Clinical features of isolated noncompaction of the ventricular myocardium: long-term clinical course, hemodynamic properties, and genetic background

A Rare Case of Renal Infarct due to Noncompaction Cardiomyopathy: A Case Report and Literature Review

Left ventricular noncompaction cardiomyopathy is a rare myocardial disorder which results from failure of left ventricle to compact in embryogenesis. We present a case of a 53-year-old female who came because of abdominal pain and was found to have renal infarct secondary to noncompaction cardiomyopathy.

A rare form of cardiomyopathy: left ventricular non-compaction cardiomyopathy

Left ventricular non-compaction is a recently recognized, rare form of cardiomyopathy. It is based on the arrest of endomyocardial morphogenesis during embryogenesis. It was first described in 1984 by Engberding who described it as isolated ‘sinusoids’ within the LV. Right now its prevalence is estimated at 0.014 to 1.3 and 3–4% in heart failure patients. Its clinical manifestations are highly variable, ranging from no symptoms to disabling congestive heart failure, arrhythmias, and systemic thromboemboli. Doppler Echocardiogram is considered the diagnostic procedure of choice and treatment is symptomatic management of its symptoms and complications.

Left ventricular noncompaction: A rare indication for pediatric heart transplantation

Isolated left ventricular noncompaction is a rare congenital cardiomyopathy, characterized morphologically by a dilated left ventricle, prominent trabeculations and deep intertrabecular recesses in the ventricular myocardium, with no other structural heart disease. It is thought to be secondary to an arrest of normal myocardial compaction during fetal life. Clinically, the disease presents with heart failure, embolic events, arrhythmias or sudden death. Current diagnostic criteria are based on clinical and imaging data and two-dimensional and color Doppler echocardiography is the first-line exam. There is no specific therapy and treatment is aimed at associated comorbidities. Cases refractory to medical therapy may require heart transplantation. The authors describe a case of severe and refractory heart failure, which was the initial presentation of isolated left ventricular noncompaction in a previously healthy male child, who underwent successful heart transplantation.

Isolated Ventricular Noncompaction Cardiomyopathy Presenting as Recurrent Syncope

Isolated ventricular noncompaction (IVNC) occurs because of interruption of trabecular morphogenesis in the myocardium leading to ventricular noncompaction. Patients present with heart failure or with systemic complications secondary to thromboembolism or arrhythmias. High index of suspicion is necessary for early diagnosis. We present a case of 48-year-old male with unexplained recurrent syncope who was eventually diagnosed with IVNC.

Regression of left ventricular hypertrabeculation is associated with improvement in systolic function and favorable prognosis in adult patients with non-ischemic cardiomyopathy

BACKGROUND

We sometimes experience regression of left ventricular hypertrabeculation (LVHT), which is compatible with the diagnosis of LV non-compaction cardiomyopathy (LVNC) in adult patients. However, little is known about the association between LVHT regression and LV systolic function in adult patients.

METHODS

We prospectively examined 23 consecutive adult patients who fulfilled the echocardiographic criteria for LVNC. LV reverse remodeling (RR) was defined as an absolute increase in LV ejection fraction of >10% at 6 months follow-up. LVHT area was calculated by subtraction from the outer edge to the inner edge of the LVHT at end-systole.

RESULTS

The mean follow-up period was 61 months. LVRR was observed in 9 patients (39%). The changes in the mean LVHT area showed significant correlation with the changes in LV ejection fraction (r=-0.78, p<0.0001). Cardiac death occurred in 7 patients (50%) without LVRR, but no patients with LVRR died (log-rank, p=0.003). Furthermore, composite of cardiac death and hospitalization for heart failure occurred in 10 patients (71%) without LVRR, whereas there was one patient with LVRR (log-rank, p<0.001).

CONCLUSIONS

Regression of LVHT is associated with improvement in LV systolic function. LVRR might be associated with a favorable prognosis in patients with LVHT.

The pathogenicity of genetic variants previously associated with left ventricular non-compaction

Background

Left ventricular non‐compaction (LVNC) is a rare cardiomyopathy. Many genetic variants have been associated with LVNC. However, the number of the previous LVNC‐associated variants that are common in the background population remains unknown. The aim of this study was to provide an updated list of previously reported LVNC‐associated variants with biologic description and investigate the prevalence of LVNC variants in healthy general population to find false‐positive LVNC‐associated variants.

Methods and Results

The Human Gene Mutation Database and PubMed were systematically searched to identify all previously reported LVNC‐associated variants. Thereafter, the Exome Sequencing Project (ESP) and the Exome Aggregation Consortium (ExAC), that both represent the background population, was searched for all variants. Four in silico prediction tools were assessed to determine the functional effects of these variants. The prediction results of those identified in the ESP and ExAC and those not identified in the ESP and ExAC were compared. In 12 genes, 60 LVNC‐associated missense/nonsense variants were identified. MYH7 was the predominant gene, encompassing 24 of the 60 LVNC‐associated variants. The ESP only harbored nine and ExAC harbored 18 of the 60 LVNC‐associated variants. In total, eight out of nine ESP‐positive variants overlapped with the 18 variants identified in ExAC database.

Conclusions

In this article, we identified 9 ESP‐positive and 18 ExAC‐positive variants of 60 previously reported LVNC‐associated variants, suggesting that these variants are not necessarily the monogenic cause of LVNC.

Cardiomyopathy Phenotypes and Outcomes for Children With Left Ventricular Myocardial Noncompaction: Results From the Pediatric Cardiomyopathy Registry

BACKGROUND

Left ventricular noncompaction (LVNC) is a distinct form of cardiomyopathy characterized by hypertrabeculation of the left ventricle. The LVNC phenotype may occur in isolation or with other cardiomyopathy phenotypes. Prognosis is incompletely characterized in children.

METHODS AND RESULTS

According to diagnoses from the National Heart, Lung, and Blood Institute-funded Pediatric Cardiomyopathy Registry from 1990 to 2008, 155 of 3,219 children (4.8%) had LVNC. Each LVNC patient was also classified as having an associated echocardiographically diagnosed cardiomyopathy phenotype: dilated (DCM), hypertrophic (HCM), restrictive (RCM), isolated, or indeterminate. The time to death or transplantation differed among the phenotypic groups (P = .035). Time to listing for cardiac transplantation significantly differed by phenotype (P < .001), as did time to transplantation (P = .015). The hazard ratio for death/transplantation (with isolated LVNC as the reference group) was 4.26 (95% confidence interval [CI] 0.78-23.3) for HCM, 6.35 (95% CI 1.52-26.6) for DCM, and 5.66 (95% CI 1.04-30.9) for the indeterminate phenotype. Most events occurred in the 1st year after diagnosis.

CONCLUSIONS

LVNC is present in at least 5% of children with cardiomyopathy. The specific LVNC-associated cardiomyopathy phenotype predicts the risk of death or transplantation and should inform clinical management.

The hypertrabeculated (noncompacted) left ventricle is different from the ventricle of embryos and ectothermic vertebrates

Ventricular hypertrabeculation (noncompaction) is a poorly characterized condition associated with heart failure. The condition is widely assumed to be the retention of the trabeculated ventricular design of the embryo and ectothermic (cold-blooded) vertebrates. This assumption appears simplistic and counterfactual. Here, we measured a set of anatomical parameters in hypertrabeculation in man and in the ventricles of embryos and animals. We compared humans with left ventricular hypertrabeculation (N=21) with humans with structurally normal left ventricles (N=54). We measured ejection fraction and ventricular trabeculation using cardiovascular MRI. Ventricular trabeculation was further measured in series of embryonic human and 9 animal species, and in hearts of 15 adult animal species using MRI, CT, or histology. In human, hypertrabeculated left ventricles were significantly different from structurally normal left ventricles by all structural measures and ejection fraction. They were far less trabeculated than human embryonic hearts (15-40% trabeculated volume versus 55-80%). Early in development all vertebrate embryos acquired a ventricle with approximately 80% trabeculations, but only ectotherms retained the 80% trabeculation throughout development. Endothermic (warm-blooded) animals including human slowly matured in fetal and postnatal stages towards ventricles with little trabeculations, generally less than 30%. Further, the trabeculations of all embryos and adult ectotherms were very thin, less than 50 μm wide, whereas the trabeculations in adult endotherms and in the setting of hypertrabeculation were wider by orders of magnitude. It is concluded in contrast to a prevailing assumption, the hypertrabeculated left ventricle is not like the ventricle of the embryo or of adult ectotherms. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

PLEKHM2 mutation leads to abnormal localization of lysosomes, impaired autophagy flux and associates with recessive dilated cardiomyopathy and left ventricular noncompaction

Gene mutations, mostly segregating with a dominant mode of inheritance, are important causes of dilated cardiomyopathy (DCM), a disease characterized by enlarged ventricular dimensions, impaired cardiac function, heart failure and high risk of death. Another myocardial abnormality often linked to gene mutations is left ventricular noncompaction (LVNC) characterized by a typical diffuse spongy appearance of the left ventricle. Here, we describe a large Bedouin family presenting with a severe recessive DCM and LVNC. Homozygosity mapping and exome sequencing identified a single gene variant that segregated as expected and was neither reported in databases nor in Bedouin population controls. The PLEKHM2 cDNA2156_2157delAG variant causes the frameshift p.Lys645AlafsTer12 and/or the skipping of exon 11 that results in deletion of 30 highly conserved amino acids. PLEKHM2 is known to interact with several Rabs and with kinesin-1, affecting endosomal trafficking. Accordingly, patients' primary fibroblasts exhibited abnormal subcellular distribution of endosomes marked by Rab5, Rab7 and Rab9, as well as the Golgi apparatus. In addition, lysosomes appeared to be concentrated in the perinuclear region, and autophagy flux was impaired. Transfection of wild-type PLEKHM2 cDNA into patient's fibroblasts corrected the subcellular distribution of the lysosomes, supporting the causal effect of PLEKHM2 mutation. PLEKHM2 joins LAMP-2 and BAG3 as a disease gene altering autophagy resulting in an isolated cardiac phenotype. The association of PLEKHM2 mutation with DCM and LVNC supports the importance of autophagy for normal cardiac function.

A rare case of heterotaxy and left ventricular non-compaction in an adult

Heterotaxy syndrome with left ventricular non-compaction is a rare co-existence of abnormalities with unknown cause. It can be isolated with no other associations, or associated with congenital heart diseases, or it can occur with multiple other congenital abnormalities. We describe the third reported case of heterotaxy syndrome with left ventricular non-compaction presenting in an adult.

Left ventricular non-compaction cardiomyopathy

Left ventricular non-compaction, the most recently classified form of cardiomyopathy, is characterised by abnormal trabeculations in the left ventricle, most frequently at the apex. It can be associated with left ventricular dilation or hypertrophy, systolic or diastolic dysfunction, or both, or various forms of congenital heart disease. Affected individuals are at risk of left or right ventricular failure, or both. Heart failure symptoms can be induced by exercise or be persistent at rest, but many patients are asymptomatic. Patients on chronic treatment for compensated heart failure sometimes present acutely with decompensated heart failure. Other life-threatening risks of left ventricular non-compaction are ventricular arrhythmias or complete atrioventricular block, presenting clinically as syncope, and sudden death. Genetic inheritance arises in at least 30-50% of patients, and several genes that cause left ventricular non-compaction have been identified. These genes seem generally to encode sarcomeric (contractile apparatus) or cytoskeletal proteins, although, in the case of left ventricular non-compaction with congenital heart disease, disturbance of the NOTCH signalling pathway seems part of a final common pathway for this form of the disease. Disrupted mitochondrial function and metabolic abnormalities have a causal role too. Treatments focus on improvement of cardiac efficiency and reduction of mechanical stress in patients with systolic dysfunction. Further, treatment of arrhythmia and implantation of an automatic implantable cardioverter-defibrillator for prevention of sudden death are mainstays of therapy when deemed necessary and appropriate. Patients with left ventricular non-compaction and congenital heart disease often need surgical or catheter-based interventions. Despite progress in diagnosis and treatment in the past 10 years, understanding of the disorder and outcomes need to be improved.

Biventricular Noncompaction Cardiomyopathy in an Adult with Unique Facial Dysmorphisms: Case Report and Brief Review

Left ventricular noncompaction (LVNC) is a rare cardiomyopathy that is believed it to arise from an arrest in embryonic endomyocardial development. More recent studies suggest that it can be acquired later on in life sporadically. It may be accompanied by life-threatening complications, which are most commonly heart failure, arrhythmias, and thromboembolic events. We report a case of biventricular noncompaction cardiomyopathy in a 36-year-old man presenting for the first time with clinical heart failure as well as atrial arrhythmia. Transthoracic echocardiography (TTE) revealed LVNC with depressed ejection fraction (EF). Cardiac magnetic resonance imaging (MRI) further revealed a left atrial appendage thrombus as well as right ventricular noncompaction involvement. His physical exam was unique for a characteristic facial dysmorphisms pattern and developmental delays reminiscent of the earliest descriptions of LVNC in the pediatric population and it was rarely described in adult patients. This unique presentation underscores the importance of a better understanding of the genetics and natural course of LVNC. This will help us to elucidate the uncertainty surrounding its clinical management, discussed in a brief review of the literature following the case.

Adherence to thresholds: overdiagnosis of left ventricular noncompaction cardiomyopathy

Thresholds derived from quantification in imaging are increasingly used to define disease. This derivation is not an exact science. When one uses a threshold to define a disease, one does not clearly demarcate disease from normality because the threshold includes overlapping spectra of mild disease and normality. Thus, use of the threshold will mislabel normal individuals with disease. In this perspective, we will describe how the threshold has been derived for left ventricular noncompaction cardiomyopathy, the statistical biases in the design of studies used to derive the threshold, and the dangers of overdiagnosis when the threshold is used to rule out left ventricular noncompaction cardiomyopathy.

Noncompaction Cardiomyopathy with Charcot-Marie-Tooth Disease

We report a case of a 53-year-old female presenting with a new-onset heart failure that was contributed secondary to noncompaction cardiomyopathy. The diagnosis was made by echocardiogram and confirmed by cardiac MRI. Noncompaction cardiomyopathy (also known as ventricular hypertrabeculation) is a newly discovered disease. It is considered to be congenital (genetic) cardiomyopathy. It is usually associated with genetic disorders and that could explain the genetic pathogenesis of the non-compaction cardiomyopathy. Our case had a history of Charcot-Marie-Tooth disease. There is a high incidence of arrhythmia and embolic complications. The treatment usually consists of the medical management, defibrillator placement, and lifelong anticoagulation. Heart transplantation will be the last resort.

Noncompaction Cardiomyopathy and Stroke: Case Report and Literature Review

BACKGROUND

To describe a rare case of isolated noncompaction cardiomyopathy and stroke and to review the medical literature on noncompaction cardiomyopathy.

METHODS

Retrospective chart review of the case was performed. Extensive literature review on etiology, clinical presentation, diagnosis, and management of noncompaction cardiomyopathy was also performed.

RESULTS

Our patient is a healthy 20-year-old woman who presented with sudden onset left face and arm weakness and hypesthesia. Magnetic resonance imaging (MRI) brain showed right middle cerebral artery (MCA) infarct. Magnetic resonance angiography head showed right MCA artery (M2) cutoff. MRI neck was nonsignificant. Echocardiogram was suggestive of noncompaction of left ventricle. Cardiac MRI confirmed the noncompaction of the left ventricle myocardium, which was thought to be the etiology of stroke. Patient was started on anticoagulation for secondary stroke prevention.

CONCLUSIONS

Isolated left ventricular noncompaction cardiomyopathy (LVNC) is a rare form of primary genetic cardiomyopathy, which occurs because of the arrest of the process of compaction of ventricular myocardium during embryogenesis. Noncompaction cardiomyopathy is usually associated with other primary cardiac structural abnormalities like dysfunctional cardiac valves. In isolated noncompaction cardiomyopathy, there are no other primary cardiac structural abnormalities. The most common clinical features seen in LVNC include left ventricular systolic dysfunction, congestive heart failure, arrhythmias, and cardiac embolic events theorized to result from thrombus formation within the intertrabecular recesses. As it is a rare disease, evidence-based recommendations for preventing thromboembolic events in isolated left ventricular noncompaction have not been established.

Arrhythmias in left ventricular noncompaction

Left ventricular noncompaction (LVNC) is a newly recognized form of cardiomyopathy that has been associated with heart failure, arrhythmias, thromboembolic events, and sudden death. Both ventricular and supraventricular arrhythmias are now well described as prominent clinical components of LVNC. Throughout the spectrum of age, these arrhythmias have been associated with prognosis and outcome, and their clinical management is therefore an important aspect of patient care. The risk of sudden death seems to be associated with ventricular dilation, systolic dysfunction, and the presence of arrhythmias. Proposed management strategies shown to have efficacy include antiarrhythmic therapy, ablation techniques, and implantable cardioverter-defibrillator implantation.

Comparison of cardiovascular magnetic resonance characteristics and clinical consequences in children and adolescents with isolated left ventricular non-compaction with and without late gadolinium enhancement

BACKGROUND

Although cardiovascular magnetic resonance (CMR) is showing increasingly diagnostic potential in left ventricular non-compaction (LVNC), relatively little research relevant to CMR is conducted in children with LVNC. This study was performed to characterize and compare CMR features and clinical outcomes in children with LVNC with and without late gadolinium enhancement (LGE).

METHODS

A cohort of 40 consecutive children (age, 13.7 ± 3.3 years; 29 boys and 11 girls) with isolated LVNC underwent a baseline CMR scan with subsequent clinical follow-up. Short-axis cine images were used to calculate left ventricular (LV) ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), myocardial mass, ratio of non-compacted-to-compacted myocardial thickness (NC/C ratio), and number of non-compacted segments. The LGE images were analyzed to assess visually presence and patterns of LGE. The primary end point was a composite of cardiac death and heart transplantation.

RESULTS

The LGE was present in 10 (25%) children, and 46 (27%) segments were involved, including 23 non-compacted segments and 23 normal segments. Compared with LGE- cohort, LGE+ cohort had significantly lower LVEF (23.8 ± 10.7% vs. 42.9 ± 16.7%, p < 0.001) and greater LVEDV (169.2 ± 65.1 vs. 118.2 ± 48.9 mL/m2, p = 0.010), LVESV (131.3 ± 55.5 vs. 73.3 ± 46.7 mL/m2, p = 0.002), and sphericity indices (0.75 ± 0.19 vs. 0.60 ± 0.20, p = 0.045). There were no differences in terms of number and distribution of non-compacted segments, NC/C ratio, and myocardial mass index between LGE+ and LGE- cohort. In the LGE+ cohort, adverse events occurred in 6 patients compared to 2 events in the LGE- cohort. Kaplan-Meier analysis showed a significant difference in outcome between LGE+ and LGE- cohort for cardiac death and heart transplantation (p = 0.011).

CONCLUSIONS

The LGE was present in up to one-fourth of children with LVNC, and the LGE+ children exhibited a more maladaptive LV remodeling and a higher incidence of cardiovascular death and heart transplantation.

Outcomes, arrhythmic burden and ambulatory monitoring of pediatric patients with left ventricular non-compaction and preserved left ventricular function

Pediatric patients with left ventricular noncompaction (LVNC) and severe ventricular dysfunction are at risk for sudden death. The aims of this study were to (1) evaluate outcomes, (2) describe arrhythmic burden on Holter monitoring, and (3) analyze the utility of Holter monitoring and its impact on care in pediatric patients with LVNC and preserved or mild ventricular dysfunction. This was a retrospective study including patients <21 years of age with LVNC and ejection fractions ≥45%. Demographic and outcome data were analyzed. Individual and cumulative Holter data were evaluated for all patients. Arrhythmias, conduction system disease, and symptoms were analyzed for each Holter recording. The incidence of significant findings and the impact on care were determined for each study. Outcome and Holter data were compared between patients on the basis of the ejection fraction (≥55% [normal] or ≥45% to <55% [mild]). This study included 72 patients, 65 with normal function and 7 with mild dysfunction (mean age 13 years). There was a single death in the cohort, which was sudden in nature. Simple ventricular ectopy was common on Holter monitoring and more common in patients with mild dysfunction (86% vs 27%, p = 0.005). Significant Holter findings (4% vs 6%) and changes to patient care (2% vs 4%) improved with cumulative Holter monitoring. In conclusion, in contrast to patients with severe dysfunction, pediatric patients with LVNC and normal or mild dysfunction have significantly better outcomes. However, worsening LV systolic function was correlated with increasing ventricular ectopy. The role of Holter monitoring is unknown, but it may have utility in patient care if used as part of ongoing screening.

Use of genetic testing to identify sudden cardiac death syndromes

Sudden cardiac death (SCD) is a leading cause of mortality worldwide. Although coronary artery disease remains the most common substrate for SCD, primary cardiac genetic diseases, presenting with or without structural heart abnormalities, play a significant role. In the last 30 years, the study of large family pedigrees allowed the discovery of causative genes unveiling the genetic basis of diseases such as primary cardiomyopathies and arrhythmia syndromes, which are known to increase the risk of SCD. However, recent technological advancement with the ability to perform massive parallel sequencing and analyze the entire genome has uncovered a higher level of complexity in the genetic predisposition for cardiac diseases, which are usually characterized by Mendelian inheritance patterns. Clinical genetic testing, historically shaped around a monogenic Mendelian disorder paradigm, is now facing the challenge to adopt and adapt to a more complex model in which a significant portion of subjects may present with multi-allelic inheritance involving additional genes that could modulate the severity and type of disease-related phenotypes. Here, we will try to provide a viewpoint that will hopefully foster further debate in the field.

Semaphorin signaling in cardiovascular development

Semaphorins were originally identified as neuronal guidance molecules mediating their attractive or repulsive signals by forming complexes with plexin and neuropilin receptors. Subsequent research has identified functions for semaphorin signaling in many organs and tissues outside of the nervous system. Vital roles for semaphorin signaling in vascular patterning and cardiac morphogenesis have been demonstrated, and impaired semaphorin signaling has been associated with various human cardiovascular disorders, including persistent truncus arteriosus, sinus bradycardia and anomalous pulmonary venous connections. Here, we review the functions of semaphorins and their receptors in cardiovascular development and disease and highlight important recent discoveries in the field.

Inherited cardiomyopathies

Cardiomyopathies (ie, diseases of the heart muscle) are major causes of morbidity and mortality. A significant percentage of patients with cardiomyopathies have genetic-based, inheritable disease and, over the past 2 decades the genetic causes of these disorders have been increasingly discovered. The genes causing these disorders when they are mutated appear to encode proteins that frame a "final common pathway" for that specific disorder, but the specifics of the phenotype, including age of onset, severity, and outcome is variable for reasons not yet understood. The "final common pathways" for the classified forms of cardiomyopathy include the sarcomere in the primarily diastolic dysfunction disorders hypertrophic cardiomyopathy and restrictive cardiomyopathy, the linkage of the sarcomere and sarcolemma in the systolic dysfunction disorder dilated cardiomyopathy, and the desmosome in arrhythmogenic cardiomyopathy. Left ventricular noncompaction cardiomyopathy (LVNC) is an overlap disorder and it appears that any of these "final common pathways" can be involved depending on the specific form of LVNC. The genetics and mechanisms responsible for these clinical phenotypes will be described.

Clinical outcomes in patients with isolated left ventricular noncompaction and heart failure

BACKGROUND

We prospectively evaluated long-term clinical outcomes of patients diagnosed with isolated left ventricular noncompaction (ILVNC) and heart failure from a sub-Saharan African population.

METHODS AND RESULTS

Patients in this single-center study were followed at a tertiary care institution. Clinical follow-up was performed with the use of protocol-driven echocardiographic screening for ventricular thrombus every 4 months. Warfarin was maintained or initiated only if thrombus was detected with the use of echocardiography. Fifty-five patients were followed for 16.7 ± 5.9 (range 12-33) months. All individuals had left ventricular (LV) ejection fraction <50% (mean 29.6 ± 11.8%). Of the 55 patients, 7 (12.7%) died, and sudden cardiac death was the cause in 5 (71.4%). There were no differences in baseline clinical, echocardiographic, or electrocardiographic characteristics between survivors and nonsurvivors. Recurrent heart failure developed in 12 patients (21.8%); 1 patient developed a ventricular arrhythmia. No thromboembolic or major bleeding complications occurred in the 16 patients on warfarin; 1 episode of thromboembolism occurred in the 39 patients not on warfarin. Mean survival probability at 33 months was 0.64.

CONCLUSIONS

Sudden cardiac death was the most common cause of death in patients with ILVNC and heart failure. Recurrent heart failure occurred in 21.8% of patients. Development of LV thrombus and cardioembolism is uncommon in this population.

Isolated right ventricular noncompaction in a newborn

Noncompaction of the ventricular myocardium is a rare cardiomyopathy characterized by a pattern of prominent trabecular meshwork and deep intertrabecular recesses. The prevalence of left ventricular noncompaction is 0.01% in adults and 0.14% in pediatric patients. Although the usual site of involvement is the left ventricle, the right ventricle and septum can be affected as well. Previously, right ventricular noncompaction has been described only in a few cases of newborns with congenital heart defects and in adult patients. This report presents a newborn with isolated right ventricular noncompaction. To the authors' knowledge, this is the first newborn patient with isolated right ventricular noncompaction but no congenital heart defect involving only the right ventricle.

Electrocardiographic findings in correlation to magnetic resonance imaging patterns in African patients with isolated ventricular noncompaction

OBJECTIVE

Isolated ventricular noncompaction is a rare primary genetic cardiomyopathy characterized by persistent embryonic myocardial morphology without any other cardiac anomalies. Arrhythmias are frequently present, including both tachyarrhythmia and conduction disturbance. Our study aimed to describe the electrocardiographic findings and to correlate them with the clinical presentation and cardiac magnetic resonance imaging findings.

METHODS

We retrospectively reviewed 24 patients diagnosed with isolated ventricular noncompaction (IVNC) by cardiac magnetic resonance imaging. Correlations were investigated between arrhythmias and the site of ventricular noncompaction, number of noncompacted segments, presence of fibrosis, and left ventricular dysfunction.

RESULTS

The mean age was 42.7±13.1 years. Patients were first presented with heart failure in 41.7% and arrhythmia in 45.8%. Electrocardiogram was abnormal in 91.6% of patients; the most common anomaly was left bundle branch block (LBBB) (41.7%), followed by supraventricular arrhythmias (29.1%), repolarization abnormalities (29.1%), and ventricular tachycardia (20.8%). A normal left ventricular systolic function was frequently observed in patients who first presented with rhythm disorders than heart failure (p=0.008). There was also a delayed diagnosis of IVNC when presented with arrhythmia versus heart failure (p=0.02). We found no correlation between arrhythmias and the noncompaction site or fibrosis, except for LBBB, which was associated to left ventricle lateral wall involvement (p=0.028). No correlation between systolic dysfunction and the number of noncompacted segments, fibrosis, or arrhythmia was demonstrated.

CONCLUSION

While electrocardiographic abnormalities are frequent in isolated ventricular noncompaction, no specific patterns were identified. More large studies are needed for stratification of arrhythmic risk of this highly arrhythmogenic substrate.

Left ventricular noncompaction cardiomyopathy: updated review

The first case of noncompaction was described in 1932 after an autopsy performed on a newborn infant with aortic atresia/coronary-ventricular fistula. Isolated noncompaction cardiomyopathy was first described in 1984. A review on selected/relevant medical literature was conducted using Pubmed from 1984 to 2013 and the pathogenesis, clinical features, and management are discussed. Left ventricular noncompaction (LVNC) is a relatively rare congenital condition that results from arrest of the normal compaction process of the myocardium during fetal development. LVNC shows variability in its genetic pattern, pathophysiologic findings, and clinical presentations. The genetic heterogeneity, phenotypical overlap, and variety in clinical presentation raised the suspicion that LVNC might just be a morphological variant of other cardiomyopathies, but the American Heart Association classifies LVNC as a primary genetic cardiomyopathy. The familiar type is common and follows a X-linked, autosomal-dominant, or mitochondrial-inheritance pattern (in children). LVNC can occur in isolation or coexist with other cardiac and/or systemic anomalies. The clinical presentations are variable ranging from asymptomatic patients to patients who develop ventricular arrhythmias, thromboembolism, heart failure, and sudden cardiac death. Increased awareness over the last 25 years and improvements in technology have increased the identification of this illness and improved the clinical outcome and prognosis. LVNC is commonly diagnosed by echocardiography. Other useful diagnostic techniques for LVNC include cardiac magnetic resonance imaging, computerized tomography, and left ventriculography. Management is symptom based and patients with symptoms have a poorer prognosis. LVNC is a genetically heterogeneous disorder which can be associated with other anomalies. Making the correct diagnosis is important because of the possible associations and the need for long-term management and screening of living relatives.

Revisiting Non-Compaction Cardiomyopathy Through a Case with Cyanosis and Complete Heart Block

Left ventricular non-compaction or “spongy myocardium”, is a rare congenital cardiomyopathy that should be considered as a possible diagnosis because of its potential complications. Echocardiography is the diagnostic tool of choice, and cardiomagnetic resonance (CMR) can confirm or rule out this disease. Herein, we report the case of an 8-month-old female child who presented with congestive cardiac failure (CCF) and symptomatic complete heart block (CHB). An echocardiogram established the diagnosis as non-compaction cardiomyopathy (NCCM). An associated double outlet right ventricle with ventricular septal defect and valvular pulmonary stenosis was found. Cardiac magnetic resonance study confirmed the findings. This singular case report of NCCM highlights the importance of clinical awareness of this rare abnormality, its varied presentation and associated cardiac anomalies. The article revisits NCCM and focuses on the practical issues for a proper echodiagnosis.

Echocardiography in the diagnosis of apical non-compaction associated with congenital heart diseases

BACKGROUND

Isolated left ventricular non-compaction has been reported extensively. However, apical non-compaction of both ventricles and the interventricular septum (IVS) is not often reported in the literature. The objective of our study is to evolve the echocardiographic diagnostic criteria and to assess the types and impact of the associated lesions in "apical non-compaction".

METHODS AND RESULTS

Seventy consecutive cases that fulfilled standard echocardiographic criteria for non-compaction of the left ventricle and, in addition, N/C ratio of >3 for the right ventricle and apical IVS formed the material. The age of patients ranged from 3 days to 35 years, with 37 males and 33 females. The associated lesions were present in all 70 cases: 62 had acyanotic (88.6 %) and 8 had cyanotic congenital heart diseases (11.4 %). Of the 70 cases, 18 had pump failure (25.7 %): 8 cases had left ventricular dysfunction, 7 had right ventricular dysfunction, and 3 had biventricular dysfunction; 33 (47.1 %) had pulmonary hypertension, 2 (2.9 %) had thrombus, and 1 (1.4 %) had tachyarrhythmia. Pump failure was worsened by volume overload in 33.9 % and by pressure overload in 8.1 % of cases. Some very rare lesions were detected. All 70 cases had Swiss cheese appearance of the apical half of the IVS, looking like the delta of a river.

CONCLUSION

All of the apical non-compaction syndrome cases had associated lesions, mostly acyanotic congenital heart disease with volume overload, rather than obstructive lesions. Transthoracic echocardiography plays an important role in the diagnosis of apical non-compaction syndrome and associated lesions that worsen the pump failure.

Left Ventricular Non-Compaction Syndrome Misdiagnosed as Dilated Cardiomyopathy on Several Occasions, Presenting With Recurrent Stroke

A 57-year-old African American female with a history of ischemic cardiomyopathy and a recent stroke with no residual deficits presented with apraxia and confusion. Non-contrast CT scan of the head revealed multiple embolic strokes in both cerebral hemispheres. Transthoracic echocardiography raised the suspicion for increased trabecular meshwork in the left ventricle. Cardiac MRI confirmed the findings of isolated left ventricular non-compaction (LVNC) syndrome. A contrast-enhanced transesophageal echocardiogram demonstrated the characteristic features of this unusual disease with the additional demonstration of contrast filling the trabecular meshwork. Interestingly multiple transthoracic echocardiograms in the past had failed to identify myocardial non-compaction. The patient was started on warfarin for prophylactic anticoagulation and an implantable defibrillator was placed to lower the risk of sudden death. LVNC is a rare type of genetic cardiomyopathy characterized by excessively prominent trabeculations and deep inter-trabecular recesses in the ventricle wall. Non-compaction remains frequently overlooked even by experienced echocardiographers. Failure to diagnosis may lead to insufficient treatment since it is often associated with a risk of thromboembolism, life-threatening arrhythmias and sudden death. Furthermore, because of the familial association described with ventricular non-compaction, screening of first relatives with echocardiography is recommended.

New molecular genetic tests in the diagnosis of heart disease

With the increasing use of next-generation sequencing applications, there has been an increase in identification of genetic causes of cardiac disease. This technology has also enabled the transition of these genes into the clinical setting and the rapid growth of large gene tests for the diagnosis of heart disorders. The ability to combine tests to include similar, but distinct, diseases has shown that many genes can be responsible for a wide variety of both syndromic and nonsyndromic disorders. This article discusses the current state of molecular genetic diagnosis for cardiac disorders, focusing on diseases with mendelian inheritance.

Genetics of inherited cardiomyopathies

Cardiomyopathies are the most common disorders resulting in heart failure, with dilated cardiomyopathy being responsible for the majority of cases. Other forms of cardiomyopathy, especially hypertrophic forms, are also important causes of heart failure. The mortality rate due to cardiomyopathy in the USA is over 10,000 deaths per year, and the costs associated with heart failure are approximately 200 million US dollars per year in the USA alone. Over the past few years, breakthroughs have occurred in understanding the basic mechanisms of these disorders, potentially enabling clinicians to devise improved diagnostic strategies and therapies. As at least 30 to 40% of cases are inherited, it is now imperative that the genetic basis for these disorders is clearly recognized by caregivers and scientists. However, it has also become clear that these diseases are genetically highly heterogeneous, with multiple genes identified for each of the major forms of cardiomyopathy, and most patients having private mutations. These data suggest that the genetic diagnosis of most patients with cardiomyopathy will be impractical with current technologies. However, there are a few exceptions, such as patients with X-linked cardiomyopathies, with or without the concomitant abnormalities of cyclic neutropenia and 3-methylglutaconic aciduria, or patients with cardiomyopathy associated with conduction disease: these appear to be associated with mutations in a small subset of genes, and can be investigated by certified diagnostic laboratories. This review will summarize current knowledge of the genetics of inherited cardiomyopathies and how findings from research laboratories may be translated into the diagnostic laboratory.

Magnetic resonance assessment of prevalence and correlates of right ventricular abnormalities in isolated left ventricular noncompaction

The aim of the present study was to evaluate the prevalence and correlates of right ventricular (RV) noncompaction (RVNC), RV systolic dysfunction, and RV myocardial fibrosis in patients with isolated left ventricular (LV) noncompaction (LVNC). For this purpose, cine and contrast-enhanced cardiac magnetic resonance imaging (MRI) was used. A total of 56 consecutive patients with isolated LVNC were included in the study. The diagnosis of isolated LVNC was based on the presence of standard cardiac MRI and clinical criteria. For each patient, cine and contrast-enhanced cardiac MR images were analyzed to evaluate the prevalence and correlates of RVNC, RV dysfunction, and late gadolinium enhancement (a surrogate of myocardial fibrosis) involving the RV. Mean age of the patient population was 45 ± 19 years; 35 patients (63%) were men. RVNC was observed in 5 patients (9%). Impaired RV systolic function was observed in 9 patients (16%). Late gadolinium enhancement was not observed in any RV segment. No association was found between wall motion abnormalities and noncompaction at RV segmental level (φ coefficient 0.041, p = 0.26). At multivariate analysis, LV ejection fraction was the only variable independently related to RV ejection fraction (β = 0.62, p <0.001). In conclusion, RV systolic dysfunction is present in a non-negligible proportion of patients with isolated LVNC; LV systolic function is the only variable independently related to RV systolic function.

Biventricular non-compaction with predominant right ventricular involvement, reduced left ventricular systolic and diastolic function, and pulmonary hypertension in a Hispanic male

Patient: Male, 22

Final Diagnosis: Cardiomyopathy

Symptoms: Shortness of breath • dispnoea • chest discomfort

Medication: —

Clinical Procedure: Echocardiogram • cardiac MRI

Specialty: Cardiology

Pediatric cardiomyopathies: causes, epidemiology, clinical course, preventive strategies and therapies

Pediatric cardiomyopathies, which are rare but serious disorders of the muscles of the heart, affect at least one in every 100,000 children in the USA. Approximately 40% of children with symptomatic cardiomyopathy undergo heart transplantation or die from cardiac complications within 2 years. However, a significant number of children suffering from cardiomyopathy are surviving into adulthood, making it an important chronic illness for both pediatric and adult clinicians to understand. The natural history, risk factors, prevalence and incidence of this pediatric condition were not fully understood before the 1990s. Questions regarding optimal diagnostic, prognostic and treatment methods remain. Children require long-term follow-up into adulthood in order to identify the factors associated with best clinical practice including diagnostic approaches, as well as optimal treatment approaches. In this article, we comprehensively review current research on various presentations of this disease, along with current knowledge about their causes, treatments and clinical outcomes.

Left ventricular noncompaction (LVNC) and low mitochondrial membrane potential are specific for Barth syndrome

Barth syndrome (BTHS) is an X-linked mitochondrial defect characterised by dilated cardiomyopathy, neutropaenia and 3-methylglutaconic aciduria (3-MGCA). We report on two affected brothers with c.646G > A (p.G216R) TAZ gene mutations. The pathogenicity of the mutation, as indicated by the structure-based functional analyses, was further confirmed by abnormal monolysocardiolipin/cardiolipin ratio in dry blood spots of the patients as well as the occurrence of this mutation in another reported BTHS proband. In both brothers, 2D-echocardiography revealed some features of left ventricular noncompaction (LVNC) despite marked differences in the course of the disease; the eldest child presented with isolated cardiomyopathy from late infancy, whereas the youngest showed severe lactic acidosis without 3-MGCA during the neonatal period. An examination of the patients' fibroblast cultures revealed that extremely low mitochondrial membrane potentials (mtΔΨ about 50 % of the control value) dominated other unspecific mitochondrial changes detected (respiratory chain dysfunction, abnormal ROS production and depressed antioxidant defense). 1) Our studies confirm generalised mitochondrial dysfunction in the skeletal muscle and the fibroblasts of BTHS patients, especially a severe impairment in the mtΔΨ and the inhibition of complex V activity. It can be hypothesised that impaired mtΔΨ and mitochondrial ATP synthase activity may contribute to episodes of cardiac arrhythmia that occurred unexpectedly in BTHS patients. 2) Severe lactic acidosis without 3-methylglutaconic aciduria in male neonates as well as an asymptomatic mild left ventricular noncompaction may characterise the ranges of natural history of Barth syndrome.