An anatomical study of the human cardiac veins with special reference to the drainage of the great cardiac vein.

Many case reports in which the main aim was to clarify the development of the superior vena cava (SVC) with persistent SVC have so far been published. However, there have only been a few systematic studies of the cardiac veins. Therefore, we macroscopically investigated the cardiac veins using 337 human adult hearts to obtain a detailed understanding of the morphology of the heart. From our study, we obtained the following results. 1. The frequency of persistent left SVC including one case of bilateral SVC was observed to be higher 7 cases (2.1%) than in previous reports. 2. We observed a second case in which the great cardiac vein drained directly into the right SVC (the first case being reported by Bergman et al. 1988). 3. Variations in the drainage of the great cardiac vein (GV) were observed from the right SVC to the left SVC, while the middle cardiac vein (MV) showed less variations of the drainage and course. 4. The drainage boundary between the GV and MV was classified into 3 types: MV-dominant type in 123 cases (36.5%), intermediate type in 182 cases (54.0%), and GV-dominant type in 32 cases (9.5%). From our results, we speculated that the MV did not generate any variations due to its short course before draining into the right atrium, while the GV had many variations due to its long course before draining into the right atrium. From the few GV-dominant types, the halfway boundary between the anterior (GV) and posterior (MV) route for drainage into the right atrium could be considered to be the anterior side rather than the Apex cordis.