Left ventricular pacing via the coronary sinus is being increasingly used. There is little data to guide possible lead extractions that might be required in the future. Significant adhesions to the coronary veins were found 12 years after placing a pacing lead in the posterolateral coronary vein in a man with double inlet left ventricle and severe subpulmonary stenosis who had undergone a Fontan operation. The appearances suggest that percutaneous extraction from the proximal coronary sinus may be feasible but that difficulty may be encountered if the lead tip is placed into the distal coronary veins.