The nurse administers a beta-adrenergic agent to a patient with congestive heart failure.What assessment findings would indicate the drug was working?

A) Heart rate changes from 92 beats/min to 76 beats/min.
B) Cardiac monitor shows narrowing of the QRS segment.
C) There is tingling in the fingers and toes.
D) There is increased urine output.

Beta-adrenergic blockers reduce heart rate and myocardial oxygen demand,and improve contractility of the heart.Therefore,the patient's reduced rate would be an expected finding that indicates the drug is working.Beta blockers would not alter the movement of the electrical impulse through the ventricle,so there should be no change in QRS appearance.There would be no expectation of tingling in the hands and feet after taking a beta blocker.Increased urine output would be anticipated with use of diuretics,but the only improvement in urine output with beta blockers would be indirect if the patient had reduced kidney perfusion.This would not be a primary anticipated effect.