PREDICTION OF INTRACARDIAC PRESSURES (Reynolds, 2013)

2-D echocardiography combined with cardiac Doppler may be utilized to predict intracardiac pressures.

Right Atrial Pressure (RAP)

v Normal 2 to 5 mmHg, to approximate the RAP, examine the IVC by 2-D and substitute one of the following values for the actual RAP.

Variable	Normal (0-5(3)mmHg)	Intermediate (5-10(8) mmHg)		High (15 mmHg)
IVC diameter	Less than 2.1 cm	Less than 2.1 cm	More than 2.1 cm	More than 2.1 cm
Collapse with sniff	More than 50 %	Less than 50 %	More than 50 %	Less than 50 %

 

Secondary indices of elevated RAP:

ü Restrictive filling

ü Tricuspid E/E’ more than 6

ü Diastolic flow predominance in hepatic veins (systolic filling fraction less than 55 %).

 

v Dilated hepatic veins with a dilated inferior vena cava suggest increased right Atrial pressure.

 

v A dilated coronary sinus (normal 4 to 8 mm as measured in the A4C with a posterior tilt) suggests increased RAP; it may be dilated also with persistent left superior vena cava, coronary artery AV fistula, anomalous hepatic vinous drainage to the left coronary sinus, and total anomalous pulmonary venous return or severe tricuspid regurgitation.

 

 

 

 

 

 

 

 

 

 

 

 

v In the absence of significant tricuspid regurgitation (TR), a right atrium that is increased in dimension especially when compared to the left atrium, suggests increased RAP.

 

v A right atrium maximal volume measured at end-systole of more than 45 +/- 14 cm3 suggests a mean RAP of more than 8 mmHg.

v A right Atrial maximal volume measured at end-diastole of more than 30 +/- 15 cm3 suggests a mean RAP of more than 8 mmHg.

v Interatrial septal deviation towards the left atrium may indicate increased RAP.

v A PW Doppler tricuspid valve E/A ratio of equal or more than 1.1 may indicate a mean RAP of > 8 mmHg, assumes the absence of right ventricular inflow tract obstruction.

 

v A dagger shaped CW tricuspid regurgitation velocity spectral display suggests increased RAP.

 

 

v A decreased right ventricular IVRT (normal 54 +/- 3.55 msec) suggests increased RAP.

 

 

 

v A patient with left heart disease and pulmonary hypertension may eventually develop elevated right heart pressures.

 

Bibliography

Reynolds, T. (2013). The Echocardiographer's Pocket Reference. USA: Arizona Heart Foundation.