History: This is an EKG of a 70 yo hispanic female with PMHx significant for hypertension, diabetes, COPD and atrial fibrillation who presents with c/o lightheadedness and feelings of “about to pass out”. The patient states that she has been hospitalized multiple times for fleeting extremity and facial weakness, which she states were diagnosed as TIAs, however she is not a good candidate for anticoagulant therapy secondary to frequent falls and history of SDH. She also tells you that her heart rate has been very hard to control for the past 2 years and that the medications she was taking would not slow her heart down, so she was started on another agent with her last admission 2 month ago. However, she is unable to recall the medication, but notes it has done the trick.

Q: What is the above rhythm and what agents may cause these changes?