<prompt> Direct opening in the right atrium withAnterior cardiac veinOblique veinMiddle cardiac veinGreat cardiac vein  <response>: All veins of hea except the anterior cardiac veins and the venae cordis minimi drain into the coronary sinus which opens into the right atrium.The anterior cardiac veins and the venae cordis minimi open directly into the right atrium. BD CHAURASIAS HUMAN ANATOMY .VOLUME 1.FIFTH EDITION.Page no-254 