The appearance of the inferior vena cava in imaging studies can help to identify a patient with right ventricular overload.
Features of a distended inferior vena cava in right ventricular overload:
(1) maximum diameter > 2.1 cm
(2) percent collapsibility < 50% (inferior vena cava collapse index)
The maximum diameter of the IVC is at the end of expiration.
The minimum is during inspiration.
percent collapse =
= ((maximum diameter) - (minimum diameter)) / (maximum diameter) * 100%
NOTE: The inferior vena cava collapse index can help in identifying a patient with hypovolemia.
