Figure 4.

Posterolateral and Middle Cardiac Vein: RAO (left panel) and LAO (right panel) projections showing a typical anastomotic vein between the posterior and anterior circulation that traverses the lateral wall. Placing a lead via either of these veins using the anastomosis is entirely identical to pacing the lateral wall through a vein through a direct lateral vein. When difficulty occurs in negotiating a lateral vein, using an anterior or posterior vein and the linking anastomosis should be considered.