LETTER TO THE EDITOR A 40-year old man with a history of surgically corrected congenital infundibular pulmonal stenosis and subvalvular membranous aortic stenosis presented with symptomatic sick sinus syndrome. Sick sinus syndrome may be related to stretching of the atrioventricular node and bundle of His, often a result of changed hemodynamics due to the underlying congenital disease. Implantation of a DDDR pacemaker was initiated, but positioning of the pacemaker leads proved to be difficult while pushing the lead forward. Radiographic imaging with contrast media was performed, revealing a persistent left superior vena cava (PLSVC). In knowledge of the abnormal anatomy, placement of the atrial and ventricular leads was still challenging but could be completed using fluoroscopy without major problems. The chest radiograph after the procedure showed a left-sided path of both pacemaker leads via the PLSVC (arrowheads), with correct position of the tips in the right atrium (open arrow) and in the right apical ventricle (arrow), suggesting connection