Right ventricular diastolic performance in children with pulmonary arterial hypertension associated with congenital heart disease: correlation of echocardiographic parameters with invasive reference standards by high-fidelity micromanometer catheter

Guidelines for Performing a Comprehensive Pediatric Transthoracic Echocardiogram: Recommendations From the American Society of Echocardiography

Echocardiography is a fundamental component of pediatric cardiology, and appropriate indications have been established for its use in the setting of suspected, congenital, or acquired heart disease in children. Since the publication of guidelines for pediatric transthoracic echocardiography in 2006 and 2010, advances in knowledge and technology have expanded the scope of practice beyond the use of traditional modalities such as two-dimensional, M-mode, and Doppler echocardiography to evaluate the cardiac segmental structures and their function. Adjunct modalities such as contrast, three-dimensional, and speckle-tracking echocardiography are now used routinely at many pediatric centers. Guidelines and recommendations for the use of traditional and newer adjunct modalities in children are described in detail in this document. In addition, suggested protocols related to standard operations, infection control, sedation, and quality assurance and improvement are included to provide an organizational structure for centers performing pediatric transthoracic echocardiograms.

Echocardiographic evaluation of right ventricular diastolic function in pulmonary hypertension

Background

Right ventricular (RV) diastolic dysfunction may be prognostic in pulmonary hypertension (PH). However, its assessment is complex and relies on conductance catheterisation. We aimed to evaluate echocardiography-based parameters as surrogates of RV diastolic function, provide validation against the gold standard, end-diastolic elastance (Eed), and define the prognostic impact of echocardiography-derived RV diastolic dysfunction.

Methods

Patients with suspected PH who underwent right heart catheterisation including conductance catheterisation were prospectively recruited. In this study population, an echocardiography-based RV diastolic function surrogate was derived. Survival analyses were performed in patients with precapillary PH in the Giessen PH Registry, with external validation in patients with pulmonary arterial hypertension at Sapienza University (Rome).

Results

In the derivation cohort (n=61), the early/late diastolic tricuspid inflow velocity ratio (E/A) and early tricuspid inflow velocity/early diastolic tricuspid annular velocity ratio (E/e') did not correlate with Eed (p>0.05). Receiver operating characteristic analysis revealed a large area under the curve (AUC) for the peak lateral tricuspid annulus systolic velocity/right atrial area index ratio (S'/RAAi) to detect elevated Eed (AUC 0.913, 95% confidence interval (CI) 0.839-0.986) and elevated end-diastolic pressure (AUC 0.848, 95% CI 0.699-0.998) with an optimal threshold of 0.81 m2·s-1·cm-1. Subgroup analyses demonstrated a large AUC in patients with preserved RV systolic function (AUC 0.963, 95% CI 0.882-1.000). Survival analyses confirmed the prognostic relevance of S'/RAAi in the Giessen PH Registry (n=225) and the external validation cohort (n=106).

Conclusions

Our study demonstrates the usefulness of echocardiography-derived S'/RAAi for noninvasive assessment of RV diastolic function and prognosis in PH.

Normal Echocardiographic Reference Values of the Right Ventricular to Left Ventricular Endsystolic Diameter Ratio and the Left Ventricular Endsystolic Eccentricity Index in Healthy Children and in Children With Pulmonary Hypertension

Background

An accurate assessment of the right and left ventricle and their interaction is important in pediatric pulmonary hypertension (PH). Our objective was to provide normal reference values for the right ventricular to left ventricular endsystolic (RV/LVes) ratio and the LV endsystolic eccentricity index (LVes EI) in healthy children and in children with PH.

Methods

We conducted an echocardiographic study in 769 healthy children (median age: 3.36 years; range: 1 day—18 years) and validated abnormal values in 44 children with PH (median age: 2.1 years; range: 0.1 months—17.7 years). We determined the effects of gender, age, body length, body weight, and body surface area (BSA) on RV/LVes ratio and LVes EI values. The RV/LVes ratio and LVes EI were measured from the parasternal short axis view between papillary muscle from the endocardial to endocardial surfaces.

Results

Both, the RV/LVes ratio and the LVes EI were highly age-dependent: (i) neonates RV/LVes ratio [median 0.83 (range 0.53–1.37)], LVes EI [1.21 (0.92–1.45)]; (ii) 12–24 months old: RV/LVes ratio: [0.55 (0.35–0.80)], LVes EI: [1.0 (0.88–1.13)]; iii) 18th year of life RV/LVes ratio: [0.53 (0.32–0.74)], LVes EI: [1.0 (0.97–1.07)]. Healthy neonates had high LVes EI and RV/LVes ratios, both gradually decreased within the first year of life and until BSA values of about 0.5 m2, body weight to about 15 kg and body length to about 75 cm, but were almost constant thereafter. Children (>1 year) and adolescents with PH had significantly higher RV/LVes ratio (no PH: median 0.55, IQR 0.49–0.60; PH: 1.02, 0.87–1.26; p < 0.001) and higher LVes EI values (no PH: 1.00, 0.98–1.00; PH: 1.53, 1.26–1.71; p < 0.001) compared to those without PH. To predict the presence of PH in children > 1 year, we found the following best cutoff values: RV/LVes ratio ≥ 0.67 (sensitivity: 1.00, specificity: 0.95) and LVes EI ≥ 1.06 (sensitivity: 1.00, specificity: 0.97).

Conclusion

We provide normal echocardiographic reference values of the RV/LVes ratio and LVes EI in healthy children, as well as statistically determined cutoffs for the increased values in children with PH.

Right Atrial Strain in Preterm Infants With a History of Bronchopulmonary Dysplasia

BACKGROUND

Few studies have utilized right atrial (RA) strain to evaluate right ventricular (RV) diastolic dysfunction in preterm infants with bronchopulmonary dysplasia (BPD). We aimed to evaluate the associations of RA strain with BPD severity and respiratory outcomes in preterm infants with BPD.

METHODS

We retrospectively studied 153 infants with BPD born before 32 weeks of gestational age at CHA Bundang Medical Center. Peak longitudinal right atrial strain (PLRAS) was obtained using velocity vector imaging and compared among infants across BPD severity. Conventional echocardiographic parameters and clinical characteristics were also evaluated.

RESULTS

In infants with severe BPD, mean gestational age (27.4 ± 2.1 weeks) and mean birth weight (971.3 ± 305.8 g) were significantly smaller than in those with mild BPD (30.0 ± 0.9 weeks, 1,237.3 ± 132.2 g) and moderate BPD (29.6 ± 1.3 weeks, 1,203.2 ± 214.4 g). PLRAS was significantly lower in infants with severe BPD (26.3 ± 10.1%) than in those in the moderate BPD group (32.4 ± 10.9%) or mild BPD group (31.9 ± 8.3%). Tricuspid E/e′ and maximum RA volume index were similar across BPD severity. A decrease in PLRAS was significantly correlated with increased duration of mechanical ventilation duration; however, tricuspid E/e′ and maximum RA volume index were not.

CONCLUSIONS

Evaluating PLRAS with other parameters in infants with BPD might detect RV diastolic dysfunction. Longer follow-up and larger study populations may elucidate the association between PLRAS and respiratory outcomes in infants with BPD.

Right Ventricular Diastolic Performance in Patients With Chronic Thromboembolic Pulmonary Hypertension Assessed by Echocardiography

Background: There have been no systemic studies about right heart filling pressure and right ventricular (RV) distensibility in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Therefore, we aimed to explore combinations of echocardiographic indices to assess the stages of RV diastolic dysfunction.

Methods and Results: We recruited 32 healthy volunteers and 71 patients with CTEPH. All participants underwent echocardiography, cardiac catheterization (in patients with CTEPH), and a 6-min walk test (6MWT). The right atrial (RA) end-systolic area was adjusted for body surface area (BSA) (indexed RA area). RV global longitudinal diastolic strain rates (SRs) and RV ejection fraction (EF) were measured by speckle tracking and three-dimensional echocardiography (3D echo), respectively. All 71 patients with CTEPH underwent pulmonary endarterectomy. Of the 71 patients, 52 (73%) had decreased RV systolic function; 12 (16.9%), 26 (36.6%), and 33 (46.5%) patients had normal RV diastolic pattern, abnormal relaxation (stage 1), and pseudo-normal patterns (stage 2), respectively. The receiver operating characteristic curve analysis showed that the optimal cut-off values of early diastolic SR <0.8 s⁻¹ and indexed RA area > 8.8 cm²/BSA had the best accuracy in identifying patients with RV diastolic dysfunction, with 87% sensitivity and 82% specificity. During a mean follow-up of 25.2 months after pulmonary endarterectomy, the preoperative indexed RA area was shown as an independent risk factor of the decreased 6MWT distance.

Conclusions: Measuring early diastolic SR and indexed RA area would be useful in stratifying RV diastolic function.

Right ventricular function as assessed by cardiac magnetic resonance imaging-derived strain parameters compared to high-fidelity micromanometer catheter measurements

Right ventricular function has prognostic significance in patients with pulmonary hypertension. We evaluated whether cardiac magnetic resonance-derived strain and strain rate parameters could reliably reflect right ventricular systolic and diastolic function in precapillary pulmonary hypertension. End-systolic elastance and the time constant of right ventricular relaxation tau, both derived from invasive high-fidelity micromanometer catheter measurements, were used as gold standards for assessing systolic and diastolic right ventricular function, respectively. Nineteen consecutive precapillary pulmonary hypertension patients underwent cardiac magnetic resonance and right heart catheterization prospectively. Cardiac magnetic resonance data were compared with those of 19 control subjects. In pulmonary hypertension patients, associations between strain- and strain rate-related parameters and invasive hemodynamic parameters were evaluated. Longitudinal peak systolic strain, strain rate, and early diastolic strain rate were lower in PAH patients than in controls; peak atrial-diastolic strain rate was higher in pulmonary hypertension patients. Similarly, circumferential peak systolic strain rate was lower and peak atrial-diastolic strain rate was higher in pulmonary hypertension. In pulmonary hypertension, no correlations existed between cardiac magnetic resonance-derived and hemodynamically derived measures of systolic right ventricular function. Regarding diastolic parameters, tau was significantly correlated with peak longitudinal atrial-diastolic strain rate (r = -0.61), deceleration time (r = 0.75), longitudinal systolic to diastolic time ratio (r = 0.59), early diastolic strain rate (r = -0.5), circumferential peak atrial-diastolic strain rate (r = -0.52), and deceleration time (r = 0.62). Strain analysis of the right ventricular diastolic phase is a reliable non-invasive method for detecting right ventricular diastolic dysfunction in PAH.

A guide to echocardiographic assessment in children and adolescents with pulmonary hypertension

While the current definition of pulmonary hypertension (PH) is still based on haemodynamic variables, transthoracic echocardiography is the most important diagnostic clinical tool for the first assessment and evaluation of a patient, in whom PH is suspected. In addition, it is the most important clinical modality in long term follow-up and the utility of echocardiography has widely been demonstrated in patients with PH. Echocardiography not only reveals the underlying cardiac morphology and diagnosis of any associated cardiac defects. In most patients with PH right ventricular (RV) pressure estimation is feasible. In addition, ventricular systolic and diastolic function, as well as ventricular-ventricular interactions of both ventricles can be assessed by using echocardiography. Maximizing the use of echocardiography by reporting several measures to gain information and quantitatively describe the parameters, that are linked to prognosis, seem particularly appealing in these children, in whom other advanced imaging modalities requiring anaesthesia is associated with a considerable risk. Herein we provide a practical approach and a concise and clinically applicable echocardiographic guidance and present basic variables, which should be obtained at any assessment. Moreover, we present additional advanced echocardiographic measures, that can be applied in a research or clinical setting when progressive PH needs a deeper insight to assess heart function, estimation of pulmonary artery pressures among others, by echocardiography. Finally, clinically relevant studies in view of the prognostic properties with a focus on the most important echocardiographic variables in pediatric PH are summarized.

Right ventricular diastolic dysfunction and failure: a review

Right ventricular diastolic dysfunction and failure (RVDDF) has been increasingly identified in patients with cardiovascular diseases, including heart failure and other diseases with cardiac involvement. It is unknown whether RVDDF exists as a distinct clinical entity; however, its presence and degree have been shown to be a sensitive marker of end-organ dysfunction related to multiple disease processes including systemic hypertension, pulmonary hypertension, heart failure, and endocrine disease. In this manuscript, we review issues pertaining to RVDDF including anatomic features of the right ventricle, physiologic measurements, RVDDF diagnosis, underlying mechanisms, clinical impact, and clinical management. Several unique features of RVDDF are also discussed.

Echocardiography for the Assessment of Pulmonary Hypertension and Congenital Heart Disease in the Young

While invasive assessment of hemodynamics and testing of acute vasoreactivity in the catheterization laboratory is the gold standard for diagnosing pulmonary hypertension (PH) and pulmonary vascular disease (PVD) in children, transthoracic echocardiography (TTE) serves as the initial diagnostic tool. International guidelines suggest several key echocardiographic variables and indices for the screening studies when PH is suspected. However, due to the complex anatomy and special physiological considerations, these may not apply to patients with congenital heart disease (CHD). Misinterpretation of TTE variables can lead to delayed diagnosis and therapy, with fatal consequences, or–on the other hand-unnecessary invasive diagnostic procedures that have relevant risks, especially in the pediatric age group. We herein provide an overview of the echocardiographic workup of children and adolescents with PH with a special focus on children with CHD, such as ventricular/atrial septal defects, tetralogy of Fallot or univentricular physiology. In addition, we address the use of echocardiography as a tool to assess eligibility for exercise and sports, a major determinant of quality of life and outcome in patients with PH associated with CHD.

Pulmonary hypertension associated with congenital heart disease; clinical decision scenario

Pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) is one type under group 1 PH. Undiagnosed or delayed diagnosis of significant CHD might lead to significant PAH and at the end might lead to Eisenmenger syndrome. We could expect the degree of PAH in patients with CHD by proper clinical assessment as well as by the basic assessment tools including the chest x-ray (CXR), ECG, and transthoracic echocardiography (TTE). We are presenting a three and half years old child with a delayed/missed diagnosis of large patent ductus arteries (PDA) who present with significant PAH. Clinical evaluation, CXR, ECG, TTE, as well as cardiac catheterization data are presented, with a review of the current guidelines regarding the management of pediatric patients with PAH-CHD.

Atrial Function and Its Role in the Non-invasive Evaluation of Diastolic Function in Congenital Heart Disease

Diastolic dysfunction has correlated with adverse outcomes in various forms of unrepaired and repaired or palliated congenital heart disease (CHD). The non-invasive assessment of diastolic function in pediatric and adult patients with CHD remains challenging. Atrial size has a pivotal role in the evaluation of diastolic function; however, a growing body of evidence supports the additional role of atrial function as a more sensitive parameter of ventricular diastolic dysfunction. While the importance of atrial function is becoming clearer in adult acquired heart disease, it remains ambiguous in those with CHD. In this review we set the stage with the current understanding of diastolic function assessment in CHD, followed by insight into atrial form and function including its non-invasive assessment, and conclude with the current knowledge of atrial function in CHD. A general pattern of decrease in reservoir and conduit function with compensatory increase followed by decompensatory decrease in contractile function seems to be the common pathway of atrial dysfunction in most forms of CHD.

Comparison of echocardiographic measurements to invasive measurements of diastolic function in infants with single ventricle physiology: a report from the Pediatric Heart Network Infant Single Ventricle Trial

BACKGROUND

While echocardiographic parameters are used to quantify ventricular function in infants with single ventricle physiology, there are few data comparing these to invasive measurements. This study correlates echocardiographic measures of diastolic function with ventricular end-diastolic pressure in infants with single ventricle physiology prior to superior cavopulmonary anastomosis.

METHODS

Data from 173 patients enrolled in the Pediatric Heart Network Infant Single Ventricle enalapril trial were analysed. Those with mixed ventricular types (n = 17) and one outlier (end-diastolic pressure = 32 mmHg) were excluded from the analysis, leaving a total sample size of 155 patients. Echocardiographic measurements were correlated to end-diastolic pressure using Spearman's test.

RESULTS

Median age at echocardiogram was 4.6 (range 2.5-7.4) months. Median ventricular end-diastolic pressure was 7 (range 3-19) mmHg. Median time difference between the echocardiogram and catheterisation was 0 days (range -35 to 59 days). Examining the entire cohort of 155 patients, no echocardiographic diastolic function variable correlated with ventricular end-diastolic pressure. When the analysis was limited to the 86 patients who had similar sedation for both studies, the systolic:diastolic duration ratio had a significant but weak negative correlation with end-diastolic pressure (r = -0.3, p = 0.004). The remaining echocardiographic variables did not correlate with ventricular end-diastolic pressure.

CONCLUSION

In this cohort of infants with single ventricle physiology prior to superior cavopulmonary anastomosis, most conventional echocardiographic measures of diastolic function did not correlate with ventricular end-diastolic pressure at cardiac catheterisation. These limitations should be factored into the interpretation of quantitative echo data in this patient population.

Blueberry extract decreases oxidative stress and improves functional parameters in lungs from rats with pulmonary arterial hypertension

OBJECTIVES

Pulmonary arterial hypertension (PAH) is a condition characterized by an increased resistance of pulmonary vasculature, culminating in an increase in pulmonary pressure. This process involves disturbances in lung redox homeostasis, causing progressive right heart failure. In this context, the use of natural antioxidants, such as those found in blueberries, may represent a therapeutic approach. The aim of this study was to evaluate the effect of blueberry extract (BB) on functional parameters and oxidative stress levels in rat lungs with induced PAH.

METHODS

Forty-eight male Wistar rats (weighing 200 ± 20 g) were randomized into five groups: control, monocrotaline, monocrotaline + BB 50, monocrotaline + BB 100, and monocrotaline + BB 200. PAH was induced by the administration of monocrotaline (60 mg/kg, intraperitoneal). Rats were treated with BB at doses of 50, 100, and 200 mg/kg via gavage for 5 wk (2 wk before monocrotaline and 3 wk after monocrotaline injection). At day 35, rats were submitted to echocardiography and catheterization. They were then sacrificed and lungs were harvested for biochemical analyses.

RESULTS

BB increased the E/A ratio of blood flow across the tricuspid valve and tricuspid annular phase systolic excursion, as wells as decreased the mean pulmonary artery pressure of animals compared with the PAH group. Moreover, BB decreased total reactive species concentration and lipid oxidation, reduced activity of nicotinamide adenine dinucleotide phosphate oxidase and expression of xanthine oxidase, increased the activity of superoxide dismutase and restored sulfhydryl content in the animal lungs compared with those in the PAH group. Additionally, BB restored expression of the antioxidant transcriptional factor Nrf2 in the lungs of the animal subjects. Finally, BB normalized the endothelin receptor (ETA/ETB) expression ratio in the animal lungs, which were increased in the PAH group.

CONCLUSION

Intervention with BB mitigated functional PAH outcomes through improvement of the pulmonary redox state. Our results provide a basis for future research on natural antioxidant interventions as a novel treatment strategy in PAH.

Right Ventricular Myocardial Stiffness and Relaxation Components by Kinematic Model-Based Transtricuspid Flow Analysis in Children and Adolescents with Pulmonary Arterial Hypertension

We hypothesized that the kinematic model-based parameters obtained from the transtricuspid E-wave would be useful for evaluating the right ventricular diastolic property in pediatric pulmonary arterial hypertension (PAH) patients. The model was parametrized by stiffness/elastic recoil k, relaxation/damping c and load x. These parameters were determined as the solution of m⋅d²x/dt² + c⋅dx/dt + kx = 0, which is based on the theory that the E-wave contour is determined by the interplay of stiffness/restoring force, damping/relaxation force and load. The PAH group had a significantly higher k and c compared with the control group (182.5 ± 72.4 g/s vs. 135.7 ± 49.5 g/s², p = 0.0232, and 21.9 ± 6.5 g/s vs. 10.6 ± 5.2 g/s, p <0.0001, respectively). These results indicate that in the PAH group, the right ventricle had higher stiffness/elastic recoil and inferior cross-bridge relaxation. The present findings indicate the feasibility and utility of using kinematic model parameters to assess right ventricular diastolic function.

Ventricular-ventricular interaction variables correlate with surrogate variables of clinical outcome in children with pulmonary hypertension

Determination of biventricular dimensions, function, and ventricular–ventricular interactions (VVI) is an essential part of the echocardiographic examination in adults with pulmonary hypertension (PH); however, data from according pediatric studies are sparse. We hypothesized that left and right heart dimensions/function and VVI variables indicate disease severity and progression in children with PH. Left heart, right heart, and VVI variables (e.g. end-systolic LV eccentricity index [LVEI], right ventricular [RV]/left ventricular [LV] dimension ratio) were echocardiographically determined in 57 children with PH, and correlated with New York Heart Association (NYHA) functional class (FC), N-terminal-pro brain natriuretic peptide (NT-proBNP), and invasive hemodynamic variables (e.g. pulmonary vascular resistance index [PVRi]). Clinically sicker patients (higher NYHA FC) had lower LV ejection fraction (LVEF) and higher LVEI – a surrogate of LV compression. In PH children, the ratio of systolic pulmonary arterial pressure divided by systolic systemic arterial pressure (sPAP/sSAP) and the PVRi correlated well with the LVEI (P < 0.001). Patients with more severe PH (sPAP/sSAP ratio, PVRi) had increased RV/LV and right-to-left atrial dimension ratios (P < 0.01). When stratified using NYHA-FC, sicker PH children had greater RV and right atrial dimensions with lower exercise capacity, while the tricuspid annular plane systolic excursion as surrogate for longitudinal systolic RV function decreased. Consistent with previous studies, serum NT-proBNP correlated with both, sPAP/sSAP ratio (P < 0.001) and NYHA FC (P < 0.01). Taken together, the VVI variables LVEI and RV/LV dimension ratio are associated with lower FC, worse hemodynamics, and higher NT-proBNP levels, thus highlighting the importance of ventricular interdependence in pediatric PH.

Right Atrial Deformation Mechanics in Children with Adenotonsillar Hypertrophy

BACKGROUND

Children with significant adenotonsillar hypertrophy (ATH) may show right ventricular (RV) dysfunction. We aimed to evaluate RV dysfunction in such children before adenotonsillectomy by evaluating peak longitudinal right atrial (RA) strain (PLRAS) in systole. PLRAS, electrocardiogram (ECG) and conventional echocardiographic parameters were compared to distinguish children with significant ATH with sleep-related breathing disorder (ATH-SRBD) from controls.

METHODS

Fifty-six children (23 controls and 33 children with ATH-SRBD without symptoms of heart failure) were retrospectively studied. Preoperative echocardiograms and ECGs of children with ATH-SRBD who underwent adenotonsillectomy were compared to those of controls. Available postoperative ECGs and echocardiograms were also analyzed.

RESULTS

Preoperatively, prolonged maximum P-wave duration (Pmax) and P-wave dispersion (PWD), decreased PLRAS, and increased tricuspid annulus E/E′ were found in children with ATH-SRBD compared to those of controls. From the receiver operating characteristic curves, PLRAS was not inferior compared to tricuspid annulus E/E′, Pmax, and PWD in differentiating children with ATH-SRBD from controls; however, the discriminative abilities of all four parameters were poor. In children who underwent adenotonsillectomy, echocardiograms 1.2 ± 0.4 years after adenotonsillectomy showed no difference in postoperative PLRAS and tricuspid annulus E/E′ when compared with those of the preoperative period.

CONCLUSIONS

Impaired RA deformation was reflected as decreased PLRAS in children with ATH-SRBD before adenotonsillectomy. Decreased PLRAS in these children may indicate subtle RV dysfunction and increased proarrhythmic risk. However, usefulness of PLRAS as an individual parameter in differentiating preoperative children with ATH-SRBD from controls was limited, similar to those of tricuspid annulus E/E′, Pmax, and PWD.

The continuing challenge of evaluating diastolic function by echocardiography in children: developing concepts and newer modalities

PURPOSE OF REVIEW

Assessment of diastolic function by echocardiography is challenging but important. Left ventricular filling has been more extensively studied than the right ventricle, and predominantly in adult populations. Although multiple parameters exist to assess diastolic function, they all have limitations, including load and heart rate dependency, which make assessment of diastolic function particularly challenging. The purpose of this article is to review evolving concepts and modalities for echo assessment of diastolic function in children.

RECENT FINDINGS

The paradigm whereby diastolic dysfunction severity progresses in a staged fashion from impaired relaxation to increasing ventricular stiffness, may not apply in children. In addition, previous adult guidelines are not readily applicable to children with cardiomyopathy and the applicability of the newly revised adult guidelines needs to be evaluated in children. It is unlikely that any one single echocardiographic diastolic parameter will adequately reflect diastolic function. Hence, parameters derived from atrioventricular valve inflow, pulmonary venous, and tissue Doppler need to be integrated. Newer modalities such as diastolic strain rate and rotation mechanics may be useful as more sensitive markers of early ventricular dysfunction but have important limitations and require more evaluation before routine use in practice. Assessment of systolic-diastolic coupling may enhance assessment of diastolic function.

SUMMARY

Diastolic function impacts outcomes and should be part of routine echocardiographic assessment of function. An integrative approach combining different parameters, possibly with contribution of newer modalities in the future, is required.

Tissue Motion Annular Displacement of the Mitral Valve Can Be a Useful Index for the Evaluation of Left Ventricular Systolic Function by Echocardiography in Normal Children

As the important role of longitudinal shortening in ventricular function has been well recognized over the past decade, evaluation of longitudinal systolic function of the left ventricle has become a subject of growing interest. Tissue motion annular displacement of the mitral valve (TMAD) is a new parameter of longitudinal systolic function. Although some studies have reported that this new parameter correlates with left ventricular ejection fraction (LVEF) in adults, little is known about TMAD in normal children. In this work, we investigated 94 children with no history of cardiovascular disease. TMAD was measured in the apical four-chamber view using the two-dimensional speckle tracking technique. Three points for tracking were selected in a diastolic frame: the lateral mitral valve annulus, medial mitral valve annulus, and left ventricular apex. The value was expressed as the percentage of displacement of the midpoint of the mitral valve annulus, using software to correct for left ventricular length at end-diastole. Pearson's coefficient was used to estimate the correlation between TMAD and left ventricular systolic function parameters including the biplane modified Simpson method-derived ejection fraction and global longitudinal strain (GLS). We also analyzed the correlation between TMAD and heart rate (HR), height, age, and body surface area (BSA). TMAD was found to correlate significantly with LVEF (r = 0.71, p < 0.01) and GLS (r = -0.77, p < 0.01). However, no correlation was revealed for HR (r = -0.14, p = 0.19), height (r = -0.17, p = 0.10), age (r = -0.19, p = 0.09), or BSA (r = -0.19, p = 0.08). These results indicate that TMAD is useful for assessing LVEF and longitudinal systolic function in normal children, and is not influenced by changes in HR, height, age, or BSA.

Analysis of Right Ventricular Myocardial Stiffness and Relaxation Components in Children and Adolescents With Pulmonary Arterial Hypertension

Background

The rate of left ventricular pressure decrease during isovolumic relaxation is traditionally assessed algebraically via 2 empirical indices: the monoexponential and logistic time constants (τ_E and τ_L). Since the pattern of right ventricular (RV) pressure decrease is quite different from that of the left ventricular, we hypothesized that novel kinematic model parameters are more appropriate and useful to evaluate RV diastolic dysfunction.

Methods and Results

Eight patients with pulmonary arterial hypertension (age 12.5±4.8 years) and 20 normal subjects (control group; age 12.3±4.4 years) were enrolled. The kinematic model was parametrized by stiffness/restoring Ek and damping/relaxation μ. The model predicts isovolumic relaxation pressure as a function of time as the solution of d²P/dt²+(1/μ)dP/dt+EkP=0, based on the theory that the pressure decay is determined by the interplay of inertial, stiffness/restoring, and damping/relaxation forces. In the assessment of RV diastolic function, τ_E and τ_L did not show significant differences between the pulmonary arterial hypertension and control groups (46.8±15.5 ms versus 32.5±14.6 ms, and 19.6±5.9 ms versus 14.5±7.2 ms, respectively). The pulmonary arterial hypertension group had a significantly higher Ek than the control group (915.9±84.2 s⁻² versus 487.0±99.6 s⁻², P<0.0001) and a significantly lower μ than the control group (16.5±4.3 ms versus 41.1±10.4 ms, P<0.0001). These results show that the RV has higher stiffness/elastic recoil and lower cross‐bridge relaxation in pulmonary arterial hypertension.

Conclusions

The present findings indicate the feasibility and utility of kinematic model parameters for assessing RV diastolic function.

The clinical value of assessing right ventricular diastolic function after balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) has a poor prognosis because of the associated progressive right heart failure. Accurate evaluation of right ventricular (RV) function would thus be useful to predict prognosis. However, the significance of RV diastolic function remains unclear. We aimed to identify which echocardiographic measures are most accurate, and potentially useful, in assessing RV diastolic function in patients with CTEPH, and to study the effects of balloon pulmonary angioplasty (BPA) on them. We enrolled 53 CTEPH patients who underwent BPA. Echocardiographic parameters, including two-dimensional speckle-tracking echocardiography, were compared to the hemodynamic parameters measured by right heart catheterization before and after BPA. RV strain rate during early diastole (SR_E), tricuspid e' and right atrial area (RAA) were ameliorated after BPA, concomitant with a decrease in the time constant of the RV pressure curve during diastole (tau), indicating the improvement of RV diastolic function. Among them, SR_E had the strongest correlation with tau (r = - 0.39, p < 0.001). Furthermore, the receiver operating characteristic analyses revealed that E/SR_E (AUC 0.704) and inferior vena cava diameter (AUC 0.726) had a stronger association with higher mean right atrial pressure than RAA (AUC 0.632). In contrast, RAA had a stronger correlation with 6 min-walk distances than SR_E (r = - 0.39, p < 0.001 vs. r = 0.30, p = 0.005). Taken together, echocardiographic assessment of RV diastolic function might be associated with hemodynamics as well as exercise tolerance in patients with CTEPH, indicating its benefits in evaluating the therapeutic effects of BPA.

The impact of ambrisentan and tadalafil upfront combination therapy on cardiac function in scleroderma associated pulmonary arterial hypertension patients: cardiac magnetic resonance feature tracking study

The aim of this study was to evaluate the effect of upfront combination therapy with ambrisentan and tadalafil on left ventricular (LV) and right ventricular (RV) function in patients with systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH). LV and RV peak longitudinal and circumferential strain and strain rate (SR), which consisted of peak systolic SR (SRs), peak early diastolic SR (SRe), and peak atrial-diastolic SR (SRa) were analyzed using cardiac magnetic resonance imaging (CMRI) data from the recently published ATPAHSS-O trial (ambrisentan and tadalafil upfront combination therapy in SSc-PAH). Twenty-one patients completed the study protocol. Measures of RV systolic function (RV free wall [RVFW] peak longitudinal strain [pLS], RVFW peak longitudinal SRs [pLSRs]) and RV diastolic function (RVFW peak longitudinal SRa [pLSRa], RVFW peak circumferential SRe) were improved after treatment. LV systolic function (LV peak global longitudinal strain [pGLS]) and diastolic function (LV peak global longitudinal SRe [pGLSRe]) were also significantly improved at follow-up. Increased 6-min walk distance was significantly correlated with RVFW pLS and pLSRs, while the decrease in N-terminal pro-brain natriuretic peptide was correlated with LV pGLS. Increased cardiac index was associated with improved LV pGLSRe, and reduction in mean right atrial pressure was correlated with improved RVFW pLS and pLSRa. Combination therapy was associated with a significant improvement in both RV and LV function as assessed by CMR-derived strain and SR. Importantly, the improvement in RV and LV strain and SR correlated with improvements in known prognostic markers of PAH. (Approved by clinicaltrials.gov [NCT01042158] before patient recruitment.)

Echocardiographic right ventricular function correlations with cardiac catheterisation data in biventricular congenital heart patients

BACKGROUND

Newer echocardiographic techniques may allow for more accurate assessment of right ventricular function. Adult studies have correlated these echocardiographic measurements with invasive data, but minimal data exist in the paediatric congenital heart population. The purpose of this study was to evaluate echocardiographic measurements that correlate best with right ventricular systolic and diastolic catheterisation parameters.

METHODS

Patients with two-ventricle physiology who underwent simultaneous echocardiogram and cardiac catheterisation were included in this study. Right ventricular systolic echocardiographic data included fractional area change, displacement, tissue Doppler imaging s' wave, global longitudinal strain, and strain rate s' wave. Diastolic echocardiographic data included tricuspid E and A waves, tissue Doppler imaging e' and a' waves, and strain rate e' and a' waves. E/tissue Doppler imaging e', tissue Doppler imaging e'/tissue Doppler imaging a', E/strain rate e', and strain rate e'/strain rate a' ratios were also calculated. Catheterisation dP/dt was used as a marker for systolic function and right ventricular end-diastolic pressure for diastolic function.

RESULTS

A total of 32 patients were included in this study. The median age at catheterisation was 3.1 years (0.3-17.6 years). The DP/dt was 493±327 mmHg/second, and the right ventricular end-diastolic pressure was 7.7±2.4 mmHg. There were no significant correlations between catheterisation dP/dt and systolic echocardiographic parameters. Right ventricular end-diastolic pressure correlated significantly with strain rate e' (r=-0.4, p=0.02), strain rate a' (r=-0.5, p=0.03), and E/tissue Doppler imaging e' (r=0.4, p=0.04).

CONCLUSION

Catheterisation dP/dt did not correlate with echocardiographic measurements of right ventricular systolic function. Strain rate and tissue Doppler imaging analysis significantly correlated with right ventricular end-diastolic pressure. These values should be further studied to determine whether they may be used as an alternative method to estimate right ventricular end-diastolic pressure in this patient population.

Diagnostics in Children and Adolescents with Suspected or Confirmed Pulmonary Hypertension

We provide a practical approach on the initial assessment and diagnostic work-up of children and adolescents with pulmonary hypertension (PH). Transthoracic echocardiography (TTE) often serves as initial study tool before invasive cardiac catheterization. Misinterpretation of TTE variables may lead to missed or delayed diagnosis with devastating consequences, or unnecessary invasive diagnostics that have inherited risks. In addition to clinical and biochemical markers, serial examination of patients with PH using a standardized TTE approach, determining conventional and novel echocardiographic variables, may allow early diagnosis and treatment in paediatric PH. Cardiac magnetic resonance imaging and computed tomography represent important non-invasive imaging modalities, that together with TTE may enable comprehensive assessment of ventricular function and pulmonary hemodynamics. Invasive assessment of haemodynamics (ventricular, pulmonary) and testing of acute vasoreactivity in the catheterization laboratory is still the gold standard for the diagnosis of PH and pulmonary hypertensive vascular disease (PHVD) in children and for the initiation of specific PH therapy. We suggest the regular assessment of prognostic TTE variables as part of a standardized approach for initial diagnosis of children with PH. Overreliance on any single TTE variable should be avoided as it detracts from the overall diagnostic potential of a standardized TTE examination for PH.

Impact of Pulmonary Hemodynamics and Ventricular Interdependence on Left Ventricular Diastolic Function in Children With Pulmonary Hypertension

BACKGROUND

Through ventricular interdependence, pulmonary hypertension (PH) induces left ventricular (LV) dysfunction. We hypothesized that pediatric PH patients have LV diastolic dysfunction, related to adverse pulmonary hemodynamics, leftward septal shift, and prolonged right ventricular systole.

METHODS AND RESULTS

Echocardiography was prospectively performed at 2 institutions in 54 pediatric PH patients during cardiac catheterization and in 54 matched controls. Diastolic LV measures including myocardial deformation were assessed by echocardiography. PH patients had evidence of LV diastolic dysfunction, most consistent with impaired LV relaxation, though some features of reduced ventricular compliance were present. PH patients demonstrated the following: reduced mitral E velocity and inflow duration, mitral E' and E'/A', septal E' and A', pulmonary vein S and D wave velocities, and LV basal global early diastolic circumferential strain rate and increased mitral E deceleration time, LV isovolumic relaxation time, mitral E/E', and pulmonary vein A wave duration. PH patients demonstrated leftward septal shift and prolonged right ventricular systole, both known to affect LV diastole. These changes were exacerbated in severe PH. There were no statistically significant differences in diastolic measures between patients with and without a shunt and minimal differences between patients with and without congenital heart disease. Multiple echocardiographic LV diastolic parameters demonstrated weak-to-moderate correlations with invasively determined PH severity, leftward septal shift, and prolonged right ventricular systole.

CONCLUSIONS

Pediatric PH patients exhibit LV diastolic dysfunction most consistent with impaired relaxation and reduced myocardial deformation, related to invasive hemodynamics, leftward septal shift, and prolonged right ventricular systole.

Regional right ventricular remodeling and function in children with idiopathic pulmonary arterial hypertension vs those with pulmonary valve stenosis: Insights into mechanics of right ventricular dysfunction

BACKGROUND

Right ventricular (RV) pressure overload in the context of pulmonary stenosis (PS) has a much better prognosis than in the context of idiopathic pulmonary arterial hypertension (iPAH), which may be related to differences in global and regional RV remodeling and systolic function. We compared RV mechanics in children with PS to those with iPAH, aiming to identify mechanisms and markers of RV dysfunction.

METHODS

Eighteen controls, 18 iPAH and 16 PS patients were retrospectively studied. Age, BSA, and sex distribution were comparable. Two-dimensional echocardiography, blood flow and tissue Doppler, and longitudinal RV deformation were analyzed. ANCOVA-including RV systolic pressure (RVSP) and length as covariates-was used to compare patient groups.

RESULTS

RV systolic pressure was higher in iPAH vs PS (96.8±25.4 vs 75.4±18.9 mm Hg, P=.011). Compared to controls, PS patients showed mild dilation (P<.01) and decreased longitudinal deformation (P<.001) at the RV apex. Compared to both PS and controls, iPAH patients showed marked spherical RV dilation (P<.001), reduced global, RV free wall and septal longitudinal deformation (iPAH -22.07%±4.35% vs controls -28.18%±1.69%; -9.98%±4.30% vs -17.45%±2.52%; P<.001) and RV postsystolic shortening (P<.001). RV transverse shortening (radial performance) was increased in PS (31.75%±10.35%; P<.001) but reduced in iPAH (-1.62%±11.11% vs controls 12.00%±7.74%; P<.001).

CONCLUSION

Children with iPAH demonstrate adverse global and regional RV remodeling and mechanics compared to those with PS. Mechanisms of RV systolic dysfunction in iPAH include decreased longitudinal deformation, decreased or absent transverse shortening, and postsystolic shortening. These markers may be useful to identify children at risk of RV failure.

Utility of Echocardiography in the Assessment of Left Ventricular Diastolic Function and Restrictive Physiology in Children and Young Adults with Restrictive Cardiomyopathy: A Comparative Echocardiography-Catheterization Study

The aim of the study is to determine the utility of echocardiography in the assessment of diastolic function in children and young adults with restrictive cardiomyopathy (RCM). RCM is a rare disease with high mortality requiring frequent surveillance. Accurate, noninvasive echocardiographic measures of diastolic function may reduce the need for invasive catheterization. Single-center, prospective, observational study of pediatric and young adult RCM patients undergoing assessment of diastolic parameters by simultaneous transthoracic echocardiogram (TTE) and invasive catheterization. Twenty-one studies in 15 subjects [median (IQR) = 13.8 years (7.0-19.2), 60% female] were acquired with median left ventricular end-diastolic pressure (LVEDP) 21 (IQR 18-25) mmHg. TTE parameters of diastolic function, including pulmonary vein A wave duration (r _s  = 0.79) and indexed left atrial volume (r _s  = 0.49), demonstrated significant positive correlation, while mitral valve A (r _s  = -0.44), lateral e' (r _s  = -0.61) and lateral a' (r _s  = -0.61) velocities showed significant negative correlation with LVEDP. Lateral a' velocity (≤0.042 m/s) and pulmonary vein A wave duration (≥156 m/s) both had sensitivity and specificity ≥80% for LVEDP ≥ 20 mmHg. In pediatric and young adult patients with RCM, lateral a' velocity and pulmonary vein A wave duration predicted elevated LVEDP with high sensitivity and specificity; however, due to technical limitations the latter was reliably measured in 12/21 patients. These noninvasive parameters may have utility in identifying patients that require further assessment with invasive testing. These findings require validation in a multicenter prospective cohort prior to widespread clinical implementation.

Speckle-Tracking Echocardiographic Measures of Right Ventricular Diastolic Function Correlate with Reference Standard Measures Before and After Preload Alteration in Children

The accuracy of echocardiographic measures of right ventricular (RV) diastolic function has been sparsely studied. Our objective was to evaluate the correlation between echocardiographic and reference standard measures of RV diastolic function derived from micromanometer pressure analysis before and after preload alteration in children. Echocardiograms and micromanometer pressure analyses were prospectively performed before and after fluid bolus in children undergoing right heart catheterization. The isovolumic relaxation time constant (τ) and end-diastolic pressure (EDP) were measured. Conventional and speckle-tracking echocardiographic (STE) parameters of RV systolic and diastolic function were assessed. Normal saline bolus was given to increase RV EDP by 20 %. Twenty-eight studies were performed in 22 patients with congenital heart disease or postheart transplantation. Mean age was 8.7 ± 6.1 years. RV longitudinal early diastolic strain rate (EDSR) correlated with τ before (r = 0.57, p = 0.001) and after fluid bolus (r = 0.48, p = 0.008). No conventional echocardiographic measures correlated with τ both before and after fluid bolus. Multiple regression analysis revealed RV EDSR and LV circumferential EDSR as independent predictors of RV τ. There were no independent predictors of EDP. RV EDSR appears to correlate with the reference standard measure of early active ventricular relaxation in children at baseline and after changes in preload. Conventional echocardiographic measures of diastolic function were not predictive of diastolic function after preload alteration. Future studies should assess the prognostic significance of STE measures of diastolic function in this population.

A comparison of echocardiographic variables of right ventricular function with exercise capacity after bosentan treatment in patients with pulmonary arterial hypertension: Results from a multicenter, prospective, cohort study

PURPOSE

Bosentan reduces pulmonary arterial pressure and improves exercise capacity in patients with pulmonary arterial hypertension (PAH). However, there are limited data regarding the extent to which the changes in echocardiographic variables reflect improvements in exercise capacity. We aimed to assess the improvement of echocardiographic variables and exercise capacity after 6 months of bosentan treatment for PAH.

METHODS

We performed a prospective study from June 2012 to June 2015 in seven participating medical centers. Echocardiography, including tissue Doppler imaging (TDI) and the 6-minute walk test distance (6MWD), was performed at baseline and after 6 months of bosentan treatment.

RESULTS

We analyzed 19 patients with PAH: seven with congenital shunt, six with collagen vascular disease, and six with idiopathic PAH. After bosentan treatment, mean 6MWD increased by 50 meters. Right ventricle (RV) systolic pressure, tricuspid annular plane systolic excursion, myocardial performance index (MPI) derived from TDI (MPI-TDI) of RV and left ventricle (LV), RV fractional area change, and RV ejection fraction were significantly improved. In particular, the magnitude of RV and LV MPI-TDI showed good correlation with changes in the 6MWD.

CONCLUSIONS

The magnitude of RV and LV MPI-TDI was strongly associated with improvements in exercise capacity. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:28-34, 2017.

Atrial chamber remodelling in healthy pre-adolescent athletes engaged in endurance sports: A study with a longitudinal design. The CHILD study

AIMS

Previous studies investigated the exercise-induced adaptation of left (LA) and right atrium (RA) in adults, but little is known about respective changes in the growing heart of children. We aimed to longitudinally investigate the effects of endurance training on biatrial remodelling in preadolescent athletes.

METHODS AND RESULTS

Ninety-four children (57 endurance athletes, 37 sedentary controls; mean age 10.8±0.2 and 10.2±0.2years, respectively) were evaluated at baseline and after 5months by ECG and by two-dimensional, three-dimensional (3D) and speckle-tracking echocardiography. Athletes were trained at least 10h/week. The resting heart rate was lower in athletes (p=0.046) and decreased further after training (p<0.0001). Neither athletes nor controls had ECG evidence for LA or RA enlargement. At baseline, indexed LA volumes did not differ between groups (p=0.14) but indexed RA dimensions were larger in athletes (p=0.007). After 5months, indexed LA volumes increased in athletes but not in controls (p<0.0001, p=0.29; respectively) while indexed RA volumes increased in both groups (p<0.0001, p=0.018; respectively). At the same time, slight differences in biatrial reservoir and contractile function were found either in athletes, as demonstrated by speckle-tracking echocardiography, but 3D-derived LA and RA ejection fraction remained stable in both groups.

CONCLUSION

Endurance training influences the growing heart of preadolescent athletes with an additive increase in biatrial size, suggesting that morphological adaptations can occur also in the early phases of the sports career. Training-induced remodelling was associated with a preserved biatrial function, supporting the hypothesis of a physiological remodelling.

Transthoracic echocardiography in the evaluation of pediatric pulmonary hypertension and ventricular dysfunction

Transthoracic echocardiography (TTE) is the most accessible noninvasive diagnostic procedure for the initial assessment of pediatric pulmonary hypertension (PH). This review focuses on principles and use of TTE to determine morphologic and functional parameters that are also useful for follow-up investigations in pediatric PH patients. A basic echocardiographic study of a patient with PH commonly includes the hemodynamic calculation of the systolic pulmonary artery pressure (PAP), the mean and diastolic PAP, the pulmonary artery acceleration time, and the presence of a pericardial effusion. A more detailed TTE investigation of the right ventricle (RV) includes assessment of its size and function. RV function can be evaluated by RV longitudinal systolic performance (e.g., tricuspid annular plane systolic excursion), the tricuspid regurgitation velocity/right ventricular outflow tract velocity time integral ratio, the fractional area change, tissue Doppler imaging-derived parameters, strain measurements, the systolic-to-diastolic duration ratio, the myocardial performance (Tei) index, the RV/left ventricle (LV) diameter ratio, the LV eccentricity index, determination of an enlarged right atrium and RV size, and RV volume determination by 3-dimensional echocardiography. Here, we discuss the potential use and limitations of TTE techniques in children with PH and/or ventricular dysfunction. We suggest a protocol for TTE assessment of PH and myocardial function that helps to identify PH patients and their response to pharmacotherapy. The outlined protocol focuses on the detailed assessment of the hypertensive RV; RV-LV crosstalk must be analyzed separately in the evaluation of different pathologies that account for pediatric PH.

Echocardiographic Reference Values for Right Atrial Size in Children with and without Atrial Septal Defects or Pulmonary Hypertension

Right atrial (RA) size may become a very useful, easily obtainable, echocardiographic variable in patients with congenital heart disease (CHD) with right-heart dysfunction; however, according studies in children are lacking. We investigated growth-related changes of RA dimensions in healthy children. Moreover, we determined the predictive value of RA variables in both children with secundum atrial septal defect (ASD) and children with pulmonary hypertension (PH) secondary to CHD (PH-CHD). This is a prospective study in 516 healthy children, in 80 children with a secundum ASD (>7 mm superior-inferior dimension), and in 42 children with PH-CHD. We determined three RA variables, i.e., end-systolic major-axis length, end-systolic minor-axis length, and end-systolic area, stratified by age, body weight, length, and surface area. RA end-systolic length and area z scores were increased in children with ASD and PH-CHD when compared to those variables in the healthy control population. Using the Youden Index to determine the best cutoff scores in sex- and age-specific RA dimensions, we observed a sensitivity and specificity up to 94 and 91 %, respectively, in ASD children and 98 and 94 %, respectively, in PH-CHD children. We provide normal values (z scores -2 to +2) for RA size and area in a representative, large pediatric cohort. Enlarged RA variables with scores >+2 were predictive of secundum ASD and PH-CHD. Two-dimensional determination of RA size can identify enlarged RAs in the setting of high volume load (ASD) or pressure load (PH-CHD).

Correlations Between Echocardiographic Systolic and Diastolic Function with Cardiac Catheterization in Biventricular Congenital Heart Patients

Newer echocardiographic techniques may allow for more accurate assessment of left ventricular (LV) function. Adult studies have correlated these echocardiographic measurements with invasive data, but minimal data exist in the pediatric congenital heart population. Purpose of this study was to evaluate which echocardiographic measurements correlated best with LV systolic and diastolic catheterization parameters. Patients with two-ventricle physiology who underwent simultaneous echocardiogram and cardiac catheterization were included. Images were obtained in the four-chamber view. LV systolic echocardiographic data included ejection fraction, displacement, tissue Doppler imaging (TDI) s' wave, global longitudinal strain, and strain rate (SR) s' wave. Diastolic echocardiographic data included mitral E and A waves, TDI e' and a' waves, and SRe' and SRa' waves. E/TDI e', TDI e'/TDI a', E/SRe', and SRe'/SRa' ratios were also calculated. Catheterization dP/dt was used as a marker for systolic function, and LV end-diastolic pressure (EDP) was used as a marker for diastolic function. Correlations of the echocardiographic and catheterization values were performed using Pearson correlation. Twenty-nine patients were included (14 females, 15 males). Median age at catheterization was 3.4 years (0.04-17.4 years). dP/dt was 1258 ± 353 mmHg/s, and LVEDP was 10.8 ± 2.4 mmHg. There were no significant correlations between catheterization dP/dt and systolic echocardiographic parameters. LVEDP correlated significantly with SRe' (r = -0.4, p = 0.03), SRa' (r = -0.4, p = 0.03), and E/SRe' (r = 0.5, p = 0.004). In pediatric congenital heart patients, catheterization dP/dt did not correlate with echocardiographic measurements of LV systolic function. Further studies are needed to determine which echocardiographic parameter best describes LV systolic function in this population. Strain rate analysis significantly correlated with LVEDP. Strain rate analysis should be considered as an alternative method to estimate LVEDP in this patient population.

Right ventricular diastolic function and exercise capacity in COPD

BACKGROUND

Decreased exercise capacity in chronic obstructive pulmonary disease (COPD) is incompletely explained by pulmonary pathologic and physiologic abnormalities. We evaluated the extent to which right ventricular diastolic function (RVDF) is associated with exercise capacity in COPD.

METHODS

Fifty-one patients with COPD were evaluated by echocardiography, spirometry, and the 6 min walk test (6MWT). RVDF was assessed using 4 echocardiographic parameters: 1) the ratio of tricuspid valve (TV) early (E) and late (A) inflow velocities (TV E/A) 2) TV early tissue Doppler velocity (TV e') 3) TV deceleration time (DT) and 4) the ratio of TV E and e' velocities (TV E/e'). Multiple linear regression was used to examine the extent to which these parameters were associated with 6MWT distance. All models adjusted for age, sex, post-bronchodilator FEV1/FVC, resting heart rate, and use of supplemental O2 during 6MWT. A regression model was calculated for each of the 4 markers of RVDF.

RESULTS

Forty-seven percent of the sample had GOLD stage III or IV COPD. All 51 subjects had preserved left ventricular ejection fraction (LVEF, mean = 71.7%, SD = 7.8%). A higher TV E/A ratio was associated with increased 6MWT distance (p = 0.001). TV e', TV DT and TV E/e' did not have a statistically significant association with 6MWT distance in regression models.

CONCLUSIONS

In a cohort with moderate to severe COPD and normal LVEF, TV E/A was associated with 6MWT distance after adjusting for relevant demographic and medical covariates. RV diastolic dysfunction may independently contribute to exercise intolerance in COPD.

Abnormal right ventricular relaxation in pulmonary hypertension

Left ventricular diastolic dysfunction is a well-described complication of systemic hypertension. However, less is known regarding the effect of chronic pressure overload on right ventricular (RV) diastolic function. We hypothesized that pulmonary hypertension (PHT) is associated with abnormal RV early relaxation and that this would be best shown by invasive pressure measurement. Twenty-five patients undergoing right heart catheterization for investigation of breathlessness and/or suspected PHT were studied. In addition to standard measurements, RV pressure was sampled with a high-fidelity micromanometer, and RV pressure/time curves were analyzed. Patients were divided into a PHT group and a non-PHT group on the basis of a derived mean pulmonary artery systolic pressure of 25 mmHg. Eleven patients were classified to the PHT group. This group had significantly higher RV minimum diastolic pressure ([Formula: see text] vs. [Formula: see text] mmHg, [Formula: see text]) and RV end-diastolic pressure (RVEDP; [Formula: see text] vs. [Formula: see text] mmHg, [Formula: see text]), and RV τ was significantly prolonged ([Formula: see text] vs. [Formula: see text] ms, [Formula: see text]). There were strong correlations between RV τ and RV minimum diastolic pressure ([Formula: see text], [Formula: see text]) and between RV τ and RVEDP ([Formula: see text], [Formula: see text]). There was a trend toward increased RV contractility (end-systolic elastance) in the PHT group ([Formula: see text] vs. [Formula: see text] mmHg/mL, [Formula: see text]) and a correlation between RV systolic pressure and first derivative of maximum pressure change ([Formula: see text], [Formula: see text]). Stroke volumes were similar. Invasive measures of RV early relaxation are abnormal in patients with PHT, whereas measured contractility is static or increasing, which suggests that diastolic dysfunction may precede systolic dysfunction. Furthermore, there is a strong association between measures of RV relaxation and RV filling pressures.

Right ventricular dysfunction in children and adolescents conceived by assisted reproductive technologies

Assisted reproductive technologies (ART) predispose the offspring to vascular dysfunction, arterial hypertension, and hypoxic pulmonary hypertension. Recently, cardiac remodeling and dysfunction during fetal and early postnatal life have been reported in offspring of ART, but it is not known whether these cardiac alterations persist later in life and whether confounding factors contribute to this problem. We, therefore, assessed cardiac function and pulmonary artery pressure by echocardiography in 54 healthy children conceived by ART (mean age 11.5 ± 2.4 yr) and 54 age-matched (12.2 ± 2.3 yr) and sex-matched control children. Because ART is often associated with low birth weight and prematurity, two potential confounders associated with cardiac dysfunction, only singletons born with normal birth weight at term were studied. Moreover, because cardiac remodeling in infants conceived by ART was observed in utero, a situation associated with increased right heart load, we also assessed cardiac function during high-altitude exposure, a condition associated with hypoxic pulmonary hypertension-induced right ventricular overload. We found that, while at low altitude cardiac morphometry and function was not different between children conceived by ART and control children, under the stressful conditions of high-altitude-induced pressure overload and hypoxia, larger right ventricular end-diastolic area and diastolic dysfunction (evidenced by lower E-wave tissue Doppler velocity and A-wave tissue Doppler velocity of the lateral tricuspid annulus) were detectable in children and adolescents conceived by ART. In conclusion, right ventricular dysfunction persists in children and adolescents conceived by ART. These cardiac alterations appear to be related to ART per se rather than to low birth weight or prematurity.

Echocardiographic correlates of persistent pulmonary hypertension of the newborn

AIMS

To compare echocardiographic (ECHO) measures of ventricular function and hemodynamics of infants with persistent pulmonary hypertension of the newborn (PPHN) and normal controls; and to examine their association with clinical outcomes in PPHN.

DESIGN/SUBJECTS

We performed a retrospective review of ECHOs of mechanically ventilated infants (≥ 34 weeks gestational age) with PPHN. Infants with congenital heart disease were excluded. Controls had normal ECHOs within 1 week of age.

OUTCOMES

ECHOs measures included a) right (RVO) and left ventricular output (LVO) b) RV and LV myocardial performance index (MPI) c) right ventricular systolic to diastolic duration (S/D) ratio and d) eccentricity index in systole (EIs) and diastole (EId).

RESULTS

Infants with PPHN (n = 117), 63% of whom were males, had mean (SD) GA and birth weights of 38.6 (1.9) weeks and 3.3 (0.65) kg respectively. LVO, RVO and EIs were significantly lower and heart rate, MPI and RV S/D ratio were significantly higher in infants with PPHN, compared to controls (n = 35). The mean RV S/D ratios were significantly higher in infants with PPHN who died or required ECMO (n = 61), compared to survivors without ECMO (n = 56). Increasing RV S/D ratio was independently associated with a reduction in survival without ECMO [0.21; 95% C.I. 0.06-0.74, p = 0.015]. RV S/D ratio >1.3 had a sensitivity of 93 (95% C.I. 85-99) % for death or ECMO.

CONCLUSIONS

Elevated RV S/D ratio, a marker of global RV dysfunction, was associated with adverse outcomes in PPHN. Its routine measurement in this population may aid risk-identification and targeted interventions.

Echocardiography in pediatric pulmonary hypertension

Pulmonary hypertension (PH) can be a rapidly progressive and fatal disease. Although right heart catheterization remains the gold standard in evaluation of PH, echocardiography remains an important tool in screening, diagnosing, evaluating, and following these patients. In this article, we will review the important echocardiographic parameters of the right heart in evaluating its anatomy, hemodynamic assessment, systolic, and diastolic function in children with PH.