Right ventricular systolic pressure (RVSP) can be estimated by measuring the TR jet maximum velocity by continuous wave (CW) spectral Doppler. If there is no significant stenosis at the right ventricular outflow tract, or the pulmonic valve, the RVSP is equivalent to the systolic pulmonary artery pressure (SPAP).
The RA pressure (RAP) can be estimated by the size and respiratory collapsibility of the inferior vena cava. For simplicity and uniformity of reporting, specific values of RAP, rather than ranges, should be used in the determination of RVSP.
| IVC Diameter |
Collapse with Sniff |
RA Pressure (mmHg) |
| ≤21 mm |
>50 % |
Normal 3 (0-5) |
| Intermediate |
Intermediate |
Intermediate 8 (5-10) |
| >21 mm |
<50 % |
High 15 (10-20) |
Secondary indices of elevated RA pressure include:
- Restrictive filling
- Tricuspid E/E' >6
- Diastolic flow predominance in hepatic vein (HV) i.e. HV systolic filling fraction Vs/(Vs+Vd) <55%
In young athletes, IVC may be dilated in the presence of normal pressure. IVC is commonly dilated and may not collapse in patients on ventilators, so it should not be used in such cases to estimate RA pressure.
Normal resting values are usually defined as a peak TR gradient of 2.8 to 2.9 m/s or a peak systolic pressure of 35 to 36 mmHg, assuming an RA pressure of 3 to 5 mmHg. SPAP may increase with age and increasing body surface area and this should be considered when estimations are at the upper limits of normal. Some cardiologists who care for patients with congenital heart disease will consider SPAP greater than two thirds of the systemic blood pressure as indicative of severe pulmonary hypertension.
| RVSP = |
|
4(TR VMax)2 + RA pressure |
| Variable |
Definition |
| TR VMax |
TR Max Jet Velocity (m/sec) |
| RA Pressure |
Choose between 3, 8, or 15 mmHg, or other (mmHg) |
| RVSP |
Right ventricular systolic pressure (mmHg) |

References

| Rudski LG, et al. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography. J Am Soc Echocardiogr. 2010 Jul;23(7):687-8, 691-2, 698-9. | |  |
| | | | | Yock PG, et al. Noninvasive estimation of right ventricular systolic pressure by Doppler ultrasound in patients with tricuspid regurgitation. Circulation. 1984; 70(4):657-62. | |  |
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