Pulmonary Annular Motion Velocity Assessed Using Doppler Tissue Imaging - Novel Echocardiographic Evaluation of Right Ventricular Outflow Tract Function

Assessing pulmonary circulation in severe bronchopulmonary dysplasia using functional echocardiography

Pulmonary hypertension (PH) is common in infants with severe bronchopulmonary dysplasia (BPD) and increases the risk of death. The objectives of this preliminary study were to compare responses of pulmonary circulation parameters to 100% oxygen (O₂) and inhaled nitric oxide (iNO) in infants with BPD and PH using echocardiography. Responses between fetal growth restriction (FGR) and appropriate for gestational age infants were compared. Ten infants <28 weeks GA at birth were assessed at ≥36 weeks corrected gestation. Baseline echocardiography1 was performed which was repeated (echocardiography2) after 30 minutes of O₂. After a gap of 2–3 hours, iNO was administered for 15 minutes and echocardiography3 was performed, followed by iNO weaning. The gestation and birthweight of the cohort were 25.9 ± 1.6 weeks and 612 ± 175 g. Assessments were performed at 38.7 ± 1.4 weeks corrected gestational age. Baseline time to peak velocity: right ventricular ejection time (TPV/RVETc) increased from 0.24 ± 0.02 to 0.27 ± 0.02 (O₂, p = .01) and 0.31 ± 0.03 (iNO, p < .001), indicating a decrease in pulmonary vascular resistance [PVR]. Baseline tricuspid annular plane systolic excursion (TAPSE) increased from 8.1 ± 0.6 mm to 9.3 ± 0.7 mm (O₂, p = .01) and 10.5 ± 1.1 mm (iNO, p = .0004), indicating improved ventricular systolic performance. Percentage change for all parameters was greater with iNO. Significant correlations between cardiac performance and PVR were noted. FGR infants noted higher baseline PVR (TPV/RVETc, 0.21 ± 0.02 vs. 0.25 ± 0.01, p = .002), lower ventricular performance (TAPSE, 7 ± 1.2 mm vs. 8.6 ± 6 mm, p = .003), and lower percentage change with O₂ and iNO. A reactive component of pulmonary circulation provides real‐time physiological information, which could rationalize treatment decisions.

Cardiovascular response and sequelae after minimally invasive surfactant therapy in growth-restricted preterm infants

OBJECTIVE

To study cardiovascular response to minimally invasive surfactant therapy in preterm infants with and without foetal growth restriction (FGR).

DESIGN

Poractant alfa was administered and echocardiograms were performed before and 30 min after. FGR infants were compared with those appropriate for gestational age (AGA).

RESULTS

Ten FGR infants were compared with 20 AGA infants (gestation [weeks], 28.9 ± 2 vs. 28.6 ± 1, p = 0.55 and birthweight [g], 813 ± 157 vs. 1141 ± 257, p = 0.01, respectively). The change in echocardiographic parameters was more prominent in AGA infants ([global contractility] fractional area change [FAC, %], FGR, 24.7 ± 2.2 to 27.9 ± 0.4, p = 0.08 vs. AGA, 26.6 ± 3 to 30.5 ± 1, p < 0.01, and [longitudinal contractility] tricuspid annular plane systolic excursion [mm], FGR, 3.9 ± 0.3 to 4.6 ± 0.5, p = 0.003 vs. AGA, 4.6 ± 0.3 to 5.5 ± 0.4, p = 0.0001). Significant difference was noted for change in FAC (%), FGR 2.1 ± 1.7 vs. AGA 4.1 ± 1.2, p = 0.02.

CONCLUSIONS

Differential cardiovascular response to minimally invasive surfactant therapy amongst FGR infants may reflect an in-utero maladaptive state.

Assessment of right ventricular function by isovolumic acceleration of pulmonary and tricuspid annulus in surgically repaired tetralogy of Fallot

Assessment of right ventricular (RV) function is quite important in patients with surgically corrected tetralogy of Fallot (TOF). However, quantitative assessment of RV function remains challenging, mainly because of the complex RV geometry. This prospective study investigated isovolumic acceleration (IVA), a parameter of myocardial systolic function not influenced by either preload or afterload, using tissue Doppler imaging. We evaluated IVA measured on pulmonary annulus (PA-IVA) and tricuspid annulus (TA-IVA), because we considered that PA-IVA and TA-IVA correspond with systolic function of the RV outflow tract (RVOT) and RV basal function, respectively. Thirty-nine patients with surgically repaired TOF (TOF group) and 40 age-matched healthy children (control group) were enrolled in this study. No significant difference was seen between TA-IVA (2.5 ± 0.8 m/s2) and PA-IVA (2.4 ± 0.8 m/s2) in the control group. In the TOF group, PA-IVA (1.0 ± 0.5 m/s2) was significantly lower than TA-IVA (1.3 ± 0.6 m/s2, p < 0.05). Both TA-IVA and PA-IVA were significantly lower in the TOF group than in the control group (p < 0.05 each). We concluded that PA-IVA offers a useful index to assess RVOT function in TOF patients. J. Med. Invest. 67 : 145-150, February, 2020.

Velocity Vector Imaging Assessment of Functional Change in the Right Ventricle during Transcatheter Closure of Atrial Septal Defect by Intracardiac Echocardiography

The functional change of the right ventricle (RV) after atrial septal defect (ASD) via transcatheter closure is well known. We assessed the immediate RV functional change using velocity vector imaging (VVI) with intracardiac echocardiography (ICE). Seventy-four patients who underwent transcatheter closure of an ASD were enrolled. VVI in the “home view” of ICE showing the RV was obtained before and after the procedure. Velocity, strain, strain rate (SR), and longitudinal displacement were analyzed from VVI data, and the changes of these parameters before and after the procedure were compared. The velocity of the RV decreased after ASD transcatheter closure (3.97 ± 1.48 to 3.56 ± 1.4, p = 0.024), especially in the RV inlet and outlet. The average strain decreased (−19.21 ± 5.79 to −16.87 ± 5.03, p = 0.002), as did the average SR (−2.28 ± 0.64 to −2.03 ± 0.61, p = 0.006). The average longitudinal displacement did not differ. With the VVI technique, we could clearly observe RV functional change immediately after transcatheter closure of the ASD. RV functional change with regional difference may reflect the heterogeneity of volume reduction and suggest subclinical RV dysfunction. These findings can enhance our understanding of the physiologic changes in the RV during reverse remodeling.

Cardiorespiratory Physiology following Minimally Invasive Surfactant Therapy in Preterm Infants

INTRODUCTION

Surfactant replacement therapy through the endotracheal tube has been shown to improve lung compliance and reduce pulmonary pressures. Minimally invasive surfactant therapy (MIST) combines the benefits of continuous positive airway pressure (CPAP) and surfactant for spontaneously breathing preterm infants. We aimed to characterize the haemodynamic changes accompanying the first dose of MIST in preterm infants.

METHODS

Poractant alfa (200 mg/kg) was administered as MIST while on CPAP support. Echocardiograms were performed before (T1) and 30 (T2) and 60 min (T3) after MIST to assess serial change.

RESULTS

Twenty infants (mean gestational age 29.5 ± 2.8 weeks, median birth weight 1,102 g, IQR 840-1,940) received MIST at a median age of 16 h (IQR 3-24). FiO2 decreased significantly at 30 min (0.41 ± 0.08 to 0.27 ± 0.03, p < 0.001). Significant changes were noted at T2 for ductal parameters (decreased % time right to left shunt: 25% [15-33] to 14.5% [6-22], p = 0.013). Reduced pulmonary vascular resistance (PVR; increased pulmonary artery time velocity ratio 0.23 ± 0.05 to 0.28 ± 0.04 ms, p = 0.004) and improved longitudinal (tricuspid annular plane systolic excursion 4.5 ± 0.8 to 5.3 ± 0.9 mm, p = 0.004) and global (fractional area change 25 ± 2.3 vs. 27 ± 2%, p = 0.002) ventricular function were noted.

CONCLUSIONS

This is the first study assessing cardiovascular adaptation to MIST, a procedure fast gaining acceptance in the neonatal community. Increased pulmonary blood flow is likely due to a combined effect of increased ductal flow, reduced PVR, and increased ventricular function.

Left ventricular end-diastolic dimension and septal e' are predictors of cardiac index at rest, while tricuspid annular plane systolic excursion is a predictor of peak oxygen uptake in patients with pulmonary hypertension

Little is known regarding a correlation of hemodynamics at rest or exercise capacity with echocardiographic parameters in patients with pulmonary hypertension (PH). To clarify these potential correlations, we performed transthoracic echocardiography, right heart catheterization, and cardiopulmonary exercise testing in 53 patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Left ventricular end-diastolic dimension (LVDd), early diastolic velocity of the septal mitral annulus (septal e'), tricuspid regurgitation peak gradient (TRPG), and tricuspid annular plane systolic excursion (TAPSE) were significantly correlated with cardiac index (LVDd; r = 0.477, P < 0.001, septal e'; r = 0.463, P = 0.001, TRPG; r = - 0.455, P = 0.001 and TAPSE; r = 0.406, P = 0.003, respectively). Multiple regression analysis revealed that LVDd and septal e' were significantly associated with cardiac index (CI) and stroke volume index at rest. Among the exercise capacity markers evaluated, TAPSE, TRPG, and LVDd were significantly correlated with peak oxygen uptake (TAPSE; r = 0.534, P < 0.001, TRPG; r = - 0.466, P = 0.001 and LVDd; r = 0.411, P = 0.002, respectively). Multiple regression analysis showed that TAPSE was significantly associated with peak oxygen uptake (VO₂). In PAH and CTEPH patients, LVDd and septal e' were significantly associated with CI at rest, whereas TAPSE was significantly associated with peak VO₂. Echocardiographic parameters may predict the prognostic factors of PAH and CTEPH patients.

Pulmonary annular motion velocity reflects right ventricular outflow tract function in children with surgically repaired congenital heart disease

Right ventricular (RV) dysfunction is generally evaluated using analyses of tricuspid annular motion. However, it represents only one aspect of RV performance. Whether measuring pulmonary annular motion velocity could serve as a novel way to evaluate global RV and/or RV outflow tract (RVOT) performance in pediatric congenital heart disease (CHD) patients with surgically repaired RVOT was evaluated. In this prospective study, tissue Doppler-derived pulmonary annular motion velocity was measured in children (aged 2-5 years) with RVOT reconstruction (RVOTR group, n = 48) and age-matched healthy children (Control, n = 60). The types of RVOTR procedures were as follows: pulmonary valve-sparing procedure (PVS, n = 7); transannular patch with monocusp valve reconstruction (TAP, n = 29); and RV-to-PA conduit reconstruction using a pericardial valve with expanded polytetrafluoroethylene conduit (Rastelli, n = 12). Pulmonary annular motion velocity waveforms comprised systolic bimodal (s1' and s2') and diastolic e' and a' waves in all participants. The peak velocities of s1', s2', e', and a' were significantly lower in the RVOTR group than in the control group (all p < 0.0001). Furthermore, these parameters depended significantly on the type of surgical procedure. The peak velocities of s1', s2', and e' had significant correlations with RVOT ejection fraction (RVOT-EF) (r = 0.56, 0.49, and 0.34, respectively), and RVOT fractional shortening (RVOT-FS) (r = 0.72, 0.55, and 0.41, respectively), although there were no significant correlations between pulmonary annular motion and global RV function, including RV ejection fraction (RVEF) and RV fractional area change (RVFAC) in the assessment of all RVOTR group patients. The pulmonary annular motion parameters in the PVS group had significant correlations with both global RV and RVOT performance. The TAP group showed significant correlations between RVOT function and pulmonary annular motion. The Rastelli group showed almost no significant correlations between RV/RVOT function and tissue Doppler parameters. Pulmonary annular motion velocity is a simple, rapid, reproducible, and useful method of assessing RVOT function in children with surgically repaired CHD.

Noninvasive assessment of pulmonary arterial capacitance by pulmonary annular motion velocity in children with ventricular septal defect

Background

We hypothesized that longitudinal pulmonary arterial deformation during the cardiac cycle reflects pulmonary arterial capacitance. To examine this hypothesis, we assessed whether tissue Doppler-derived pulmonary annular motion could serve as a novel way to evaluate pulmonary arterial capacitance in pediatric patients with ventricular septal defect (VSD).

Methods

In this prospective study, pulmonary annular velocity was measured in children (age, 6 months–5 years) with a preoperative VSD (VSD group, n = 35) and age-matched healthy children (Control group, n = 23). Pulmonary artery capacitance was calculated by two methods. Systolic pulmonary arterial capacitance (sPAC) was expressed as the stroke volume/pulmonary arterial pulse pressure. Diastolic pulmonary arterial capacitance (dPAC) was determined according to a two-element windkessel model of the pulmonary arterial diastolic pressure profile.

Results

Pulmonary annular velocity waveforms comprised systolic bimodal (s1′ and s2′) and diastolic e’ and a’ waves in all participants. The peak velocities of s1′, s2′, and e’ were significantly lower in the VSD group than in the Control group. On multiple regression analysis, sPAC was an independent variable affecting the peak velocities of the s1′, s2′, and e’ waves (β = 0.41, 0.62, and 0.35, respectively). The dPAC affected the s1′ wave peak velocity (β = 0.34). The time durations of the s1′ and e’ waves were independently determined by the sPAC (β = 0.49 and 0.27).

Conclusion

Pulmonary annular motion velocity evaluated using tissue Doppler is a promising method of assessing pulmonary arterial capacitance in children with VSD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12947-016-0081-4) contains supplementary material, which is available to authorized users.