Angioplasty opens blocked arteries and restores normal blood flow to your heart muscle. It's not major surgery. It's done by threading a catheter (thin tube) through a small puncture in a leg or arm artery to the heart. The catheter places a tiny balloon at the site of blockage in the artery. When the balloon is inflated, it pushes the plaque flat against the artery wall. This widens the artery and improves blood flow. © AHA