Carl Edwards is a 75-years old man with congestive heart failure. Having sustained three myocardial infarction in the 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 vitals signs are assessed, and an IV is inserted. He currently denies chest pain, but experiencing some shortness of breath, and is placed on 2L of oxygen via nasal cannula .Which of his medications might be contributing to his symptoms of generalized weakness and heart irregularities?