Investigating the Accuracy of Quantitative Echocardiographic-Modified Task Force Criteria for Arrhythmogenic Ventricular Cardiomyopathy in Adolescent Male Elite Athletes

Athlete preparticipation screening focuses on preventing sudden cardiac death (SCD) by detecting diseases such as arrhythmogenic ventricular cardiomyopathy (AVC), which affects primarily the right ventricular myocardium. Diagnosis may be obscured by physiological remodeling of the athlete heart. Healthy athletes may meet the 2010 Task Force Criteria right ventricular outflow tract (RVOT) dimension cut-offs, questioning the suitability of the modified Task Force Criteria (mTFC) in adolescent athletes. In this study, 67 male adolescent footballers undergoing preparticipation screening were reviewed. All athletes underwent a screening for resting ECG and echocardiogram according to the English FA protocol, as well as cardiopulmonary exercise testing, stress ECG, and exercise echocardiography. Athletes' right ventricular outflow tract (RVOT) that met the major AVC diagnostic criteria for dilatation were identified. Of 67 evaluated athletes, 7 had RVOT dilatation that met the major criteria, all in the long axis parasternal view measurement. All had normal right ventricular systolic function, including normal free-wall longitudinal strain (ranging from - 21.5 to - 32.7%). Left ventricular ejection fraction ranged from 52 to 67%, without evidence of structural changes. Resting ECGs and cardiopulmonary exercise tests were normal in all individuals. In a series of healthy athletes meeting the major AVC diagnostic criteria for RVOT dilatation, none had any other pathological changes on a detailed screening including ECG, exercise testing, and echocardiography. This report highlights that current AVC echocardiographic diagnosis criteria have limitations in this population.

Cardiac Outpouchings: Definitions, Differential Diagnosis, and Therapeutic Approach

Background and Aims

Cardiac outpouchings encounter a series of distinct congenital or acquired entities (i.e. aneurysms, pseudoaneurysms, diverticula, and herniations), whose knowledge is still poorly widespread in clinical practice. This review aims to provide a comprehensive overview focusing on definition, differential diagnosis, and prognostic outcomes of cardiac outpouchings, as well as further insights on therapeutic options, in order to assist physicians in the most appropriate decision-making.

Methods

The material reviewed was obtained by the following search engines: MEDLINE (PubMed), EMBASE, Google Scholar, and Clinical Trials databases, from January 1966 until March 2021. We searched for the following keywords (in title and/or abstract): (“cardiac” OR “heart”) AND (“outpouching” OR “outpouch” OR “aneurysm” OR “pseudoaneurysm” OR “false aneurysm” OR “diverticulum” OR “herniation”). Review articles, original articles, case series, and case reports with literature review were included in our search. Data from patients with congenital or acquired cardiac outpouchings, from prenatal to geriatric age range, were investigated.

Results

Out of the 378 papers initially retrieved, 165 duplicates and 84 records in languages other than English were removed. Among the 129 remaining articles, 76 were included in our research material, on the basis of the following inclusion criteria: (a) papers pertaining to the research topic; (b) peer-reviewed articles; (c) using standardized diagnostic criteria; and (d) reporting raw prevalence data. Location, morphologic features, wall motion abnormalities, and tissue characterization were found to have a significant impact in recognition and differential diagnosis of cardiac outpouchings as well as to play a significant role in defining their natural history and prognostic outcomes.

Conclusions

Careful recognition of cardiac outpouchings remains a diagnostic challenge in clinical practice. Due to a broad cluster of distinctive and heterogeneous entities, their knowledge and timely recognition play a pivotal role in order to provide the most appropriate clinical management and therapeutic approach.

The Assessment of Myocardial Strain by Cardiac Imaging in Healthy Infants with Acute Bronchiolitis: A Systematic Review and Meta-Analysis

This study aims to systematically review the incidence of myocardial strain detected by echocardiography in previously healthy infants with acute bronchiolitis and its role as a predictor for adverse outcomes in this setting.

METHODS

Pubmed/Medline, Excerpta Medica Data Base (EMBASE), and Cochrane Library were searched in April 2020 to identify original observational prospective studies that systematically performed echocardiography for the screening of myocardial strain in healthy infants with acute bronchiolitis. Pooled estimates were generated using random-effects models. Heterogeneity within studies was assessed using Cochran's Q and I² statistics. Funnel plots and Egger´s regression method were constructed to evaluate publication bias. Sensitivity analyses were also conducted to evaluate potential sources of heterogeneity.

RESULTS

After a detailed screening of 305 articles, a total of 10 studies with 395 participants (mean of 40 participants per study) was included. Five of them were classified as high-quality studies. Up to 28% of cases presented adverse outcomes. The echocardiographic screening for myocardial strain was performed within the first 24 h of admission in 92% cases. Tissue Doppler imaging and Speckle-Tracking echocardiography were performed only in 20% of cases. The presence of pulmonary hypertension was evaluated with methods different from the tricuspid regurgitation jet in 64% of cases. Seven studies found some grade of myocardial strain with a pooled incidence of 21% (CI 95%, 11-31%), in the form of pulmonary hypertension (pooled incidence of 20% (CI 95%, 11-30%)), and myocardial dysfunction (pooled incidence of 5% (CI 95%, 1-9%)). The presence of these echocardiographic alterations was associated with adverse outcomes (pooled relative risk = 16; CI 95%, 8.2-31.5). After a subgroup analysis based on the echocardiographic techniques used, no significant heterogeneity across the studies was observed. There was no evidence of publication bias when assessed by Egger´s test. Cardiac biomarkers to assess myocardial strain were used in five studies. Only N-terminal-pro-brain natriuretic peptide accurately predicted the presence of myocardial strain by echocardiography.

CONCLUSIONS

Myocardial strain is not infrequent in previously healthy infants with acute bronchiolitis, and it could be present at the early stages of the disease with prognostic implications. There is a need for sufficiently powered prospective studies with a similar methodology, preferably employing advanced imaging techniques, to conclusively address the usefulness of the assessment of myocardial strain in this setting.

Do right-ventricular trabeculae gain energetic advantage from having a greater velocity of shortening?

KEY POINTS

We designed a study to test whether velocity of shortening in right-ventricular tissue preparations is greater than that of the left side under conditions mimicking those encountered by the heart in vivo. Our experiments allowed us to explore whether greater velocity of shortening results in any energetic advantage. We found that velocity of shortening was higher in the rat right-ventricular trabeculae. These results at the tissue level seem paradoxical to the velocity of ventricular ejection at the organ level, and are not always in accord with shortening of unloaded cells. Despite greater velocity of shortening in right-ventricular trabeculae, they neither gained nor lost advantage with respect to both mechanical efficiency and the heat generated during shortening.

ABSTRACT

Our study aimed to ascertain whether the interventricular difference of shortening velocity, reported for isolated cardiac tissues in vitro, affects interventricular mechano-energetic performance when tested under physiological conditions using a shortening protocol designed to mimic those in vivo. We isolated trabeculae from both ventricles of the rat, mounted them in a calorimeter, and performed experiments at 37°C and 5 Hz stimulus frequency to emulate conditions of the rat heart in vivo. Each trabecula was subjected to two experimental protocols: (i) isotonic work-loop contractions at a variety of afterloads, and (ii) isometric contractions at a variety of preloads. Velocity of shortening was calculated from the former protocol during the isotonic shortening phase of the contraction. Simultaneous measurements of force-length work and heat output allowed calculation of mechanical efficiency. The shortening-dependent thermal component was quantified from the difference in heat output between the two protocols. Our results show that both extent of shortening and velocity of shortening were higher in trabeculae from the right ventricle. Despite these differences, trabeculae from both ventricles developed the same stress, performed the same work, liberated the same amount of heat, and hence operated at the same mechanical efficiency. Shortening heat was also ventricle independent. The interventricular differences in velocity of shortening and extent of shortening of isolated trabeculae were not manifested in any index of energetics. These collective results underscore the absence of any mechano-energetic advantage or disadvantage conferred on right-ventricular trabeculae arising from their superior velocity of shortening.

Evaluation of myocardial function in pediatric patients with transposition of great arteries after arterial switch operation

OBJECTIVE

An arterial switch operation converts the left ventricle (LV) into the systemic ventricle, replacing the right ventricle (RV), which is the systemic ventricle during the prenatal period. The procedure is performed in patients with arterial transposition and those in whom a coronary reimplantation procedure is performed. Therefore, the adaptation of LV and RV to the arterial switch operations is an interesting issue. This study aimed to evaluate systolic and diastolic functions in the LV and RV myocardium using echocardiography in pediatric patients with transposed great arteries after an arterial switch operation.

METHODS

This observational case control study included 28 patients and 20 gender-and age-matched healthy controls. A group study was performed using patients who were followed for at least 6 months after the operation and who visited the pediatric cardiology outpatient between October 2009 and May 2011. Systolic and diastolic parameters, LV and RV myocardial performance index (MPI) values, and left atrium (LA) volume index were assessed in both groups.

RESULTS

The LV MPI and tricuspid valve (TV) E/Ea ratio measured using pulsed-wave Doppler were higher in the patient group than in the control group. The TV E/A ratio and late velocity of lateral mitral annulus (Aa) and systolic velocity (Sa)-early diastolic velocity (Ea)-late velocity (Aa) of the septal mitral annulus and systolic velocity (Sa)-early diastolic velocity (Ea)-late velocity (Aa) of the lateral tricuspid annulus were lower in the patient group than in the control group.

CONCLUSION

Considering the present study's findings obtained during short-to mid-term follow-up, the RV tissue Doppler flows and the LV MPI were found impaired.

Changes in Myocardial Contractility and Electromechanical Interval During the First Month of Life in Healthy Neonates

This study aims at documenting the changes in ventricular tissue velocities, longitudinal strain and electromechanical coupling during the first month of life. During the neonatal period, when the ventricular myocardium is not yet fully maturated, the heart is subjected to significant hemodynamic changes. We studied the ventricular performance of 16 healthy neonates at three time points over the first month of life: on days 2 (IQR [2;2]), 13 [12;14] and 27 [25;29]. We found that systolic and diastolic tissue velocities increased significantly in both left and right ventricle (by 1.2-1.7 times, p < 0.001). Congruently, we found that peak systolic longitudinal strain of the right and left ventricles increased significantly. However, no significant changes in longitudinal strain rate were observed. Finally, QS-intervals shortened during the neonatal period: being measured at 12 points throughout the left ventricle, time to peak systolic velocity decreased on average to 89 % in the second and to 80 % in the fourth week of life (22.3 ± 0.2 vs. 19.8 ± 0.3 vs. 17.8 ± 0.5 ms, r = -0.564, p < 0.001). When comparing opposing walls of the left ventricle, no dyssynchrony in left ventricular contraction was found. In addition to increasing systolic and diastolic tissue velocities during the first month of life, the time to peak systolic contraction shortens in the neonatal heart, which may reflect an increasing efficiency of the excitation-contraction coupling in the maturing myocardium. While there appears to be no dyssynchrony in ventricular contraction, these findings may extend our appreciation of the immature neonatal heart and certain disease states.

Specifics of cardiac magnetic resonance imaging in children

This review points out three specific features of cardiac magnetic resonance imaging (MRI) in children: the small size of the heart modifies the usual balance between signal-to-noise ratio and spatial resolution; the higher and more variable heart rate limits tissue characterization and temporal resolution; and motion artefacts (notably respiratory motions) must be dealt with. In the second part of this review, we present the current and future practices of cardiac magnetic resonance (CMR) in children, based on the experience of all French paediatric cardiac MRI centres.

Determinants and Regression Equations for the Calculation of z Scores of Left Ventricular Tissue Doppler Longitudinal Indexes in a Healthy Italian Pediatric Population

Aim. We investigated the predictors of tissue Doppler left ventricular (LV) longitudinal indexes in a healthy Italian pediatric population and established normative data and regression equations for the calculation of z scores. Methods and Results. A total of 369 healthy subjects aged 1–17 years (age of 6.4 ± 1.1 years, 49.1% female) underwent echocardiography. LV peak longitudinal velocity at systole (s^'), early diastole (e^'), and late diastole (a^') was determined by tissue Doppler. The ratio of peak early diastolic LV filling velocity to e^' was calculated. Age was the only independent determinant of s^' (β = 0.491, p < 0.0001) and the strongest determinant of e^' (β = 0.334, p < 0.0001) and E/e^' (β = −0.369, p < 0.0001). Heart rate was the main determinant of a^' (β = 0.265, p < 0.0001). Male gender showed no effects except for a weak association with lateral s^', suggesting no need of gender-specific reference ranges. Age-specific reference ranges, regression equations, and scatterplots for the calculation of z scores were determined for each index. Conclusion. In a pediatric Italian population, age was the strongest determinant of LV longitudinal dynamics. The availability of age-specific normality data for the calculation of z scores may allow for correctly detecting LV dysfunction in pediatric pathological populations.

Nomograms for mitral inflow Doppler and tissue Doppler velocities in Caucasian children

BACKGROUND

Pediatric echocardiographic nomograms for systolic/diastolic functional indices are limited by small sample size and inconsistent methodologies. Our aim was to establish pediatric nomograms for mitral valve (MV) pulsed wave Doppler (PWD) and tissue Doppler imaging (TDI) velocities.

METHODS

We performed PWD/TDI measurements of MV velocities and generated models testing for linear/logarithmic/exponential/square root relationships. Heteroscedasticity was accounted for by White test or Breusch-Pagan test. Age, weight, height, heart rate (HR), and body surface area (BSA) were used as independent variables in different analyses to predict the mean values of each measurement.

RESULTS

In all, 904 Caucasian Italian healthy children (age 0 days-17 years; 45.5% females; BSA 0.12-2.12m(2)) were prospectively studied. No individual variable provided equations with an acceptable coefficient of determination (R(2)) and even the inclusion of multiple variables in the model resulted in only a partial amelioration of the R(2). Higher R(2) were obtained for PWD-E deceleration time (0.53), septal (Se') and lateral (Le') MV-TDI e' velocity (Se': 0.54; Le': 0.55). Variability was higher at lower age and BSA. In older children patterns were more reproducible; however, the exclusion of neonates did not substantially improve the final models. The low R(2) hampered building of z-scores and calculation of estimated percentiles. Thus normative data have been presented as observed percentile according to age for all measurements.

CONCLUSIONS

We report normal ranges for PWD and TDI mitral velocities derived from a large population of Caucasian children. Variability of diastolic patterns especially at lower ages needs to be taken into account.

Echocardiographic reference ranges for normal cardiac Doppler data: results from the NORRE Study

AIMS

Reference values for Doppler parameters according to age and gender are recommended for the assessment of heart physiology, specifically for left ventricular (LV) diastolic function. In this study, we report normal reference ranges for Doppler parameters obtained in a large group of healthy volunteers. Echocardiographic data were acquired using state-of-the-art cardiac ultrasound equipment following Doppler acquisition and measurement protocols approved by the European Association of Cardiovascular Imaging.

METHODS AND RESULTS

A total of 449 (mean age: 45.8 ± 13.7 years) healthy volunteers (198 men and 251 women) were enrolled at the collaborating institutions of the Normal Reference Ranges for Echocardiography (NORRE) study. A comprehensive echocardiographic examination was obtained from all subjects following predefined protocols. The majority of the Doppler diastolic parameters (e', E/e') as well as right ventricle systolic s' wave velocity were similar in men and women. Left ventricle s' wave velocity was higher in men than in women. E wave and e' were higher in younger subjects and decreased progressively in the older ones. E/e' ratio increased with ageing. Septal e' <8 cm/s was present in 19.7% of the subjects in the 40-60 year group and in 55% of those in the ≥60 year group. However, the cut-off value of average E/e' or lateral E/e' remained <15 or 13, respectively, in the majority of patients.

CONCLUSION

The NORRE study provides the reference values for the most useful Doppler parameters in the evaluation of heart physiology. These data highlight the need of using age-specific reference values especially for the diagnosis of LV systolic and diastolic dysfunction and for the estimation of LV filling pressures.

Neonatal cardiac dysfunction in intrauterine growth restriction

BACKGROUND

The early postnatal cardiovascular consequences of intrauterine growth restriction (IUGR) have not been completely elucidated. This study aimed to evaluate the effect of IUGR on neonatal myocardial function and cardiovascular adaptation to extrauterine life.

METHODS

Conventional and tissue Doppler echocardiographic parameters were compared on the second and fifth postnatal day between 30 IUGR and 30 appropriate-for-gestational age (AGA) neonates.

RESULTS

IUGR neonates presented relative interventricular septum (IVS) hypertrophy (IVS to left ventricular (LV) posterior wall diastolic ratio: median IUGR-AGA difference of 0.05 (interquartile range: 0.04-0.06); P = 0.020), relative LV dilatation (wall thickness to end-diastolic LV dimension difference of 0.12 (0.06-0.16); P = 0.012), and increased left myocardial performance index (MPI difference of 0.19 (0.05-0.28); P = 0.012). Repeated measurements ANOVA revealed a different pattern of change in LV stroke volume (LVSV; P < 0.001), LV cardiac output (LVCO; P < 0.001), MPI (P < 0.001), and heart rate (HR; P = 0.025) between AGA and IUGR infants. From the second to the fifth postnatal day, AGA neonates presented a decrease in MPI and HR with an increase in LVSV and LVCO. IUGR neonates failed to achieve similar changes in MPI, HR, and LVSV, whereas their LVCO decreased.

CONCLUSION

IUGR neonates present changes in cardiac morphology and subclinical myocardial dysfunction, which may result in an altered pattern of cardiovascular adaptation to extrauterine life.

Reference intervals for the echocardiographic measurements of the right heart in children and adolescents: a systematic review

Background

Transthoracic echocardiography is the primary imaging modality for the diagnosis of right ventricular (RV) involvement in congenital and acquired heart diseases. There is increasing recognition of the contribution of RV dysfunction in heart diseases affecting children and adolescents, but there is insufficient information on reference intervals for the echocardiographic measurements of the right heart in children and adolescents that represent all the continental populations of the world.

Objective

The aim of this systematic review was to collate, from published studies, normative data for echocardiographic evaluation of the right heart in children and adolescents, and to identify gaps in knowledge in this field especially with respect to sub-Saharan Africans.

Methods

We performed a systematic literature search to identify studies of reference intervals for right heart measurements as determined by transthoracic echocardiography in healthy children and adolescents of school-going age. Articles were retrieved from electronic databases with a combination of search terms from the earliest date available until May 2013.

Results

Reference data were available for a broad range of variables. Fifty one studies out of 3096 publications were included. The sample sizes of the reference populations ranged from 13 to 2036 with ages varying from 5 to 21 years. We identified areas lacking sufficient reference data. These included reference data for determining right atrial size, tricuspid valve area, RV dimensions and areas, the RV % fractional area change, pulmonary artery pressure gradients and the right-sided haemodynamics, including the inferior vena cava dimensions and collapsibility. There were no data for sub-Saharan African children and adolescents.

Conclusion

Reliable reference data are lacking for important echocardiographic measurements of the RV in children and adolescents, especially for sub-Saharan Africans.

The early diastolic myocardial velocity: a marker of increased risk in patients with coronary heart disease

OBJECTIVE

Tissue Doppler imaging (TDI) is a promising echocardiographic modality allowing quantification of myocardial performance. However, the prognostic potential of TDI in patients with acute myocardial infarction (AMI) is not yet investigated. We sought to explore the ability of TDI in identifying patients at risk for new cardiovascular events after AMI.

METHODS

One hundred and nineteen patients with AMI were recruited prospectively (mean age 61 years; range 32-81 years of age). Patients with diabetes mellitus (DM) were excluded. Echocardiography was performed 3-12 months after AMI. Two-dimensional (2-D) and TDI variables were recorded. The patients were followed during a mean period of 4·6 years (range 1-8 years). The primary end-point was defined as any of the following: death from any cause, non-fatal reinfarction or stroke, unstable angina pectoris, congestive heart failure requiring hospitalization and coronary revascularization procedure.

RESULTS

Thirty patients had some form of cardiovascular events during follow-up. Seven patients had cardiovascular death, 13 patients had reinfarction and four patients had a stroke. New angina or unstable angina was recorded in 21 patients. Of these patients, 13 underwent percutaneous coronary angioplasty (PCI) or coronary artery bypass grafting (CABG). The early diastolic myocardial velocity (E(m)) emerged as the only echocardiographic variable that offered a clear differentiation between patients that presented with new cardiovascular (CV) events as compared to the corresponding group without any CV events at follow-up (P<0·05). In multivariate statistical analysis and after adjustment for age, sex, total cholesterol, body mass index (BMI) and other baseline characteristics, Em remained as independent predictors of CV events (HR, 1·18, 95% CI, 1·02-1·36; P<0·05). However, none of the investigated variables evolved as an independent predictor of cardiovascular morbidity and mortality.

CONCLUSION

E(m) appears to be a sensitive echocardiographic index in identifying non-diabetic patients with AMI at risk of new cardiovascular events.

Growth-differentiation factor-15 and tissue doppler ımaging in detection of asymptomatic anthracycline cardiomyopathy in childhood cancer survivors

OBJECTIVES

Anthracyclines have led to an increased risk of cardiac morbidity and mortality. Late cardiac complications in cancer survivors may develop from subclinical myocardial damage. Tissue Doppler imaging (TDI) also has potential as a clinically useful technique for the assessment of myocardial function. Biochemical markers may be used to detect cardiac damage growth-differentiation factor-15 (GDF-15) and are emerging as a biomarker of cardiac dysfunction. The aim of this study is to assess the value of the plasma levels of GDF-15 and TDI in detecting late myocardial dysfunction in childhood cancer survivors (CCS) who were treated with anthracyclines.

DESIGN AND METHODS

Thirty-eight CCS who had completed chemotherapy treatment with anthracyclines were included in this study. Control group consisted of 32 age- and gender-matched healthy volunteers. All children underwent a detailed echocardiography, which contained an M-mode, pulse Doppler and tissue Doppler imaging. However, GDF-15 and cardiac troponin-I (cTnI) were measured.

RESULTS

Although, systolic function of the left ventricular was similar in all groups, there were significant differences between parameters of diastolic function of the heart. The mitral valve E wave, E/A ratio, left ventricular E'm wave, and E'm/A'm ratio were different in the patients than in the controls (p = 0.049, p = 0.037, p < 0.0001, p = 0.001, respectively). The tricuspid valve E/A ratio, right ventricular E't wave, and E't/A't ratio in the patients were also different from those of the controls (p = 0.031, p < 0.0001, p < 0.0001, respectively). Mean plasma GDF-15 was significantly higher in patients than healthy controls (p = 0.027). There were no significant differences in cTnI between both groups.

CONCLUSIONS

Growth-differentiation factor-15 level may be used as a biomarker of anthracycline-induced cardiovascular disease severity in the CCS.

Peak systolic velocity using color-coded tissue Doppler imaging, a strong and independent predictor of outcome in acute coronary syndrome patients

Background

Traditional echocardiographic methods like left ventricular ejection fraction(EF) and wall motion scoring (WMS) and new methods like speckle tracking (ST) based 2D strain carry important prognostic information in acute coronary syndrome (ACS) patients. Parameters from tissue Doppler imaging (TDI), with its high time resolution, may further increase the prognostic value. Peak systolic velocity (PSV) of the basal segments of the left ventricle from TDI is a robust and user independent parameter. The aim was to investigate the prognostic value of PSV compared to EF, WMS, 2D strain and E/e'.

Methods

Echocardiographic images were collected and post processed in 227 ACS patients. Additional clinical data was prospectively gathered and patients were followed for 3-5 years regarding the combined endpoint of death or re-admission due to ACS or heart failure.

Results

The combined endpoint occurred in 85 (37%) patients. Those with an event had lower median PSV than those without (4,4 cm/s) vs. (5,3 cm/s), (p<0.001). In a ROC analysis, the AUC was larger for PSV (0.75) than for EF (0.68), WMS (0.63), 2D strain (0.67) and E/e'(0.70). The combined endpoint increased with decreasing PSV. When adjusting for differences in baseline characteristics in a COX-regression model, PSV remained independently associated with outcome where the others did not. PSV was also less sensitive to image quality with fewer values missing or unacceptable for analysis.

Conclusion

Peak systolic velocity (PSV) is a robust measurement that seems to have a strong and independent association with outcome compared to traditional echocardiographic measurements in ACS patients.

Nomograms for blood flow and tissue Doppler velocities to evaluate diastolic function in children: a critical review

Interest in diastolic function in children has increased recently. However, the strengths and limitations of published pediatric nomograms for echocardiographic diastolic parameters have not been critically evaluated, especially in the neonatal population. A literature search was performed within the National Library of Medicine using the keywords normal/reference values, power Doppler/tissue Doppler velocities, and children/neonates. The search was further refined by adding the keywords diastolic function, myocardial, mitral/tricuspid inflow, pulmonary vein, and Tei index. Thirty-three published studies evaluating diastolic function in normal children were included in this review. In many studies, sample sizes were limited, particularly in terms of neonates. There was heterogeneity in the methodologies to perform and normalize measurements and to express normalized data (Z scores, percentiles, and mean values). Although most studies adjusted measurements for age, classification by specific age subgroups varied, and few addressed the relationships of measurements to body size and heart rate (especially with higher neonatal heart rates). Although reference values were reproducible in older children, they varied significantly in neonates and infants. Pediatric diastolic nomograms are limited by small sample sizes and inconsistent methodologies for the performance and normalization of measurements, with few data on neonates. Some studies do reveal reproducible patterns in diastolic function in older children. A comprehensive pediatric nomogram of diastolic function involving a large population of normal infants and older children and using standardized methodology is warranted and would have tremendous impact in the care of children with acquired and congenital heart disease.

Echocardiographic evaluation of the single right ventricle in congenital heart disease: results of new techniques

Right ventricular (RV) function is increasingly recognized as having prognostic significance in various disease processes. The current gold standard for noninvasive measurement of RV function is cardiac magnetic resonance imaging; however, because of practical considerations, echocardiography remains the most often used modality for evaluating the RV. In the past, because of its complex morphology, echocardiographic assessment of the RV was usually qualitative in nature. Current advances in echocardiographic techniques have been able to overcome some of the previous limitations and thus quantification of RV function is increasingly being performed. In addition, recent echocardiographic guidelines for evaluating the RV have been published to aid in standardizing practice. The evaluation of RV function almost certainly has no greater importance than in the congenital heart population, especially in those patients that have a single RV acting as the systemic ventricle. As this complex population continues to increase in number, accurate and precise evaluation of RV function will be a major issue in determining clinical care.