Right Ventricle and Pulmonary Hypertension: Calculation of SPAP, TAPSE, S', and TAPSE/SPAP

Calculation of SPAP (Systolic Pulmonary Artery Pressure) Using the Bernoulli Equation

In the absence of RVOT obstruction, the systolic pressure in the RV (RVSP) is assessed using the maximum velocity of the tricuspid regurgitation jet (TRVmax) and the right atrial pressure (RAP). The PA-RV pressure gradient is calculated using the modified Bernoulli equation (4V²), and the systolic pressure in the RV is the sum of this gradient and RAP. In the absence of a gradient through the PV or RVOT, PASP (SPAP) equals RVSP (Mukherjee, Rudski et al., 2025).

The upper limit of normal TRVmax is <2.5 m/s. A complete Doppler envelope of the TR jet is required to indicate RVSP (ASE, 2015). The TR flow spectrogram is evaluated in LAX/SAX RVIT, 4C, 3C RVIT, Sub4C/SAX positions; if the spectrum is incomplete, the patient is repositioned (Blagodir, 2024).

Assessment of Right Atrial Pressure (RAP)

RAP corresponds to central venous pressure (CVP), but in the absence of a catheter, the specialist uses an average RAP based on the size and collapsibility of the inferior vena cava (ASE, 2015). According to the 2025 consensus: positive secondary indices → RAP 20 mmHg; indeterminate secondary indices → RAP 5–10 mmHg, averaging 8 mmHg.

Normal Values and Criteria for Pulmonary Hypertension

Normally, SPAP at rest is 15–25 mmHg. An SPAP value >25 mmHg at rest (or >30 mmHg during physical exertion) corresponds to pulmonary hypertension (Blagodir, 2024).

Pulmonary HypertensionRVSP/SPAP (mmHg)Normal18–25Mild30–40Moderate40–70Severe>70

TAPSE

TAPSE (Tricuspid Annular Plane Systolic Excursion) is a simple quantitative measure of RV longitudinal function, reflecting the level of systolic excursion of the lateral part of the tricuspid valve fibrous annulus towards the apex in the four-chamber view. It is measured in M-mode with optimal alignment of the cursor along the direction of the lateral tricuspid annulus in the apical 4-chamber view (ASE, 2015). The measure shows excellent correlation with RV EF (radionuclide ventriculography) and is a significant predictor of prognosis in heart failure (EAE/ASE, 2011). As a one-dimensional measurement relative to the probe position, TAPSE may overestimate or underestimate RV function due to heart translation (ASE, 2015). Specific threshold values for TAPSE are not provided in the given excerpts [to be clarified].

S' (Systolic Velocity of the Tricuspid Annulus, DTI)

The systolic function of the RV is assessed by at least one of the indicators or their combination: fractional area change (FAC), systolic velocity of the lateral fibrous annulus of the tricuspid valve by tissue Doppler imaging (S'), TAPSE, and the RV myocardial performance index (RIMP) (ASE, 2015). Threshold values for S' are not provided in the given excerpts [to be clarified].

TAPSE/SPAP

Specific data on the TAPSE/SPAP ratio and its threshold values are not provided in the given excerpts [to be clarified].

Exclusion of Obstruction with Elevated RVSP

With elevated RVSP, it is important to exclude obstruction at the level of the pulmonary valve (PV) or supra- or subvalvular obstruction, especially in patients with ACHD (e.g., PS, RVOT obstruction, proximal PA stenosis) or after PV surgery. In postoperative patients with ACHD without residual obstruction, PA pressure is considered significantly elevated if PASP exceeds two-thirds of systemic arterial pressure (Mukherjee, Rudski et al., 2025).