3 patients (rows A, B, C), each with whole heart MRI angiogram (left column), X-ray angiogram (middle) and implanted LV lead (right). GCV = great cardiac vein, PV = posterior vein, CS = coronary sinus, RA = right atrium. Vein bifurcations are marked with numbers. Patient A has 2 bifurcations, where bifurcation 1 was used for implantation. Patient B has 1 bifurcation used for implantation. Patient C has 1 bifurcation very close to the CS, implantation in this patient was not successful due to lack of a viable lateral branch.