Why are the criteria for Vasopressin dosings categorized by Asystole, V-fib and V-tach? Should it not be for severe/acute phase hypotension and cardiogenic shock? Vasopressin has no direct effect on spontaneous return of circulation as it is listed here since it is simply antidiuretic hormone. It has no direct inotropic or chronotropic function, just an indirect effect due to the rise in blood pressure.