Echocardiographic investigations in suspected or confirmed paediatric PH
| Echocardiographic variables | Interpretation | At diagnosis | Follow-up | Ref. |
|---|---|---|---|---|
| PASP (mm Hg) | Bernoulli equation (dP=4×v2): TR velocity used to estimate RVSP (≈PASP) | Yes | Yes | 10 11 |
| PASP >50 mm Hg at rest, makes PAH highly likely in adults | ||||
| Mean PAP (mm Hg) | Estimated mPAP=maximum PR velocity plus mean RAP | Yes | Yes | 11 |
| Def. paediatric PH: mean PAP >25 mm Hg and PVRi >3.0 WU m2 | ||||
| Diastolic PAP (mm Hg) | Estimated PADP=minimal (end diastolic) PR velocity plus mean RAP | Yes | Yes | 12 |
| PADP independent of RV stroke volume | ||||
| TR peak velocity (m/s) | RVSP=maximum instantaneous TR gradient across tricuspid valve plus the | Yes | Yes | 11 |
| right atrial v wave. If TR velocity >3.4 m/s, PH is likely (see PASP) | ||||
| TAPSE (mm) | Decreased in advanced PH with systolic RVD in children and adults | Yes | Yes | 17 18 |
| Tricuspid Em (cm/s)—TV inflow | Impaired <8 cm/s indicates higher mortality risk in children with PH | Yes | Yes | 35 |
| S/D ratio | Increased S/D duration ratio >1.4 inversely correlates with survival in children with PH; indicator of PH severity | Yes | Probably | 31 32 |
| Strain (%) | Patients with PH may have lower end-systolic longitudinal strain (RV free wall) | If available | 20 23 | |
| Strain rate (s–1) | RV strain rate at the RV free wall may be impaired in patients with PH | If available | 21 | |
| RV strain and strain rate are frequently altered in severe PH with RVD | ||||
| 3D echocardiography | Useful for determination of RV and LV volumes | If available | 28 | |
| S′ in RV TDI (cm/s) | Decreased in advanced PH with systolic RV dysfunction; an impaired S′ | Yes | Yes | 34 |
| (measured in TDI, lateral RV wall) predicts adverse outcome | ||||
| RV/LV ratio | RV/LV ratio >1 indicates increased risk for adverse events in paediatric PH | Yes | Yes | 39 |
| PA acceleration time (ms) | PAAT of <100 ms—high probability of PH in adults (HR dependent) | Yes | Yes | 41 |
| RV FAC (%) | Decreased RV FAC indicated decreased systolic RV function in adult PH | Probably | 17 | |
| E/A ratio (mitral inflow) | Reversed E/A (E>A) indicates a high LAP and a high LVEDP | Yes | Yes | 36 37 |
| S′ TDI (cm/s; LV lateral, septal) | Nagueh formula may be used to estimate the PCWP (≈ LVEDP) | Probably | 36 | |
| LVEF (%; LV systolic function) | LVEF (Simpson’s method) may be decreased in severe RV–LV interaction | Yes | Yes | 37 |
Em, early diastolic myocardial relaxation velocity; FAC, fractional area change; LAP, left atrial pressure; LVEDP, LV end-diastolic pressure; PAAT, pulmonary artery acceleration time; PCWP, pulmonary capillary wedge pressure; PADP, pulmonary artery end-diastolic pressure; PAH, pulmonary arterial hypertension; PAP, pulmonary artery pressure; PASP, pulmonary artery systolic pressure; PVR, pulmonary vascular resistance; PR, pulmonary regurgitation; RAP, right atrial pressure; RVD, RV dysfunction; RVSP, RV systolic pressure; S′, peak systolic velocity; S/D, systolic/diastolic ratio; TAPSE, tricuspid annular plane systolic excursion; TDI, tissue Doppler imaging; TR, tricuspid regurgitation; TV, tricuspid valve.