Hypertrophic cardiomyopathy in childhood

Cardiac MRI in diagnosis, prognosis, and follow-up of hypertrophic cardiomyopathy in children: current perspectives

Hypertrophic Cardiomyopathy (HCM) is an inherited myocardial disease characterised by left ventricular hypertrophy, which carries an increased risk of life-threatening arrhythmias and sudden cardiac death. The age of presentation and the underlying aetiology have a significant impact on the prognosis and quality of life of children with HCM, as childhood-onset HCM is associated with high mortality risk and poor long-term outcomes. Accurate cardiac assessment and identification of the HCM phenotype are therefore crucial to determine the diagnosis, prognostic stratification, and follow-up. Cardiac magnetic resonance (CMR) is a comprehensive evaluation tool capable of providing information on cardiac morphology and function, flow, perfusion, and tissue characterisation. CMR allows to detect subtle abnormalities in the myocardial composition and characterise the heterogeneous phenotypic expression of HCM. In particular, the detection of the degree and extent of myocardial fibrosis, using late-gadolinium enhanced sequences or parametric mapping, is unique for CMR and is of additional value in the clinical assessment and prognostic stratification of paediatric HCM patients. Additionally, childhood HCM can be progressive over time. The rate, timing, and degree of disease progression vary from one patient to the other, so close cardiac monitoring and serial follow-up throughout the life of the diagnosed patients is of paramount importance. In this review, an update of the use of CMR in childhood HCM is provided, focussing on its clinical role in diagnosis, prognosis, and serial follow-up.

Natural history and outcomes in paediatric RASopathy-associated hypertrophic cardiomyopathy

AIMS

This study aimed to describe the natural history and predictors of all-cause mortality and sudden cardiac death (SCD)/equivalent events in children with a RASopathy syndrome and hypertrophic cardiomyopathy (HCM).

METHODS AND RESULTS

This is a retrospective cohort study from 14 paediatric cardiology centres in the United Kingdom and Ireland. We included children <18 years with HCM and a clinical and/or genetic diagnosis of a RASopathy syndrome [Noonan syndrome (NS), NS with multiple lentigines (NSML), Costello syndrome (CS), cardiofaciocutaneous syndrome (CFCS), and NS with loose anagen hair (NS-LAH)]. One hundred forty-nine patients were recruited [111 (74.5%) NS, 12 (8.05%) NSML, 6 (4.03%) CS, 6 (4.03%) CFCS, 11 (7.4%) Noonan-like syndrome, and 3 (2%) NS-LAH]. NSML patients had higher left ventricular outflow tract (LVOT) gradient values [60 (36-80) mmHg, P = 0.004]. Over a median follow-up of 197.5 [inter-quartile range (IQR) 93.58-370] months, 23 patients (15.43%) died at a median age of 24.1 (IQR 5.6-175.9) months. Survival was 96.45% [95% confidence interval (CI) 91.69-98.51], 90.42% (95% CI 84.04-94.33), and 84.12% (95% CI 75.42-89.94) at 1, 5, and 10 years, respectively, but this varied by RASopathy syndrome. RASopathy syndrome, symptoms at baseline, congestive cardiac failure (CCF), non-sustained ventricular tachycardia (NSVT), and maximal left ventricular wall thickness were identified as predictors of all-cause mortality on univariate analysis, and CCF, NSVT, and LVOT gradient were predictors for SCD or equivalent event.

CONCLUSIONS

These findings highlight a distinct category of patients with Noonan-like syndrome with a milder HCM phenotype but significantly worse survival and identify potential predictors of adverse outcome in patients with RASopathy-related HCM.

Assessment of cardiac dimensions in children diagnosed with hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is an inherited autosomal dominant heart disease, characterized by increased left ventricular wall thickness and abnormal loading conditions. Imaging modalities are the first choice for diagnosis and risk stratification. Although heart dimensions have been characterized widely in HCM adults from cardiac imaging, there is limited information about children affected by HCM. The aim of this study is to evaluate left ventricular function and left heart dimensions in a small population of children diagnosed with HCM.

METHODS

A total of 16 (seven male, nine female) pediatric patients with an average age of 14.0 ± 2.5 years diagnosed with HCM at Great Ormond Street Hospital for Children were included in this study. Cardiac magnetic resonance (CMR) images were used to measure left and right ventricular dimensions, and septal and left ventricular free wall thicknesses in Simpleware ScanIP. The gender groups were compared using student t-test or non-parametric Mann-Whitney U-test depending on the sample distribution.

RESULTS

Differences in heart rate, left ventricular end-diastolic volume and end-diastolic volume index, left ventricular stroke volume and stroke volume index, left ventricular end-systolic long axis length, left ventricular end-systolic long axis length index, left ventricular end-diastolic mid-cavity diameter, left ventricular end-diastolic free wall thickness, left ventricular end-diastolic free wall thickness index, right ventricular end-diastolic long axis length were statistically significant in males and females.

CONCLUSION

Left ventricular wall and intraventricular septal thickness increase affecting left ventricle cavity dimensions and there may be differences in anatomical and physiological parameters in males and females affected by HCM.

Clinical characteristics and survival of children with hypertrophic cardiomyopathy in China: A multicentre retrospective cohort study

BACKGROUND

Few data on paediatric hypertrophic cardiomyopathy (HCM) are available in developing countries. A multicentre, retrospective, cohort study was conducted to profile the clinical characteristics and survival of children with HCM in China.

METHODS

We collected longitudinal data on children with HCM aged 0-18 years at three participating institutions between January 1, 2010 and December 31, 2019. Patients were identified by searching for the diagnosis using ICD-10 codes from the electronic medical records database. HCM was diagnosed morphologically with echocardiography or cardiovascular magnetic resonance imaging. The exclusion criteria were secondary aetiologies of myocardial hypertrophy. The primary outcomes were all-cause death or heart transplantation. The Kaplan-Meier method was used to estimate the survival rate of different groups.

FINDINGS

A total of 564 children were recruited, with a median age at diagnosis of 1.0 year (interquartile range, IQR: 0.4-8.0 years), followed for a median of 2.6 years (1977 patient-years, IQR:0.5, 5.9 years). The underlying aetiology was sarcomeric (382, 67.7%), inborn errors of metabolism (IEMs) (108, 19.2%), and RASopathies (74, 13.1%). A total of 149 patients (26.4%) died and no patients underwent heart transplantation during follow-up. The survival probability was 71.1% (95% confidence interval [CI], 66.3%-75.3%) at 5 years. Patients with IEMs or those diagnosed during infancy had the poorest outcomes, with an estimated 5-year survival rate of 16.9% (95% CI, 7.7%-29.1%) and 56.0% (95% CI, 48.8%-62.5%), respectively. Heart failure was the leading cause of death in the cohort (90/149, 60.4%), while sudden cardiac death was the leading cause in patients with sarcomeric HCM (32/66, 48.5%).

INTERPRETATION

There is a high proportion of patients with IEM and a low proportion of patients with neuromuscular disease in children with HCM in China. Overall, mortality remains high in China, especially in patients with IEMs and those diagnosed during infancy.

FUNDING

National Natural Science Fund of China (81770380, 81974029), China Project of Shanghai Municipal Science and Technology Commission (20MC1920400, 21Y31900301).

Assessment of Exercise Function in Children and Young Adults with Hypertrophic Cardiomyopathy and Correlation with Transthoracic Echocardiographic Parameters

Exercise function is well characterized in adults with hypertrophic cardiomyopathy (HCM); however, there is a paucity of data in children and young adults with HCM. Here we sought to characterize exercise function in young people with HCM, understand limitations in exercise function by correlating exercise function parameters with echocardiogram parameters and identify prognostic value of exercise parameters. We performed a retrospective, single-center cohort study characterizing exercise function in patients < 26 years old with HCM undergoing cardiopulmonary exercise testing (CPET). Patients with syndromic HCM or submaximal effort were excluded. We compared exercise function in this cohort to population normal values and measured changes in exercise function over time. We correlated exercise function parameters with echocardiographic parameters and investigated the relationship between exercise test parameters and a clinical composite outcome comprised of significant ventricular arrhythmia, death, or heart transplantation. We identified 229 CPETs performed by 117 patients (mean age at time of first CPET 15.6 ± 3.2 years). Mean %-predicted peak VO2, O2 pulse, and peak heart rate were statistically significantly depressed compared to population normal values and exercise function gradually worsened over time. Abnormal exercise testing correlated closely with echocardiographic indices of diastolic dysfunction. There was a trend toward increased incidence of poor clinical outcome in patients with abnormal exercise function. While adverse clinical outcomes were rare, normal exercise function appears to be a marker of low risk for adverse clinical outcomes in this population.

Non-Cardiac Cause of Death in Selected Group Children with Cardiac Pathology: A Retrospective Single Institute Study

Background: Pediatricians and pediatric surgeons often face children with cardiomegaly and dilatative or hypertrophic cardiomyopathies presenting with or without symptoms. Some of these patients have already been diagnosed and received medication, and some present with completely unrelated pathologies. Methods: We performed a 4-year retrospective study on the causes and mechanisms of death of children with cardiac pathology who died outside the cardiology clinic of our hospital by studying the hospital charts and necropsy reports. All children who were in this situation in our hospital were included. Results: Most children in our study group were infants (81.82%), most were boys (81.82%), and in most cases, the cause or mechanism of death was unrelated to their heart condition, whether it had already been diagnosed or not (one case probably died as a result of a malignant ventricular arrhythmia). Additionally, 27.27% of children died as a consequence of bronchopneumonia, the same percentage died as a consequence of an acquired non-pulmonary disease or after surgery, and 18.18% died as a consequence of congenital malformations. Conclusions: Cardiac disease needs to be thoroughly investigated using multiple tools for all children presenting with heart failure symptoms, those with heart murmurs, and children scheduled for surgery of any type. The intensive care specialist and surgeon need to be aware of any heart pathology before non-cardiac surgical interventions.

Hypertrophic cardiomyopathy in infant newborns of diabetic mother: a heterogeneous condition, the importance of anamnesis, physical examination and follow-up

Background

Hypertrophic cardiomyopathy (HCM) in neonates is a rare and heterogeneous disorder. HCM accounts for 25 to 40% of all pediatric cardiomyopathy cases and the highest incidence in pediatric population is reported in children < 1 year.

Case presentation

we report two clinical cases of neonates, born to mothers respectively with a pre-pregnancy insulin-dependent diabetic mellitus type 2 and a suspected diabetes, with inadequate prenatal glycemic control for the first and underestimated glycemic control for the second case, with a different evolution.

In the first case, a slow evidence of improvement of the HCM was observed, persuading us to the diagnosis of a diabetes-related HCM; In the second case the progressive worsening of the HCM during follow-up in association with further investigations, resulted in the diagnosis of Pompe disease.

Conclusions

Hypertrophic cardiomyopathy in newborns can be the clinical expression of different underlying disorders. We aim to show the importance both to reassess maternal and family history and critically evaluate the physical examination in order to address the correct differential diagnosis. Furthermore it is important to continue a regular cardiologic follow-up for this pathology with neonatal onset to prevent a poor prognosis.

Clinical Insights Into Heritable Cardiomyopathies

Cardiomyopathies (CMs) encompass a heterogeneous group of structural and functional abnormalities of the myocardium. The phenotypic characteristics of these myocardial diseases range from silent to symptomatic heart failure, to sudden cardiac death due to malignant tachycardias. These diseases represent a leading cause of cardiovascular morbidity, cardiac transplantation, and death. Since the discovery of the first locus associated with hypertrophic cardiomyopathy 30 years ago, multiple loci and molecular mechanisms have been associated with these cardiomyopathy phenotypes. Conversely, the disparity between the ever-growing landscape of cardiovascular genetics and the lack of awareness in this field noticeably demonstrates the necessity to update training curricula and educational pathways. This review summarizes the current understanding of heritable CMs, including the most common pathogenic gene variants associated with the morpho-functional types of cardiomyopathies: dilated, hypertrophic, arrhythmogenic, non-compaction, and restrictive. Increased understanding of the genetic/phenotypic associations of these heritable diseases would facilitate risk stratification to leveraging appropriate surveillance and management, and it would additionally provide identification of family members at risk of avoidable cardiovascular morbidity and mortality.

Left Atrial Strain and Function in Pediatric Hypertrophic Cardiomyopathy

BACKGROUND

Left atrial (LA) strain and dysfunction are early markers of diastolic dysfunction, associated with poor exercise capacity in adults with hypertrophic cardiomyopathy (HCM). Literature on assessment of LA mechanics in pediatric HCM is lacking. The aim of this study was to assess LA strain and LA function in pediatric patients who have HCM with (phenotype positive [P+]) and without (genotype positive, phenotype negative [G+P-]) ventricular hypertrophy and evaluate their correlation with exercise stress test parameters.

METHODS

Seventy-eight children (3-25 years of age) with HCM (P+, n = 46; G+P-, n = 32) and 20 healthy control subjects were retrospectively studied. LA conduit function, reservoir function, and pump function were computed using phasic LA volumetric analysis. LA reservoir strain (LASr) and LA contractile strain were measured using speckle-tracking echocardiography. Exercise test findings within 12 months of echocardiography were recorded.

RESULTS

LA conduit function (36% vs 48%, P < .001) and LA reservoir function (137% vs 180%, P < .001) were lower in P+ than in G+P- patients. LA contractile function did not differ between the groups (31% vs 32%, P = .87). Compared with patients with G+P- HCM, those with P+HCM had lower four-chamber LASr (29% vs 41%, P < .001), two-chamber LASr (30% vs 41%, P < .001), average LASr (29% vs 42%, P < .001), and LA contractile strain (9% vs 12%, P = .016). In the cohort of patients with HCM who underwent stress testing (n = 35), LA conduit function weakly correlated with aerobic capacity (r = 0.42, P = .019).

CONCLUSIONS

Children with P+HCM have reduced LA function, measurable by both volumetric and strain analysis. Altered LA mechanics are associated with poor exercise capacity. This study lays the foundation for the evaluation of novel LA parameters in pediatric HCM and warrants larger longitudinal studies to assess its clinical significance.

Loss of Consciousness in the Young Child

In the very young child (less than eight years of age), transient loss of consciousness represents a diagnostic and management dilemma for clinicians. While most commonly benign, syncope may be due to cardiac dysfunction which can be life-threatening. It can be secondary to an underlying ion channelopathy, cardiac inflammation, cardiac ischemia, congenital heart disease, cardiomyopathy, or pulmonary hypertension. Patients with genetic disorders require careful evaluation for a cardiac cause of syncope. Among the noncardiac causes, vasovagal syncope is the most common etiology. Breath-holding spells are commonly seen in this age group. Other causes of transient loss of consciousness include seizures, neurovascular pathology, head trauma, psychogenic pseudosyncope, and factitious disorder imposed on another and other forms of child abuse. A detailed social, present, past medical, and family medical history is important when evaluating loss of consciousness in the very young. Concerning characteristics of syncope include lack of prodromal symptoms, no preceding postural changes or occurring in a supine position, after exertion or a loud noise. A family history of sudden unexplained death, ion channelopathy, cardiomyopathy, or congenital deafness merits further evaluation. Due to inherent challenges in diagnosis at this age, often there is a lower threshold for referral to a specialist.

Hypertrophic cardiomyopathy: genetics and clinical perspectives

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease and defined by unexplained isolated progressive myocardial hypertrophy, systolic and diastolic ventricular dysfunction, arrhythmias, sudden cardiac death and histopathologic changes, such as myocyte disarray and myocardial fibrosis. Mutations in genes encoding for proteins of the contractile apparatus of the cardiomyocyte, such as β-myosin heavy chain and myosin binding protein C, have been identified as cause of the disease. Disease is caused by altered biophysical properties of the cardiomyocyte, disturbed calcium handling, and abnormal cellular metabolism. Mutations in sarcomere genes can also activate other signaling pathways via transcriptional activation and can influence non-cardiac cells, such as fibroblasts. Additional environmental, genetic and epigenetic factors result in heterogeneous disease expression. The clinical course of the disease varies greatly with some patients presenting during childhood while others remain asymptomatic until late in life. Patients can present with either heart failure symptoms or the first symptom can be sudden death due to malignant ventricular arrhythmias. The morphological and pathological heterogeneity results in prognosis uncertainty and makes patient management challenging. Current standard therapeutic measures include the prevention of sudden death by prohibition of competitive sport participation and the implantation of cardioverter-defibrillators if indicated, as well as symptomatic heart failure therapies or cardiac transplantation. There exists no causal therapy for this monogenic autosomal-dominant inherited disorder, so that the focus of current management is on early identification of asymptomatic patients at risk through molecular diagnostic and clinical cascade screening of family members, optimal sudden death risk stratification, and timely initiation of preventative therapies to avoid disease progression to the irreversible adverse myocardial remodeling stage. Genetic diagnosis allowing identification of asymptomatic affected patients prior to clinical disease onset, new imaging technologies, and the establishment of international guidelines have optimized treatment and sudden death risk stratification lowering mortality dramatically within the last decade. However, a thorough understanding of underlying disease pathogenesis, regular clinical follow-up, family counseling, and preventative treatment is required to minimize morbidity and mortality of affected patients. This review summarizes current knowledge about molecular genetics and pathogenesis of HCM secondary to mutations in the sarcomere and provides an overview about current evidence and guidelines in clinical patient management. The overview will focus on clinical staging based on disease mechanism allowing timely initiation of preventative measures. An outlook about so far experimental treatments and potential for future therapies will be provided.

Prevalence and clinical significance of red flags in patients with hypertrophic cardiomyopathy

INTRODUCTION

We sought to determine prevalence and predictive accuracy of clinical markers (red flags, RF), known to be associated with specific systemic disease in a consecutive cohort of patients with hypertrophic cardiomyopathy (HCM).

METHODS

We studied 129 consecutive patients (23.7 ± 20.9 years, range 0-74 years; male/female 68%/32%). Pre-specified RF were categorized into five domains: family history; signs/symptoms; electrocardiography; imaging; and laboratory. Sensitivity (Se), specificity (Sp), negative predictive value (NPV), positive predictive value (PPV), and predictive accuracy of RF were analyzed in the genotyped population.

RESULTS

In the overall cohort of 129 patients, 169 RF were identified in 62 patients (48%). Prevalence of RF was higher in infants (78%) and in adults >55 years old (58%). Following targeted genetic and clinical evaluation, 94 patients (74%) had a definite diagnosis (sarcomeric HCM or specific causes of HCM). We observed 14 RF in 13 patients (21%) with sarcomeric gene disease, 129 RF in 34 patients (97%) with other specific causes of HCM, and 26 RF in 15 patients (45%) with idiopathic HCM (p < 0.0001). Non-sarcomeric causes of HCM were the most prevalent in ages <1yo and > 55yo. Se, Sp, PPV, NPV and PA of RF were 97%, 70%, 55%, 98% and 77%, respectively. Single and clinical combination of RF (clusters) had an high specificity, NPV and predictive accuracy for the specific etiologies (syndromes/metabolic/infiltrative disorders associated with HCM).

CONCLUSIONS

An extensive diagnostic work up, focused on analysis of specific diagnostic RF in patients with unexplained LVH facilitates a clinical diagnosis in 74% of patients with HCM.

Green tea extract catechin improves cardiac function in pediatric cardiomyopathy patients with diastolic dysfunction

Background

Our previous studies have demonstrated that Ca²⁺ desensitizing catechin could correct diastolic dysfunction in experimental animals with restrictive cardiomyopathy. In this study, it is aimed to assess the effects of green tea extract catechin on cardiac function and other clinical features in pediatric patients with cardiomyopathies.

Methods

Twelve pediatric cardiomyopathy patients with diastolic dysfunction were enrolled for the study. Echocardiography, ECG, and laboratory tests were performed before and after the catechin administration for 12 months. Comparison has been made in these patients before and after the treatment with catechin. Next Generation Sequencing was conducted to find out the potential causative gene variants in all patients.

Results

A significant decrease of isovolumetric relaxation time (115 ± 46 vs 100 ± 42 ms, P = 0.047 at 6 months; 115 ± 46 vs 94 ± 30 ms, P = 0.033 at 12 months), an increase of left ventricle end diastolic volume (40 ± 28 vs 53 ± 28 ml, P = 0.028 at 6 months; 40 ± 28 vs 48 ± 33 ml, P = 0.011 at 12 months) and stroke volume (25 ± 16 vs 32 ± 17 ml, P = 0.022 at 6 months; 25 ± 16 vs 30 ± 17 ml, P = 0.021 at 12 months) were observed with echocardiography in these patients 6-month after the treatment with catechin. Ejection fraction, left ventricular wall thickness, biatrial dimension remained unchanged. No significant side effects were observed in the patients tested.

Conclusions

This study indicates that Ca²⁺ desensitizing green tea extract catechin, is helpful in correcting the impaired relaxation in pediatric cardiomyopathy patients with diastolic dysfunction.

Electronic supplementary material

The online version of this article (10.1186/s12929-019-0528-7) contains supplementary material, which is available to authorized users.

Patient characteristics and incidence of childhood hospitalisation due to hypertrophic cardiomyopathy in the United States of America 2001-2014

This study investigated patient characteristics in paediatric hospitalisations for hypertrophic cardiomyopathy. We used Nationwide Inpatient Sample, which is the largest all-payer inpatient database in the United States, yielding nationally representative estimates, from 2001 to 2014. ICD-9-CM diagnostic codes identified hospitalisations for patients with hypertrophic cardiomyopathy and &lt;18 years. Outcomes included yearly rate of hospitalisation, death, admission via emergency department, and need for surgery. Predictors of interest were age groups (&lt;1, 1-9, and ⩾10 y/o), sex, and race/ethnicity. Logistic regression modelled associations, adjusted by patient- and hospital-level variables. With 2302 weighted hospitalisations, hospitalisation rates were 0.22 per 100,000 children/year, with higher rates for &lt;1 y/o (0.42) and ⩾10 y/o (0.31). Male-to-female ratios were more prominent in the oldest age group; 2.7:1 in ⩾10 y/o versus less than 1.7:1 for &lt;10 y/o. In-hospital mortality was 1.5%, with highest mortality rates among the &lt;1 y/o (6.3%). Children ⩾10 y/o had 5.59 times higher risk of admission from the emergency department than 1-9 y/o age group. Both ⩾10 and &lt;1 y/o age groups had lower risk of surgical intervention compared to the 1-9 y/o group with odds ratio 0.56 and 0.26, respectively. Black children had higher risk of admission from the emergency department than White children with odds ratio 2.78. A relation between age group and sex was observed, with sex-based differences in prevalence and treatment of hypertrophic cardiomyopathy becoming more pronounced with age. Further studies are needed to clarify mechanisms behind age and racial disparity in hospitalisation, especially admission source.

What is the role of apical ventriculotomy in children and young adults with hypertrophic cardiomyopathy?

BACKGROUND

The transapical approach has been utilized in adult HCM patients with either midventricular obstruction or a small LV cavity; however, there are little data on its use in children.

METHODS

We retrospectively reviewed all patients (age <21 years) with HCM who underwent a transapical myectomy from January 2002 to December 2016. Indication for surgery was midventricular obstruction in 19/23 (83%) and small LV cavity in 4 (17%). Preoperative symptoms included: dyspnea (96%), chest pain (65%), presyncope (61%), and syncope (35%). The mean age at the time of operation was 14 ± 4.0 years (range, 4-20).

RESULTS

Overall, 23 patients (12 males) underwent transapical myectomy. A concomitant transaortic approach was performed in 16/19 (84%) with obstruction. The intraventricular gradient decreased from 71 mm Hg (IQR 44-92 mm Hg) preoperatively to 18 mm Hg (IQR 8-34 mm Hg, P < .0001) after myectomy. In patients with a small LV cavity, the mean left ventricular end diastolic dimension (LVEDD) increased from 40 ± 3 mm to 46 ± 3 mm (P = .05) after myectomy. There were no early deaths. Postoperative morbidity included complete heart block in 3 patients, 2 of which required pacemakers. Median follow up was 3.5 years (IQR 1.6-5.6). Symptoms improved in 95% of patients; the number of patients in NYHA class 3 or 4 heart failure decreased from 10/23 (43%) preoperatively to 3/23 (13%) postoperatively (P < .0001). Overall survival at 5 years postsurgery was 100%. Transplant-free survival was 91% and 87% at 1 and 5 years, respectively.

CONCLUSION

In children with HCM, transapical myectomy is an effective adjunct to a transaortic approach to abolish midventricular obstruction and it effectively increases LV stroke volume in patients with small LV cavities and nonobstructive HCM. It may be beneficial for these patients with significant symptoms and who have failed medical therapy as a treatment alternative to cardiac transplantation.

Symptomatic myocardial bridging: a frequently occurring coronary variation can cause severe myocardial ischaemia in affected children with underlying cardiac conditions

Myocardial bridging is a congenital coronary artery anomaly in which the coronary artery has a partly "tunnelled" intramyocardial course. This tunnelling leads to compression of the affected vessel segment during ventricular systole. It is considered to be a benign variation of the norm in about 25% of the population caused by an aberrancy of embryologic coronary development. The bridging is also thought to cause severe cardiac conditions in a few of those affected. The series of six young patients presented here is the largest series so far to report on symptomatic myocardial bridging in children with different underlying heart diseases. All patients recently presented to our centre with signs of myocardial ischaemia. They subsequently underwent coronary angiography, which revealed myocardial bridging of the ramus interventricularis anterior. In all patients, therapy with β blockers was started to reduce heart rate and myocardial contractility. β Blocker treatment was also given in order to prolong diastole and improve coronary artery blood flow. Two patients underwent surgical exposure of the involved coronary segment: a 2-year-old boy because of recurrent, severe myocardial ischaemia in combination with a reduction of general health, changes in ST-segments, and the presence of a dilative cardiomyopathy; and a 13-year-old girl because of evidence of myocardial ischaemia during exercise testing after surviving sudden cardiac death. Surgery was successful and recovery was complete and uneventful. The presented series shows that myocardial bridging can be symptomatic and may require urgent treatment and even surgical intervention in early childhood in rare cases.

Cardiomyopathy in the pediatric patients

Pediatric cardiomyopathies are a group of myocardial diseases with complex taxonomies. Cardiomyopathy can occur in children at any age, and it is a common cause of heart failure and heart transplantation in children. The incidence of pediatric cardiomyopathy is increasing with time. They may be associated with variable comorbidities, which are most often arrhythmia, heart failure, and sudden death. Medical imaging technologies, including echocardiography, cardiac magnetic resonance, and nuclear cardiology, are helpful in reaching a diagnosis of cardiomyopathy. Nevertheless, endomyocardial biopsy is the final diagnostic method of diagnosis. Patients warrant surgical operations, such as palliative operations, bridging operations, ventricular septal maneuvers, and heart transplantation, if pharmaceutical therapies are ineffective. Individual therapeutic regimens due to pediatric characteristics, genetic factors, and pathogenesis may improve the effects of treatment and patients' survival.

PRKAG2 mutations presenting in infancy

PRKAG2 encodes the γ2 subunit of AMP-activated protein kinase (AMPK), which is an important regulator of cardiac metabolism. Mutations in PRKAG2 cause a cardiac syndrome comprising ventricular hypertrophy, pre-excitation, and progressive conduction-system disease, which is typically not diagnosed until adolescence or young adulthood. However, significant variability exists in the presentation and outcomes of patients with PRKAG2 mutations, with presentation in infancy being underrecognized. The diagnosis of PRKAG2 can be challenging in infants, and we describe our experience with three patients who were initially suspected to have Pompe disease yet ultimately diagnosed with mutations in PRKAG2. A disease-causing PRKAG2 mutation was identified in each case, with a novel missense mutation described in one patient. We highlight the potential for patients with PRKAG2 mutations to mimic Pompe disease in infancy and the need for confirmatory testing when diagnosing Pompe disease.

Survival and prognostic factors in hypertrophic cardiomyopathy: a meta-analysis

Hypertrophic cardiomyopathy (HCM) is a clinically and genetically heterogeneous disorder but data on survival rates are still conflicting and have not so far been quantitatively reviewed. The aim of this study is to conduct a meta-analysis of cohort studies to assess pooled survival rates and prognostic factors for survival in patients with HCM. Nineteen studies were included representing 12,146 HCM patients. The pooled 1-, 3-, 5- and 10-year survival rates were 98.0%, 94.3%, 82.2% and 75.0%, respectively. Among patients with HCM, age, NYHA functional class, family history of sudden death (FHSD), syncope, atrial fibrillation, non-sustained ventricular tachycardia (nsVT), maximum left ventricular wall thickness and obstruction were significant prognostic factors for cardiovascular death. For sudden cardiac death, FHSD, nsVT, and obstruction showed significant predictive values. Moreover, estimation of population attributable risk (PAR) suggested that nsVT was the strongest predictor for cardiovascular death (13.02%, 95% CI 3.60–25.91%), while left ventricular outflow tract obstruction/mid-ventricular obstruction (LVO/MVO) was the strongest predictor for all-cause death and sudden cardiac death (10.09%, 95% CI 4.72–20.42% and 16.44%, 95% CI 7.45–31.55%, respectively). These risk factors may thus be useful for identifying HCM patients who might benefit from early diagnosis and therapeutic interventions.

Discrimination of the "Athlete's Heart" from real disease by electrocardiogram and echocardiogram

Chronic physical training has been shown to produce multiple changes in the heart, resulting in the athlete's heart phenotype. Some of the changes can make it difficult to discern athlete's heart from true cardiac disease, most notably hypertrophic cardiomyopathy. Other diseases such as dilated cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy may be difficult to rule in or out. In this article, the physiological cardiac changes of chronic athletic training are reviewed. A methodological approach using electrocardiography and echocardiography to differentiate between athlete's heart and cardiac disease is proposed.

Congenital heart defects in newborns with apparently isolated single gastrointestinal malformation: A retrospective study

BACKGROUND

Congenital gastrointestinal system malformations/abdominal wall defects (GISM) may appear as isolated defects (single or complex), or in association with multiple malformations. The high incidence of association of GISM and congenital heart defects (CHD) in patients with syndromes and malformative sequences is known, but less expected is the association of apparently isolated single GISM and CHD. The aim of this study was to investigate the frequency of CHD in newborns with isolated GISM, and the possibility to modify the diagnostic-therapeutic approach just before the onset of cardiac symptoms or complications.

METHODS

Anamnestic, clinical, and imaging data of newborns requiring abdominal surgery for GISM, between 2009 and 2014, were compared with a control group of healthy newborns. Distribution of GISM and cardiovascular abnormalities were analyzed, and risk factors for adverse outcomes were identified.

RESULTS

Seventy-one newborns with isolated GISM were included in this study. More frequent GISM were intestinal rotation and fixation disorders. CHD were observed in 15.5% of patients, augmenting their risk for morbidity. Risk factors for morbidity related to sepsis were identified in central venous catheter, intestinal stoma, and H2-inhibitor-drugs. Moreover, 28.2% of newborns presented only functional cardiac disorders but an unexpectedly higher mortality.

CONCLUSIONS

The high incidence of congenital heart disease in infants with apparently isolated GISM confirms the need to perform an echocardiographic study before surgery to improve perioperative management and prevent complications such as sepsis and endocarditis.

Update on hypertrophic cardiomyopathy and a guide to the guidelines

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disorder, affecting 1 in 500 individuals worldwide. Existing epidemiological studies might have underestimated the prevalence of HCM, however, owing to limited inclusion of individuals with early, incomplete phenotypic expression. Clinical manifestations of HCM include diastolic dysfunction, left ventricular outflow tract obstruction, ischaemia, atrial fibrillation, abnormal vascular responses and, in 5% of patients, progression to a 'burnt-out' phase characterized by systolic impairment. Disease-related mortality is most often attributable to sudden cardiac death, heart failure, and embolic stroke. The majority of individuals with HCM, however, have normal or near-normal life expectancy, owing in part to contemporary management strategies including family screening, risk stratification, thromboembolic prophylaxis, and implantation of cardioverter-defibrillators. The clinical guidelines for HCM issued by the ACC Foundation/AHA and the ESC facilitate evaluation and management of the disease. In this Review, we aim to assist clinicians in navigating the guidelines by highlighting important updates, current gaps in knowledge, differences in the recommendations, and challenges in implementing them, including aids and pitfalls in clinical and pathological evaluation. We also discuss the advances in genetics, imaging, and molecular research that will underpin future developments in diagnosis and therapy for HCM.

T1 mapping in children and young adults with hypertrophic cardiomyopathy

To assess the global and segmental left ventricular (LV) native T1 and extracellular volume fraction (ECV) in children and young adults with hypertrophic cardiomyopathy (HCM) compared to a control cohort. The study population included 21 HCM patients (mean 14.1 ± 4.6 years) and 21 controls (mean 15.7 ± 1.5 years). Native modified Look-Locker inversion recovery sequence was performed before and after contrast injection in 3 short axis planes. Global and segmental LV native T1 and ECV were quantified and compared between HCM patients and controls. Mean native T1 in HCM patients and controls was 1020.4 ± 41.2 and 965.6 ± 30.2 ms respectively (p < 0.0001). Hypertrophied myocardium had significantly higher native global T1 and global ECV compared to non-hypertrophied myocardium in HCM (p < 0.0001, = 0.14 and 0.048, = 0.01 respectively). In a subset of patients, ECV was higher in LV segments with LGE compared to no LGE (p < 0.0001). No significant correlation was identified between global native T1 and ECV and parameters of LV structure and function. Native T1 cut-off of 987 ms provided the highest sensitivity (95 %) and specificity (91 %) to separate HCM patients from controls. Global and segmental native T1 are elevated in HCM patients. LV segments with hypertrophy and/or LGE had higher ECV in a subset of HCM patients. LV native T1 and ECV do not correlate with parameters of LV structure and function. T1 in children and young adults may be used as a non-invasive tool to assess for HCM and related fibrosis.

Spectrum of heart diseases in children: an echocardiographic study of 1,666 subjects in a pediatric hospital, Yaounde, Cameroon

BACKGROUND

Children's health programs in Sub-Saharan Africa have always been oriented primarily to infectious diseases and malnutrition. We are witnessing in the early 21(st) century an epidemiological transition marked by the decline of old diseases and the identification of new diseases including heart disease. Therefore, it is necessary to describe the spectrum of these diseases in order to better prepare health workers to these new challenges.

METHODS

We conducted a cross-sectional study focused on heart disease diagnosed by echocardiography in children seen from January 2006 to December 2014 in a pediatric hospital of Yaounde. We collected socio-demographic data and the types of heart disease from registers, patients files as well as the electronic database of echocardiographic records.

RESULTS

A total of 2,235 patients underwent echocardiographic examination during the study period including 1,666 subjects with heart disease. Congenital cardiopathies were found in 1,230 (73.8%) patients and acquired abnormalities in 429 (25.8%). Seven children (0.4%) had a combination of both types. Congenital heart defects (CHD) were dominated by ventricular septal defect (VSD). Acquired heart disease was mostly rheumatic valvulopathies. Dyspnea on exertion was the most frequent presenting complaint (87.6%). Discovery of a heart murmur was the principal clinical finding on physical examination (81.4%). The median age was 9 months for congenital heart disease and 132 months for acquired heart disease.

CONCLUSIONS

As infectious diseases recede and the diagnostic facilities are improving, pediatric heart diseases occupy a more important position in the spectrum of pediatric diseases in our context. However, the ability to evoke the diagnosis remains unsatisfactory by the majority of health personnel and therefore needs to be improved. Apart from congenital heart diseases, the impact of acquired heart diseases, rheumatic valvulopathy being the highest ranking, is remarkable in pediatrics. Awareness of health personnel for better management of child tonsillitis is more than ever a necessity. This preventive attitude of rheumatic heart disease is the main attitude available in our disadvantaged economic environment.

Predictors of Long-Term Outcome in Children with Hypertrophic Cardiomyopathy

To date limited data are available to predict the progression to end-stage heart failure (HF) with subsequent death (non-SCD), need for heart transplantation, or sudden cardiac death (SCD) in children with hypertrophic cardiomyopathy (HCM). We aimed to determine predictors of long-term outcome in children with HCM. A total of 112 children (median 14.1, IQR 7.8-16.6 years) were followed up for the median of 6.5 years for the development of morbidity and mortality, including arrhythmic and HF-related secondary end points. HF end point included HF-related death or heart transplant, and arrhythmic end point included resuscitated cardiac arrest, appropriate ICD discharge, or SCD. Overall, 23 (21 %) patients reached the pre-defined composite primary end point. At 10-year follow-up, the event-free survival rate was 76 %. Thirteen patients (12 %) reached the secondary arrhythmic end point, and 10 patients (9 %) reached the secondary HF end point. In multivariate model, prior cardiac arrest (r = 0.658), QTc dispersion (r = 0.262), and NSVT (r = 0.217) were independent predictors of the arrhythmic secondary end point, while HF (r = 0.440), LV posterior wall thickness (r = 0.258), LA size (r = 0.389), and decreased early transmitral flow velocity (r = 0.202) were all independent predictors of the secondary HF end point. There are differences in the risk factors for SCD and for HF-related death in childhood HCM. Only prior cardiac arrest, QTc dispersion, and NSVT predicted arrhythmic outcome in patients aged <18 years. LA size, LV posterior wall thickness, and decreased early transmitral flow velocity were strong independent predictors of HF-related events.

Co-occurrence of hypertrophic cardiomyopathy and myeloproliferative disorder in a neonate with Noonan syndrome carrying Thr73Ile mutation in PTPN11

Most cases of Noonan syndrome (NS) result from mutations in one of the RAS-MAPK signaling genes, including PTPN11, SOS1, KRAS, NRAS, RAF1, BRAF, SHOC2, MEK1 (MAP2K1), and CBL. Cardiovascular diseases of varying severity, such as pulmonary stenosis and hypertrophic cardiomyopathy (HCM), are common in NS patients. RAF1 mutations are most frequent in NS with HCM, while PTPN11 mutations are also well known. Thr73Ile is a gain-of-function mutation of PTPN11, which has been highly associated with juvenile myelomonocytic leukemia and NS/myeloproliferative disease (MPD), but has not previously been reported in HCM. Here, we report a Japanese female infant with NS carrying the PTPN11 T73I mutation with NS/MPD, complete atrio-ventricular septal defect, and rapidly progressive HCM. No other HCM-related mutations were detected in PTPN11, RAF1, KRAS, BRAF, and SHOC2. This patient provides additional information regarding the genotype-phenotype correlation for PTPN11 T73I mutation in NS.

Heart transplantation in pediatric cardiomyopathies

Cardiomyopathies represent an uncommon but serious cause of heart disease in the pediatric population and can be categorized as dilated, hypertrophic, restrictive and left ventricular non-compaction. Each of these subtypes has multiple potential genetic etiologies in addition to possible non-genetic causes. Many patients with cardiomyopathies can benefit from transplantation, although there is not insignificant morbidity and mortality for those patients. Outcomes both prior to and following transplantation depend on the underlying etiology, the amount of support needed prior to transplantation and the illness severity of the patient prior to transplantation. Mechanical circulatory support is frequently used to bridge patients to transplantation, and newer technologies are currently in development.

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.

Cardiological manifestations of mitochondrial respiratory chain disorders

Mitochondrial Respiratory Chain Disorders (MRCD) are a heterogeneous group of disorders that share the involvement of the cellular bioenergetic machinery due to molecular defects affecting the mitochondrial oxidative phosphorylation system (OXPHOS). Clinically, they usually involve multiple tissues although they tend to mainly affect nervous system and skeletal muscle. Cardiological manifestations are frequent and include hypertrophic or dilated cardiomyopathies and heart conduction defects, being part of adult or infantile multisystemic mitochondrial disorders or, less frequently, presenting as isolated clinical condition. The aim of this review is to update the cardiological manifestations in both adult and infantile mitochondrial disorders going briefly over mitochondrial genetics. Cardiac involvement is a common feature associated with early and late onset forms of MRCD. In particular cases, these conditions should be considered into the diagnostic algorithm of idiopathic cardiomyopathies. Physicians strictly related with this disorders need to be aware of heart complications and therefore periodical cardiological examinations should be performed in such patients. Finally, therapeutic strategies are suggested to treat cardiac disorders in MRCD

Cardiomyopathy and heart failure in children: anesthetic implications

The purpose of this article is to provide a brief but systematic overview of heart failure and cardiomyopathy in children and the anesthetic management of these patients. We will begin with disease definitions and descriptions of the disorders. Our review will include the epidemiology and etiology of the more prevalent underlying causes of heart failure, the principal pathophysiology of the specific cardiomyopathies, as well as the common therapies in use today in both inpatient and outpatient settings. Important implications for anesthetic management will be highlighted.