1 AFib reduces the ability of the atria to pump blood into the ventricles, and usually causes the heart to beat too rapidly. 2  One-half million new cases of atrial fibrillation are diagnosed every year in the U.S., and billions of dollars are spent annually on its diagnosis and treatment.
noun, (used with a singular verb) 1. the branch of mechanics that deals with the motion of air and other gases and with the effects of such motion on bodies in the medium. Compare aerostatics (def 1). Origin of aerodynamics.
Aerodynamics, from Greek á¼Î®Ï aer (air) + Î´ÏÎ½Î±Î¼Î¹ÎºÎ® (dynamics), is a branch of Fluid dynamics concerned with studying the motion of air, particularly when it interacts with a solid object, such as an airplane wing.n aerodynamics, hypersonic speeds are speeds that are highly supersonic. In the 1970s, the term generally came to refer to speeds of Mach 5 (5 times the speed of sound) and above. The hypersonic regime is a subset of the supersonic regime.