A transient, closed-loop network of wireless, body-integrated devices for autonomous electrotherapy

Science · 2022 · 249 citations

• Computer Science
• Computer Science
• Electrical engineering

Temporary postoperative cardiac pacing requires devices with percutaneous leads and external wired power and control systems. This hardware introduces risks for infection, limitations on patient mobility, and requirements for surgical extraction procedures. Bioresorbable pacemakers mitigate some of these disadvantages, but they demand pairing with external, wired systems and secondary mechanisms for control. We present a transient closed-loop system that combines a time-synchronized, wireless network of skin-integrated devices with an advanced bioresorbable pacemaker to control cardiac rhythms, track cardiopulmonary status, provide multihaptic feedback, and enable transient operation with minimal patient burden. The result provides a range of autonomous, rate-adaptive cardiac pacing capabilities, as demonstrated in rat, canine, and human heart studies. This work establishes an engineering framework for closed-loop temporary electrotherapy using wirelessly linked, body-integrated bioelectronic devices.

Fully implantable and bioresorbable cardiac pacemakers without leads or batteries

Nature Biotechnology · 2021 · 332 citations

• Medicine
• Cardiology
• Biomedical engineering

Use of a novel 4D intracardiac echocardiography catheter to guide interventional electrophysiology procedures

Journal of Cardiovascular Electrophysiology · 2021 · 20 citations

• Medicine
• Cardiology
• Radiology

INTRODUCTION: Standard two-dimensional (2D), phased-array intracardiac echocardiography (ICE) is routinely used to guide interventional electrophysiology (EP) procedures. A novel four-dimensional (4D) ICE catheter (VeriSight Pro, Philips) can obtain 2D and three-dimensional (3D) volumetric images and cine-videos in real-time (4D). The purpose of this study was to determine the early feasibility and safety of this 4D ICE catheter during EP procedures. METHODS: The 4D ICE catheter was placed from the femoral vein in ten patients into various cardiac chambers to guide EP procedures requiring transseptal catheterization, including ablation for atrial fibrillation and left atrial appendage closure. 2D- and 3D-ICE images were acquired in real-time by the electrophysiologist. A dedicated imaging expert performed digital steering to optimize and postprocess 4D images. RESULTS: Eight patients underwent pulmonary vein isolation (cryoballoon in seven patients, pulsed field ablation in one, additional radiofrequency left atrial ablation in one). Two patients underwent left atrial appendage closure. High quality images of cardiac structures, transseptal catheterization equipment, guide sheaths, ablation tools, and closure devices were acquired with the ICE catheter tip positioned in the right atrium, left atrium, pulmonary vein, coronary sinus, right ventricle, and pulmonary artery. There were no complications. CONCLUSION: This is the first experience of a novel deflectable 4D ICE catheter used to guide EP procedures. 4D ICE imaging is safe and allows for acquisition of high-quality 2D and 3D images in real-time. Further use of 4D ICE will be needed to determine its added value for each EP procedure type.

Impact of pre‐ablation weight loss on the success of catheter ablation for atrial fibrillation

Journal of Cardiovascular Electrophysiology · 2021 · 32 citations

• Medicine
• Cardiology
• Internal medicine

INTRODUCTION: Obesity is an established risk factor for recurrent atrial fibrillation (AF) after ablation. The impact of pre-procedure weight changes on freedom from AF (FFAF) after ablation in obese and nonobese patients is unknown. METHODS: A single-center retrospective cohort study of patients undergoing pulmonary vein isolation was performed. Before ablation, all candidates were encouraged to adopt healthy lifestyle habits according to American Heart Association guidelines, including weight loss, by their physician. The primary endpoint was FFAF through 1-year after completion of the 3-month blanking period. RESULTS: Of the 601 patients (68% male; average age 62.1 ± 10.3 years) included in analysis, 234 patients (38.9%) were obese (body mass index ≥ 30) and 315 (52.4%) had paroxysmal AF. FFAF was observed in 420 patients (69.9%) at 15 months. Percent change in weight that occurred during the year before ablation independently predicted FFAF through 15-months in all patients (adjusted odds ratio = 1.17, 95% confidence interval: 1.11-1.23). Subgroup analyses based on paroxysmal vs persistent AF, presence of obesity, and history of prior ablation were performed. Percent change in weight over the year before ablation was independently associated with FFAF in all subgroups except nonobese patients with persistent AF. CONCLUSION: Pre-ablation weight loss was associated with FFAF in both obese and nonobese patients. Further studies are needed to define the optimal approach to weight loss before AF ablation.

Left Ventricular Extracellular Volume Expansion Is Not Associated with Atrial Fibrillation or Atrial Fibrillation–mediated Left Ventricular Systolic Dysfunction

Radiology Cardiothoracic Imaging · 2020 · 18 citations

• Medicine
• Cardiology
• Internal medicine

PURPOSE: To determine whether left ventricular (LV) extracellular volume (ECV) expansion is associated with atrial fibrillation (AF) or AF-mediated LV systolic dysfunction (LVSD) while minimizing the influence of biologic and imaging methodologic confounders. MATERIALS AND METHODS: This study examined the prevalence of LV ECV expansion in 137 patients with AF (mean age, 62 years ± 11 [standard deviation]; 92 male patients and 45 female patients; 83 paroxysmal and 54 persistent) who underwent preablation cardiovascular MRI. Biologic confounders were minimized by measuring the ECV fraction and excluding patients with severe LV hypertrophy, defined as wall thickness greater than 1.5 cm. Imaging confounders were minimized by using an arrhythmia-insensitive-rapid (AIR) cardiac T1 mapping pulse sequence. Other cardiac functional parameters, including LV ejection fraction (LVEF) and left atrial end-diastolic volume indexed to body surface area, were assessed using cine cardiovascular MRI. A substudy was conducted in 32 patients with no AF (mean age, 54 years ± 16) in sinus rhythm to establish control values and convert these values between the AIR sequence and literature-based modified Look-Locker inversion recovery (MOLLI) values. RESULTS: -VASc score (0/1 for men/women). CONCLUSION: . © RSNA, 2020See also the commentary by Stillman in this issue.