• Initial screening and follow-up of suspected Pulmonary Hypertension (PH) during transthoracic echocardiography (TTE).
• To assess right ventricular afterload in patients with chronic heart failure or lung disease.

In the absence of pulmonary valve or outflow tract stenosis, RVSP (Right Ventricular Systolic Pressure) is physiologically equivalent to PASP (Pulmonary Artery Systolic Pressure).

The simplified Bernoulli equation (ΔP = 4v2) converts the peak velocity (v) of the Tricuspid Regurgitation (TR) jet into a pressure gradient. To find the absolute RV pressure, the Right Atrial Pressure (RAP) must be added back to this gradient.

• RAP 3 mmHg: IVC ≤ 2.1 cm AND > 50% collapse with sniff.
• RAP 15 mmHg: IVC > 2.1 cm AND < 50% collapse with sniff.
• RAP 8-10 mmHg (Intermediate): If one feature is positive but not both.

A high RVSP on echo is a marker of concern, but not a diagnosis of Pulmonary Arterial Hypertension (PAH). The diagnosis of PAH strictly requires Right Heart Catheterization (RHC) to confirm a mean PAP ≥ 20 mmHg and PCWP ≤ 15 mmHg.