CURNIS, A., et al.: Implantation of a Single Chamber Pacemaker in Patients with Triple Mechanical Valve Prosthesis: Utilization of Coronary Sinus Distal Branches to Stimulate the Left Ventricle. The implantation of a permanent pacemaker and its relative leads is still a challenge in patients with mechanical tricuspid valve prosthesis. The implant is usually performed epicardially or during valve replacement to avoid any damage to the valve and/or early damages to the lead. We describe the case of a patient with a tricuspid valve prosthesis implanted with a permanent single-chamber pacemaker using an endocardial lead positioned in a distal branch of the coronary sinus to stimulate the left ventricle.