Hypoplastic Left Heart Syndrome: A condition caused by underdevelopment of the whole left half of the heart. It is characterized by hypoplasia of the left cardiac chambers (HEART ATRIUM; HEART VENTRICLE), the AORTA, the AORTIC VALVE, and the MITRAL VALVE. Severe symptoms appear in early infancy when DUCTUS ARTERIOSUS closes.Norwood Procedures: A set of surgical procedures performed to establish sufficient outflow to the systemic circulation in individuals with univentricular congenital heart malformations, such as HYPOPLASTIC LEFT HEART SYNDROME, and MITRAL VALVE atresia, associated with systemic outflow obstruction. Follow-on surgeries may be performed and consist of a HEMI-FONTAN PROCEDURE as the stage 2 Norwood procedure and a FONTAN PROCEDURE as the stage 3 Norwood procedure.Heart Defects, Congenital: Developmental abnormalities involving structures of the heart. These defects are present at birth but may be discovered later in life.Palliative Care: Care alleviating symptoms without curing the underlying disease. (Stedman, 25th ed)Fontan Procedure: A procedure in which total right atrial or total caval blood flow is channeled directly into the pulmonary artery or into a small right ventricle that serves only as a conduit. The principal congenital malformations for which this operation is useful are TRICUSPID ATRESIA and single ventricle with pulmonary stenosis.Fetal Heart: The heart of the fetus of any viviparous animal. It refers to the heart in the postembryonic period and is differentiated from the embryonic heart (HEART/embryology) only on the basis of time.Fetal Therapies: Prenatal interventions to correct fetal anomalies or treat FETAL DISEASES in utero. Fetal therapies include several major areas, such as open surgery; FETOSCOPY; pharmacological therapy; INTRAUTERINE TRANSFUSION; STEM CELL TRANSPLANTATION; and GENETIC THERAPY.Infant, Newborn: An infant during the first month after birth.Cardiac Surgical Procedures: Surgery performed on the heart.Heart Bypass, Right: Diversion of the flow of blood from the entrance to the right atrium directly to the pulmonary arteries, avoiding the right atrium and right ventricle (Dorland, 28th ed). This a permanent procedure often performed to bypass a congenitally deformed right atrium or right ventricle.Pulmonary Artery: The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs.Aortic Coarctation: A birth defect characterized by the narrowing of the AORTA that can be of varying degree and at any point from the transverse arch to the iliac bifurcation. Aortic coarctation causes arterial HYPERTENSION before the point of narrowing and arterial HYPOTENSION beyond the narrowed portion.Ultrasonography, Prenatal: The visualization of tissues during pregnancy through recording of the echoes of ultrasonic waves directed into the body. The procedure may be applied with reference to the mother or the fetus and with reference to organs or the detection of maternal or fetal disease.Syndrome: A characteristic symptom complex.Blalock-Taussig Procedure: A cardiovascular procedure performed to create a blood supply to the PULMONARY CIRCULATION. It involves making a connection between the subclavian, or carotid branch of the AORTA, or the AORTIC ARCH to the PULMONARY ARTERY.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.Anastomosis, Surgical: Surgical union or shunt between ducts, tubes or vessels. It may be end-to-end, end-to-side, side-to-end, or side-to-side.Heart Septal Defects, Atrial: Developmental abnormalities in any portion of the ATRIAL SEPTUM resulting in abnormal communications between the two upper chambers of the heart. Classification of atrial septal defects is based on location of the communication and types of incomplete fusion of atrial septa with the ENDOCARDIAL CUSHIONS in the fetal heart. They include ostium primum, ostium secundum, sinus venosus, and coronary sinus defects.Ventricular Function, Right: The hemodynamic and electrophysiological action of the right HEART VENTRICLE.Endocardial Fibroelastosis: A condition characterized by the thickening of ENDOCARDIUM due to proliferation of fibrous and elastic tissue, usually in the left ventricle leading to impaired cardiac function (CARDIOMYOPATHY, RESTRICTIVE). It is most commonly seen in young children and rarely in adults. It is often associated with congenital heart anomalies (HEART DEFECTS CONGENITAL;) INFECTION; or gene mutation. Defects in the tafazzin protein, encoded by TAZ gene, result in a form of autosomal dominant familial endocardial fibroelastosis.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.Pulmonary Circulation: The circulation of the BLOOD through the LUNGS.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.Aortic Valve: The valve between the left ventricle and the ascending aorta which prevents backflow into the left ventricle.Prenatal Diagnosis: Determination of the nature of a pathological condition or disease in the postimplantation EMBRYO; FETUS; or pregnant female before birth.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.Vascular Fistula: An abnormal passage between two or more BLOOD VESSELS, between ARTERIES; VEINS; or between an artery and a vein.Pulmonary Veins: The veins that return the oxygenated blood from the lungs to the left atrium of the heart.Aorta, Thoracic: The portion of the descending aorta proceeding from the arch of the aorta and extending to the DIAPHRAGM, eventually connecting to the ABDOMINAL AORTA.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Echocardiography: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.Heart Transplantation: The transference of a heart from one human or animal to another.Abnormalities, MultipleGestational Age: The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated as the time from the last day of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization.Echocardiography, Doppler, Color: Echocardiography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image.Cardiac Catheterization: Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.Transposition of Great Vessels: A congenital cardiovascular malformation in which the AORTA arises entirely from the RIGHT VENTRICLE, and the PULMONARY ARTERY arises from the LEFT VENTRICLE. Consequently, the pulmonary and the systemic circulations are parallel and not sequential, so that the venous return from the peripheral circulation is re-circulated by the right ventricle via aorta to the systemic circulation without being oxygenated in the lungs. This is a potentially lethal form of heart disease in newborns and infants.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.Coronary Vessel Anomalies: Malformations of CORONARY VESSELS, either arteries or veins. Included are anomalous origins of coronary arteries; ARTERIOVENOUS FISTULA; CORONARY ANEURYSM; MYOCARDIAL BRIDGING; and others.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.Heart: The hollow, muscular organ that maintains the circulation of the blood.Heart Bypass, Left: Diversion of the flow of blood from the pulmonary veins directly to the aorta, avoiding the left atrium and the left ventricle (Dorland, 27th ed). This is a temporary procedure usually performed to assist other surgical procedures.Echocardiography, Doppler: Measurement of intracardiac blood flow using an M-mode and/or two-dimensional (2-D) echocardiogram while simultaneously recording the spectrum of the audible Doppler signal (e.g., velocity, direction, amplitude, intensity, timing) reflected from the moving column of red blood cells.Cardiopulmonary Bypass: Diversion of the flow of blood from the entrance of the right atrium directly to the aorta (or femoral artery) via an oxygenator thus bypassing both the heart and lungs.Postoperative Period: The period following a surgical operation.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Aorta: The main trunk of the systemic arteries.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Pregnancy Outcome: Results of conception and ensuing pregnancy, including LIVE BIRTH; STILLBIRTH; SPONTANEOUS ABORTION; INDUCED ABORTION. The outcome may follow natural or artificial insemination or any of the various ASSISTED REPRODUCTIVE TECHNIQUES, such as EMBRYO TRANSFER or FERTILIZATION IN VITRO.Cardiovascular Surgical Procedures: Surgery performed on the heart or blood vessels.Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.