Objective: To describe the functional anatomy of the epicardial veins, including their dimensional changes in systole and diastole, and to relate these observations to the pattern of bloodflow in these veins.
Design: Using quantitative angiography and casts of epicardial veins in dogs, measurements of dimensions and anatomical patterns were observed.
Interventions: Venous angiograms were performed on 21 mongrel dogs. The diameters of epicardial veins in systole and diastole were measured using ECG gating. The dynamic anatomy of epicardial veins observed from video tapes was compared with static images and casts.
Results: The transverse diameter of the epicardial veins was similar in systole and diastole. The accuracy of measurement was limited by definition of the edges of the veins. An area of reduced contrast was observed in the posterior lateral section of the great cardiac vein and the appearance of gaps in the column of contrast material within the epicardial veins was consistently seen.
Conclusions: These observations suggest that flow in epicardial coronary veins occurs as a bolus during each cardiac cycle.