Cardiology is the study of the heart. Cardiology is a branch of medicine that deals with disorders of the heart and the cardiovascular system. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology. Physicians who specialize in this field of medicine are called cardiologists, a specialty of internal medicine. Pediatric cardiologists are pediatricians who specialize in cardiology. Physicians who specialize in cardiac surgery are called cardiothoracic surgeons or cardiac surgeons, a specialty of general surgery.
Electrocardiography is the process of producing an electrocardiogram, a recording of the heart's electrical activity through repeated cardiac cycles. It is an electrogram of the heart which is a graph of voltage versus time of the electrical activity of the heart using electrodes placed on the skin. These electrodes detect the small electrical changes that are a consequence of cardiac muscle depolarization followed by repolarization during each cardiac cycle (heartbeat). Changes in the normal ECG pattern occur in numerous cardiac abnormalities, including cardiac rhythm disturbances, inadequate coronary artery blood flow, and electrolyte disturbances.
An artificial cardiac pacemaker or artificial pacemaker, and sometimes just pacemaker—although the term is also used to refer to the body's natural cardiac pacemaker—is a medical device, nowadays always implanted, that generates electrical pulses delivered by electrodes to the chambers of the heart, either the upper atria or lower ventricles. Each pulse causes the targeted chambers to contract and pump blood, thus regulating the function of the electrical conduction system of the heart.
Defibrillation is a treatment for life-threatening cardiac arrhythmias, specifically ventricular fibrillation (V-Fib) and non-perfusing ventricular tachycardia (V-Tach). A defibrillator delivers a dose of electric current to the heart. Although not fully understood, this process depolarizes a large amount of the heart muscle, ending the arrhythmia. Subsequently, the body's natural pacemaker in the sinoatrial node of the heart is able to re-establish normal sinus rhythm. A heart which is in asystole (flatline) cannot be restarted by a defibrillator, but would be treated by cardiopulmonary resuscitation (CPR).
Atrial natriuretic peptide (ANP) or atrial natriuretic factor (ANF) is a natriuretic peptide hormone secreted from the cardiac atria that in humans is encoded by the NPPA gene. Natriuretic peptides are a family of hormone/paracrine factors that are structurally related. The main function of ANP is causing a reduction in expanded extracellular fluid (ECF) volume by increasing renal sodium excretion. ANP is synthesized and secreted by cardiac muscle cells in the walls of the atria in the heart. These cells contain volume receptors which respond to increased stretching of the atrial wall due to increased atrial blood volume.
The sinoatrial node is an oval shaped region of special cardiac muscle in the upper back wall of the right atrium made up of cells known as pacemaker cells. The sinus node is approximately 15 mm long, 3 mm wide, and 1 mm thick, located directly below and to the side of the superior vena cava.
Diastole is the relaxed phase of the cardiac cycle when the chambers of the heart are re-filling with blood. The contrasting phase is systole when the heart chambers are contracting. Atrial diastole is the relaxing of the atria, and ventricular diastole the relaxing of the ventricles.
Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria of the heart. Some flow is a normal condition both pre-birth and immediately post-birth via the foramen ovale; however, when this does not naturally close after birth it is referred to as a patent (open) foramen ovale (PFO). It is common in patients with a congenital atrial septal aneurysm (ASA).
Cardiac electrophysiology is a branch of cardiology and basic science focusing on the electrical activities of the heart. The term is usually used in clinical context, to describe studies of such phenomena by invasive (intracardiac) catheter recording of spontaneous activity as well as of cardiac responses to programmed electrical stimulation - clinical cardiac electrophysiology. However, cardiac electrophysiology also encompasses basic research and translational research components. Specialists studying cardiac electrophysiology, either clinically or solely through research, are known as cardiac electrophysiologists.
The atrium is one of two upper chambers in the heart that receives blood from the circulatory system. The blood in the atria is pumped into the heart ventricles through the atrioventricular valves.
The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next. It consists of two periods: one during which the heart muscle relaxes and refills with blood, called diastole, following a period of robust contraction and pumping of blood, called systole. After emptying, the heart immediately relaxes and expands to receive another influx of blood returning from the lungs and other systems of the body, before again contracting to pump blood to the lungs and those systems. A normally performing heart must be fully expanded before it can efficiently pump again. Assuming a healthy heart and a typical rate of 70 to 75 beats per minute, each cardiac cycle, or heartbeat, takes about 0.8 second to complete the cycle. There are two atrial and two ventricle chambers of the heart; they are paired as the left heart and the right heart—that is, the left atrium with the left ventricle, the right atrium with the right ventricle—and they work in concert to repeat the cardiac cycle continuously. At the start of the cycle, during ventricular diastole–early, the heart relaxes and expands while receiving blood into both ventricles through both atria; then, near the end of ventricular diastole–late, the two atria begin to contract, and each atrium pumps blood into the ventricle below it. During ventricular systole the ventricles are contracting and vigorously pulsing two separated blood supplies from the heart—one to the lungs and one to all other body organs and systems—while the two atria are relaxed. This precise coordination ensures that blood is efficiently collected and circulated throughout the body.
John G. Webster is an American electrical engineer and a founding pioneer in the field of biomedical engineering. In 2008, Professor Webster was awarded the University of Wisconsin, College of Engineering, Polygon Engineering Council Outstanding Instructor Award.
Morton Maimon Mower was an American cardiologist specializing in electrophysiology and the co-inventor of the automatic implantable cardioverter defibrillator. He served in several professional capacities at Sinai Hospital and Cardiac Pacemakers Inc. In 1996, he became the chairman and chief executive officer of Mower Research Associates. He was inducted into the National Inventors Hall of Fame in 2002 for the development of the automatic implantable cardioverter defibrillator with Michel Mirowski in the 1970s. He continued his research in the biomechanical engineering laboratories at Johns Hopkins University.
Right atrial pressure (RAP) is the blood pressure in the right atrium of the heart. RAP reflects the amount of blood returning to the heart and the ability of the heart to pump the blood into the arterial system. RAP is often nearly identical to central venous pressure (CVP), although the two terms are not identical, as a pressure differential can sometimes exist between the venae cavae and the right atrium. CVP and RAP can differ when venous tone is altered. This can be graphically depicted as changes in the slope of the venous return plotted against right atrial pressure.
Jonathan L. Halperin is an American cardiologist and the author of Bypass (ISBN 0-89586-509-2), among the most comprehensive works on the subject of coronary artery bypass surgery. In addition, he is the Robert and Harriet Heilbrunn Professor of Medicine at The Mount Sinai School of Medicine as well as Director of Clinical Cardiology in the Zena and Michael A. Wierner Cardiovascular Institute at The Mount Sinai Medical Center, both in New York City. Halperin was the principal cardiologist responsible for both the design and execution of the multi-center Stroke Prevention in Atrial Fibrillation (SPAF) clinical trials, funded by the National Institutes of Health, which helped develop antithrombotic strategies to prevent stroke, and he subsequently directed the SPORTIF clinical trials, which evaluated the first oral direct thrombin inhibitor for prevention of stroke in patients with atrial fibrillation.
A. Marc Gillinov is an American cardiac surgeon at The Cleveland Clinic
Masonic Medical Research Institute (MMRI) is a non-profit medical research center located in Utica, New York. The institute studies experimental cardiology with an emphasis on cardiac arrhythmias, ischemic heart disease and sudden cardiac death. Research topics also include autism, Noonan Syndrome, brown fat, nano-imaging, targeted drug delivery, and more. There are five Principal Investigators at MMRI, each with their own lab, team, and area of study. The Institute's research and staff are independent, but MMRI gets its name from its original funding in 1958 by the Masonic Grand Lodge of New York.
Donald S. Baim was a researcher and clinician in the field of interventional cardiology. Baim's primary research focused on coronary blood flow, catheter intervention in heart disease, and congestive heart failure. His work helped to shift the use of catheters from a purely diagnostic tool to a therapeutic tool. After receiving a medical degree from Yale and initial medical training, residency and a fellowship at Stanford University Medical Center, Baim spent the bulk of his career at Beth Israel Hospital and at the Brigham and Women's Hospital in Boston. In 1993, Baim founded the Beth Israel Hospital's Cardiovascular Data Analysis Center (CDAC) -- later to be named Harvard Clinical Research Institute (HCRI). Baim died of cancer in November 2009. In October 2016, HCRI changed its name to the Baim Institute for Clinical Research.
Martin Lane Scheiner was an American inventor of electronics devices for medical purposes. He founded Electronics for Medicine in 1950, and served as president and research director until selling it to Honeywell in 1979. Scheiner was a dedicated traveler and passionate about social causes.
Bruce B. Lerman is a cardiologist. He is the Hilda Altschul Master Professor of Medicine at Weill Cornell Medical College, and is chief of the Division of Cardiology and director of the Cardiac Electrophysiology Laboratory at Weill Cornell Medicine and the New York Presbyterian Hospital.
