can cover the catheter-tissue ablation site.

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.

A novel percutaneous stabilizing sheath for minimal invasive epicardial echocardiography and ablation.

Purpose: Epicardial ablation and mapping are critical adjuncts to the electrophysiologist's approach to arrhythmias; however, ablation within the epicardial space requires the avoidance of coronary arteries (CA). We aimed to evaluate the feasibility and performance of a novel-stabilizing ablation sheath housing an intracardiac echocardiography (ICE) catheter to (1) obtain Epicardial Echocardiography (EE) images, (2) visualize CAs, and (3) enable targeted delivery of radiofrequency energy away from visualized CAs.

Methods: We designed a sheath that could enclose a regular ICE catheter.

Radiofrequency ablation of the cavotricuspid isthmus for management of atrial flutter in patients with congenital heart disease after tricuspid valve surgery: A single-center experience.

Background: Typical atrial flutter involving the cavotricuspid isthmus (CTI) is the most common reentrant arrhythmia in congenital heart disease and ablation is effective in its management. However, congenital heart disease patients often require surgical interventions on their tricuspid valve that utilize prosthetic material, making CTI ablation technically challenging.

Objective: To describe the techniques and outcomes of CTI ablation in the presence of prior tricuspid valve repair or replacement.

Quantitative fundus autofluorescence in smokers compared to non-smokers.

Increased fundus autofluorescence is directly related to increased RPE lipofuscin deposition in the retina and has been observed in eyes with age-related macular degeneration (AMD). Smoking is the most significant modifiable risk factor for the development and progression of AMD, in which one of the main mechanisms is oxidative damage from smoking leading to RPE cell toxicity. The relationship between smoking and autofluorescence is not established and could provide insight into pathogenic mechanism of AMD.

Comparing the incidence of ventricular arrhythmias during epicardial ablation in swine versus canine models.

Background: Choosing the appropriate animal model for development of novel technologies requires an understanding of anatomy and physiology of these different models. There are little data about the characteristics of different animal models for the study of technologies used for epicardial ablation. We aimed to compare the incidence of ventricular arrhythmias during epicardial radiofrequency ablation between swine and canine models using novel epicardial ablation catheters.

Detection of Human Chorionic Gonadotropin (hCG) Hormone using Digital Lateral Flow Immunoassay.

The main goal of this work was to establish a hybrid device incorporating an electrochemical-based transducer on a conventional lateral flow assay strip in order to perform an on-chip fast testing method for the detection of various bio-analyses. In this context, the expected development of the digital lateral-flow immunoassay to be considered a reliable low-cost instrument improves the future of the very simple and flexible approach oflateral-flow assays. It is anticipated to achieve a digital quantitative lateral-flow immunoassay by exploring the electrochemical transducers alongwith recognition elements for digitization of commercially available rapid tests.

Errors of Classification With Potassium Blood Testing: The Variability and Repeatability of Critical Clinical Tests.

Objective: To understand the performance of a currently used clinical blood test with regard to the frequency and size of variation of the results.

Patients And Methods: From November 29, 2012, through November 29, 2013, patients were recruited at 65 sites as part of a previously reported clinical trial (ClinicalTrials.gov Identifier: NCT01737697).

Anatomy and Physiologic Roles of the Left Atrial Appendage: Implications for Endocardial and Epicardial Device Closure.

The left atrial appendage has been implicated as a major nidus for thrombus formation, particularly in atrial fibrillation. This discovery has prompted substantial interest in the development of left atrial appendage exclusion devices aimed at decreasing systemic thromboembolism risk. Its deceptively simple appearance belies the remarkable complexity that characterizes its anatomy and physiology.

Noninvasive blood potassium measurement using signal-processed, single-lead ecg acquired from a handheld smartphone.

Objective: We have previously used a 12-lead, signal-processed ECG to calculate blood potassium levels. We now assess the feasibility of doing so with a smartphone-enabled single lead, to permit remote monitoring.

Patients And Methods: Twenty-one hemodialysis patients held a smartphone equipped with inexpensive FDA-approved electrodes for three 2min intervals during hemodialysis.

Wellens Syndrome with Syncope but Not Chest Pain.

We report the case of a woman in her 70s presenting to the emergency department with syncope, troponemia, and an electrocardiogram with deep symmetric T-wave inversions in V2 and V3 and prolonged QTc. Her presentation was concerning for acute coronary syndrome, Wellens syndrome in particular, given the elevated troponin levels, lack of ST segment changes, and characteristic T-wave findings. The diagnosis was confirmed with angiography that showed a critical left anterior descending (LAD) artery occlusion.