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.
1 Drag is a component of the aerodynamic force, namely the projection onto the direction parallel to the relative wind. 2  Lift is another component of the aerodynamic force, namely the projection onto the two directions perpendicular to the relative wind.  Weight is the force of gravity.