A5069326283- Atrial Fibrillation Management and Outcomes
- Cardiac Arrhythmias and Treatments
- Cardiac electrophysiology and arrhythmias
- Electrostatic Discharge in Electronics
- Cardiac Valve Diseases and Treatments
- Microbial Inactivation Methods
- Nonlinear Dynamics and Pattern Formation
- Neuroscience and Neural Engineering
- Cardiac pacing and defibrillation studies
- Optical Imaging and Spectroscopy Techniques
- Ion channel regulation and function
- Microfluidic and Bio-sensing Technologies
- Non-Invasive Vital Sign Monitoring
- Advanced MRI Techniques and Applications
- Cardiovascular Syncope and Autonomic Disorders
- Cardiovascular Health and Disease Prevention
- Photoreceptor and optogenetics research
- Cardiac Imaging and Diagnostics
- stochastic dynamics and bifurcation
- Neural dynamics and brain function
- Mechanical and Optical Resonators
- Congenital heart defects research
- Connexins and lens biology
- Cardiovascular Function and Risk Factors
- Cancer survivorship and care
Jewish Hospital
2021-2025
Barnes-Jewish Hospital
2021-2025
Old Dominion University
2014-2024
Washington University in St. Louis
2021-2024
University of Washington
2024
Society of Thoracic Surgeons
2015
SUNY Upstate Medical University
2003-2010
Universitätsklinikum Gießen und Marburg
2008
University of Leeds
2008
University of Rhode Island
2005
This study described the structural and mechanical changes in left atrium (LA) ventricle (LV) a canine model of chronic mitral regurgitation (MR), an attempt to identify markers linked onset atrial tachyarrhythmias (ATA) or LV dysfunction. Animals underwent baseline terminal echocardiography cardiac magnetic resonance imaging. Under echocardiographic guidance, chordae tendinae were avulsed until there was severe MR, defined by regurgitant jet area LA (RJA/LAA) >70%. At surgery, rapid pacing...
Ablation of cardiac tissue is an essential tool for the treatment arrhythmias, particularly atrial fibrillation, flutter, and ventricular tachycardia. Current ablation technologies suffer from substantial recurrence rates, thermal side effects, long procedure times. We demonstrate that with nanosecond pulsed electric fields (nsPEFs) can potentially overcome these limitations.We used optical mapping to monitor electrical activity in Langendorff-perfused New Zealand rabbit hearts (n = 12)....
Intense electric shocks of nanosecond (ns) duration can become a new modality for more efficient but safer defibrillation. We extended strength-duration curves excitation cardiomyocytes down to 200 ns, and compared electroporative damage by proportionally intense different duration. Enzymatically isolated murine, rabbit, swine adult ventricular (VCM) were loaded with Ca2+ indicator Fluo-4 or Fluo-5N subjected increasing amplitude until transient was optically detected. Then, the voltage...
The analysis of surface-activation patterns and measurements conduction velocity in ventricular myocardium is complicated by the fact that electrical wavefront has a complex 3D shape can approach heart surface at various angles. Recent theoretical studies suggest optical upstroke sensitive to subsurface orientation wavefront. Our goal here was (1) establish quantitative relationship between morphology using computer modeling (2) test predictions experimentally isolated coronary-perfused...
Anchoring of spiral and scroll waves in excitable media has attracted considerable interest the context cardiac arrhythmias. Here, by bombarding inclusions with drifting waves, we explore forces exerted onto an approaching derive equations motion governing dynamics vicinity inclusion. We demonstrate that these nonmonotonically depend on distance can lead to complex behavior: (a) anchoring small but circumnavigating larger inclusions; (b) chirality-dependent anchoring.
Here, we investigate the mechanisms underlying onset of conduction-related arrhythmias in a three-dimensional (3D) computational model acute regional ischaemia.Ischaemia was introduced by realistic gradients potassium, pH, oxygen and electrical coupling 3D slab ventricular tissue using LRd model. We focused on specific stage (10-15 min after occlusion) at which an intramural non-conductive ischaemic core (IC) surrounded border zone (BZ) has formed.At pacing frequencies greater than 4.5 Hz,...
Rotigaptide is proposed to exert its anti-arrhythmic effects by improving myocardial gap-junction communication. To directly investigate the mechanisms of rotigaptide action, we treated cultured neonatal murine ventricular cardiomyocytes with clinical pharmacological doses and determined on gap-junctional currents.
Reliable defibrillation with reduced energy deposition has long been the focus of research. We studied efficacy single shocks 300 ns duration in defibrillating rabbit hearts as well tissue damage they may cause.New Zealand white were Langendorff-perfused and two planar electrodes placed on either side heart. Shocks 0.3-3 kV amplitude generated a transmission line generator. Single nanosecond consistently induced waves electrical activation, stimulation threshold 0.9 (over 3 cm) consistent...
Ischemia and reperfusion (I/R) of the heart is associated with biochemical ionic changes that result in cardiac contractile electrical dysfunction. In rabbits, platelet-rich plasma activated using nanosecond pulsed electric fields (nsPRP) has been shown to improve left ventricular pumping. Here, we demonstrate nsPRP causes a similar improvement mouse function. We also show injection recovers activity even before begins. To uncover mechanism action, studied whether enhanced function rabbit...
Ablation of cardiac tissue with pulsed electric fields is a promising alternative to current thermal ablation methods, and it critically depends on the field distribution in heart.We developed model that incorporates twisted anisotropy computed tissue. We also performed experiments rabbit ventricles validate our model. find agrees well experimentally determined volume if we assume all exposed greater than 3 kV/cm ablated. In numerical analysis, considered how thickness, degree anisotropy,...
Expert consensus guidelines recommend surgical ablation (SA) for patients with symptomatic atrial fibrillation (AF), but less than half of AF undergoing cardiac procedures receive concomitant SA. Complete isolation the left posterior wall (LAPW) has been shown to be most critical part Cox maze procedure. The purpose this study was investigate performance a novel radiofrequency (RF) bipolar device, EnCompass™ (AtriCure, Inc., Mason, OH, USA), designed isolate LAPW in single application.Five...
Abstract Mapping the myocardial fiber organization is important for assessing electrical and mechanical properties of normal diseased hearts. Current methods to determine have several limitations: histological sectioning mechanically distorts tissue labor‐intensive, while diffusion tensor imaging has low spatial resolution requires expensive MRI scanners. Here, we utilized optical clearing, a fluorescent dye, confocal microscopy create three‐dimensional reconstructions guinea pig mouse We...
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, and results in significant morbidity mortality. The Cox-Maze IV procedure (CMP-IV) has been shown to have excellent efficacy returning patients sinus rhythm, but there few reports of late follow-up sizable cohorts with longstanding persistent AF, difficult type AF treat.Between May 2003 March 2020, 174 consecutive underwent a stand-alone CMP-IV for AF. Rhythm outcome was assessed postoperatively up 10 years, primarily...
The development of voltage-sensitive dyes has revolutionized cardiac electrophysiology and made optical imaging electrical activity possible. Photon diffusion models coupled to excitation have been successful in qualitatively predicting the shape action potential its dependence on subsurface wave orientation. However, accuracy equation visible range, especially for thin tissue preparations, remains unclear. Here, we compare Monte Carlo (MC) based investigate role thickness. All computational...