Digitalis digitalis. As a result of increased contractility, stroke volume is increased. Ultimately, digitalis increases cardiac output (Cardiac Output=Stroke Volume x Heart Rate). This is the mechanism that makes this drug a popular treatment for congestive heart failure, which is characterized by low cardiac output. Digitalis also has a vagal effect on the parasympathetic nervous system, and as such is used in re-entrant cardiac arrhythmias and to slow the ventricular rate during atrial fibrillation. The dependence on the vagal effect means digitalis is not effective when a patient has a high sympathetic nervous system drive, which is the case with acutely
Nothing comes from nothing Nothing comes from nothing Nothing comes from nothing () is a philosophical expression of a thesis first argued by Parmenides. It is associated with ancient Greek cosmology, such as is presented not just in the works of Homer and Hesiod, but also in virtually every internal system—there is no break in-between a world that did not exist and one that did, since it could not be created in the first place. The idea that "nothing comes from nothing", as articulated by Parmenides, first appears in his "Physics": The above, in a translation based on the John Burnet translation, appears as