We describe a case of a 76-year-old patient with advanced block in the His-Purkjnie system, who underwent implantation of a cardioverter-defibrillator with cardiac resynchronisation therapy. Complete heart block occurred during the insertion of the coronary sinus cathether. The implantation of the left ventricular (LV) lead was impossible due to difficult anatomy of the coronary venous system. The right ventricular pacing caused the further prolongation of the QRS duration and exacerbation of heart failure symptoms. Thus, the LV lead was successfully implanted during the second procedure after the balloon venoplasty of the lateral cardiac vein. The biventricular pacing was successful during 4 months follow-up.