Space
Oblique pericardial sinus
A blind recess behind the left atrium
High-yield
Oblique sinus: behind the left atrium and blind above. Transverse sinus: behind the arterial roots and open at both sides.
Overview
Behind the left atrium, the pericardial reflections around the pulmonary veins and inferior vena cava outline the oblique sinus. It opens inferiorly into the wider cavity but ends blindly superiorly. The esophagus lies outside the posterior pericardial wall.
Reference facts
- Boundaries
- Posterior left atrial surface anteriorly, posterior pericardial sac behind, with pulmonary venous and inferior caval reflections at its margins
- Contents
- Pericardial fluid, normally in a thin layer
- Communications
- An inferior opening into the pericardial cavity and a blind superior end
Clinical correlation
Fluid can collect in this posterior recess and influence its appearance on imaging. Its location must be distinguished from the adjacent esophagus, atrial wall and other mediastinal structures.
Frequently asked questions
What are the boundaries of the oblique pericardial sinus?
Posterior left atrial surface anteriorly, posterior pericardial sac behind, with pulmonary venous and inferior caval reflections at its margins.
What does the oblique pericardial sinus contain?
The oblique pericardial sinus contains the pericardial fluid, normally in a thin layer.
What does the oblique pericardial sinus communicate with?
An inferior opening into the pericardial cavity and a blind superior end.