Characterization of Left Ventricular Diastolic Function by Tissue Doppler Imaging and Clinical Status in Children With Hypertrophic Cardiomyopathy

The association between brain natriuretic peptide and tissue Doppler parameters in children with hypertrophic cardiomyopathy

In this study, we investigated the association between brain natriuretic peptide (BNP) levels and tissue Doppler imaging measurements and also screening for deadly mutations in patients with hypertrophic cardiomyopathy (HCM). We enrolled 20 patients diagnosed with HCM (age:10.7±5 years (1-17), 85% male, weight:42.25±23.10 kg, height:141.80±32.45 cm) and 20 age, gender and body weight-matched control subjects. We performed electrocardiography, transthoracic echocardiography, and tissue Doppler echocardiography in each group, as well as genetic tests (for Arg403Gln, Arg453Cys, Arg719Trp and Arg719Gln mutations in MYH7 Exons 13, 14, 19) and BNP in the patients. The patients were divided into two groups according to the presence (Group 1) or absence (Group 2) of left ventricular (LV) outflow tract obstruction. QTc dispersion and the LV ejection fraction and left atrial (LA) volume index were increased in Group 1. The LA volume index and the mitral and septal E/Ea ratio and septum Z-score were increased while the mitral lateral annulus and septal annulus Ea wave velocities and the mitral and tricuspid E/A ratio were decreased in patients with high levels of BNP compared to those with normal BNP levels. There were no mutations that are associated with increased risk of sudden death found in patients included in this study. In the light of our data, we conclude that such parameters BNP levels above the 98 pg/mL, septal thickness Z-score ˃6, and higher mitral and septal E/Ea ratios can be used for management of patients with HCM according to life-threatening conditions.

Echocardiographic evaluation of the failing heart

Heart failure in children can result from a wide range of aetiologies and can manifest in systolic and/or diastolic dysfunction. Echocardiography is the primary test for the diagnosis and follow-up of children with heart failure. In this article, we critically review standard echocardiographic measurements that have been shown to have prognostic importance in children with various types of heart failure. Each of the common forms of cardiomyopathy that is encountered in childhood--dilated, hypertrophic, restrictive, left ventricular non-compaction, and arrhythmogenic right ventricular cardiomyopathy--is discussed separately. Special attention is paid to the failing right ventricle, both in the systemic and in the sub-pulmonary position, to the failing univentricular heart, and to the assessment of diastolic function in children.

Biomarkers in pediatric heart disease

A biomarker is a characteristic that can be used as an indicator of a biological state. A biomarker can be a clinical observation, laboratory test or an imaging parameter. In this review, we discuss the use of biomarkers in differentiating cardiac from noncardiac disease; predicting the prognosis of patients with heart failure, pulmonary hypertension and dilated cardiomyopathy; diagnosing subclinical cardiac involvement in muscular dystrophy and postchemotherapy cancer patients; detecting acute rejection following heart transplantation; diagnosing Kawasaki disease; aiding the management of postoperative cardiac patients; and managing both common (tetralogy of Fallot) and complex (single-ventricle physiology) congenital heart diseases.

Peripheral microvascular function is altered in young individuals at risk for hypertrophic cardiomyopathy and correlates with myocardial diastolic function

Hypertrophic cardiomyopathy (HCM) is a major cause of sudden cardiac death in the young. Based on previous reports of functional abnormalities in not only coronary but also peripheral vessels in adults with HCM, we aimed to assess both peripheral vascular and myocardial diastolic function in young individuals with an early stage of HCM and in individuals at risk for HCM. Children, adolescents, and young adults (mean age: 12 yr) with a family history of HCM who either had (HCM group; n = 36) or did not have (HCM-risk group; n = 30) echocardiography-documented left ventricular (LV) hypertrophy as well as healthy matched controls (n = 85) and healthy young athletes (n = 12) were included in the study. All underwent assessment with 12-lead electrocardiography, two-dimensional echocardiography, tissue Doppler imaging and laser Doppler with transdermal iontophoresis of ACh and sodium nitroprusside. LV thickness and mass were increased in HCM and athlete groups compared with control and HCM-risk groups. The mitral E-to-e' ratio, measured via tissue Doppler, was increased in HCM (P < 0.0001) and HCM-risk (P < 0.01) groups compared with control and athlete groups, as were microvascular responses to ACh (HCM group: P = 0.045 and HCM-risk group: P = 0.02). Responses to ACh correlated with the E-to-e' ratio (r = 0.5, P = 0.001). Microvascular responses to sodium nitroprusside were similar in all groups (P > 0.2). HCM-causing mutations or its familial history are associated with changes in cardiac diastolic function and peripheral microvascular function even before the onset of myocardial hypertrophy. Tissue Doppler can be used to differentiate HCM from physiological LV hypertrophy in young athletes.

Role of multimodality cardiac imaging in the management of patients with hypertrophic cardiomyopathy: an expert consensus of the European Association of Cardiovascular Imaging Endorsed by the Saudi Heart Association

Taking into account the complexity and limitations of clinical assessment in hypertrophic cardiomyopathy (HCM), imaging techniques play an essential role in the evaluation of patients with this disease. Thus, in HCM patients, imaging provides solutions for most clinical needs, from diagnosis to prognosis and risk stratification, from anatomical and functional assessment to ischaemia detection, from metabolic evaluation to monitoring of treatment modalities, from staging and clinical profiles to follow-up, and from family screening and preclinical diagnosis to differential diagnosis. Accordingly, a multimodality imaging (MMI) approach (including echocardiography, cardiac magnetic resonance, cardiac computed tomography, and cardiac nuclear imaging) is encouraged in the assessment of these patients. The choice of which technique to use should be based on a broad perspective and expert knowledge of what each technique has to offer, including its specific advantages and disadvantages. Experts in different imaging techniques should collaborate and the different methods should be seen as complementary, not as competitors. Each test must be selected in an integrated and rational way in order to provide clear answers to specific clinical questions and problems, trying to avoid redundant and duplicated information, taking into account its availability, benefits, risks, and cost.

Left ventricular diastolic function in hypertension: methodological considerations and clinical implications

The assessment of left ventricular (LV) diastolic function should be an integral part of a routine examination of hypertensive patient; indeed when LV diastolic function is impaired, it is possible to have heart failure even with preserved LV ejection fraction. Left ventricular diastolic dysfunction (LVDD) occurs frequently and is associated to heart disease. Doppler echocardiography is the best tool for early LVDD diagnosis. Hypertension affects LV relaxation and when left ventricular hypertrophy (LVH) occurs, it decreases compliance too, so it is important to calculate Doppler echocardiography parameters, for diastolic function evaluation, in all hypertensive patients. The purpose of our review was to discuss about the strong relationship between LVDD and hypertension, and their relationship with LV systolic function. Furthermore, we aimed to assess the relationship between the arterial stiffness and LV structure and function in hypertensive patients.

Influence of dynamic obstruction and hypertrophy location on diastolic function in hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a disease with marked genetic and phenotypic heterogeneity. It is well known that obstructive septal forms of this disease entail worse clinical outcome compared with nonobstructive septal and apical forms. The objective of this study was to analyze the differences in left ventricular diastolic function in different subgroups of HCMs and to assess the influence of the location of myocardial hypertrophy and the presence of dynamic obstruction on impairment of diastolic function and its correlation with the clinical status.

METHODS

We studied 86 patients with HCM; 27 with the obstructive asymmetric septal type (OAS), 37 with the nonobstructive asymmetric septal type (NOAS) and 22 with apical hypertrophic cardiomyopathy (ApHCM). Patients underwent conventional and tissue Doppler echocardiography and were assessed applying the latest recommendations regarding diastolic dysfunction. Cardiac magnetic resonance was used to study the various morphologic subtypes and quantify left ventricular mass (LVM).

RESULTS

The early diastolic annular velocity (e') was significantly lower in OAS with a median of 5 cm/s compared with NOAS with 7 cm/s and ApHCM with 7.5 cm/s (P = 0.0002), and the E/e' ratio was 8.5 in ApHCM, 10 in NOAS and 14 in OAS (P = 0.0001); no significant differences were found in LVM or maximal wall thickness.

CONCLUSION

In HCM, the location of left ventricular hypertrophy and the presence of dynamic obstruction affect the degree of diastolic dysfunction; impairment is greater in patients with the OAS type, and markedly less in patients with apical involvement.

Hypertrophic cardiomyopathy: prognostic factors and survival analysis in 128 Egyptian patients

BACKGROUND

Hypertrophic cardiomyopathy is an important cause of disability and death in patients of all ages. Egyptian children may differ from Western and Asian patients in the pattern of hypertrophy distribution, clinical manifestations, and risk factors.

OBJECTIVES

The aim of our study was to report the clinical characteristics and outcomes of Egyptian children with hypertrophic cardiomyopathy studied over a 7-year duration and to determine whether the reported adult risk factors for sudden cardiac death are predictive of the outcome in these affected children.

STUDY DESIGN AND METHODS

This retrospective study included 128 hypertrophic cardiomyopathy children. The data included personal history, family history, physical examination, baseline laboratory measurements, electrocardiogram, and Holter and echocardiographic results. Logistic regression analysis was used for the detection of risk factors of death.

RESULTS

Fifty-one out of 128 patients died during the period of the study. Of the 51 deaths, 36 (70.5%) occurred in patients presenting before 1 year of age. Only eight patients had surgical intervention. Extreme left ventricular hypertrophy, that is, interventricular septal wall thickness or posterior wall thickness Z-score >6, sinus tachycardia, and supraventricular tachycardia were found to be independent risk factors for prediction of death in patients with hypertrophic cardiomyopathy.

CONCLUSIONS

At our Egyptian tertiary care centre, hypertrophic cardiomyopathy has a relatively worse prognosis when compared with reports from Western and Asian series. Infants have a worse outcome than children presenting after the age of 1 year. A poorer prognosis in childhood hypertrophic cardiomyopathy is predicted by an extreme left ventricular hypertrophy, the presence of sinus tachycardia, and supraventricular tachycardia.

Cardiomyopathies encountered commonly in the teenage years and their presentation

Cardiomyopathy encompasses a broad range of inherited and acquired abnormalities affecting the myocardium. This heterogeneous group of disorders is an important cause of morbidity and mortality in the adolescent patient as a result of the presence of systolic or diastolic dysfunction, as well as the risk of coexisting arrhythmias and sudden cardiac death. It is important for the primary care physician involved in the care of adolescents to understand the different causes of cardiomyopathy and their typical clinical presentations. The cause, pathogenesis, clinical presentation, and diagnostic evaluation for adolescents with cardiomyopathy are reviewed. An overview of treatment modalities is also presented.

Evaluation of left ventricular diastolic function by global strain rate imaging in patients with obstructive hypertrophic cardiomyopathy: a simultaneous speckle tracking echocardiography and cardiac catheterization study

BACKGROUND

Impaired left ventricular (LV) diastolic function is a common pathophysiological feature of patients with hypertrophic cardiomyopathy (HCM). The noninvasive evaluation of diastolic function in these patients remains a challenge. Speckle tracking echocardiography (STE) provides direct information on intrinsic myocardial function and may improve the diagnostic of diastolic dysfunction in HCM patients.

METHODS AND RESULTS

We retrospectively analyzed 51 patients with obstructive HCM (HOCM). Strain rate (SR) curves were obtained for 18 different segments of the LV myocardium. The peak SR during the isovolumic relaxation period (SRIVR ) and the peak early diastolic strain rate (SRE ) were measured for each segment. Cardiac catheterization was performed within 24 hours after echocardiographic analysis. LV end-diastolic pressure (LVEDP) was measured and time constant of myocardial relaxation (τ) was calculated. We therefore correlated STE-derived with invasive indices and compared it with flow and tissue Doppler measurements. SRIVR and SRE were significantly reduced in all 51 HOCM patients (0.16 ± 0.09%/sec and 0.71 ± 0.25%/sec).The ratio of peak early mitral inflow velocities to SRIVR and SRE (E/SRIVR and E/SRE ) correlated well with LVEDP (r = 0.760, P < 0.001; r = 0.401, P = 0.004). Receiver operating characteristic analysis shown E/SRE ratio had the largest under curve area in predicting HOCM patients with seriously elevated LVEDP. In addition, SRIVR and SRE significantly related with τ (r = -0.611, P < 0.001; r = -0.369, P = 0.008).

CONCLUSIONS

Diastolic function was seriously impaired in HOCM patients. The E/SRE ratio can be used to predict LVEDP with acceptable accurate in HOCM patients. In addition, SRIVR is a reliable parameter to assess LV relaxation in patients with HOCM.

Isolated X-linked hypertrophic cardiomyopathy caused by a novel mutation of the four-and-a-half LIM domain 1 gene

BACKGROUND

Hypertrophic cardiomyopathy with severe left ventricular diastolic dysfunction has been associated with marked exercise intolerance and poor prognosis. However, molecular pathogenesis of this phenotype remains unexplained in a large proportion of cases.

METHODS AND RESULTS

We performed whole exome sequencing as an initial genetic test in a large Czech family with 3 males affected by nonobstructive hypertrophic cardiomyopathy with severe left ventricular diastolic dysfunction in end-stage disease. A novel frameshift mutation of four-and-a-half LIM domain 1 gene (FHL1) (c.599_600insT; p.F200fs32X) was detected in these individuals. The mutation does not affect transcription, splicing, and stability of FHL1 mRNA and results in production of truncated FHL1 protein, which is contrary to heart tissue homogenate not detectable in frozen tissue sections of myocardial biopsy of affected males. The identified mutation cosegregated also with abnormal ECG and with 1 case of apical hypertrophic cardiomyopathy in heterozygous females. Although skeletal muscle involvement is a common finding in FHL1-related diseases, we could exclude myopathy in all mutation carriers.

CONCLUSIONS

We identified a novel FHL1 mutation causing isolated hypertrophic cardiomyopathy with X-chromosomal inheritance.

Hemodynamic patterns for symptomatic presentations of severe aortic stenosis

OBJECTIVES

The aim of this study was to investigate intracardiac hemodynamic idiosyncrasies responsible for various presentations of severe aortic stenosis (AS).

BACKGROUND

Syncope, dyspnea, and chest pain are well-established indications for aortic valve replacement in patients with severe AS. Patients' survival is limited once they develop symptoms from AS, and survival depends on what type of symptoms a patient develops. We hypothesized that there would be a relationship between the type of AS symptoms and intracardiac hemodynamics as well as AS severity.

METHODS

We analyzed 498 patients (men: 58.4%, 66 ± 12 years of age) with severe AS and normal left ventricular ejection fraction from 2003 to 2009 who had comprehensive echocardiography examination for AS. The study population was divided into 4 groups based on presenting symptom(s) (341 in group I, asymptomatic; 15 in group II, syncope; 110 in group III, dyspnea; 32 in group IV, chest pain). Echocardiographic measurements for cardiac structure, function, and intracardiac hemodynamic parameters were compared among these 4 groups.

RESULTS

Mean aortic valve pressure gradient and aortic valve area were 57.1 ± 15.2 mm Hg and 0.74 ± 0.19 cm(2), respectively. AS severity based on mean gradient and aortic valve area was similar among 4 groups. Compared with the asymptomatic group, symptomatic patients were older and had lower cardiac output, and higher E/e' ratio while having a similar aortic valve area and gradient. Group II (syncope) displayed smaller LV dimension, stroke volume, cardiac output, left atrial volume index, and E/e' ratio. Conversely, group III (dyspnea) was found to have the worst diastolic function with largest left atrial volume index and highest E/e' ratio.

CONCLUSIONS

Among patients with severe AS, their symptoms are often linked to specific hemodynamic patterns associated with AS: smaller left ventricular cavity and reduced output for syncope versus more advanced diastolic dysfunction for dyspnea. Hence, comprehensive intracardiac hemodynamics including diastolic function and stroke volume need to be evaluated in addition to aortic valve area and pressure gradient for assessment of AS.

Serial change in myocardial tissue Doppler imaging from fetus to neonate

BACKGROUND

Our goal was to evaluate the serial change in myocardial performance from fetus to neonate using tissue Doppler imaging (TDI).

METHOD AND RESULTS

There were 37 term infants in the present study. The TDI sensor was placed at the level of the lateral mitral annulus (M-TDI), inter-ventricular septum (IVS-TDI) and the lateral tricuspid annulus (T-TDI). We measured TDI parameters from fetus to neonate. On univariate analysis, E' (cm/s), A' (cm/s), and S' (cm/s) of three ventricular walls of TDI parameters excluding E' IVS-TDI significantly decreased during the transition from fetal to neonatal circulation. E'/A' ratio, E/E' ratio and myocardial performance index (MPI) of three ventricular walls of TDI parameters excluding T-TDI MPI significantly increased during the transition from fetal to neonatal circulation. When multiple linear regression analysis with a step-wise procedure during the transition from fetus to neonate for TDI parameters was applied to variables, significant differences were noted for predicting decreases in M-TDI S' (6.55 to 3.97, p < 0.001) and IVS-TDI A', (6.69 to 4.69, p < 0.001), and increases in IVS-TDI E'/A' ratio (0.77 to 1.02, p < 0.001) and IVS-TDI E/E' ratio (8.25 to 13.65, p < 0.001).

CONCLUSION

In conclusion, we found that the myocardial performances of both ventricles decreased during the transition from fetus to neonate using TDI parameters. In particular, left ventricular systolic performance was affected more than when fetal circulation changed to neonate circulation. Our findings suggest that serial change in TDI can give new information to estimate myocardial performance of the neonate.

Ventricular dyssynchrony and function improve following catheter ablation of nonseptal accessory pathways in children

Introduction. Paradoxical or hypokinetic interventricular septal motion has been described in patients with septal or paraseptal accessory pathways. Data regarding nonseptal pathways is limited. Methods and Results. We quantified left ventricular dyssynchrony and function in 16 consecutive children, 14.2 ± 3.7 years, weighing 53 ± 17 kg, prior to and following catheter ablation of bidirectional septal (N = 6) and nonseptal (N = 10) accessory pathways. Following ablation, the left ventricular ejection fraction increased by 4.9 ± 2.1% (P = 0.038) from a baseline value of 57.0% ± 7.8%. By tissue Doppler imaging, the interval between QRS onset and peak systolic velocity (Ts) decreased from a median of 33.0 ms to 18.0 ms (P = 0.013). The left ventricular ejection fraction increased to a greater extent following catheter ablation of nonseptal (5.9% ± 2.6%, P = 0.023) versus septal (2.5% ± 4.1%, P = 0.461) pathways. The four patients with an ejection fraction <50%, two of whom had left lateral pathways, improved to >50% after ablation. Similarly, the improvement in dyssynchrony was more marked in patients with nonseptal versus septal pathways (difference between septal and lateral wall motion delay before and after ablation 20.6 ± 7.1 ms (P = 0.015) versus 1.4 ± 11.4 ms (P = 0.655)). Conclusion. Left ventricular systolic function and dyssynchrony improve after ablation of antegrade-conducting accessory pathways in children, with more pronounced changes noted for nonseptal pathways.

Cardiac effects in perinatally HIV-infected and HIV-exposed but uninfected children and adolescents: a view from the United States of America

Introduction

Human immunodeficiency virus (HIV) infection is a primary cause of acquired heart disease, particularly of accelerated atherosclerosis, symptomatic heart failure, and pulmonary arterial hypertension. Cardiac complications often occur in late-stage HIV infections as prolonged viral infection is becoming more relevant as longevity improves. Thus, multi-agent HIV therapies that help sustain life may also increase the risk of cardiovascular events and accelerated atherosclerosis.

Discussion

Before highly active antiretroviral therapy (HAART), the two-to-five-year incidence of symptomatic heart failure ranged from 4 to 28% in HIV patients. Patients both before and after HAART also frequently have asymptomatic abnormalities in cardiovascular structure. Echocardiographic measurements indicate left ventricular (LV) systolic dysfunction in 18%, LV hypertrophy in 6.5%, and left atrial dilation in 40% of patients followed on HAART therapy. Diastolic dysfunction is also common in long-term survivors of HIV infection. Accelerated atherosclerosis has been found in HIV-infected young adults and children without traditional coronary risk factors. Infective endocarditis, although rare in children, has high mortality in late-stage AIDS patients with poor nutritional status and severely compromised immune systems. Although lymphomas have been found in HIV-infected children, the incidence is low and cardiac malignancy is rare. Rates of congenital cardiovascular malformations range from 5.6 to 8.9% in cohorts of HIV-uninfected and HIV-infected children with HIV-infected mothers. In non-HIV-infected infants born to HIV-infected mothers, foetal exposure to ART is associated with reduced LV dimension, LV mass, and septal wall thickness and with higher LV fractional shortening and contractility during the first two years of life.

Conclusions

Routine, systematic, and comprehensive cardiac evaluation, including a thorough history and directed laboratory assays, is essential for the care of HIV-infected adults and children as cardiovascular illness has become a part of care for long-term survivors of HIV infection. The history should include traditional risk factors for atherosclerosis, prior opportunistic infections, environmental exposures, and therapeutic and illicit drug use. Laboratory tests should include a lipid profile, fasting glucose, and HIV viral load. Asymptomatic cardiac disease related to HIV can be fatal, and secondary effects of HIV infection often disguise cardiac symptoms, so systematic echocardiographic monitoring is warranted.

Cardiac disease in children and young adults with various lysosomal storage diseases: Comparison of echocardiographic and ECG changes among clinical groups

BACKGROUND

Lysosomal storage disease (LSD) is a rare inherited disease group. Consecutively there are few data on cardiac changes in mucopolysaccharidosis (MPS), Anderson Fabry disease (AFD), and other LSD (oLSD) including Pompe disease (PD) and Danon disease (DD), I-cell disease ICD and mucolipidosis III (ML III).

METHODS

Between 1994 and 2011, we identified 39 patients with LSD: 25 with MPS, 8 with AFD, and 6 with oLSD including PD (1), ML III (2), DD (1), and ICD (2) at our institution fulfilling the inclusion criteria of at least one echocardiogram and ECG.

RESULTS

Median age was 11.4 years (range: 2-27), 22 were females (56%). Normal echocardiograms were present in 12 patients (31%): 4 with MPS (16%), 7 AFD (88%), and 1 oLSD (17%). Valvular heart disease was present in 23 patients (59%) occurring more often in MPS (76%) and oLSD (67%) than in AFD (0%) (p < 0.001). The most common ECG abnormality was a short PR interval in 10 of 35 patients (29%) occurring in all LSD groups. Median follow-up was 5.8 (0.2-22.2) years showing diminished 5-year survival compared to an age-matched group. However, no patient died due to a cardiac cause and no cardiovascular intervention was necessary.

CONCLUSION

Echocardiographically detectable cardiovascular involvement in children with LSD is mostly confined to MPS and oLSD. Valve thickening in echo and a short PR interval in the ECG are the most frequent abnormalities. Routine repeat assessment is recommended in LSD. However, significant cardiac disease necessitating cardiac intervention is rare during a short follow-up.

Cardiomyopathies in children

Cardiomyopathy (CMP) is a heterogeneous disease caused by a functional abnormality of the cardiac muscle. CMP is of 2 major types, dilated and hypertrophic, and is further classified as either primary or secondary. Secondary CMP is caused by extrinsic factors, including infection, ischemia, hypertension, and metabolic disorders. Primary CMP is diagnosed when the extrinsic factors of secondary CMP are absent. Furthermore, the World Health Organization, American Heart Association, and European Cardiology Association have different systems for clinically classifying primary CMP. Primary CMP is rare and associated with a family history of the disease, implying that genetic factors might affect its incidence. In addition, the incidence of CMP varies widely according to patient ethnicity. Genetic testing plays an important role in the care of patients with CMP and their families because it confirms diagnosis, determines the appropriate care for the patient, and possibly affects patient prognosis. The diagnosis and genetic identification of CMP in patients' families allow the possibility to identify novel genes that may lead to new treatments. This review focuses on the epidemiology, pathophysiology, diagnosis, and treatment of CMP, with the aim of providing pediatricians with insights that may be helpful in the early identification and management of idiopathic CMP in children.

Interpretation of left ventricular diastolic dysfunction in children with cardiomyopathy by echocardiography: problems and limitations

BACKGROUND

Left ventricular diastolic dysfunction (DD) is a key determinant of outcomes in pediatric cardiomyopathy (CM), but remains very challenging to diagnose and classify. Adult paradigms and guidelines relating to DD are currently applied in children. However, it is unknown whether these are applicable to children with CM. We investigated the assessment of DD in children with CM using adult and pediatric echocardiographic criteria and tested whether recent adult guidelines are applicable to this population.

METHODS AND RESULTS

Three investigators independently classified diastolic function in 4 study groups: controls, dilated, hypertrophic, and restrictive CM. Agreement among investigators, failure to classify DD, and the reasons for diagnostic failure were determined. The usefulness of individual echo parameters to diagnose and classify DD was assessed. One hundred seventy-five children (aged 0-18 years) were studied. DD diagnostic criteria were discrepant in the majority of patients. Delayed relaxation was diagnosed in only 14% of hypertrophic CM patients and never in dilated CM and restrictive CM, with 50% of those patients having coexisting findings of elevated filling pressures. Many key parameters, such as mitral and pulmonary venous Doppler, were not informative. Agreement among investigators for grading of DD was poor (36% of CM patients).

CONCLUSIONS

Assessment of DD in childhood CM seems inadequate using current guidelines. The large range of normal pediatric reference values allows diagnosis of DD in only a small proportion of patients. Key echo parameters to assess DF are not sufficiently discriminatory in this population, and discrepancies between criteria within individuals prevent further classification and result in poor interobserver agreement.

The association between arterial stiffness and left ventricular filling pressure in an apparently healthy Korean population

BACKGROUND

The aim of this study is to investigate the association between arterial stiffness and left ventricular filling pressure in an apparently healthy Korean population.

METHODS

A total of 115 healthy subjects without known cardiovascular risk factors or overt heart disease who underwent both transthoracic echocardiography and brachial-ankle pulse wave velocity (baPWV) measurement at the same day during their routine check-ups were analyzed.

RESULTS

The mean age of study subjects was 52.8 ± 8.4 years, and 78 (67.8%) were men. The mean baPWV value was 1,325 ± 185 cm/s. Study subjects were divided into 3 groups according to E/E' value: subjects with E/E' < 8, 8-12.9 and E/E' ≥ 13. As E/E' increased, baPWV value increased gradually: baPWV in subjects with E/E' < 8, E/E' 8-12.9 and E/E' ≥ 13, were 1,261 ± 163, 1,345 ± 169, 1,569 ± 232 cm/s, respectively (p < 0.001). In multiple linear regression analyses, baPWV was significantly associated with E/E' (β = 0.371, p < 0.001) after controlling confounders including age, sex and body mass index. In receiver-operating characteristic (ROC) curve analysis, the sensitivity and specificity for detection of E/E' ≥ 10 were 78.6% and 59.8%, respectively with mean baPWV of 1,282 cm/s as the cut off value. The discriminatory capacity for predicting E/E' ≥ 10 was improved from an area under the ROC curve of 0.646 with age alone to 0.734 when baPWV was added (p < 0.001).

CONCLUSIONS

There is a significant association between baPWV and E/E' in an apparently healthy Korean population. BaPWV is useful as a simple and non-invasive method for early detection of increased LV filling pressure among these people.

Genetic variations in hypoxia response genes influence hypertrophic cardiomyopathy phenotype

BACKGROUND

Risk factors for diastolic dysfunction in hypertrophic cardiomyopathy (HCM) are poorly understood. We investigated the association of variants in hypoxia-response genes with phenotype severity in pediatric HCM.

METHODS

A total of 80 unrelated patients <21 y and 14 related members from eight families with HCM were genotyped for six variants associated with vascular endothelial growth factor A (VEGFA) downregulation, or hypoxia-inducible factor A (HIF1A) upregulation. Associations between risk genotypes and left-ventricular (LV) hypertrophy, LV dysfunction, and freedom from myectomy were assessed. Tissue expression was measured in myocardial samples from 17 patients with HCM and 20 patients without HCM.

RESULTS

Age at enrollment was 9 ± 5 y (follow-up, 3.1 ± 3.6 y). Risk allele frequency was 67% VEGFA and 92% HIF1A. Risk genotypes were associated with younger age at diagnosis (P < 0.001), septal hypertrophy (P < 0.01), prolonged E-wave deceleration time (EWDT) (P < 0.0001) and isovolumic relaxation time (IVRT) (P < 0.0001), and lower freedom from myectomy (P < 0.05). These associations were seen in sporadic and familial HCM independent of the disease-causing mutation. Risk genotypes were associated with higher myocardial HIF1A and transforming growth factor B1 (TGFB1) expression and increased endothelial-fibroblast transformation (P < 0.05).

CONCLUSION

HIF1A-upregulation and/or VEGFA-downregulation genotypes were associated with more severe septal hypertrophy and diastolic dysfunction and may provide genetic markers to improve risk prediction in HCM.

Myocardial tissue Doppler velocities in fetuses with hypoplastic left heart syndrome

BACKGROUND

Tissue Doppler Imaging (TDI) is a sensitive index of myocardial function. Its role in the fetus has not been extensively evaluated.

OBJECTIVE

To compare myocardial tissue Doppler velocities in fetuses with hypoplastic left heart syndrome (HLHS) to those of normal fetuses (matched for gestational age.)

METHODS

Cross-sectional retrospective study conducted at 2 large perinatal centers (2003-2007). Fetuses with HLHS (n = 13) were compared with normal fetuses (n = 207) in 5 gestational age groups. TDI data included peak systolic (s'), peak early (e'), and late diastolic velocities (a'). Linear regression was used to compare TDI parameters in fetuses with HLHS to normal fetuses matched for gestational age.

RESULTS

Fetuses with HLHS had significantly reduced lateral tricuspid annular e' as compared to normal fetuses. Both normal fetuses and those with HLHS had linear increase in TDI velocities with advancing gestational age.

CONCLUSIONS

TDI velocities are abnormal in fetuses with HLHS. TDI can be useful in serial follow-up of cardiac function in fetuses with HLHS.

Hypertrophic cardiomyopathy: infants, children, and adolescents

Hypertrophic cardiomyopathy (HCM) is characterized by inappropriate left ventricular hypertrophy (LVH) in the setting of a nondilated left ventricle. HCM is often associated with asymmetric LVH, a family history of HCM, sarcomeric genetic mutations, and an increased risk of sudden cardiac death. There is a wide clinical variability in HCM presenting during childhood and a relative lack of data on the pediatric population. This review will cover HCM presenting in infancy, childhood, and adolescence.

Restrictive physiology is associated with poor outcomes in children with hypertrophic cardiomyopathy

Pediatric patients with hypertrophic cardiomyopathy (HCM) and restrictive physiology (RP) with poor outcomes have been identified, but data on their course are limited. Our goal was to delineate the clinical features and course of children with HCM and RP. An institutional review of 119 patients identified between 1985 and 2010 with the diagnosis of HCM was performed. The diagnosis of RP was based on >1 echocardiogram along with at least one of the following: left atrial enlargement without evidence of left ventricle dilation, E/E' ratio ≥ 10, and E/A ratio ≥ 3. Outcomes analysis was performed using Cox or Poisson regression when appropriate. RP was present in 50 (42%) patients. In patients without RP, 10-year freedom-from-death or aborted sudden cardiac death (aSCD), and death or heart transplant (HT), were 93.6 and 98.5%, respectively. In patients with RP, 10-year freedom-from-death or aSCD, and death or HT, were 59.0 and 71.2%, respectively. RP conferred a 3.5-fold increase in incidence rate of hospitalization (P = 0.01), a 3.8-fold increase in hazard of death or aSCD (P = 0.02), and a 5.7-fold increase in hazard of death or HT (P = 0.04). Assessment for RP is of paramount importance in children with HCM because those without RP have a good prognosis, and those with RP account for the majority of poor outcomes.

Usefulness of left ventricular diastolic dysfunction assessed by pulsed tissue Doppler imaging as a predictor of atrial fibrillation recurrence after successful electrical cardioversion

The impact of left ventricular (LV) diastolic dysfunction on risk of atrial fibrillation (AF) recurrence is still unknown. The aim of this study was to assess the role of LV diastolic dysfunction in predicting AF recurrence after successful electrical cardioversion in patients with nonvalvular AF. In 51 patients with a first episode of nonvalvular AF undergoing successful electrical cardioversion, tissue Doppler echocardiography was performed to measure peak early diastolic mitral annulus velocity (E(m)) and the ratio of mitral inflow to mitral annulus velocity at end-diastole (E/E(m)). Clinical end points were recurrent persistent AF at 2-week follow-up (early AF recurrence [ERAF]) and at 1-year follow-up (including ERAF and late AF recurrence). Seventeen patients showed evidence of ERAF, whereas late AF recurrence occurred in another 5 patients. In time-independent analysis E/E(m) (odds ratio [OR] 1.746, p = 0.0084) and indexed LV end-systolic volume (OR 1.083, p = 0.040) were independent predictors of ERAF. Based on a logistic model risk of ERAF was 25% for an E/E(m) of 5.6 but increased to 50% for an E/E(m) of 8.1 and to 75% for an E/E(m) of 10.5. In time-dependent analysis E/E(m) emerged as the only predictor of ERAF (OR 1.757, p = 0.0078). E/E(m) also independently predicted risk of recurrence at 1 year in time-independent (OR 1.757, p = 0.0078) and time-dependent (OR 1.319, p = 0.0003) analyses. In conclusion LV diastolic dysfunction independently predicts AF recurrence in patients with nonvalvular AF undergoing successful electrical cardioversion.

Sudden cardiac death in young athletes

Athletic activity is associated with an increased risk of sudden death for individuals with some congenital or acquired heart disorders. This review considers in particular the causes of death affecting athletes below 35 years of age. In this age group the largest proportion of deaths are caused by diseases with autosomal dominant inheritance such as hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, long QT-syndrome, and Marfan's syndrome. A policy of early cascade-screening of all first-degree relatives of patients with these disorders will therefore detect a substantial number of individuals at risk. A strictly regulated system with preparticipation screening of all athletes following a protocol pioneered in Italy, including school-age children, can also detect cases caused by sporadic new mutations and has been shown to reduce excess mortality among athletes substantially. Recommendations for screening procedure are reviewed. It is concluded that ECG screening ought to be part of preparticipation screening, but using criteria that do not cause too many false positives among athletes. One such suggested protocol will show positive in approximately 5% of screened individuals, among whom many will be screened for these diseases. On this point further research is needed to define what kind of false-positive and false-negative rate these new criteria result in. A less formal system based on cascade-screening of relatives, education of coaches about suspicious symptoms, and preparticipation questionnaires used by athletic clubs, has been associated over time with a sizeable reduction in sudden cardiac deaths among Swedish athletes, and thus appears to be worth implementing even for junior athletes not recommended for formal preparticipation screening. It is strongly argued that in families with autosomal dominant disorders the first screening of children should be carried out no later than 6 to 7 years of age.

Relationship of brain natriuretic peptide concentrations to left ventricular function and adverse outcomes in children with end-stage renal disease undergoing hemodialysis

B-type natriuretic peptide (BNP) is a biomarker of cardiovascular disease that is common in adults with chronic kidney disease (CKD). However, in children with CKD, the range and predictive power of BNP concentrations are not known. We aimed to determine the effect of HD on BNP, as well as the prognostic impact of BNP, in end-stage renal disease (ESRD) children undergoing hemodialysis (HD). Thirty-five children with chronic renal failure (16 boys age 12.1 ± 3.7 years) on maintenance HD were included. BNP level was measured, and Doppler echocardiography was performed 30 min before (pre-HD BNP) and 30 min after (post-HD BNP) HD in each patient. An adverse event was defined as all-cause death and heart failure hospitalization. The median pre-HD BNP, the post-HD BNP, and the change in BNP were, respectively, 240 pg/ml (72 to 3346), 318 pg/ml (79 to 3788), and 9 pg/ml (-442 to 1889). Pre-HD BNP concentration was negatively correlated with left ventricular (LV) ejection fraction (r = -0.41, P = 0.018). During a mean follow-up of 39 ± 14 months, 6 patients died, and 3 were hospitalized for heart failure. Using univariate analysis, BNP before and after HD as well as Doppler tissue imaging velocities had a strong graded relationship with adverse events. Cox proportional hazards model demonstrated that pre-HD body weight (P = 0.008), pre-HD BNP (P = 0.011), and post-HD BNP (P = 0.038) remained independent predictors of adverse outcome. Even in case of ESRD, BNP still strongly correlated with LV systolic and diastolic dysfunction and was associated with mortality in HD children.

A comparison of echocardiographic measures of diastolic function for predicting all-cause mortality in a predominantly male population

BACKGROUND

Prior studies demonstrating the prognostic value of echocardiographic measures of diastolic function have been limited by sample size, have included only select clinical populations, and have not incorporated newer measures of diastolic function nor determined their independent prognostic value. The objective of this study is to determine the independent prognostic value of established and new echocardiographic parameters of diastolic function.

METHODS

We included 3,604 consecutive patients referred to 1 of 3 echocardiography laboratories over a 2-year period. We obtained measurements of mitral inflow velocities, pulmonary vein filling pattern, mitral annulus motion (e'), and propagation velocity (V(p)). The primary end point was 1-year all-cause mortality.

RESULTS

The mean age of the patients was 68 years, and 95% were male. There were 277 deaths during a mean follow-up of 248 ± 221 days. For patients with reduced left ventricular ejection fraction (LVEF), all measured parameters except for e' were associated with mortality (P < .05) on univariate analysis. For patients with preserved LVEF, the E-wave velocity was significantly associated with mortality (P < .05) on univariate analysis. The deceleration time/E-wave velocity ratio, V(p), and pulmonary vein filling pattern were borderline significant (P < .10). With multivariate analysis, only V(p) was associated with survival for both reduced (P = .02) and preserved LVEF groups (P = .01).

CONCLUSION

In a large, clinically diverse population, most measures of diastolic function were predictive of all-cause mortality without adjustment for patient characteristics. On multivariate analysis, only V(p) was independently associated with total mortality. This association with mortality may be related to factors other than diastolic function and warrants further investigation.

Assessment of left ventricular diastolic function in children after successful repair of aortic coarctation

The purpose of the study was an assessment of left ventricular diastolic function in children after the successful repair of aortic coarctation (CoA). The prospective study concerned 32 pediatric patients after the CoA surgery. Tissue Doppler imaging parameters including strain and strain rate and the conventional echocardiographic indexes were analyzed in patients and healthy controls. Analysis of mitral annulus velocities, E–E′ ratio, strain, and strain rate of left ventricular mid-cavity segments and conventional indexes of mitral inflow showed the worsening of left ventricular diastolic mechanics in the study group compared to healthy controls. The E/E′ ratio was significantly higher in the study group compared to the control group (8.30 ± 3.24 vs. 6.95 ± 1.36; p < 0.05). The early diastolic strain rate to late diastolic strain rate ratio as well as early to late diastolic strain ratio of the left ventricular mid-cavity segments were significantly lower in the study group compared to healthy controls (1.81 ± 0.63 vs. 3.74 ± 1.53; p < 0.001 and 1.20 ± 0.49 vs. 3.41 ± 1.26; p < 0.001). No differences of the pulmonary venous flow parameters between those two groups were observed. The left ventricular diastolic mechanics in hypertensive patients after CoA repair did not differ from normotensive subjects. Hypertensive and normotensive children after surgical repair of CoA are found to have worsening of the left ventricular diastolic mechanics suggesting the impairment of the active myocardial relaxation.

Atorvastatin and cardiac hypertrophy and function in hypertrophic cardiomyopathy: a pilot study

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a genetic paradigm of cardiac hypertrophy. Cardiac hypertrophy is a major determinant of risk of sudden death and morbidity in HCM. Treatment with statins reverses hypertrophy in animal models of HCM. Thus, statins may afford therapeutic benefits in HCM.

METHODS

We performed a feasibility study with atorvastatin to gather the pre-requisite data for designing randomized efficacy studies.

RESULTS

We screened 32 patients with HCM in 18months. Twenty-one patients met the study criteria and consented to participate. The demographics and echocardiographic phenotype of those who did and those who did not participate were not significantly different. We treated the participants with escalating doses of atorvastatin (20, 40 and 80mgday(-1) ) for 2years. We performed ECG and echocardiography and measured plasma lipids, liver enzymes, creatine kinase and B-type natriuretic peptide levels before and after 3, 6, 12 and 24months of therapy. Fifteen, 12 and 11 patients completed 6, 12 and 24months of therapy respectively. Six patients discontinued atorvastatin because of perceived lack of benefit. We stopped atorvastatin in 4 patients because of modest elevations in liver enzymes, creatine kinase or back pain. The characteristics of those who did or did not complete the study were not significantly different. The mean plasma low-density lipoprotein-cholesterol level was reduced by 55%. However, echocardiographic indices of cardiac hypertrophy and function remained unchanged.

CONCLUSIONS

The findings illustrated the challenges that will be encountered in designing efficacy studies to test the potential beneficial effects of atorvastatin in human HCM.

Diastolic dysfunction in pediatric cardiac patients: evaluation and management

OPINION STATEMENT

The heart is a complex and sophisticated pump that cycles between two phases: diastole, during which a compliant chamber (ventricle) allows the blood to fill from a reservoir chamber (atrium) of low pressure, and systole, during which a stiff chamber with rapidly rising pressure ejects the blood into an arterial circuit of high pressure. However, the systolic and diastolic cycles are not dichotomous. They have complex interactions with interrelated segments of the cardiac cycle. Although the entity of "diastolic heart failure with preserved systolic function" has been applied in adult patients, a discrete diagnosis of systolic and diastolic heart failure may be difficult to apply in pediatric patients. Advances in echocardiography have helped decipher the morphologic and physiologic expression of congenital and acquired heart disease and have increased our understanding the diastolic function and dysfunction. The evolving concept of systolic and diastolic heart failure is helping us develop a strategy for its management in pediatric patients with complex heart diseases.

Evaluation of the myocardial performance index and tissue doppler imaging by comparison to near-simultaneous catheter measurements in pediatric cardiac transplant patients

BACKGROUND

Parameters derived from Doppler echocardiography, such as the myocardial performance index (MPI) and the ratio of peak velocity of early diastolic prograde flow (E) across the atrioventricular valve (AVV) divided by the peak velocity of early diastolic tissue motion at the AVV annulus (E') (E:E' ratio), are routinely used to assess ventricular function. However, they have not been compared with measurements obtained by cardiac catheterization (CC) in children.

METHODS

We prospectively studied post-cardiac transplant children undergoing CC with near-simultaneous echocardiographic imaging for MPI and E:E'. CC data included right atrial pressure (RAp), pulmonary artery wedge pressure (PAWp) and cardiac index (CI). One investigator, who was blinded to the CC data, measured right ventricular (RV) and left ventricular (LV) MPI and E:E' offline. Correlations between echocardiographic and catheter measurements were calculated. Receiver-operating-characteristics (ROC) curves were created to evaluate the utility of echocardiographic measurements that exhibited statistically significant correlations with CC measurements.

RESULTS

Twenty-four patients (age range 0.8 to 21 years) underwent 142 CCs during the study period. Of the 12 correlations studied, 3 met statistical significance (p < 0.05) (RV E:E' vs RAp, RV E:E' vs PAWp and LV MPI vs CI). The ROC areas for these correlations were 0.38, 0.42 and 0.68, respectively. There were no cut-off points where both the sensitivity and specificity for any measurement were >0.80.

CONCLUSIONS

Our data suggest that MPI and E:E' are poor predictors of simultaneously obtained, catheter-derived hemodynamic parameters in post-transplant children. These limitations should be carefully considered before ascribing diagnostic value to these measurements.

Differential effects of antihypertensive treatment on left ventricular diastolic function: an ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial) substudy

OBJECTIVES

We hypothesized that an amlodipine-based regimen would have more favorable effects on left ventricular (LV) diastolic function.

BACKGROUND

Different antihypertensive therapies may vary in their effect on LV diastolic function.

METHODS

The HACVD (Hypertension Associated Cardiovascular Disease) substudy of ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial) collected detailed cardiovascular phenotypic data on a subset of 1,006 participants recruited from 2 centers (St. Mary's Hospital, London, and Beaumont Hospital, Dublin). Conventional and tissue Doppler echocardiography and measurement of plasma B-type natriuretic peptide (BNP) were performed approximately 1 year after randomization to atenolol-based or amlodipine-based antihypertensive treatment to assess LV diastolic function.

RESULTS

On-treatment blood pressure (BP) (mean +/- SD) was similar in both groups: atenolol-based regimen, systolic BP of 137 +/- 17 mm Hg, diastolic BP of 82 +/- 9 mm Hg; amlodipine-based regimen, systolic BP of 136 +/- 15 mm Hg, diastolic BP of 80 +/- 9 mm Hg. Ejection fraction did not differ between groups, but early diastolic mitral annular velocity (E'), a measure of diastolic relaxation, was lower in patients on the atenolol-based regimen: atenolol-based regimen, 7.9 +/- 1.8; amlodipine-based regimen, 8.8 +/- 2.0. A measure of left ventricular filling pressure, E/E', and BNP were significantly higher in patients on the atenolol-based regimen. Differences in E', E/E', and BNP remained significant after adjustment for age and sex. Further adjustment for systolic BP, LV mass index, and heart rate had no impact on differences in mean E' or BNP. The difference in E/E' was attenuated.

CONCLUSIONS

Patients receiving treatment with an amlodipine-based regimen had better diastolic function than patients treated with the atenolol-based regimen. Treatment-related differences in diastolic function were independent of BP reduction and other factors that are known to affect diastolic function.

Echocardiography in patients with hypertrophic cardiomyopathy: usefulness of old and new techniques in the diagnosis and pathophysiological assessment

Hypertrophic cardiomyopathy (HCM) is one of the most common inherited cardiomyopathy. The identification of patients with HCM is sometimes still a challenge. Moreover, the pathophysiology of the disease is complex because of left ventricular hyper-contractile state, diastolic dysfunction, ischemia and obstruction which can be coexistent in the same patient. In this review, we discuss the current and emerging echocardiographic methodology that can help physicians in the correct diagnostic and pathophysiological assessment of patients with HCM.