Variance in coronary venous anatomy: a critical determinant in optimal candidate selection for cardiac resynchronization therapy.

BACKGROUND: Knowledge of coronary sinus (CS) anatomy and its variations is one of the important factors determining the final position of left ventricle pacing lead during cardiac resynchronization therapy.
METHODS: Coronary venous system anatomy, including number, diameter, and opening angles of tributaries, was studied in 50 normal formalin-fixed adult cadaveric hearts.
RESULTS: Thebesian valve (TV) and Vieussens valve were present in 64% and 60% cases, respectively. CS ostium coverage of ≥75% by TV was seen in 25% (8/32) cases. Number of prominent tributaries lying between anterior interventricular vein and middle cardiac vein varied from 1-4. In 28% of hearts, only one prominent tributary was present. Midlateral vein (average diameter 1.75 ± 0.66 mm) with an average distance of 43.5 ± 12.2 mm from coronary ostium was present in 58% (29/50) hearts, of which it formed an acute angle with CS axis in four (13.39%) cases. Posterolateral vein (average diameter 1.62 ± 0.45 mm) with an average distance of 33.4 ± 11.7 mm from coronary ostium was found in 72% (36/50) cases and formed an acute angle with CS in three (8.33%) cases.
CONCLUSIONS: Restrictive TV covering ≥75% CS ostium (25% cases), presence of single prominent tributary (28% cases), and formation of acute angle of tributary with CS axis (1/4 cases with anterolateral vein, 4/29 cases with midlateral vein, 3/36 cases with posterolateral vein, and 3/28 cases with posterior veins of the left ventricle) can impede successful cannulation of CS. ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.