Intra-Aortic Balloon Pumping: Counterpulsation in which a pumping unit synchronized with the patient's electrocardiogram rapidly fills a balloon in the aorta with helium or carbon dioxide in early diastole and evacuates the balloon at the onset of systole. As the balloon inflates, it raises aortic diastolic pressure, and as it deflates, it lowers aortic systolic pressure. The result is a decrease in left ventricular work and increased myocardial and peripheral perfusion.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.Aortic Valve Stenosis: A pathological constriction that can occur above (supravalvular stenosis), below (subvalvular stenosis), or at the AORTIC VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.Angioplasty, Balloon: Use of a balloon catheter for dilation of an occluded artery. It is used in treatment of arterial occlusive diseases, including renal artery stenosis and arterial occlusions in the leg. For the specific technique of BALLOON DILATION in coronary arteries, ANGIOPLASTY, BALLOON, CORONARY is available.Balloon Occlusion: Use of a balloon CATHETER to block the flow of blood through an artery or vein.Superficial Back Muscles: The top layer of the back muscles whose function is to move the SCAPULA. This group of muscles consists of the trapezius, latissimus dorsi, rhomboid major, rhomboid minor and levator scapulae.Observer Variation: The failure by the observer to measure or identify a phenomenon accurately, which results in an error. Sources for this may be due to the observer's missing an abnormality, or to faulty technique resulting in incorrect test measurement, or to misinterpretation of the data. Two varieties are inter-observer variation (the amount observers vary from one another when reporting on the same material) and intra-observer variation (the amount one observer varies between observations when reporting more than once on the same material).Gastric Balloon: An inflatable device implanted in the stomach as an adjunct to therapy of morbid obesity. Specific types include the silicone Garren-Edwards Gastric Bubble (GEGB), approved by the FDA in 1985, and the Ballobes Balloon.Angioplasty, Balloon, Coronary: Dilation of an occluded coronary artery (or arteries) by means of a balloon catheter to restore myocardial blood supply.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Coronary Circulation: The circulation of blood through the CORONARY VESSELS of the HEART.Assisted Circulation: Pumping that aids the natural activity of the heart. (Dorland, 27th ed)Shock, Cardiogenic: Shock resulting from diminution of cardiac output in heart disease.Transducers, Pressure: Transducers that are activated by pressure changes, e.g., blood pressure.Subclavian Artery: Artery arising from the brachiocephalic trunk on the right side and from the arch of the aorta on the left side. It distributes to the neck, thoracic wall, spinal cord, brain, meninges, and upper limb.Heart-Assist Devices: Small pumps, often implantable, designed for temporarily assisting the heart, usually the LEFT VENTRICLE, to pump blood. They consist of a pumping chamber and a power source, which may be partially or totally external to the body and activated by electromagnetic motors.Counterpulsation: A technique for assisting the circulation by decreasing the afterload of the left ventricle and augmenting the diastolic pressure. It may be achieved by intra-aortic balloon, or by implanting a special pumping device in the chest, or externally by applying a negative pressure to the lower extremities during cardiac systole.Coronary Artery Bypass: Surgical therapy of ischemic coronary artery disease achieved by grafting a section of saphenous vein, internal mammary artery, or other substitute between the aorta and the obstructed coronary artery distal to the obstructive lesion.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.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.Cardiac Surgical Procedures: Surgery performed on the heart.Hydrazones: Compounds of the general formula R:N.NR2, as resulting from the action of hydrazines with aldehydes or ketones. (Grant & Hackh's Chemical Dictionary, 5th ed)Polyurethanes: A group of thermoplastic or thermosetting polymers containing polyisocyanate. They are used as ELASTOMERS, as coatings, as fibers and as foams.Aortic Valve: The valve between the left ventricle and the ascending aorta which prevents backflow into the left ventricle.Marketing: Activity involved in transfer of goods from producer to consumer or in the exchange of services.Ventricular Outflow Obstruction: Occlusion of the outflow tract in either the LEFT VENTRICLE or the RIGHT VENTRICLE of the heart. This may result from CONGENITAL HEART DEFECTS, predisposing heart diseases, complications of surgery, or HEART NEOPLASMS.Cardiomyopathy, Hypertrophic: A form of CARDIAC MUSCLE disease, characterized by left and/or right ventricular hypertrophy (HYPERTROPHY, LEFT VENTRICULAR; HYPERTROPHY, RIGHT VENTRICULAR), frequent asymmetrical involvement of the HEART SEPTUM, and normal or reduced left ventricular volume. Risk factors include HYPERTENSION; AORTIC STENOSIS; and gene MUTATION; (FAMILIAL HYPERTROPHIC CARDIOMYOPATHY).Heart Septum: This structure includes the thin muscular atrial septum between the two HEART ATRIA, and the thick muscular ventricular septum between the two HEART VENTRICLES.Mitral Valve Insufficiency: Backflow of blood from the LEFT VENTRICLE into the LEFT ATRIUM due to imperfect closure of the MITRAL VALVE. This can lead to mitral valve regurgitation.Mitral Valve: The valve between the left atrium and left ventricle of the heart.Cardiac Catheterization: Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.Chondromalacia Patellae: A degeneration of the ARTICULAR CARTILAGE of the PATELLA, caused by a decrease in sulfated MUCOPOLYSACCHARIDES in the ground substance. When accompanied by pain, it is sometimes considered part of or confused with PATELLOFEMORAL PAIN SYNDROME.Patellofemoral Joint: The articulation between the articular surface of the PATELLA and the patellar surface of the FEMUR.Research Report: Detailed account or statement or formal record of data resulting from empirical inquiry.Alloys: A mixture of metallic elements or compounds with other metallic or metalloid elements in varying proportions.Absorbable Implants: Implants constructed of materials designed to be absorbed by the body without producing an immune response. They are usually composed of plastics and are frequently used in orthopedics and orthodontics.Titanium: A dark-gray, metallic element of widespread distribution but occurring in small amounts; atomic number, 22; atomic weight, 47.90; symbol, Ti; specific gravity, 4.5; used for fixation of fractures. (Dorland, 28th ed)Hydrostatic Pressure: The pressure due to the weight of fluid.Nickel: A trace element with the atomic symbol Ni, atomic number 28, and atomic weight 58.69. It is a cofactor of the enzyme UREASE.Patents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Iliac Artery: Either of two large arteries originating from the abdominal aorta; they supply blood to the pelvis, abdominal wall and legs.Femoral Artery: The main artery of the thigh, a continuation of the external iliac artery.Leg: The inferior part of the lower extremity between the KNEE and the ANKLE.PyridazinesAngioscopes: Endoscopes used for viewing the interior of blood vessels.Surgical Instruments: Hand-held tools or implements used by health professionals for the performance of surgical tasks.Cellular Phone: Analog or digital communications device in which the user has a wireless connection from a telephone to a nearby transmitter. It is termed cellular because the service area is divided into multiple "cells." As the user moves from one cell area to another, the call is transferred to the local transmitter.Hospital Rapid Response Team: Multidisciplinary team most frequently consisting of INTENSIVE CARE UNIT trained personnel who are available 24 hours per day, 7 days per week for evaluation of patients who develop signs or symptoms of severe clinical deterioration.Equipment Design: Methods of creating machines and devices.DNA Repair: The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.Steel: A tough, malleable, iron-based alloy containing up to, but no more than, two percent carbon and often other metals. It is used in medicine and dentistry in implants and instrumentation.