What procedure involves inserting a fine tube into an artery to diagnose and treat heart disease?

The procedure that involves inserting a fine tube into an artery to diagnose and treat heart disease is cardiac catheterization. This minimally invasive technique allows healthcare providers to access the heart's chambers and blood vessels, providing critical information about the heart's function and identifying any blockages or abnormalities.

During cardiac catheterization, a thin catheter is guided through the blood vessels to the heart, where it can help in diagnosing conditions like coronary artery disease, heart valve disease, and congenital heart defects. It can also be used therapeutically, such as to perform angioplasty, where a balloon is used to widen narrowed arteries or to place stents that keep arteries open.

This procedure is essential because it combines both diagnostic and treatment capabilities, allowing for immediate intervention if necessary. The other options are not procedures involving direct access to the heart: cardiac enzymes pertain to biomarker testing, cardiac output is a physiological measure, and cardiology is the field of medicine focused on heart health rather than a specific procedure.