Successful implantation of a left ventricular lead in an anomalous coronary sinus.

We describe the case of a 56-year-old man who was referred for CRT implantation and found to have anomalous CS. Catheterization of the CS initially failed due to this anomaly. However, a single large posterior-lateral branch with diminutive CS in the atrioventricular groove allowed for successful implantation of the LV lead.