Sonja is a fictional character from the Underworld series of films. This character is the daughter of the vampire elder Viktor, introduced by flashback, in Underworld. Red Sonja, the She-Devil with a Sword, is a fictional character who first appeared in Conan the Barbarian #23 (Marvel Comics).
tetralogy (plural tetralogies) 1  A set of four works of art that are connected, and that can be seen either as a single work or as four individual works. They are commonly found in literature, film, or video games. ( 2 medicine) A combination of four symptoms.
Tetralogy of Fallot (TOF) is a congenital heart defect that is present at birth. Symptoms include episodes of bluish color to the skin. When affected babies cry or have a bowel movement, they may develop a tet spell where they turn very blue, have difficulty breathing, become limp, and occasionally lose consciousness. Other symptoms may include a heart murmur, finger clubbing, and easy tiring upon breastfeeding. The cause is typically not known.