Hello Nini. I have had a few angiograms and 2 x angioplasty to have stents fitted following MI's. My local hospital in Bournemouth prefers to use the groin for both of these procedures, as did Hammersmith, in the case of my sister. I understand this to be similar for many hospitals.
The angiogram is a very simple and painless procedure giving one, if required, the opportunity to view the heart on monitor - which I did. I understand why this procedure is called 'invasive' though it certainly felt nothing like that.
I have also had a perfusion MRI scan which is classed as non-invasive. After fitting a cannula in both wrists, one's heart is scanned at length. One is told when to breath - in and out - and when to hold one's breath. One is then injected into one cannula and and the heart is re-scanned. I was given a panic button to press if I found it all too much. I must say that I was very surprised at the speed in which the injection worked and I cannot say I found it a very pleasant experience. I was sorely tempted, more than once, to press that button, but having been engaged in a lengthy debate with the cardiologist that I was not suffering mere indigestion I persisted with the scan. I must add that it was this scan alone which persuaded the surgeon to give me my first 2 stents and that probably saved my life, so it was worth the unpleasantness.
http://www.heartandmetabolism.org/pdf/38/4.pdf
I know of no other 'manually done angiogram' and wait to be corrected by the experts.
My only advice is to trust in the hospital and wonderful staff, wherever your father is seen and for you not to worry unduly. I am sure he is in good, safe hands. i wish him well with whatever treatment/procedures he is given.