Atrial Fibrillation:
Abnormal cardiac rhythm that is characterized by rapid, uncoordinated firing of electrical impulses in the upper chambers of the heart (Heart atria). In such case, blood cannot be effectively pumped into the lower chambers of the heart (Heart ventricles). It is caused by abnormal impulse generation.
JoVE Clinical and Translational Medicine
Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation
Department of Cardiology, St. Antonius Hospital, The Netherlands
Catheter ablation is combined with placement of the WATCHMAN Left Atrial Appendage Closure Device to prevent ischemic stroke in a patient with non-valvular atrial fibrillation.
JoVE Clinical and Translational Medicine
The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
University of Leipzig Heart Center
The accompanying video describes a procedure for percutaneous placement of the WATCHMAN Left Atrial Appendage (LAA) Device. The WATCHMAN is a nitinol device designed to be permanently implanted at, or slightly distal to, the opening of the left atrial appendage (LAA) to trap blood clots before they exit the LAA, preventing thromboembolic stroke.
JoVE Clinical and Translational Medicine
High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation
Center for Arrhythmia Research. Internal Medicine, University of Michigan
This report provides a detailed description of the methodology and results of simultaneous endocardial and epicardial optical mapping of electrical excitation in the intact left atrium of a Langendorff-perfused sheep heart during stretch-induced atrial fibrillation.
JoVE Clinical and Translational Medicine
Direct Pressure Monitoring Accurately Predicts Pulmonary Vein Occlusion During Cryoballoon Ablation
1Department of Cardiac Electrophysiology, Piedmont Heart Institute, 2Cardiac Rhythm, Medtronic Inc.
Effective pulmonary vein isolation utilizing a cryoballoon depends on complete pulmonary vein occlusion. The point of occlusion can be effectively predicted by direct analysis of pulmonary vein pressure waveform analysis during balloon inflation using a simple and reproducible technique.
JoVE Clinical and Translational Medicine
A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation
Heart Center Rostock, University Hospital of Rostock, Germany
Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the second electrode.
JoVE General
Isolation and Kv Channel Recordings in Murine Atrial and Ventricular Cardiomyocytes
1Experimental and Clinical Research Center (ECRC), Charité Medical Faculty and Max-Delbrück Center for Molecular Medicine (MDC), 2Medical Department, Division of Cardiology, Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin, 3Medical Department, Division of Cardiology and Angiology, Campus Mitte, Charité - Universitätsmedizin Berlin
Kv channel dysfunction is associated with cardiac arrhythmias. In order to study the molecular mechanisms that lead to such arrhythmias we utilize a systematic protocol for isolation of atrial and ventricular cardiomyocytes from Kv channel ancillary subunit knockout mice. Isolated cardiomyocytes can then immediately be used for cellular electrophysiological studies, biochemical or immunofluorescence (IF) assays.
JoVE Clinical and Translational Medicine
Programmed Electrical Stimulation in Mice
1Department of Molecular Physiology and Biophysics, Baylor College of Medicine (BCM), 2The Margaret M. and Albert B. Alkek Department of Medicine, Baylor College of Medicine (BCM)
Programmed electrical stimulation provides the ability to determine conduction properties of the heart, and the possibility to induce and terminate cardiac arrhythmias using various pacing protocols. Using a transvenous catheter, intracardiac electrogram recordings can be obtained in mice following programmed electrical stimulation protocols to identify arrhythmogenic substrates.
JoVE General
Ambulatory ECG Recording in Mice
1Department of Molecular Physiology and Biophysics, Baylor College of Medicine (BCM), 2The Margaret M. and Albert B. Alkek Department of Medicine, Baylor College of Medicine (BCM)
Telemetric ECG has emerged as an essential tool in evaluating animal models for cardiac arrhythmias and sudden cardiac death. Here, we present a stepwise guide to telemetric ECG recordings for application in long-term ambulatory ECG monitoring in mice.
JoVE Clinical and Translational Medicine
Remote Magnetic Navigation for Accurate, Real-time Catheter Positioning and Ablation in Cardiac Electrophysiology Procedures
1Cardiology, Robotic Cardiac Electrophysiology and Arrhythmia Unit, La Paz University Hospital, 2Magnetecs Corp., 3Cardiology, Geffen School of Medicine at UCLA Los Angeles
This report provides a detailed description of a new remote navigation system based on magnetic driven forces, which has been recently introduced as a new robotic tool for human cardiac electrophysiology procedures.
JoVE Editorial
February 2012: This Month in JoVE
Here are some highlights from the February 2012 Issue of Journal of Visualized Experiments (JoVE).
JoVE Editorial
July 2011: This Month in JoVE
Here are some highlights from the July 2011 Issue of Journal of Visualized Experiments (JoVE).
JoVE Editorial
2012: A Year In Review
1Department of Ophthalmology, Massachusetts Eye and Ear, 2JoVE Content Production
Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).
JoVE General
High-throughput Screening for Small-molecule Modulators of Inward Rectifier Potassium Channels
1Department of Pharmacology, Vanderbilt University School of Medicine, 2Department of Anesthesiology, Vanderbilt University School of Medicine, 3Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine
Methods for developing and validating a quantitative fluorescence assay for measuring the activity of inward rectifier potassium (Kir) channels for high-throughput compound screening is presented.
JoVE Clinical and Translational Medicine
Reduction in Left Ventricular Wall Stress and Improvement in Function in Failing Hearts using Algisyl-LVR
1Department of Surgery, UCSF/VA Medical Center, 2Clinical & Regulatory, LoneStar Heart, Inc.
This article describes procedures for implanting a novel hydrogel in failing hearts and quantifying its effect on left ventricular wall stress and function. These procedures have been successfully applied in dogs and humans.
JoVE Clinical and Translational Medicine
Quantitative Autonomic Testing
Department of Neurology, University of Massachusetts Medical School
Standardized, comprehensive and fully quantitative testing of autonomic functions is described. The autonomic tests consist of evaluation of all three major autonomic domains including cardiovagal, adrenergic and sudomotor. The severity and distribution of dysautonomia is quantitated using Composite Autonomic Severity Scores.
JoVE Clinical and Translational Medicine
NADH Fluorescence Imaging of Isolated Biventricular Working Rabbit Hearts
1Electrical and Computer Engineering Department, The George Washington University, 2Pharmacology and Physiology Department, The George Washington University
The objective is to monitor the mitochondrial redox state of isolated hearts within the context of physiologic preload and afterload pressures. A biventricular working rabbit heart model is presented. High spatiotemporal resolution fluorescence imaging of NADH is used to monitor the mitochondrial redox state of epicardial tissue.
JoVE Clinical and Translational Medicine
Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus
Department of Pharmacology and Toxicology, University of Utah
Techniques for measurement of electrical activity of the heart by electrocardiogram (ECG), and analysis of cardiac risk factors and susceptibility to arrhythmias following status epilepticus (SE) in the rat are described.
JoVE General
Optical Mapping of Langendorff-perfused Rat Hearts
1Department of Anesthesiology, Perioperative and Pain Medicine, Children's Hospital Boston and Harvard Medical School, 2Departments of Cardiac Surgery, Children's Hospital Boston and Harvard Medical School
This article describes a high temporal and spatial resolution technique to optically image action potential movement on the surface of Langendorff-perfused rat hearts using a potentiometric dye (di-8-ANEPPS).
JoVE General
An ex-ovo Chicken Embryo Culture System Suitable for Imaging and Microsurgery Applications
1Department of Biomedical Engineering, Cornell University, 2Current Address: Mechanical Engineering Department, Dogus University
In this article, we present a simple methodology to enable long-term ex-ovo avian embryo culture. This technique is ideal for longitudinal experimentation requiring complete optical accessibility and/or sterile transportation in avian embryos.
JoVE Clinical and Translational Medicine
Transthoracic Echocardiography in Mice
1Department of Molecular Physiology and Biophysics, Baylor College of Medicine (BCM), 2The Margaret M. and Albert B. Alkek Department of Medicine, Baylor College of Medicine (BCM)
Transthoracic echocardiography offers a noninvasive method for the evaluation of cardiac function in mice. A combination of ultrasound and Doppler imaging modalities can be used to obtain dimensional measurements of the heart and intracardiac blood flow, which together provide an assessment of cardiac systolic and diastolic performance.
JoVE General
Transverse Aortic Constriction in Mice
1Department of Molecular Physiology and Biophysics, Baylor College of Medicine (BCM), 2The Margaret M. and Albert B. Alkek Department of Medicine, Baylor College of Medicine (BCM)
Transverse aortic constriction (TAC) in the mouse is a commonly used experimental model to study mechanisms underlying cardiac hypertrophy and heart failure development. Here, we describe procedures to constrict the aorta to create a reproducible degree of cardiac hypertrophy in mice.
JoVE General
Implantation of Engineered Tissue in the Rat Heart
1Department of Anesthesiology, Perioperative and Pain Medicine, Children's Hospital Boston and Harvard Medical School, 2Department of Anesthesiology, Perioperative and Pain Medicine, Children’s Hospital Boston
Here, we describe a cardiac surgical procedure to implant engineered tissue in the atrioventricular (AV)-groove of an adult Lewis rat.
JoVE Clinical and Translational Medicine
Gene Transfer for Ischemic Heart Failure in a Preclinical Model
Cardiovascular Research Center, Mount Sinai School of Medicine
A method of gene transfer for the treatment of ischemic heart failure is described using a swine model of myocardial infarction. Our simple and reproducible method enables us to readily evaluate the efficacy of various gene transfers with a very simple and reproducible way.
JoVE General
Characterization of the Isolated, Ventilated, and Instrumented Mouse Lung Perfused with Pulsatile Flow
Department of Biomedical Engineering, University of Wisconsin – Madison
The following protocol outlines the process of isolating, ventilating and instrumenting mouse lungs to measure steady or pulsatile pulmonary vascular pressure-flow relationships in order to quantify the effects of blood flow, airflow, airway changes and vascular changes on right ventricular afterload.
JoVE Bioengineering
Optical Mapping of Action Potentials and Calcium Transients in the Mouse Heart
Department of Biomedical Engineering, Washington University in St. Louis
This paper details the dissection procedure, instrumental setup, and experimental conditions during optical mapping of transmembrane potential (Vm) and intracellular calcium transient (CaT) in intact isolated Langendorff perfused mouse hearts.
JoVE Clinical and Translational Medicine
Murine Echocardiography and Ultrasound Imaging
1Department of Pharmacology and Physiology, University of Rochester, 2Aab Cardiovascular Research Institute, University of Rochester, 3Visualsonics, 4Department of Medicine, University of Rochester
This video demonstrates use of a rail-mounted high-frequency ultrasound probe to perform echocardiography on an anesthetized mouse. The methods describe both conventional two-dimensional and M-mode measurements of cardiac function in addition to newer, more powerful tools such as color Doppler, strain analysis, as well as general and targeted contrast imaging.
JoVE Clinical and Translational Medicine
Cardiac Stress Test Induced by Dobutamine and Monitored by Cardiac Catheterization in Mice
Instituto de Ciencias, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo
We describe the protocol to perform a cardiac stress test induced by dobutamine and monitored by cardiac catheterization in normal mice. Also we show its application to unmask subclinical cardiac disease in high fat diet-induced obese mice.
JoVE Bioengineering
Multiparametric Optical Mapping of the Langendorff-perfused Rabbit Heart
Department of Biomedical Engineering, Washington University in St. Louis
This article describes the basic procedures for conducting optical mapping experiments in the Langendorff-perfused rabbit heart using the panoramic imaging system, and the dual (voltage and calcium) imaging modality.
JoVE Clinical and Translational Medicine
A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis
1Orvis School of Nursing, University of Nevada, Reno, 2The State University of New York at Buffalo, St. Joseph's Medical Center, 3Strong Memorial Hospital, University of Rochester Medical Center
Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia.
JoVE Bioengineering
Engineering a Bilayered Hydrogel to Control ASC Differentiation
1Department of Extremity Trauma Research and Regenerative Medicine, United States Army Institute of Surgical Research, 2Department of Biomedical Engineering, The University of Texas at Austin
This protocol focuses on utilizing the inherent ability of stem cells to take cue from their surrounding extracellular matrix and be induced to differentiate into multiple phenotypes. This methods manuscript extends our description and characterization of a model utilizing a bilayered hydrogel, composed of PEG-fibrin and collagen, to simultaneously co-differentiate adipose-derived stem cells1.
JoVE General
A Fluorescent Screening Assay for Identifying Modulators of GIRK Channels
A real-time screening procedure for identifying drugs that interact with G protein-gated inward rectifier K+ (GIRK) channels is described. The assay utilizes membrane potential-sensitive fluorescent dyes to measure GIRK channel activity. This technique is adaptable for use on a number of cell lines.
JoVE Clinical and Translational Medicine
A Swine Model of Neonatal Asphyxia
1Departments of Pediatrics, Pharmacology and Surgery, University of Alberta, 2Department of Surgery, University of Alberta
Large animal models have good translational values in the examination of physiology and pharmacology of neonatal asphyxia. Using newborn piglets, we develop an experimental protocol to simulate neonatal asphyxia which has advantages of studying the systemic and regional hemodynamics, oxygen transport with biochemical and pathologic pathways and correlations.
JoVE Clinical and Translational Medicine
Development of Obliterative Bronchiolitis in a Murine Model of Orthotopic Lung Transplantation
1Departments of Medicine, Microbiology and Immunology, Indiana University School of Medicine, 2Center for Immunobiology, Indiana University School of Medicine
Obliterative bronchiolitis is the key impediment to the long-term survival of lung transplant recipients and the lack of a robust preclinical model precludes examining obliterative bronchiolitis immunopathogenesis. Unlike other solid organ transplants, vascularized mouse lung transplantation has only recently been developed. Here we show our independently developed obliterative bronchiolitis model after murine orthotopic single-lung transplantation.
JoVE Bioengineering
Constructing a Collagen Hydrogel for the Delivery of Stem Cell-loaded Chitosan Microspheres
Department of Regenerative Medicine, United States Army Institute of Surgical Research
A major hurdle in current stem cell therapies is determining the most effective method to deliver these cells to host tissues. Here, we describe a chitosan-based delivery method that is efficient and simple in approach, while allowing adipose-derived stem cells to maintain their multipotency.
JoVE Bioengineering
Patient-specific Modeling of the Heart: Estimation of Ventricular Fiber Orientations
A methodology to estimate ventricular fiber orientations from in vivo images of patient heart geometries for personalized modeling is described. Validation of the methodology performed using normal and failing canine hearts demonstrate that that there are no significant differences between estimated and acquired fiber orientations at a clinically observable level.
JoVE Clinical and Translational Medicine
Normothermic Cardiac Arrest and Cardiopulmonary Resuscitation: A Mouse Model of Ischemia-Reperfusion Injury
1Department of Anesthesiology and Perioperative Medicine, Oregon Health & Sciences University, 2Department of Pharmacology, University of Colorado Denver
A powerful model for perioperative and critical care related acute kidney injury is presented. Using whole body hypoperfusion induced by cardiac arrest it is possible to nearly replicate the histologic and functional changes of clinical AKI.
JoVE General
Recapitulation of an Ion Channel IV Curve Using Frequency Components
Bioengineering, University of Utah
There are technical obstacles to measuring current flux through multiple ion channels simultaneously, and later discerning what portion of the transmembrane current is due to each channel type. To address this need, this method presents a way to generate the IV curve of individual channel types using specific frequency components.
JoVE Clinical and Translational Medicine
Assessing Endothelial Vasodilator Function with the Endo-PAT 2000
Department of Cardiovascular Medicine, Stanford University
A noninvasive procedure to assess endothelial function is demonstrated using the Endo-PAT 2000.
JoVE Bioengineering
Design of a Cyclic Pressure Bioreactor for the Ex Vivo Study of Aortic Heart Valves
Department of Agricultural and Biological Engineering, Mississippi State University
A cyclic pressure bioreactor capable of subjecting heart valve tissue to physiological and pathological pressure conditions has been designed. A LabVIEW program allows users to control pressure magnitude, amplitude and frequency. This device can be used to study the mechanobiology of heart valve tissue or isolated cells.
JoVE Clinical and Translational Medicine
Murine Fetal Echocardiography
Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development. High-frequency ultrasound imaging has improved 2-D resolution and can provide excellent information on early cardiac development and is an ideal method to detect the impact on cardiac structure and function prior to death.
JoVE Clinical and Translational Medicine
A Murine Closed-chest Model of Myocardial Ischemia and Reperfusion
1Department of Anesthesiology and Intensive Care Medicine, University of Bonn, Germany, 2Institute of Physiology, University of Bonn, Germany
Surgical trauma induces an inflammatory response. Cytokines and endogenous ligands are known to modulate myocardial infarct size following ischemia and reperfusion. We present a modified closed-chest model of murine ischemia and reperfusion using hanging weights to minimize effects of thoracotomy.
JoVE Bioengineering
Engineering Adherent Bacteria by Creating a Single Synthetic Curli Operon
1UMR CNRS 5557 Ecologie Microbienne, Université Lyon 1, Université de Lyon, 2Département Biosciences, INSA de Lyon, Université de Lyon, 3INSERM U758, Ecole Normale Supérieure de Lyon, Université de Lyon, 4Laboratoire de Génie Civil et Ingénierie Environnementale, INSA de Lyon, Université de Lyon
The design of a synthetic operon encoding both the secretory apparatus and the structural monomers of curli fibers is described. Overproduction of these amyloids and adherent polymers allows a measurable gain of adherence of the E. coli chassis1. Easy ways to visualize and quantify adherence are explained.
JoVE Editorial
July 2012: This Month in JoVE
1JoVE Content Production, 2Department of Ophthalmology, Massachusetts Eye and Ear
Historically, JoVE, The Journal of Visualized Experiments, has focused primarily on biomedical research and has developed subsections for Bioengineering, Clinical and Translational Medicine, Immunology and Infection, and Neuroscience. This July, JoVE launches its Applied Physics section, which includes a range of content from Plasma Physics to Materials Science. We begin the new section with a notable article from Purdue University, where researchers in the Center for Laser-Based Manufacturing are studying.
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