Spatial relationship of coronary sinus-great cardiac vein to mitral valve annulus and left circumflex coronary artery: implications for cardiovascular interventional procedures

Abstract

Background: The spatial relationship of the coronary sinus-great cardiac vein (CS-GCV) to free posterior portion of the mitral valve annulus (MVA) and left circumflex coronary artery (LCx) has gained importance with the advent of cardiovascular interventional procedures such as percutaneous transvenous mitral annuloplasty (PTMA) and mitral isthmus (MI) ablation.

Methods: In 50 normal (nondilated cardiomyopathy, or non-DCM) and 20 dilated cardiomyopathy (DCM) cadaveric hearts, the diameter and distance from the MVA of CS-GCV and its spatial relationship to LCx along the free posterior portion of the MVA were studied.

Results: The diameter of the CS-GCV increased from the beginning to termination in both non-DCM and DCM cases. The CS-GCV was located farthest from the MVA in the vertical plane in the middle of its course and in the horizontal plane at its beginning. The LCx was located above the CS-GCV in direct contact with the epicardial aspect of MI in 12% non-DCM and 15% DCM cases and was wedged between the CS-GCV and MI in 20% non-DCM and 15% DCM cases.

Conclusions: Knowledge of the separation between the CS-GCV and MVA in the horizontal and vertical planes could help in selecting suitable candidates and the preprocedural prediction of success of PTMA. Awareness of the spatial relationship of LCx with CS-GCV in MI would help to reduce the risk of incomplete MI block due to a heat sink effect or damage to the LCx by direct thermal injury during MI ablation.

Keywords: Ablation; Coronary sinus–great cardiac vein; Left circumflex coronary artery; Mitral isthmus; Mitral valve annulus; Percutaneous transvenous mitral annuloplasty.