Inferior venacaval dimensions and right atrial pressure

Inferior venacaval dimensions and right atrial pressure

Inferior venacaval dimensions and right atrial pressure: There is a correlation between inferior vena caval dimension and the right atrial pressure. Inferior vena caval (IVC) dimensions can be measured from the subcostal view on echocardiography. If the inferior vena caval size is small (less than 1.5 cm) and collapses with inspiration, the estimated right atrial pressure is below 5 mm Hg. When the inferior vena caval size is normal (between 1.5 to 2.5 cm) and the inspiratory decrease in diameter is more than 50 percent, the estimated right atrial pressure is between 5 and 10 mm Hg. With a normal inferior vena caval size, if the inspiratory decrease is less than 50 percent, right atrial pressure is likely to be between 10 and 15 mm Hg. If the inferior vena cava is dilated (more than 2.5 cm in diameter) and the inspiratory decrease in size is less than 50 percent, the right atrial pressure is estimated to be between 15 and 20 mm Hg. When the inferior vena cava is dilated along with dilatation of the hepatic veins and the diameter does not change with inspiration the right atrial pressure is mostly above 20 mm Hg. Inferior vena caval plethora is the term given to lack of significant inspiratory collapse with a dilated inferior vena cava, an important echocardiographic manifestation of right heart congestion.

IVC collapsibility index (IVCCI) is calculated using IVC maximum (expiratory) and minimum diameters (inspiratory):

IVCCI = (maximum IVC diameter – minimum IVC diameter/maximum IVC diameter) × 100

Lawrence G Rudski, Wyman W Lai, Jonathan Afilalo, Lanqi Hua, Mark D Handschumacher, Krishnaswamy Chandrasekaran, Scott D Solomon, Eric K Louie and Nelson B Schiller mention that if IVC diameter is >21 mm and IVCCI <50%, right atrial pressure is high (15 mm Hg) [2].

References

1. Renato De Vecchis, Cesare Baldi, Giuseppe Giandomenico, Marco Di Maio, Anna Giasi, Carmela Cioppa. Estimating Right Atrial Pressure Using Ultrasounds: An Old Issue Revisited With New Methods. J Clin Med Res. 2016 Aug;8(8):569-74.
2. Lawrence G Rudski, Wyman W Lai, Jonathan Afilalo, Lanqi Hua, Mark D Handschumacher, Krishnaswamy Chandrasekaran, Scott D Solomon, Eric K Louie, Nelson B Schiller. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. J Am Soc Echocardiogr. 2010 Jul;23(7):685-713; quiz 786-8.