A5027178877- Cardiac electrophysiology and arrhythmias
- Cardiac Arrhythmias and Treatments
- Atrial Fibrillation Management and Outcomes
- Cardiac pacing and defibrillation studies
- Venous Thromboembolism Diagnosis and Management
- Cardiac Imaging and Diagnostics
- Cellular Mechanics and Interactions
- Tendon Structure and Treatment
- Vagus Nerve Stimulation Research
- Cardiomyopathy and Myosin Studies
- Neuroscience and Neural Engineering
- Acute Ischemic Stroke Management
- Cardiovascular Effects of Exercise
- Cardiovascular Function and Risk Factors
- Radiation Dose and Imaging
- Cancer-related gene regulation
- Advanced X-ray and CT Imaging
- Elasticity and Material Modeling
- Photoreceptor and optogenetics research
- EEG and Brain-Computer Interfaces
- Viral Infections and Immunology Research
- Cardiac tumors and thrombi
- Connexins and lens biology
- Heart Rate Variability and Autonomic Control
- Cardiac Ischemia and Reperfusion
Massachusetts General Hospital
2014-2023
Harvard University
2011-2023
American College of Cardiology
2018
Pathways Behavioral Services
2018
Framingham Heart Study
2017-2018
Boston University
2017-2018
National Heart Lung and Blood Institute
2017-2018
Broad Institute
2017
Ludwig-Maximilians-Universität München
2017
Massachusetts Institute of Technology
2017
Abstract Intracellular tension is considered an important determinant of cytoskeletal architecture and cell function. However, many details about remain poorly understood because these forces cannot be directly measured in living cells. Therefore, we have developed a method to characterize the magnitude distribution pre‐extension actin stress fibers (SFs) due resting cytoskeleton. Using custom apparatus, human aortic endothelial cells (HAECs) were cultured on pre‐stretched silicone substrate...
Surface electrode recordings cannot delineate the activation within human or canine sinoatrial node (SAN) because they are intramural structures. Thus, site of origin excitation and conduction pathway(s) SAN these mammals remains unknown. Canine right atrial preparations (n=7) were optically mapped. The 3D structure protein expression mapped using immunohistochemistry. optical action potentials had diastolic depolarization multiple upstroke components that corresponded to separate...
ZFHX3 (zinc finger homeobox 3), a gene that encodes large transcription factor, is at the second-most significantly associated locus with atrial fibrillation (AF), but its function in heart unknown. This study aims to identify causative genetic variation related AF and examine impact of Zfhx3 loss on cardiac mice. CRISPR-Cas9 genome editing, chromatin immunoprecipitation, luciferase assays pluripotent stem cell-derived cardiomyocytes were used locus. Cardiac was assessed by echocardiography,...
Abstract Gap junction expression has been studied in the atrioventricular (AVJ) of many species, however, their distribution human AVJ is unknown. The gap protein connexin 43 (Cx43) species dependent; therefore we investigated its AVJ. Using Masson trichrome histology, reconstructed three normal hearts and one with dilated cardiomyopathy dimensions. Cx43 was immunolabeled vimentin α‐actinin to determine cellular origin quantified following structures: interatrial septum (IAS), His bundle,...
BACKGROUND: The CommandEP system v2 (Sentiar, St. Louis, MO) utilizes an augmented reality headset (Magic Leap, Plantation, FL) to display a real-time 3-dimensional electroanatomic map, catheter locations, and ablation contact force data the electrophysiologist using hands-free interface. In intra-PARADIGM study (Procedural Augmented Reality Assessment in 3-Dimensional Image Guided Modality), impact of on electrophysiologist’s ability navigate accurately, intraprocedural communications,...
Vagal stimulation results in complex changes of pacemaker excitability the sinoatrial node (SAN). To investigate vagal effects rabbit SAN, we used optical mapping, which is only technology that allows resolving simultaneous activation pattern and action potentials morphologies. With use immunolabeling, identified SAN as a neurofilament 160-positive but connexin 43-negative region (n = 5). Normal excitation originated center with cycle length (CL) 405 +/- 14 ms 14), spread anisotropically...
Actin stress fibers (SFs) enable cells to sense and respond mechanical stimuli affect adhesion, motility apoptosis. We others have demonstrated that cultured human aortic endothelial (HAECs) are internally stressed so SFs pre-extended beyond their unloaded lengths. The present study explores factors affecting SF pre-extension. In HAECs overnight the baseline pre-extension was 1.10 independent of amount cell shortening. Decreasing contractility with 30 mM BDM or 10 microM blebbistatin...
The structure-function relationship in the atrioventricular junction (AVJ) of various animal species has been investigated detail; however, less is known about human AVJ. In this study, we performed high-resolution optical mapping AVJ (n = 6) to define its pacemaker properties and response autonomic stimulation.Isolated, coronary-perfused preparations from failing hearts 6, 53 ± 6 years) were optically mapped using near-infrared, voltage-sensitive dye, di-4-ANBDQBS, with isoproterenol (1...
Accurate detection of recurrent same-site deep vein thrombosis (DVT) is a challenging clinical problem. Because DVT formation and resolution are associated with preponderance inflammatory cells, we investigated whether noninvasive (18)F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) imaging could identify inflamed, recently formed thrombi thereby improve the diagnosis DVT.We established stasis-induced model in murine jugular veins also novel stasis mice. C57BL/6 mice (n=35)...
Atrial fibrillation (AF) affects over 33 million individuals worldwide. Genome-wide association studies have identified at least 30 AF loci, but the mechanisms through which individual variants lead to altered disease risk remained unclear for majority of these loci. At 1q24 locus, we hypothesized that transcription factor PRRX1 could be a strong candidate gene as it is expressed in pulmonary veins, source many individuals. We sought identify molecular mechanism, whereby variation may...
Background: Genetic variants at the SCN5A / SCN10A locus are strongly associated with electrocardiographic PR and QRS intervals. While is canonical cardiac sodium channel gene, role of in conduction less well characterized. Methods: We sequenced 3699 European-ancestry individuals to identify conduction, replicated our findings 21,000 European ancestry. examined association expression human atrial tissue. explored biophysical effect variation on function using cellular electrophysiology....
Abstract To support future studies of tibial bending in a murine model senile osteoporosis (SAMP6), we sought to determine the relationship between applied external force and peak endocortical strain tibiae SAMP6 control SAMR1 mice. The lower hindlimbs mice were loaded by three‐point lateral‐medial plane with length 10 mm. Force‐periosteal relations first determined using standard gauge methods. Finite‐element analysis (FEA) models tibia‐fibula generated based on microcomputed tomography...
The electrophysiological properties of atrioventricular (AV) nodal dual pathways have traditionally been investigated with premature stimuli delivered right atrial pacing. However, little is known about the functional characteristics AV inputs outside this context. Superfused rabbit triangle Koch preparations ( n = 8) and Langendorff-perfused hearts 10) were paced throughout mapped electrically optically for activation pattern, electrogram optical action potential morphologies, stimulation...