Age and Sex Estimation Using Artificial Intelligence From Standard 12-Lead ECGs.

Background: Sex and age have long been known to affect the ECG. Several biologic variables and anatomic factors may contribute to sex and age-related differences on the ECG. We hypothesized that a convolutional neural network (CNN) could be trained through a process called deep learning to predict a person's age and self-reported sex using only 12-lead ECG signals.

Safety and compatibility of smart device heart rhythm monitoring in patients with cardiovascular implantable electronic devices.

Introduction: Emerging medical technology has allowed for monitoring of heart rhythm abnormalities using smartphone compatible devices. The safety and utility of such devices have not been established in patients with cardiac implantable electronic devices (CIEDs). We sought to assess the safety and compatibility of the Food and Drug Administration-approved AliveCor Kardia device in patients with CIEDs.

Screening for cardiac contractile dysfunction using an artificial intelligence-enabled electrocardiogram.

Asymptomatic left ventricular dysfunction (ALVD) is present in 3-6% of the general population, is associated with reduced quality of life and longevity, and is treatable when found. An inexpensive, noninvasive screening tool for ALVD in the doctor's office is not available. We tested the hypothesis that application of artificial intelligence (AI) to the electrocardiogram (ECG), a routine method of measuring the heart's electrical activity, could identify ALVD.

Intramural conduction system gradients and electrogram regularity during ventricular fibrillation.

Introduction: The His-Purkinje system has been shown to harbor triggers for ventricular fibrillation (VF) initiation. However, the substrate responsible for VF maintenance remains elusive. We hypothesized that standard, electrode-based, point-to-point mapping would yield meaningful insight into site-specific patterns and organization which may shed light on the critical substrate for maintenance of VF.

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.

Percutaneous epicardial pacing using a novel transverse sinus device.

Background: Transvenous lead implantation has multiple drawbacks and complications that can be overcome by epicardial lead placement. We aimed to design percutaneously implanted epicardial leads that are anchored through the transverse sinus (TS).

Methods And Results: We designed a novel multielectrode pacing device with four bipole electrode pairs.

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).

A Novel Defibrillation Tool: Percutaneously Delivered, Partially Insulated Epicardial Defibrillation.

Introduction: Epicardial defibrillation systems currently require surgical access. We aimed to develop a percutaneous defibrillation system with partially-insulated epicardial coils to focus electrical energy on the myocardium and prevent or minimize extra-cardiac stimulation.

Methods: We tested 2 prototypes created for percutaneous introduction into the pericardial space via a steerable sheath.

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.

Electroporation ablation of bronchial smooth muscle cells: A novel non-thermal asthma therapy.

Objective: Asthma is a common disease which places significant burden on the US healthcare system and which can be associated with significant patient morbidity and mortality. Current medical therapies are costly and not curative. A new approach for a more permanent asthma treatment is the use of radiofrequency ablation.

Evaluation of a Unique Defibrillation Unit with Dual-Vector Biphasic Waveform Capabilities: Towards a Miniaturized Defibrillator.

Background: Automated external defibrillators can provide life-saving therapies to treat ventricular fibrillation. We developed a prototype unit that can deliver a unique shock waveform produced by four independent capacitors that is delivered through two shock vectors, with the rationale of providing more robust shock pathways during emergent defibrillation. We describe the initial testing and feasibility of this unique defibrillation unit, features of which may enable downsizing of current defibrillator devices.

Remote electrocardiograph monitoring using a novel adhesive strip sensor: A pilot study.

The increase in health care costs is not sustainable and has heightened the need for innovative low cost effective strategies for delivering patient care. Remote monitoring holds great promise for preventing or shortening duration of hospitalization even while improving quality of care. We therefore conducted a proof of concept study to examine the quality of electrocardiograph (ECG) recordings obtained remotely and to test its potential utility in detecting harmful rhythms such as atrial fibrillation.

Beating Heart Validation of Safety and Efficacy of a Percutaneous Pericardiotomy Tool.

Introduction: Epicardial procedures frequently require pericardial manipulation. We aimed to develop a nonsurgical percutaneous pericardial modification tool that may (1) facilitate epicardial-based procedures by enabling adhesiolysis or (2) attenuate the myocardial constraining effect of the pericardium.

Methods: Three novel devices were developed to enable pericardiotomy, all of which can be deployed in over-the-wire fashion following percutaneous epicardial access.

Percutaneous Epicardial Pacing using a Novel Insulated Multi-electrode Lead.

Introduction: Epicardial cardiac resynchronization therapy (CRT) permits unrestricted electrode positioning. However, this requires surgical placement of device leads and the risk of unwanted phrenic nerve stimulation. We hypothesized that shielded electrodes can capture myocardium without extracardiac stimulation.

Novel Techniques in Epilepsy Management: Venous Pacing and Capture of Electrical Activity in the Primate Cortex.

Objective: Pharmacotherapy for epilepsy is limited with 30% of patients refractory to this approach of suppressing seizures. Current surgical options are invasive and carry significant morbidities including infection, bleeding, and the potential for deleterious neurocognitive effects. As a result, there is a burgeoning need for innovation to develop safer and efficacious interventions.

Blood Pressure Responses to Endovascular Stimulation: A Potential Therapy for Autonomic Disorders With Vasodilatation.

Background: We have previously shown that sympathetic ganglia stimulation via the renal vein rapidly increases blood pressure. This study further investigated the optimal target sites and effective energy levels for stimulation of the renal vasculatures and nearby sympathetic ganglia for rapid increase in blood pressure.

Methods: The pre-study protocol for endovascular stimulations included 2 minutes of stimulation (1-150 V and 10 pulses per second) and at least 2 minutes of rest during poststimulation.

Novel Percutaneous Epicardial Autonomic Modulation in the Canine for Atrial Fibrillation: Results of an Efficacy and Safety Study.

Background: Endocardial ablation of atrial ganglionated plexi (GP) has been described for treatment of atrial fibrillation (AF). Our objective in this study was to develop percutaneous epicardial GP ablation in a canine model using novel energy sources and catheters.

Methods: Phase 1: The efficacy of several modalities to ablate the GP was tested in an open chest canine model (n = 10).

Direct Pulmonary Vein Ablation With Stenosis Prevention Therapy.

Introduction: The dominant location of electrical triggers for initiating atrial fibrillation (AF) originates from the muscle sleeves inside pulmonary veins (PVs). Currently, radiofrequency ablation (RFA) is performed outside of the PVs to isolate, rather than directly ablate these tissues, due to the risk of intraluminal PV stenosis.

Methods: In 4 chronic canine experiments, we performed direct PV muscle sleeve RFA ± postablation drug-coated balloon (DCB) treatment with paclitaxel/everolimus.

Percutaneous ligation of the left atrial appendage results in atrial electrical substrate modification.

Debulking of electrically active atrial tissue may reduce the mass of fibrillating tissue during atrial fibrillation, eliminate triggers, and promote maintenance of normal sinus rhythm (NSR). We investigated whether left atrial appendage (LAA) ligation results in modification of atrial electrical substrate. Healthy male mongrel dogs (N = 20) underwent percutaneous epicardial LAA ligation.

Noninvasive potassium determination using a mathematically processed ECG: proof of concept for a novel "blood-less, blood test".

Objective: To determine if ECG repolarization measures can be used to detect small changes in serum potassium levels in hemodialysis patients.

Patients And Methods: Signal-averaged ECGs were obtained from standard ECG leads in 12 patients before, during, and after dialysis. Based on physiological considerations, five repolarization-related ECG measures were chosen and automatically extracted for analysis: the slope of the T wave downstroke (T right slope), the amplitude of the T wave (T amplitude), the center of gravity (COG) of the T wave (T COG), the ratio of the amplitude of the T wave to amplitude of the R wave (T/R amplitude), and the center of gravity of the last 25% of the area under the T wave curve (T4 COG) (Fig.

Novel balloon catheter device with pacing, ablating, electroporation, and drug-eluting capabilities for atrial fibrillation treatment--preliminary efficacy and safety studies in a canine model.

Pulmonary vein isolation is an established therapeutic procedure for symptomatic atrial fibrillation (AF). This approach involves ablation of atrial tissue just outside the pulmonary veins. However, patient outcomes are limited because of a high rate of arrhythmia recurrence.

Transvenous stimulation of the renal sympathetic nerves increases systemic blood pressure: a potential new treatment option for neurocardiogenic syncope.

Background: Neurocardiogenic syncope (NCS) is a common and sometimes debilitating disorder, with no consistently effective treatment. NCS is due to a combination of bradycardia and vasodilation leading to syncope. Although pacemaker devices have been tried in treating the bradycardic aspect of NCS, no device-based therapy exists to treat the coexistent vasodilation that occurs.