Correlative anatomy for the electrophysiologist, Part I: the pericardial space, oblique sinus, transverse sinus

There is an increasing need for invasive electrophysiologists to appreciate the exact anatomy of the epicardial space and the coronary veins. The location of the epicardial fat, the complementary relationship with the main cardiac veins, and the location of sensitive structures (arteries, phrenic nerve, esophagus) have become required knowledge for electrophysiologists, and accessing the epicardial space with this thorough knowledge of the pericardial sinuses and recesses is essential to allow radiographic correlation during catheter manipulation. In this review, we briefly describe the anatomy of the pericardial space and then discuss the specific correlation for the invasive electrophysiologist, highlighting epicardial access, catheter navigation, and avoidance of collateral injury with specific attention to the important recesses of the pericardial space, their regional anatomy, and radiographic correlation when navigating catheters to these locations. We also discuss the anatomy of the main cardiac veins in the context of catheter mapping and ablation of the epicardial substrate through the venous system and without subxiphoid pericardial access. In Part I of this two-part series, we discuss the regional anatomy of the pericardial space, oblique sinus, and transverse sinus.