In contrast to cardiac catheterization in adults, cases in patients with structural heart disease are seldom predictable. Even the most routine catheterization in a patient with congenital heart disease can reveal unexpected findings that completely change the expected course of the procedure. With that said, most cases start and proceed in logical sequence. All cases begin with setting up the table and getting access. Hemodynamic assessment is next, usually followed by angiography and, finally, intervention, if warranted. This is the usual sequence, although exceptions do exist.