1 Introduction.- 1.1 Goal of CS Catheterization.- 1.2 Objective of the Study.- 2 The Organization of the Cardiac Venous Systems.- 2.1 The Greater (Major) Cardiac Venous System.- 2.2 The Smaller (Minor) Cardiac Venous System.- 2.3 The Compound Form of Cardiac Venous Vessels: Intramural Sinuses and Tunnels.- 3 Nomenclatur.- 3.1 English and Latin Versions.- 3.2 Abbreviations.- 3.3 Commonly Used Unofficial or Alternative Terms and Synonyms for the Cardiac Veins.- 4 Microanatomy of the Coronary Sinus.- 4.1 Anatomy, Position, and Topography.- 4.2 Surface Anatomy.- 4.3 Length and Shape.- 4.4 Diameter, Area of Cross-Section, Circumference, and Volume.- 4.5 Elevation, Curvature, and Ostial Angle.- 4.6 The Ostial Valve.- 4.7 Enlargement of the CS, Aneurysm of the CS.- 4.8 Enlargement of the CS Associated with Persistent Left Superior Vena Cava.- 4.9 Enlargement of the CS Associated with Ostial Occlusion.- 4.10 Duplication of the CS (Sinus Coronarius Duplex).- 4.11 Absence of the CS.- 5 The Myocardial Cover of the Coronary Sinus and Related Veins.- 5.1 The Myocardial Cover of the CS.- 5.1.1 Peculiarity.- 5.2 The Left (Distal) Boundary of the Myocardial Coat of the CS and the Myocardial Cuff of the Terminal GCV.- 5.2.1 The Myocardial Coat of the CS.- 5.2.2 The Myocardial Cuff of the Terminal GCV.- 5.3 The Right (Proximal) Boundary of the Myocardial Coat of the CS.- 5.4 Isolated Myocardial Belts in the Terminal Portions of Other Cardiac Veins.- 5.5 Free Myocardial Cords in the Left Posterior Coronary Sulcus.- 5.6 The Proximal Origin of the CS and Its Landmarks.- 5.6.1 The OV Is the Only Exact Peripheral Landmark for the Origin of the CS.- 5.6.2 Clinical Significance of Accessory Myocardial Cuffs, Belts, and Cords.- 6 The Anatomy of the Veins Draining the Myocardium of Both Ventricles.- 6.1 The Ventricular Cardiac Veins in General.- 6.1.1 The Apical Venous Network.- 6.1.2 Venous Valves.- 6.1.3 Left and Right V entricular Veins.- 6.1.4 Left and Right Atrial Veins.- 6.2 Frequenls˘