A catheter that makes it easier to enter that vessel with other devices or instruments. Guide catheters are used to facilitate the placement of stents, balloons and lasers for angioplasty. Guide catheters are required for all coronary interventions to provide access to the coronary ostium and support equipment delivery. The ideal guide provides stability for device advancement through the coronary anatomy, while minimising vessel trauma and allowing for vessel opacification. An ideal guide catheter should have an atraumatic soft tip, excellent torque control, provide adequate support, and have a low surface frictional resistance to allow for good trackability of balloons and devices. Guide catheters are required for all coronary interventions to provide access to the coronary ostium and support equipment delivery. During a cardiac catheterization, a long, narrow tube called a catheter is inserted through a plastic introducer sheath (a short, hollow tube that is inserted into a blood vessel in your leg or arm). The catheter is guided through the blood vessel to the coronary arteries with the aid of a special x-ray machine.