Transverse sinus (pericardial cavity, anatomy)

The transverse sinus of the pericardial cavity is a channel between the posterior right and left sides of the pericardial cavity. It is formed during development of the heart by the effective division of the structures running to it into two groups by the disappearance of dorsal mesocardium between them:

• aorta and pulmonary trunk enclosed in one 'tube' by visceral pericardium that runs to and is continuous with the surrounding pericardium
• venae cavae and pulmonary veins enclosed in a second similarly structured 'tube' of visceral pericardium

Hence, within the pericardial cavity a probe can be placed into the transverse sinus running posterior to the aorta and pulmonary trunk on the left but anterior to the left atrium and superior vena cava on the right.