We present a case of a 58-year-old man. Due to high-degree mitral regurgitation an anuloplasty device (MONARCtrade mark) was inserted. During continuous pacing, inter- and intraventricular asynchrony occurred and heart failure worsened. The indication for cardiac resynchronization was established. A biventricular ICD was successfully inserted with the left ventricular approach via the coronary sinus over the MONARCtrade mark device (Edward Lifescience, Irvine, CA, USA). Biventricular pacing significantly shortened the QRS duration and improved the clinical status as well as the 6-minute walking test.