Gerbode defect		An unusual variant of atrio-ventricular septal defect, wherein the defect is in the superior portion of the atrio-ventricular septum above the insertion of the septal leaflet of the tricuspid valve, resulting in a direct communication and shunt between the left ventricle and the right atrium. see also atrio-ventricular septum.
Ghent criteria		A set of criteria for the diagnosis of Marfan syndrome, requiring involvement of three organ systems (one system must have "major" involvement), or two organ systems and a positive family history. (DePaepe A, Deitz HC, Devereux RB, et al: Revised diagnostic criteria for the Marfan syndrome. Am J Med Genet 1996;62:417-426)
Glenn shunt (operation)		A palliative operation for the purpose of increasing pulmonary blood flow, hence systemic oxygen saturation, in which a direct anastomosis is created between the superior vena cava and a pulmonary artery. This procedure does not cause systemic ventricular volume overload.
classic Glenn		Anastomosis of the SVC to the distal end of the divided right pulmonary artery with division/ligation of the SVC below the anastomosis. Acquired pulmonary arterio-venous malformations with associated systemic arterial desaturation are a common long-term complication. (Glenn WW. Circulatory bypass of the right side of the heart: IV: Shunt between superior vena cava and distal right pulmonary artery: report of clinical application. N Eng J Med 1958;259:117-120.)
bi-directional Glenn		End-to-side anastomosis of the divided SVC to the undivided pulmonary artery. (Haller JA Jr. et al. Experimental studies in permanent bypass of the right heart. Surgery 1966;59:1128-1132.) (Azzolina G et al. Tricuspid atresia: experience in surgical management with a modified cavo-pulmonary anastomosis. Thorax 1972;27:111-115.) (Hopkins RA et al. Physiologic rationale for a bi-directional cavo-pulmonary shunt. A versatile complement to the Fontan principle. J Thorac Cardiovasc Surg 1985;90:391-398)
Gore-Tex®		A synthetic material often used to fashion conduits and other prosthetic devices for the surgical palliation or repair of congenital heart disease.
GUCH		Grown-Up Congenital Heart disease. A term originated by Dr. Jane Somerville. syn. Adult Congenital Heart Disease