A heart cath, or cardiac catheterization, is a heart test used to diagnose heart disease and provide treatment. During the procedure, a catheter is inserted into a blood vessel and travels up to your heart. Dye can be injected so that abnormalities can be seen with an X-ray machine. During a heart catheterization, therapeutic interventions such as angioplasty and stenting may be done as well. Follow the links below to find WebMD's comprehensive coverage about how a heart cath is done, benefits and risks, and much more.