A review of the coronary venous system: a road less travelled.

Compared with the coronary arterial system, less attention has been paid to the coronary venous system. In the current era, there are therapeutic options for arrhythmias and for heart failure that use the coronary venous system to access target areas. We review the arrangement of the main cardiac veins to provide a morphologic background to interventionists. In general, the venous system is a useful conduit for delivery of percutaneous transcatheter treatment. But, variability in terms of valves, diameter, angulation, extent of muscular sleeves, proximity to other cardiac structures, and cross-over spatial relationship with branches of coronary arteries have implications for practitioners seeking to make use of the system.