When can I expect the results for cardiac catheterization to be available?

Usually right away. In general, your cardiologist will speak to you (and perhaps your family members) right after your angiogram. But of course, everything is individualised to the patient and the situation so speak to your cardiologist beforehand to ask when you can expect to discuss what is seen during the procedure with her/him.
Immediately. Your cardiologist is viewing the images as being obtained and therefore the results are available as soon as report is completed.