A 45-Year-Old Man Is Admitted to the ED After Developing

A 45-year-old man is admitted to the ED after developing severe chest pain while raking leaves.On admission,he has midchest dullness and a normal electrocardiogram (ECG) .The physician schedules the patient for cardiac catheterization with coronary angiography and possible percutaneous coronary intervention (PCI) .The nurse prepares the patient for the procedure by explaining that,in his case,it is used for which of the following purposes?

A) To determine whether the walls or chambers of the patient's heart have any structural defects
B) To determine whether any obstructions are present in his coronary arteries and to test for an allergy to thrombolytic agents
C) To measure the amount of blood being pumped from his heart with each contraction to determine whether the heart is damaged
D) To visualize any blockages in the coronary arteries and,if necessary,to dilate an obstructed artery with the use of a small balloon