A 54-Year-Old Man with Nonischemic Cardiomyopathy Comes to the Office

question 122

Multiple Choice

A 54-year-old man with nonischemic cardiomyopathy comes to the office for a follow-up visit.  He has been hospitalized frequently for acute decompensated heart failure, and currently has dyspnea on mild exertion.  The patient also has a history of hypertension and takes multiple medications.  Blood pressure is 116/70 mm Hg, and pulse is 72/min and regular.  Physical examination shows elevated jugular venous pressure, bibasilar lung crackles, and lower extremity edema.  Serum creatinine is 1.0 mg/dL and serum potassium is 4.2 mEq/L.  Three weeks after starting digoxin therapy, the patient reports symptomatic improvement.  Which of the following is the initial cellular event triggering this response to the new medication?

• A)Decreased sodium efflux from myocardial cells
• B)Increased intracellular calcium concentration
• C)Increased intracellular cyclic AMP concentration
• D)Increased potassium influx into myocardial cells
• E)Troponin sensitization to calcium

---

Definitions:

Human Behavior

The array of every physical action and observable emotion associated with individuals, as well as the human race as a whole.

External Influences

Factors outside an individual that affect their behavior, decisions, and attitudes, such as societal norms or environmental conditions.

Negative Punishment

A behavior modification method that involves removing a desirable stimulus to decrease the probability of an undesired behavior occurring.

Driver's License

An official document permitting a specific individual to operate one or more types of motorized vehicles on a public road.