Post-angioplasty. Coloured angiogram taken after a percutaneous transluminal coronary angioplasty (PTCA) of the right coronary artery was performed. It was done to treat a severe stenosis (narrowing) affecting the artery in a region at centre left. The blood flow in the artery is also impaired by a blood clot in the same region The PTCA technique involves catheterisation; a special double lumen catheter with a cylindrical-shaped balloon is inserted into the artery. The inflation of the balloon with a pressure up to 620,000 Pascal dilates the narrowed vessel.