Cardiac Resynchronization Therapy Implantation in a Double‐Barrel Coronary Sinus

BACKGROUND: Anatomical variations of the coronary sinus (CS) may complicate left ventricular lead placement during cardiac resynchronization therapy (CRT). A rare variant, the double-barrel coronary sinus, can result in inadvertent cannulation of non-target tributaries and procedural difficulty. CASE SUMMARY: We report a 45-year-old woman with symptomatic heart failure, left bundle branch block (LBBB), severe left ventricular dysfunction, and left ventricular dyssynchrony who underwent CRT implantation. Levophase coronary angiography demonstrated a double-barrel coronary sinus, with one channel continuing from the posterolateral vein and the other from the anterior interventricular vein. Repeated attempts to access the posterolateral vein preferentially entered the anterior interventricular vein. A modified pull-back technique using a sheath and dual guidewires enabled successful cannulation of the posterolateral branch. Left ventricular lead placement was achieved, resulting in significant QRS narrowing and marked clinical improvement. CONCLUSION: Recognition of double-barrel coronary sinus anatomy and use of alternative wiring techniques can facilitate successful CRT implantation.