Table 3.
Echocardiographic variables used at diagnosis and follow-up in pediatric PH.
| Echo variables | Interpretation | Advantage | Limitations | References |
|---|---|---|---|---|
| Interventricular septal flattening | Mild, moderate, or severe to indicate the severity of PH | Quick visual assessments when there is not adequate TR peak velocity to estimate RVSP | Qualitative. Can occur in systole and diastole depending on pressure or volume overload | 317,318 |
| Poor validation with clinically relevant measures | ||||
| TR peak velocity (m/s) | RVSP = SPAP = 4(TR max)2 + mRAP. If TR velocity is >3 m/s, PH may be suspected | Easy to obtain | 75% is measurable | 319 |
| Modest correlation with SPAP | ||||
| mPAP (mmHg) | mPAP = 4 V(early peak pulmonary regurgitation velocity)2 + RAP | Alignment of PR maybe better than TR | PR required for measurement | 260,263 |
| Modest correlation with mPAP | ||||
| Not substitute for cardiac catheterization | ||||
| Diastolic PAP (mmHg) | DPAP = 4 V(end-diastolic pulmonary regurgitation velocity)2 + RAP | Alignment of PR maybe better than TR | PR required for measurement | 260,263 |
| TAPSE (mm) | Longitudinal systolic function | Easy to obtain, impaired RV systolic function when the TAPSE is <2 standard deviation of age-related value | Single dimension, does not take into account of the circumferential or radial function of the RV. Alignment can be a problem | 320,321 |
| Poor correlation with RV function and survival | ||||
| PAAT (ms) | Abnormal PAAT values with z-score <-2 SD were predictive of PH | Can easily be measured in all patients | HR-dependent | 256,322 |
| RV TDI E’ (cm/s) | <8 cm/s may indicate increased risk of mortality | Can easily be measured in all patients | HR-dependent | 323 |
| RV TDI MPI | Abnormal TDI MPI values indicates right ventricular dysfunction | Can easily be measured in patients | HR-dependent | 324 |
| S/D ratio | >1.4 indicates severity of PH and increased risk of mortality | Can easily be measured from TR velocity | Presence of defined TR velocity in systole and diastole | 272 |
| End-systolic RV/LV ratio | >1 may indicate increased risk of adverse events in pediatric PH | Easy to obtain clinically | Cannot be used in patients with left to right shunts | 325 |
| RV FAC (%) | Decreased FAC (<35%) correlates with decreased systolic function | Clinically easy to obtain | Does not take into account of the entire right ventricle | 324 |
| 3D RV EF (%) | Decreased RV EF (<45%) indicates decreased RV function | Full volume datasets to evaluate for RV volumes and function; accurate measurements of RV function and can be prognostic in PH | Required breath-holding for adequate volumes; can be difficult even in single beat acquisitions when the pediatric probe is too big | 268,326 |
| RV strain (%) | RV free wall longitudinal strain decrease indicates decreased systolic RV function | RV free wall longitudinal strain maybe more sensitive in detecting ventricular function and is prognostic in PH | May not have adequate frame rate when the heart rate is too high | 273 |
| LV EF (%) | LV EF may be decreased in severe PH via RV-LV interaction | Quantification of LV function | Bi-plane Simpson’s may not be accurate as the LV is distorted in severe PH | 324 |
TR, tricuspid regurgitant; RVSP, right ventricle systolic pressure; SPAP, systolic pulmonary arterial pressure; V, velocity; RA, right atrium; PH, pulmonary hypertension; mRAP, mean right atrial pressure; mPAP, mean pulmonary arterial pressure; RAP, right atrial pressure; DPAP, diastolic pulmonary arterial pressure; PAAT, pulmonary arterial acceleration time; SD, standard deviation; TDI, tissue Doppler imaging; MPI, myocardial performance index; FAC, fractional area change; RVEF, right ventricle ejection fraction; LVEF, left ventricular ejection fraction.