The office receives a follow-up visit from a 54-year-old man who has nonischemic cardiomyopathy. He currently experiences dyspnea with light exertion due to acute decompensated heart failure for which he has regularly been hospitalized. Along with taking several drugs, the patient has a history of hypertension. With a steady pulse of 72 beats per minute, blood pressure measures 116/70 mm Hg. Bibasilar lung crackles, increased jugular venous pressure, and edema in the lower extremities are all visible during a physical examination. Both serum potassium and serum creatinine are 1.0 mg/dL and 4.2 mEq/L, respectively. The patient reports symptom relief three weeks after beginning digoxin treatment. Which of the following is the initial cellular event triggering this response to the new medication?

Question

Quizplus · Accepted Answer

Eductional Objective: A decrease in sodium efflux and a rise in intracellular sodium levels result from digoxin's direct inhibition of the Na-K-ATPase pump in cardiac cells. Because of the increased intracellular calcium concentration and enhanced myocyte contractility brought on by a reduction in the sodium-calcium exchanger's forward action.

The Office Receives a Follow-Up Visit from a 54-Year-Old Man