fibrin A stringy protein that is instrumental in blood clotting.
fibrinogen A component of blood that is necessary for clotting. It is converted by enzymes in the blood into fibrin.
fluoroscope An X-ray device that helps to visualize moving images of internal organs such as the heart.
X-rays are passed through the body onto a screen on which an organ can be observed in action.
Foley catheter A catheter used to drain the bladder of urine.
Fontan operation A surgical procedure for certain types of congenital heart disease, in which blood from the atrium is shunted through a conduit to the pulmonary artery.
foramen ovale An opening between the two atria that normally closes after birth. In individual cases, it may remain open and/or be one site of an atrial septal defect.
Friedreich’s ataxia A rare inherited genetic disease in which the nerve fibers break down, resulting in a loss of coordination and balance (ataxia).
fusiform aneurysm A weakening of an area of an artery that goes around its circumference. Blood pools there, causing a bulge that tapers at each end.