Cardiac Catheters: Catheters inserted into various locations within the heart for diagnostic or therapeutic purposes.Cardiac Catheterization: Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.Catheters, Indwelling: Catheters designed to be left within an organ or passage for an extended period of time.Catheters: A flexible, tubular device that is used to carry fluids into or from a blood vessel, hollow organ, or body cavity.Myocytes, Cardiac: Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).Catheterization: Use or insertion of a tubular device into a duct, blood vessel, hollow organ, or body cavity for injecting or withdrawing fluids for diagnostic or therapeutic purposes. It differs from INTUBATION in that the tube here is used to restore or maintain patency in obstructions.Catheterization, Central Venous: Placement of an intravenous CATHETER in the subclavian, jugular, or other central vein.Cardiac Output: The volume of BLOOD passing through the HEART per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with STROKE VOLUME (volume per beat).Heart: The hollow, muscular organ that maintains the circulation of the blood.Arrhythmias, Cardiac: Any disturbances of the normal rhythmic beating of the heart or MYOCARDIAL CONTRACTION. Cardiac arrhythmias can be classified by the abnormalities in HEART RATE, disorders of electrical impulse generation, or impulse conduction.Cardiac Surgical Procedures: Surgery performed on the heart.Central Venous Catheters: Catheters that are inserted into a large central vein such as a SUBCLAVIAN VEIN or FEMORAL VEIN.Catheterization, Peripheral: Insertion of a catheter into a peripheral artery, vein, or airway for diagnostic or therapeutic purposes.Death, Sudden, Cardiac: Unexpected rapid natural death due to cardiovascular collapse within one hour of initial symptoms. It is usually caused by the worsening of existing heart diseases. The sudden onset of symptoms, such as CHEST PAIN and CARDIAC ARRHYTHMIAS, particularly VENTRICULAR TACHYCARDIA, can lead to the loss of consciousness and cardiac arrest followed by biological death. (from Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 7th ed., 2005)Urinary Catheterization: Passage of a CATHETER into the URINARY BLADDER or kidney.Equipment Failure: Failure of equipment to perform to standard. The failure may be due to defects or improper use.Urinary Catheters: Catheters inserted into the URINARY BLADDER or kidney for therapeutic or diagnostic purposes.Cardiac Pacing, Artificial: Regulation of the rate of contraction of the heart muscles by an artificial pacemaker.Cardiac Tamponade: Compression of the heart by accumulated fluid (PERICARDIAL EFFUSION) or blood (HEMOPERICARDIUM) in the PERICARDIUM surrounding the heart. The affected cardiac functions and CARDIAC OUTPUT can range from minimal to total hemodynamic collapse.Catheter-Related Infections: Infections resulting from the use of catheters. Proper aseptic technique, site of catheter placement, material composition, and virulence of the organism are all factors that can influence possible infection.Equipment Design: Methods of creating machines and devices.Heart Diseases: Pathological conditions involving the HEART including its structural and functional abnormalities.Electrocardiography: Recording of the moment-to-moment electromotive forces of the HEART as projected onto various sites on the body's surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a CATHODE RAY TUBE DISPLAY.Cardiomegaly: Enlargement of the HEART, usually indicated by a cardiothoracic ratio above 0.50. Heart enlargement may involve the right, the left, or both HEART VENTRICLES or HEART ATRIA. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (HEART FAILURE) or several forms of CARDIOMYOPATHIES.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Myocardium: The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.Heart Ventricles: The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.Myocardial Contraction: Contractile activity of the MYOCARDIUM.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Heart Arrest: Cessation of heart beat or MYOCARDIAL CONTRACTION. If it is treated within a few minutes, heart arrest can be reversed in most cases to normal cardiac rhythm and effective circulation.Catheterization, Swan-Ganz: Placement of a balloon-tipped catheter into the pulmonary artery through the antecubital, subclavian, and sometimes the femoral vein. It is used to measure pulmonary artery pressure and pulmonary artery wedge pressure which reflects left atrial pressure and left ventricular end-diastolic pressure. The catheter is threaded into the right atrium, the balloon is inflated and the catheter follows the blood flow through the tricuspid valve into the right ventricle and out into the pulmonary artery.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Heart Atria: The chambers of the heart, to which the BLOOD returns from the circulation.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Heart Conduction System: An impulse-conducting system composed of modified cardiac muscle, having the power of spontaneous rhythmicity and conduction more highly developed than the rest of the heart.Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.Cardiac Imaging Techniques: Visualization of the heart structure and cardiac blood flow for diagnostic evaluation or to guide cardiac procedures via techniques including ENDOSCOPY (cardiac endoscopy, sometimes refered to as cardioscopy), RADIONUCLIDE IMAGING; MAGNETIC RESONANCE IMAGING; TOMOGRAPHY; or ULTRASONOGRAPHY.Echocardiography: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.Heart Failure: A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (VENTRICULAR DYSFUNCTION), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as MYOCARDIAL INFARCTION.Cardiomyopathies: A group of diseases in which the dominant feature is the involvement of the CARDIAC MUSCLE itself. Cardiomyopathies are classified according to their predominant pathophysiological features (DILATED CARDIOMYOPATHY; HYPERTROPHIC CARDIOMYOPATHY; RESTRICTIVE CARDIOMYOPATHY) or their etiological/pathological factors (CARDIOMYOPATHY, ALCOHOLIC; ENDOCARDIAL FIBROELASTOSIS).Foreign-Body Migration: Migration of a foreign body from its original location to some other location in the body.Myoblasts, Cardiac: Precursor cells destined to differentiate into cardiac myocytes (MYOCYTES, CARDIAC).Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)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.Cardiac Myosins: Myosin type II isoforms found in cardiac muscle.Myocardial Infarction: NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Ventricular Function, Left: The hemodynamic and electrophysiological action of the left HEART VENTRICLE. Its measurement is an important aspect of the clinical evaluation of patients with heart disease to determine the effects of the disease on cardiac performance.Cardiac Volume: The volume of the HEART, usually relating to the volume of BLOOD contained within it at various periods of the cardiac cycle. The amount of blood ejected from a ventricle at each beat is STROKE VOLUME.Cardiac Glycosides: Cyclopentanophenanthrenes with a 5- or 6-membered lactone ring attached at the 17-position and SUGARS attached at the 3-position. Plants they come from have long been used in congestive heart failure. They increase the force of cardiac contraction without significantly affecting other parameters, but are very toxic at larger doses. Their mechanism of action usually involves inhibition of the NA(+)-K(+)-EXCHANGING ATPASE and they are often used in cell biological studies for that purpose.Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.Jugular Veins: Veins in the neck which drain the brain, face, and neck into the brachiocephalic or subclavian veins.Cardiac Output, Low: A state of subnormal or depressed cardiac output at rest or during stress. It is a characteristic of CARDIOVASCULAR DISEASES, including congenital, valvular, rheumatic, hypertensive, coronary, and cardiomyopathic. The serious form of low cardiac output is characterized by marked reduction in STROKE VOLUME, and systemic vasoconstriction resulting in cold, pale, and sometimes cyanotic extremities.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Fluoroscopy: Production of an image when x-rays strike a fluorescent screen.Out-of-Hospital Cardiac Arrest: Occurrence of heart arrest in an individual when there is no immediate access to medical personnel or equipment.Subclavian Vein: The continuation of the axillary vein which follows the subclavian artery and then joins the internal jugular vein to form the brachiocephalic vein.Heart Transplantation: The transference of a heart from one human or animal to another.Ventricular Remodeling: The geometric and structural changes that the HEART VENTRICLES undergo, usually following MYOCARDIAL INFARCTION. It comprises expansion of the infarct and dilatation of the healthy ventricle segments. While most prevalent in the left ventricle, it can also occur in the right ventricle.Pulmonary Veins: The veins that return the oxygenated blood from the lungs to the left atrium of the heart.Heart Defects, Congenital: Developmental abnormalities involving structures of the heart. These defects are present at birth but may be discovered later in life.Troponin I: One of the three polypeptide chains that make up the TROPONIN complex. It inhibits F-actin-myosin interactions.Stroke Volume: The amount of BLOOD pumped out of the HEART per beat, not to be confused with cardiac output (volume/time). It is calculated as the difference between the end-diastolic volume and the end-systolic volume.