Featured Research

READING: Cardiac Electrophysiology: A Modeling and Imaging Approach

This monograph written by Dr. Yoram Rudy, a world-know expert in mathematical modeling of cardiac electrophysiology and arrhythmogenesis, attempts to establish and describe the biophysical principles and mechanisms that underlie action potential generation and propagation in cardiac tissue and the associated electric fields. The book is specifically focused on how computational biology could be used to establish relationships across scales from the molecular structure of ion channel properties, to the cell, to the multicellular tissue.

READING: Excitation-Contraction Coupling and Cardiac Contraction Force

This is the most comprehensive and detailed monograph on cellular, molecular, and electrophysiological mechanisms of cardiac EC-coupling cardiac excitation written by Dr. Donald Bers. Since it was first published in 1991, it has become a classic. “The impact of the first edition was great. It was probably greatest on those of us who work in the field because it has become an invaluable tool for us in our work. Furthermore, it has become an important component in our teaching and research programs.” (W.J. Lederer). The book presents important evolving topics, classic material and issues that are now hotly debated. All of this is done in a scholarly and evenhanded manner and would be a great resource for graduate students and postdocs working in cardiac physiology field.

METHODS: Mouse Sinoatrial Node Isolation and Optical Mapping

An experimental video protocol published in the Journal of Visualized Experiments (JoVE) describes in details how to perform the high-resolution fluorescent optical mapping of electrical activity from the mouse sinoatrial node, the primary natural pacemaker of the heart, from the intact, Langendorff-perfused heart and from the isolated atrial preparation. This protocol is a useful tool to enhance the understanding of mouse sinoatrial node physiology and pathophysiology. The study discussed and compares different fluorescent dye loading approaches, time effects on dye bleaching and heart rate stability during the experiment.

METHODS: Isolation, Culture, and Functional Characterization of Sinoatrial Node Myocytes from Adult Mice

This experimental video protocol published in the Journal of Visualized Experiments (JoVE) provides a step-by-step protocol and video demonstration for the isolation of sinoatrial node cardiomyocytes from adult mice. A method is also demonstrated for maintaining adult mouse sinoatrial node cardiomyocytes in vitro and for expression of exogenous proteins via adenoviral infection. Acutely isolated and cultured sinoatrial node cardiomyocytes prepared via these methods are suitable for a variety of electrophysiological and imaging studies.

READING: Review: The sinoatrial node, a heterogeneous pacemaker structure

This comprehensive review article focuses on the functional and structural organization of the mammalian primary pacemaker, the sinoatrial node, in terms of cell morphology, pacemaker activity, action potential configuration and conduction, densities of ionic currents, expression of gap junction proteins, autonomic regulation, and ageing. Experimental studies on the single pacemaker cell to the whole animal are reviewed. The review touches various aspects of sinoatrial node electrophysiology, regulation, and remodeling. This article could be a great start for those who wants to learn about cardiac pacemaking.

Additional review articles that are focused on more specific aspects of sinoatrial node organization and remodeling could be also considered from a list below.

METHODS: Isolation and Physiological Analysis of Mouse Cardiomyocytes

This experimental video protocol published in the Journal of Visualized Experiments (JoVE) describes a detailed, step-by-step enzymatic isolation of mouse ventricular cardiomyocytes and their use for a further analysis of cellular cytoarchitecture, cell shortening (contractility) and intracellular calcium signaling (calcium transients) measurements. The study also discusses critical steps that are important for a good cell isolation, as well as steps that might be considered for optimization, along with some suggestions for optimization.

READING: Basic Mechanisms of Cardiac Impulse Propagation and Associated Arrhythmias

Propagation of excitation in the heart involves action potential (AP) generation by cardiac cells and its propagation in the multicellular tissue. AP conduction is the outcome of complex interactions between cellular electrical activity, electrical cell-to-cell communication, and the cardiac tissue structure. As shown in this review, strong interactions occur among these determinants of electrical impulse propagation. A special form of conduction that underlies many cardiac arrhythmias involves circulating excitation. In this situation, the curvature of the propagating excitation wavefront and the interaction of the wavefront with the repolarization tail of the preceding wave are additional important determinants of impulse propagation. This review attempts to synthesize results from computer simulations and experimental preparations to define mechanisms and biophysical principles that govern normal and abnormal conduction in the heart.

PRACTICE: Minimum Information about a Cardiac Electrophysiology Experiment: standardized reporting for model reproducibility, interoperability, and data sharing

Cardiac experimental electrophysiology is in need of a well-defined Minimum Information Standard for recording, annotating, and reporting experimental data. As a step toward establishing this, the current guideline presents a draft standard, called Minimum Information about a Cardiac Electrophysiology Experiment (MICEE). The ultimate goal of this taskforce group was to develop a useful tool for cardiac electrophysiologists which facilitates and improves dissemination of the minimum information necessary for reproduction of cardiac electrophysiology research, allowing for easier comparison and utilization of findings by others. It was hoped that this will enhance the integration of individual results into experimental, computational, and conceptual models. In its present form, this guideline was intended for assessment and development by the research community.

METHODS: Optical Mapping of Action Potentials and Calcium Transients in the Mouse Heart

This experimental video protocol published in the Journal of Visualized Experiments (JoVE) details the dissection procedure, instrumental setup, and experimental conditions during optical mapping of transmembrane potential and intracellular calcium transient in intact isolated Langendorff perfused mouse hearts. The readers might be also interested in another review study which is focused on processing and analysis of cardiac optical mapping data obtained with potentiometric dyes.

HISTORY: Brief history of cardiac arrhythmias since the end of the nineteenth century

In this review series, a former president of American College of Cardiology (ACC) Dr. Borys Surawicz who was a pioneer in electrocardiography and a significant contributor to the cardiovascular academic community, provides a brief history of cardiac arrhythmias. In a very fascinating manner, he describes a history of cardiac electrophysiology from cell to bedside. Part I covers a history of clinical electrocardiography from Einthoven and Thomas Lewis until recent advances in this field. Part II combines a brief description of electrophysiological mechanisms of cardiac arrhythmias and antiarrhythmic drugs. These articles would be of significant interest to the broad readership.