A sterile, steerable, flexible tube containing electrodes intended to be introduced percutaneously into the heart chambers in order to provide a pathway for the controlled delivery and support of a selective infusion of fluids or transvenous devices to the heart (e.g., the coronary sinus) and coronary vasculature. It may also be used in the evaluation of cardiac arrhythmias from endocardial and intravascular sites. It is typically made of plastic with embedded electrodes often of platinum (Pt), iridium, or a composite and have an actuator mechanism located at the proximal end used to steer the tip in the desired direction. This is a single-use device.