The nurse understands that which of the following medications is a potassium channel blocker?

A. ambulate in the hall 3 times daily without shortness of breath: This directly reflects improved tolerance to activity, the central focus of the nursing diagnosis. Being able to ambulate without dyspnea indicates better cardiac output and ventricular function, marking resolution of the identified problem.

B. have an increase in systolic blood pressure of 20 mmHg during activity: A rise in systolic pressure may occur with exertion, but it does not necessarily indicate improved activity tolerance. In fact, an exaggerated BP response could indicate the heart is working harder than it should to meet the demands, suggesting poor cardiovascular adaptation to exercise.

C. decrease weight from 150 lbs. (68.2 kg.) to 148 lbs. (67.3 kg.) in five days: A slight weight reduction may reflect decreased fluid retention, but this outcome is more relevant to volume status and fluid balance than to resolving activity intolerance specifically.

D. verbalize the signs and symptoms of worsening heart failure by discharge:
While important for client education and self-management, this outcome relates to knowledge rather than physical tolerance to activity. It does not directly measure resolution of activity intolerance.

A. surgery has caused an episode of supraventricular tachycardia: While stress or surgery can trigger arrhythmias, the ECG shown demonstrates a sinus tachycardia pattern (narrow QRS complexes with identifiable P waves before each QRS), not supraventricular tachycardia (SVT), which typically has a very rapid, regular rhythm often without visible P waves.

B. is febrile which is causing the heart rate to be elevated: The client has a temperature of 102°F (38.8°C), which can increase metabolic demand and lead to sinus tachycardia. Fever is a common and expected cause of elevated heart rate, especially when accompanied by infection, such as the client’s post-op wound infection.

C. is in heart failure and the heart rate is elevated to compensate: There is no evidence from the scenario (no dyspnea, crackles, edema, or reduced BP) that supports heart failure. The elevated HR is more directly related to the fever and infection, not cardiac decompensation.

D. probably has a low oxygen saturation causing an increased respiratory rate: The respiratory rate is slightly elevated (22/min), but there is no mention of hypoxia or oxygen saturation levels. Tachycardia secondary to hypoxia would require clinical indicators of respiratory distress or desaturation, which are not demonstrated.