Carl Edwards is a 75-year-old man with congestive heart failure. Having sustained three myocardial infarctions in the last 40 years, he has decreased left ventricular function. Mr. Edwards takes Digoxin, Capoten, Coreg, and Lasix for management of this disease. Today he presents to the emergency department with fatigue, generalized weakness, and feelings of "skipping" heartbeats. Upon arrival, he is placed on the cardiac monitor, his vital signs are assessed, and an IV is inserted. He currently denies chest pain but is experiencing some shortness of breath and is placed on 2 L of oxygen via nasal cannula. His medications might be contributing to his symptoms of generalized weakness and heart irregularities. Assess to correlate his left-sided heart failure to what clinical manifestations should you do his medications treat his congestive heart failure? How do his medications affect the effects of Digoxin? How does the hypokalemia affect the effects of Digoxin?