Role of functional echocardiographic parameters in the diagnosis of bronchopulmonary dysplasia-associated pulmonary hypertension

Abstract

Echocardiogram (echo) is a commonly used noninvasive modality for the diagnosis of bronchopulmonary dysplasia associated pulmonary hypertension (BPD-PH). Though not considered the gold standard for the diagnosis of BPD-PH, it is an extremely valuable tool in the neonatal and pediatric population, especially when cardiac catheterization is not feasible. In addition to the traditional echo parameters that are used to assess the presence of BPD-PH, much attention has been recently placed on newer bedside echo measures, the so-called functional echo parameters, to aid and assist in the diagnosis. This review article provides a brief introduction to BPD-PH, describes the pitfalls of traditional echo parameters and details the newer echo modalities currently available for the diagnosis of neonatal PH.

Fig. 1. Figure showing tricuspid regurgitant jet velocity in a patient with severe pulmonary hypertension.

The measured tricuspid regurgitant jet velocity is 5 m/s (+sign) which translates to an estimated right ventricular systolic pressure of 100 mmHg + right atrial pressure.

Fig. 2. Subcostal coronal view in a patient with severe pulmonary hypertension.

There is right to left shunting across a patent foramen ovale (blue flow, arrow).

Fig. 3. Parasternal short axis view in a patient with severe pulmonary hypertension.

There is severe systolic interventricular septal flattening (arrow).

Fig. 4. Parasternal short axis view showing a continuous wave doppler tracing of a pulmonary regurgitant jet.

This shows a minimum end-diastolic velocity of 2.67 m/s (arrow) consistent with an estimated diastolic pulmonary artery pressure of 28 mmHg.

Fig. 5. Parasternal short axis view in a patient with severe pulmonary hypertension.

Measurement of left ventricular systolic eccentricity index (D2/D1) is performed (D2: red line; D1: yellow line).

Fig. 6. Parasternal short axis view showing a pulse wave doppler tracing across the pulmonary valve.

There is a short pulmonary artery acceleration time (PAAT) of 63.3 ms (asterisk) consistent with severe pulmonary hypertension.

Fig. 7. Measurement of tricuspid annular plane systolic excursion (TAPSE) by aligning an M-mode cursor parallel with the right ventricular free wall as it meets the tricuspid annulus from the apical four-chamber view.

The distance between the enddiastolic (vertical arrow) and end-systolic (horizontal line) represents TAPSE.

Fig. 8. Global Longitudinal Strain is measured from the apical four-chamber, three-chamber and two-chamber view.

This figure is an example of a patient with normal global longitudinal strain.

Fig. 9. Apical four-chamber view of the heart with tissue doppler deployed on the lateral tricuspid valve annulus.

This is an example of a patient with normal tricuspid annular tissue doppler measurements.

Fig. 10. Measurement of the myocardial performance (Tei) index. Sampling at tips of the mitral valve leaflets, in the apical four-chamber view, enables the measurement of the time interval between the end and the start of transmitral flow: Isovolumetric contraction time (ICT) + Ejection time (ET) + Isovolumetric Relaxation time (IRT).

Sampling in the left ventricular outflow tract, just below the aortic valve allows the measurement of the ET. The myocardial performance index is then be expressed by the formula (ICT+IRT)/ET.

Fig. 11

3D ECHO showing the posterior mitral valve leaflet.