Angioplasty involves inserting a catheter into an artery through the groin then up into the heart, attached to the catheter is a metal spring loaded tube which is then released into the narrowed or blocked artery thus enabling the blood to flow freely again. All of this takes place with the patient awake and able to watch everything happening on a large monitor over the operating table. I have had this procedure (twice) following a triple by-pass operation. Very dodgy and definitely not reccomended if there is no cardiac resus team available!!!