Balloon angioplasty: arteriogram of an adult human heart showing a balloon catheter being used to compress an atheroma plaque that has formed inside the circumflex coronary artery. The inflated balloon is coloured orange; the whip- like catheter is in red. Technically known as Percutaneous Transluminal Coronary Angioplasty - PTCA), a digital X-ray system is used to guide a catheter fitted with a cigar-shaped inflatable balloon into the obstructed coronary artery. When the deflated balloon reaches the obstruction it is carefully inflated to compress the plaque, thus relieving the obstruction & restoring the flow of blood.