An 83-year-old lady says she awoke this morning with substernal chest pain. She thought her heart was beating a little fast. She says she felt really dizzy. She was mildly short of breath and felt better when she took a few deep breaths. The patient took some aspirin with no relief. Electrolytes are normal, ECG reviewed shows patient is in atrial fibrillation. She is admitted and started on IV heparin. What is the coding for this case?