Interventional challenges due to venous occlusion during cardiac resynchronization therapy in patients with prior cardioverter-defibrillator implantation: Case report

Summary– Cardiac resynchronization therapy has become a mainstay of treatment for advanced systolic heart failure refractory to medical management. However, several limitations may affect this therapy, including a non-response rate of nearly 30%, failure to implant the leads via conventional transvenous route in an optimal location, and inability to cannulate the coronary sinus branches due to difficult anatomy or presence of venous valves. Venous occlusion may also present as a potential obstacle in patients with prior implantation of cardioverter-defibrillator. Presently described are cases of 2 patients with venous occlusion.