Identification of a rare congenital anomaly of the myocardium by two-dimensional echocardiography: persistence of isolated myocardial sinusoids

What happened to the left ventricular non-compaction cardiomyopathy? to be or not to be: This is the question

For several years, left ventricular non-compaction (LVNC) was considered as a true cardiomyopathy and several definitions have followed one another. Particularly, LVNC was characterized by prominent left ventricular trabeculae separated from deep intertrabecular recesses. Several echocardiographic criteria and cardiac magnetic resonance imaging (CMR) criteria have been used to diagnose LVNC, leading to overestimate the diagnosis of LVNC in patients with other diseases and/or physiological conditions. Left ventricular hypertrabeculation (LVH) can be present in several cardiac diseases and physiological conditions: heart failure with reduced ejection fraction, thalassemia and other hematological diseases, pregnancy, athlete's heart. Thus, the presence of LVH does not necessarily indicate the presence of an LVNC. In addition, the great heterogeneity of clinical manifestations has raised concerns regarding the existence of a true LVNC as a cardiomyopathy. In fact, LVNC ranges from genetic to acquired and even transient conditions, isolated forms or forms associated with other cardiomyopathies, congenital heart diseases or syndromes with a very different prognosis. Thus, considering LVH as a manifestation of various diseases and physiological conditions, the recent 2023 ESC guidelines on cardiomyopathies did not include LVNC among cardiomyopathies, but they suggested using the term "LVH" rather than LVNC, to describe this phenotype especially when it is transient or of adult-onset. In this review, we aimed to make an excursion on LVNC, from its initial description to the present day, to understand why current guidelines decided to consider LVH as a phenotypic trait rather than a distinct cardiomyopathy.

Myocardial Mechanics and Associated Valvular and Vascular Abnormalities in Left Ventricular Noncompaction Cardiomyopathy

Left ventricular (LV) non-compaction (LVNC) is a rare genetic cardiomyopathy due to abnormal intra-uterine arrest of compaction of the myocardial fibers during endomyocardial embryogenesis. Due to the partial or complete absence of LV compaction, the structure of the LV wall shows characteristic abnormalities, including a thin compacted epicardium and a thick non-compacted endocardium with prominent trabeculations and deep intertrabecular recesses. LVNC is frequently associated with chronic heart failure, life-threatening ventricular arrhythmias, and systemic embolic events. According to recent findings, in the presence of LVNC, dysfunctional LV proved to be associated with left atrial volumetric and functional abnormalities and consequential dilated and functionally impaired mitral annulus, partly explaining the higher prevalence of regurgitation. Although the non-compaction process morphologically affects only the LV, signs of remodeling of the right heart were also detected. Moreover, dilation and stiffening of the aorta were present. The aim of the present detailed review was to summarize findings regarding changes in cardiac mechanics, valvular abnormalities, and vascular remodeling detected in patients with LVNC.

The Rare Condition of Left Ventricular Non-Compaction and Reverse Remodeling

Left ventricular non-compaction (LVNC) is a rare disease defined by morphological criteria, consisting of a two-layered ventricular wall, a thin compacted epicardial layer, and a thick hyper-trabeculated myocardium layer with deep recesses. Controversies still exist regarding whether it is a distinct cardiomyopathy (CM) or a morphological trait of different conditions. This review analyzes data from the literature regarding diagnosis, treatment, and prognosis in LVNC and the current knowledge regarding reverse remodeling in this form of CM. Furthermore, for clear exemplification, we report a case of a 41-year-old male who presented symptoms of heart failure (HF). LVNC CM was suspected at the time of transthoracic echocardiography and was subsequently confirmed upon cardiac magnetic resonance imaging. A favorable remodeling and clinical outcome were registered after including an angiotensin receptor neprilysin inhibitor in the HF treatment. LVNC remains a heterogenous CM, and although a favorable outcome is not commonly encountered, some patients respond well to therapy.

A case of fetal isolated ventricular noncompaction with TNNT2 gene mutation and literature review

BACKGROUND

Ventricular noncompaction (VNC) is a cardiomyopathy characterized by overdeveloped ventricular trabeculaes and deep recess, which has been rarely reported.

CASE PRESENTATION

A 29-year-old Chinese pregnant woman with no obvious fetal abnormality in regular prenatal examination during first and second trimester. However, at 32 weeks of gestation, both obstetric growth scan and fetal echocardiogram revealed an enlarged heart with grid-like changes at the apical region. Eventually, the genetic and autopsy findings indicated the deceased infant with VNC.

CONCLUSION

Isolated VNC could be detected prenatally, even during the late pregnancy. Fetuses suspected of VNC should be offered genetic tests.

Established and emerging roles for ultrasound enhancing agents (contrast echocardiography)

The ability to opacify the left ventricle and delineate the endocardium after intravenous injection of microbubble ultrasound enhancing agents is of established value to quantify volumes and function in suboptimal unenhanced images, particularly in stress echocardiograms. However, applications other than quantitation of left ventricle structure and function exist for contrast enhanced left ventricular opacification. Contrast agents enable recording of Doppler velocity signals in patients with poor ultrasound transmission, providing estimates of aortic stenosis gradient and pulmonary artery pressures. Contrast echo is of value in detecting apical hypertrophic cardiomyopathy and accompanying apical aneurysms. Most importantly, ultrasound enhancing agents can identify apical and left atrial masses when they cannot be visualized in unenhanced images, and can distinguish thrombi from tumors by visualizing the vascularity inherent in tumors. Contrast agents distinguish trabecular from compacted myocardium in noncompaction syndrome, and hypertrabeculation with other abnormal conditions. A major potential application of ultrasound enhancing agents is myocardial opacification, which can assist in identifying nonviable myocardium. Also, the delayed reappearance of myocardial perfusion after microbubble destruction identifies impaired contrary flow and can diagnose coronary stenosis. Innovative applications of ultrasound contrast agents currently under investigation, include visualizing the vaso vasorum to identify plaques and assess their vulnerability, and theranostic agents to deliver drugs and biologists and to assist in sonothrombolysis. It is anticipated that the role of ultrasound contrast agents will continue to increase in the future.

Left Ventricular Non-Compaction Cardiomyopathy-Still More Questions than Answers

Left ventricular non-compaction (LVNC) describes the phenotypical phenomena characterized by the presence of excessive trabeculation of the left ventricle which forms a deep recess filled with blood. Considering the lack of a uniform definition of LVNC as well as the "golden standard" it is difficult to estimate the actual incidence of the disease, however, seems to be overdiagnosed, due to unspecific diagnostic criteria. The non-compacted myocardium may appear both as a disease representation or variant of the norm or as an adaptive phenomenon. This article covers different approaches to incidence, pathogenesis, diagnostics, and treatment of LVNC as well as recommendations for patients during follow-up.

Tricuspid Annular Abnormalities in Isolated Left Ventricular Non-compaction—Insights From the Three-dimensional Speckle-Tracking Echocardiographic MAGYAR-Path Study

Introduction

Prominent trabecular left ventricular (LV) meshwork and deep intertrabecular LV recesses are featuring LV non-compaction (LVNC). The aim of this study was to evaluate tricuspid annular (TA) morphological and functional abnormalities by three-dimensional speckle-tracking echocardiography (3DSTE) in patients with LVNC without right ventricular (RV) involvement.

Materials and Methods

This study consisted of 21 patients with isolated LVNC, from which 6 cases were excluded due to inferior image quality. The remaining patient group consisted of 15 subjects with a mean age of 52.1 ± 11.4 years (9 males). LVNC was defined according to the Jenni's criteria. Their results were compared to 21 age- and gender-matched healthy controls (mean age: 52.4 ± 3.9 years, 14 males). Complete routine 2-dimensional Doppler echocardiographic examination was performed in all the patients with isolated LVNC and healthy controls. End-systolic and end-diastolic TA dimensions were assessed on selected planes derived from full-volume 3D echocardiographic datasets during 3DSTE.

Results

Patients with isolated LVNC showed significantly dilated end-systolic and end-diastolic TA diameter and area, which were accompanied with preserved TA functional properties and associated with right atrial (RA) volumes. TA plane systolic excursion (TAPSE) showed mild correlations with TA fractional area change (TAFAC) and TA fractional shortening (TAFS). No correlations could be demonstrated between TAPSE and TA morphological features. Extent of LVNC did not correlate with any echocardiographic parameters.

Conclusion

TA is dilated with preserved sphincter-like function in patients with isolated LVNC. Longitudinal (TAPSE) and sphincter-like (TAFAC and TAFS) TA movements correlate with each other. TA dilation is associated with an increased RA volumes respecting cardiac cycle.

MRI aspects of left ventricular non compaction (LVNC): About 3 cases from Sub-Saharan Africa and review of the literature

Left ventricular non compaction (LVNC) is a relatively rare variety of cardiomyopathy of genetic origin. We report three cases of LVNC diagnosed on cardiac magnetic resonance imaging (MRI) in Abidjan in patients aged 42, 46 and 60 years, referred for suspected LVNC on echocardiography. We used a 1.5 T MRI and performed the following sequences: black blood and white blood, LV minor axis, LV major axis, 4 cavities, and T1 SPIR Gadolinium (early and late enhancement at 10 minutes). MRI made the diagnosis of LVNC based on a double-layered myocardium, the inner (endocardium) non compacted, fibrillar thickened and the outer (epicardium) compacted thin with a non compacted to compacted myocardium ratio greater than 2.3, making the formal diagnosis. Cardiac MRI is an excellent diagnostic tool for LVNC. Its recent use in Africa should be common in the management of this cardiomyopathy.

Hypertrabeculation; a phenotype with Heterogeneous etiology

Left ventricular hypertrabeculation (LVHT) is a phenotype with multiple etiologies and variable clinical presentation and significance. It is characterized by a 2-layer myocardium with an enlarged trabecular layer and a thinner compacted layer. The prevalence has been increasing due to advances in cardiac imaging. Initial attention was focused on the congenital noncompaction syndrome, and the presence of LVHT was always attributed to this etiology. However, due to the lack of consensus diagnostic criteria, LVHT has now been reported in a broad spectrum of cardiomyopathies, congenital heart diseases, monogenetic disorders, neuromuscular diseases, and even healthy individuals. LVHT is often associated with systolic dysfunction, arrhythmias, and thromboembolic events. Given the etiologic heterogeneity, the prognosis and outcomes are primarily determined by comorbidities, and treatment is dictated by known guidelines. We present hypertrabeculation (HT) as a phenotype and discuss the varied landscape in the classification, etiology, diagnosis, and management of the condition.

Correlation between pathoanatomic findings, imaging modalities, and genetic findings in patients with left ventricular hypertrabeculation/noncompaction

Introduction: Left ventricular hypertrabeculation, also named 'noncompaction' (LVHT) is a cardiac abnormality which is detected by pathoanatomic investigation or during cardiac surgery. Imaging techniques visualize LVHT by ventriculography, echocardiography, cardiac magnetic resonance imaging (CMRI) and computed tomography (CT).Areas covered: We aimed to assess 1) how often the definition of LVHT was validated against a criterion standard, 2) if inter- and intra-observer agreement was assessed, and 3) how often LVHT was associated with genetic diseases. A literature search disclosed 58 cases whose hearts were investigated pathoanatomically and by ≥1 imaging technique. Echocardiography was most frequently (95%) compared with pathoanatomy, followed by cMRI (31%), ventriculography (7%) and CT (5%). Intra- and inter-observer agreement was more frequently assessed for cMRI definitions and yielded more consistent results than for echocardiographic definitions. Since genetic findings were only reported from 4 of the 58 cases, no association with imaging findings could be carried out.Expert opinion: Correlation between pathoanatomic investigations with imaging techniques will hopefully contribute to reliable and uniformly accepted definitions of LVHT. Most probably, the echocardiographic definition of LVHT will be a synthesis of the currently used definitions, integrating short axis and four-chamber views. A refinement of cMRI definitions, considering pathoanatomic and echocardiographic investigations, seems necessary to avoid overdiagnosis.

Noncompaction Cardiomyopathy-History and Current Knowledge for Clinical Practice

Noncompaction cardiomyopathy (NCCM) has gained increasing attention over the past twenty years, but in daily clinical practice NCCM is still rarely considered. So far, there are no generally accepted diagnostic criteria and some groups even refuse to acknowledge it as a distinct cardiomyopathy, and grade it as a variant of dilated cardiomyopathy or a morphological trait of different conditions. A wide range of morphological variants have been observed even in healthy persons, suggesting that pathologic remodeling and physiologic adaptation have to be differentiated in cases where this spongy myocardial pattern is encountered. Recent studies have uncovered numerous new pathogenetic and pathophysiologic aspects of this elusive cardiomyopathy, but a current summary and evaluation of clinical patient management are still lacking, especially to avoid mis- and overdiagnosis. Addressing this issue, this article provides an up to date overview of the current knowledge in classification, pathogenesis, pathophysiology, epidemiology, clinical manifestations and diagnostic evaluation, including genetic testing, treatment and prognosis of NCCM.

State-of-the art review: Noncompaction cardiomyopathy in pediatric patients

Noncompaction cardiomyopathy (NCCM) is a disease characterized by hypertrabeculation, commonly hypothesized due to an arrest in compaction during fetal development. In 2006, NCCM was classified as a distinct form of cardiomyopathy (CMP) by the American Heart Association. NCCM in childhood is more frequently familial than when diagnosed in adulthood and is associated with other congenital heart diseases (CHDs), other genetic CMPs, and neuromuscular diseases (NMDs). It is yet a rare cardiac diseased with an estimated incidence of 0.12 per 100.000 in children up to 10 years of age. Diagnosing NCCM can be challenging due to non-uniform diagnostic criteria, unawareness, presumed other CMPs, and presence of CHD. Therefore, the incidence of NCCM in children might be an underestimation. Nonetheless, NCCM is the third most common cardiomyopathy in childhood and is associated with heart failure, arrhythmias, and/or thromboembolic events. This state-of-the-art review provides an overview on pediatric NCCM. In addition, we discuss the natural history, epidemiology, genetics, clinical presentation, outcome, and therapeutic options of NCCM in pediatric patients, including fetuses, neonates, infants, and children. Furthermore, we provide a simple classification of different forms of the disease. Finally, the differences between the pediatric population and the adult population are described.

Left Ventricular Noncompaction: Diagnostic Approach, Prognostic Evaluation, and Management Strategies

Left ventricular noncompaction cardiomyopathy is a heart disease with relevant potential complications including heart failure, life-threatening arrhythmias, and embolic events. In order to prevent adverse outcomes, it is crucial to appropriately recognize and manage this cardiomyopathy. In this paper, we report the main clinical presentations and imaging modalities used for diagnosis, including echocardiography and magnetic resonance imaging. We highlight the role of a comprehensive functional cardiac evaluation and the possible prognostic implications of both systolic and diastolic dysfunction. Furthermore, we summarize clinical factors and imaging findings which have prognostic significance. Finally, we discuss the main management strategies based on phenotypic expressions which are aimed at treating symptoms and preventing complications.

[Clinical manifestations and gene mutation analysis of children with noncompaction of the ventricular myocardium: an analysis of 6 cases]

This article summarizes and analyzes the clinical features and gene mutation characteristics of children with noncompaction of the ventricular myocardium (NVM). For the 6 children with NVM (4 boys and 2 girls), the age of onset ranged from 3 months to 12 years. Of the 6 children, 5 had arrhythmia, 3 had cardiac insufficiency, 1 had poor mental state, and 1 had chest distress and sighing. NVM-related gene mutations were detected in 4 children, among whom 2 had MYH7 gene mutation, 1 had PRDM16 gene mutation, and 1 had mutations in the ACTN2 and TNNT2 genes. Four children had improvement in cardiac function. The two children with no significant improvement in cardiac function had a younger age of onset, a greater reduction in systolic function on echocardiography, and greater increases in myocardial enzyme and N-terminal pro-brain natriuretic peptide. It is concluded that for children with the initial symptoms of chest distress, sighing, arrhythmia, enlarged heart shadow, and increased myocardial enzyme, echocardiography and cardiac magnetic resonance are recommended for the diagnosis of NVM. NVM can have various genetic mutations.

Left Ventricular Noncompaction Is More Prevalent in Ventricular Septal Defect Than Other Congenital Heart Defects: A Morphological Study

Left ventricular noncompaction (LVNC) is a condition characterized by prominent ventricular trabeculae and deep intertrabecular recesses and has been described as a possible substrate for arrhythmias, thromboembolism, and heart failure. Herein, we explored the prevalence of LVNC morphology among hearts with congenital heart defects (CHD). We examined 259 postnatal hearts with one of the following CHD: isolated ventricular septal defect (VSD); isolated atrial septal defect (ASD); atrioventricular septal defect (AVSD); transposition of the great arteries (TGA); isomerism of the atrial appendages (ISOM); Ebstein’s malformation (EB); Tetralogy of Fallot (TF). Eleven hearts from children who died of non-cardiovascular causes were used as controls. The thickness of the compacted and non-compacted left ventricular myocardial wall was determined and the specimens classified as presenting or not LVNC morphology according to three criteria, as proposed by Chin, Jenni, and Petersen. Normal hearts did not present LVNC, but the CHD group presented different percentages of LVNC in at least one diagnostic criterium. The prevalence of LVNC was respectively, according to Chin’s, Jenni´s and Petersen´s methods: for VSD—54.2%, 35.4%, and 12.5%; ASD—8.3%, 8.3%, and 8.3%; AVSD—2.9%, 2.9%, and 0.0%; TGA—22.6%, 17%, and 5.7%; ISOM—7.1%, 7.1%, and 7.1%; EB—28.6%, 9.5%, and 0.0%; TF—5.9%. 2.9%, and 2.9%. VSD hearts showed a significantly greater risk of presenting LVNC when compared to controls (Chin and Jenni criteria). No other CHD presented similar risk. Current results show some agreement with previous studies, such as LVNC morphology being more prevalent in VSDs. Nonetheless, this is a morphological study and cannot be correlated with symptoms or severity of the CHD.

Characterization of Left Ventricular Non-Compaction Cardiomyopathy

Left ventricle non-compaction cardiomyopathy (LVNC) has gained great interest in recent years, being one of the most controversial cardiomyopathies. There are several open debates, not only about its genetic heterogeneity, or about the possibility to be an acquired cardiomyopathy, but also about its possible overdiagnosis based on imaging techniques. In order to better understand this entity, we identified 38 LVNC patients diagnosed by cardiac MRI (CMRI) or anatomopathological study that could underwent NGS-sequencing and clinical study. Anatomopathological exam was performed in eight available LVNC hearts. The genetic yield was 34.2%. Patients with negative genetic testing had better left ventricular ejection fraction (LVEF) or it showed a tendency to improve in follow-up, and a possible trigger factor for LVNC was identified in 1/3 of them. Nonetheless, cerebrovascular accidents occurred in similar proportions in both groups. We conclude that in LVNC there seem to be different ways to achieve the same final phenotype. Genetic testing has a good genetic yield and provides valuable information. LVNC without an underlying genetic cause may have a better prognosis in terms of LVEF evolution. However, anticoagulation to prevent cerebrovascular accident (CVA) should be carefully evaluated in all patients. Larger series with pathologic examination are needed to help better understand this entity.

Left Ventricle Non-Compaction Cardiomyopathy Admitted With Multiorgan Failure: A Case Report

Left ventricle non-compaction (LVNC) is a rare congenital cardiomyopathy characterized by thickened myocardium due to an arrest of the normal compaction of the embryonic sponge-like meshwork of myocardial fibers. 

We present a 40-year-old man with no known systemic illnesses admitted with cardiogenic shock and multiorgan failure. Echocardiogram revealed severe enlargement of all four chambers with left ventricular ejection fraction (LVEF) <10%. Cardiac magnetic resonance imaging (CMR) showed hypertrabecular left ventricular myocardium with a ratio of non-compact to compact myocardium of 2.3, diffuse myocardial thinning, and a 16-mm left ventricular thrombus. These findings were compatible with LVNC. The patient was treated with intravenous inotropic vasopressors for cardiogenic shock and enoxaparin as bridging for warfarin to a goal of INR 2.0-3.0. Due to refractory heart failure (HF) and dependency on inotropic support, the patient was placed on the waiting list for a heart transplant. Unfortunately, 27 days after admission, he presented ventricular tachycardia arrest and did not respond to aggressive advanced cardiac life support measures. 

A high index of suspicion is required for the early diagnosis, which in turn allows the physician to prevent complications of this condition. There is no specific therapy, so management is directed toward the clinical manifestations including HF, arrhythmias, and systemic embolic events. Heart transplantation is the only definitive treatment.

Left Ventricular Noncompaction with Multiple Thrombi in Apical Aneurysm

A 44-year-old man was admitted to our hospital due to heart failure. Transthoracic echocardiography demonstrated global hypokinesis with an ejection fraction of 25%, prominent trabeculation and deep intertrabecular recesses, and apical aneurysm with multiple thrombi (10×13 mm in the inferior wall, 15×8 mm in the anterior wall). Cardiac magnetic resonance imaging showed an increased ratio of noncompacted (NC) to compacted (C) myocardium (NC/C ratio >2.3) and apical aneurysm. Coronary angiography revealed no significant stenosis. He was therefore diagnosed with left ventricular noncompaction complicated by apical aneurysm. Four weeks after starting anticoagulation, the multiple apical thrombi disappeared without clinical signs of embolism.

Screening for Fabry disease in patients with left ventricular noncompaction

INTRODUCTION AND AIM

It is unclear whether left ventricular noncompaction (LVNC) is a distinct cardiomyopathy or a morphologic manifestation of different cardiomyopathies. We previously reported a case of LVNC in a Fabry disease (FD) patient, but it remains to be clarified whether LVNC is a cardiac manifestation of FD, a coincidental finding or an overdiagnosis, which has major therapeutic implications. This study aims to determine the prevalence of FD among patients with LVNC.

METHODS

We performed a retrospective study including all patients diagnosed with LVNC in eight hospital centers. Diagnosis of LVNC was based on at least one echocardiographic or cardiac magnetic resonance criterion. FD screening was performed by combined enzyme and genetic testing.

RESULTS

The study included 78 patients diagnosed with LVNC based on the Jenni (84.6%), Stöllberger (46.2%), Chin (21.8%), Petersen (83.8%) and Jacquier (16.2%) criteria. Left ventricular systolic dysfunction was present in 48.7%. Heart failure was found in 60.3%, ventricular dysrhythmias in 21.6% and embolic events in 11.5%. FD screening found no additional cases among patients with LVNC, besides the previously described case.

CONCLUSION

No additional FD cases were found among patients with LVNC, which argues against the hypothesis that LVNC is a cardiac manifestation of FD.

Prenatal ultrasound diagnosis of fetal isolated right ventricular noncompaction with pulmonary artery sling: A rare case report

Noncompaction of the ventricular myocardium (NVM), also known as spongy myocardium, is a rare type of cardiomyopathy that has a serious impact on fetuses, children, and adults. NVM mainly affects the left ventricle, as isolated right ventricular noncompaction (IRVNC) is rare. Pulmonary artery sling (PAS) is a rare condition in which the left pulmonary artery anomalously originates from a normal positioned right pulmonary artery, and only a few studies have reported PAS in fetuses. Fetal IRVNC complicated with PAS has not been reported yet. Here, we report a case of IRVNC complicated with PAS that was diagnosed prenatally at 30 weeks gestation and confirmed by postpartum anatomy and pathology.

Right ventricle and outcome in left ventricular non-compaction cardiomyopathy

BACKGROUND

The risk of adverse events in patients with left ventricular non-compaction cardiomyopathy (LVNC) is substantial. Information on prognostic factors, however, is limited. This study was designed to assess the prognostic value of right ventricular (RV) size and function in LVNC patients.

METHODS

Cox regression analyses were used to determine the association of indexed RV end-diastolic area (RV-EDAI), indexed end-diastolic diameter (RV-EDDI), fractional area change (FAC), and tricuspid annular systolic excursion (TAPSE) with the occurrence of death or heart transplantation (composite endpoint).

RESULTS

Out of 127 patients (53.2 ± 17.8 years; 61% males, median follow-up time was 7.7 years), 17 patients reached the endpoint. In a univariate analysis, RV-EDAI was the strongest predictor of outcome [HR 1.48 (1.24-1.77) per cm²/m²; p < 0.0001]. FAC was predictive as well [HR 1.44 (1.16-1.83) per 5% decrease; p = 0.0009], while TAPSE was not (p=ns). RV-EDAI remained an independent predictor in a bivariable analysis with indexed left ventricular ED volume [HR 1.41 (1.18-1.70) per cm²/m²; p = 0.0002], while analysis of FAC and left ventricular ejection fraction demonstrated that FAC was not independent [HR 1.20 (0.98-1.52); per 5% decrease; p = 0.0721]. RV-EDAI 11.5 cm²/m² was the best cut-off value for separating patients in terms of outcome. Patients with RV-EDAI >11.5 cm²/m² had a survival rate of 18.5% over 12 years as compared to 93.8% in patients with RV-EDAI <11.5 cm²/m² (p < 0.0001).

CONCLUSION

Increased end-diastolic RV size and decreased systolic RV function are predictors of adverse outcome in patients with LVNC. Patients with RV-EDAI >11.5 cm²/m² exhibit a significantly lower survival than those <11.5 cm²/m².

Left ventricular noncompaction and orthodromic atrioventricular tachycardia observed in a patient with neurofibromatosis type 1

Isolated left ventricular noncompaction (LVNC) was described for the first time in 1984. It is a rare congenital disease, characterized by prominent trabecular meshwork pattern and deep intertrabecular recesses, communicated with the left ventricular chamber. Clinical presentation varies from asymptomatic patients, to those developing supraventricular and ventricular arrhythmias, thromboembolism, heart failure and sudden cardiac death. We present an unusual case, where the patient with Neurofibromatosis type 1 presented with a wide complex orthodromic atrioventricular reentrant tachycardia (AVRT) and a diagnosis of left posterior paraseptal accessory pathway in association with LVNC.

Understanding left ventricular hypertrabeculation/noncompaction: pathomorphologic findings and prognostic impact of neuromuscular comorbidities

INTRODUCTION

When >3 trabeculations associated with interventricular recesses are found, this is termed 'left ventricular hypertrabeculation/noncompaction' (LVHT). Cardiac-imaging methods detect LVHT in all ages, isolated or associated with extracardiac, especially neuromuscular disorders (NMDs). Many issues about LVHT are unclear. The review gives an update about pathomorphologic findings in patients >14 years and the role of NMDs in LVHT. Areas covered: A PubMed-search for the terms "noncompaction" or "non-compaction" or "hypertrabeculation" AND "autopsy" or 'biopsy' or 'ultrastructure' or 'electron microscopy' AND 'neuromuscular' or 'myopathy' or 'neuropathy' was carried out from 1985 to July 2018. Expert commentary: Macroanatomic (n = 65), histopathologic (n = 59) and ultrastructural (n = 7) reports were found. A comparison with echocardiography was described in 45 cases. Measurements of non-compacted and compacted layer were only given from hearts investigated in short-axis cuts after formaldehyde-fixation. Endocardial, subendocardial and interstitial fibrosis were frequent findings. When LVHT-patients were systematically investigated, a NMD was found in 80%, most frequently mitochondrial disorders, Barth syndrome, zaspopathy, and myotonic dystrophy type 1. LVHT does not seem to be a special type of cardiac involvement of NMDs. NMDs affect prognosis in LVHT as well as LVHT affects prognosis in patients with Duchenne muscular dystrophy.

Heart Failure Secondary to Left Ventricular Non-compaction Cardiomyopathy in a 26-Year-Old Male

Left ventricular non-compaction (LVNC) is a genetic anomaly where the ventricular wall is replaced by thick ventricular trabeculations with deep intertrabecular recesses held together by a thin compacted layer. We present a case of a 26-year-old male who presented with dyspnea on exertion and edema in his legs for the last one week.

De novo left ventricular non-compaction accompanied by severe mitral valve failure in a young pregnant

De novo left ventricular non-compaction is a rare pathology in the peripartum period. To the best of our knowledge, pregnancy-induced cardiomyopathy accompanied by severe mitral valve insufficiency requiring surgery during pregnancy has not been previously reported. Herein, we report the first postpartum case of de novo left ventricular non-compaction who underwent mitral valve repair.

Non compaction cardiomyopathy: Review of a controversial entity

Non-compaction cardiomyopathy is a heterogeneous and complex entity concerning which there are still many doubts to be resolved. While the American Heart Association includes it among genetic cardiomyopathies, the European Society of Cardiology treats it as an unclassified cardiomyopathy. It may present in a sporadic or familial form, isolated or associated with other heart diseases, affecting only the left ventricle or both and can sometimes appear as a mixed phenotype in patients with other cardiomyopathies. Different forms of clinical presentation are also associated with its different morphological manifestations, and even non-compaction of the left ventricle may be triggered by other physiological or pathological processes. The purpose of this review is an update of this entity and its controversies.

Left ventricular non-compaction cardiomyopathy with coronary artery anomaly complicated by ventricular tachycardia

Background

Non-compaction cardiomyopathy (NCCM) is characterized by prominent trabeculations, deep intertrabecular recesses, and a thick non-compacted endocardial myocardium. Prevalence in the general population remains unclear, but echocardiography series report 0.05%. During fetal development muscle fibers and trabeculae should compact into a solid myocardium and when this fails, NCCM occurs. The condition is genetic, even though acquired forms have been described. Worsening myocardial dysfunction may lead to heart failure and/or arrhythmias.

Case presentation

A 52-year-old man presented with heart failure. The diagnosis of NCCM was confirmed after echocardiography and cardiac magnetic resonance tomography. Interestingly, the angiogram revealed a coronary anomaly, in which the circumflex artery rose aberrantly from the right coronary artery. Due to left ventricular ejection fraction being less than 35% despite optimal pharmacological therapy, an implantable cardioverter defibrillator (ICD) was implanted and four years later a ventricular tachycardia was terminated by antitachycardia pacing.

Conclusion

We describe a case of NCCM with a concomitant coronary anomaly, in which systolic myocardial dysfunction developed. The ICD subsequently terminated a life-threatening ventricular arrhythmia, which supports risk stratification based on low ejection fraction and possibly coronary anomaly.

Cardiomyopathies Due to Left Ventricular Noncompaction, Mitochondrial and Storage Diseases, and Inborn Errors of Metabolism

The normal function of the human myocardium requires the proper generation and utilization of energy and relies on a series of complex metabolic processes to achieve this normal function. When metabolic processes fail to work properly or effectively, heart muscle dysfunction can occur with or without accompanying functional abnormalities of other organ systems, particularly skeletal muscle. These metabolic derangements can result in structural, functional, and infiltrative deficiencies of the heart muscle. Mitochondrial and enzyme defects predominate as disease-related etiologies. In this review, left ventricular noncompaction cardiomyopathy, which is often caused by mutations in sarcomere and cytoskeletal proteins and is also associated with metabolic abnormalities, is discussed. In addition, cardiomyopathies resulting from mitochondrial dysfunction, metabolic abnormalities, storage diseases, and inborn errors of metabolism are described.

Comparison of Echocardiographic Diagnostic Criteria of Left Ventricular Noncompaction in a Pediatric Population

BACKGROUND

There is controversy regarding the best echocardiographic diagnostic criteria for left ventricular noncompaction (LVNC). We assessed the diagnostic utility and reproducibility of the previously proposed echocardiographic diagnostic criteria in a pediatric population using a segmental approach.

METHODS

Echocardiograms were matched for patients with and without a clinical diagnosis of LVNC. Blinded reviews of echocardiograms measured (1) depths of intertrabecular recesses (X/Y), (2) noncompaction-to-compaction ratio (NC/C), and (3) number of trabeculations, using a segmental approach. Measurements were analyzed for area under the receiver operating characteristic curves (AUC), sensitivity, and specificity.

RESULTS

There were 30 echocardiograms in the initial cohort (15 LVNC cases, 15 controls). Median age was 1.7 years (IQR 0.2-6.9 years) and systolic function was decreased in 40%. Comparison of diagnostic criteria demonstrated the best interrater agreement and AUC with an X/Y ratio measured in end-diastole in the parasternal short axis in the apical anterolateral segment (κ 0.72, CI 0.43-1.00, p value <0.001), yielding 100% sensitivity and 70-86% specificity, among readers. The least predictive and reproducible method was the NC/C ratio. A validation cohort confirmed the superiority of the X/Y ratio, although the interrater agreement and AUC decreased.

CONCLUSION

Measurements according to existing LVNC diagnostic criteria vary by echocardiographic view and segment. Modification of the Chin et al. criteria (Circulation 82:507-513, 1990) using an X/Y ratio <0.5 had the greatest interrater reliability and predictive validity when measured in end-diastole in the parasternal short axis in the apical anterolateral segment. The NC/C ratio had the lowest reliability and predictive validity.

Bradycardia, Syncope, and Left Ventricular Noncompaction Cardiomyopathy

A 55-year-old man with syncopal episodes was found to have sinus bradycardia at a rate of 37 beats/min, an episode of nonsustained ventricular tachycardia, and left ventricular noncompaction cardiomyopathy. After placement of a dual-chamber cardioverter defibrillator 4 years ago, he has had no further syncopal episodes, and there have been no defibrillator shocks.

Left Ventricular Noncompaction Cardiomyopathy in Pediatric Patients: A Case Series of a Clinically Heterogeneous Disease

Left ventricular noncompaction is a rare form of cardiomyopathy, which results from multiple trabeculations in the left ventricular myocardium. The clinical presentation is highly variable, and spectrum includes asymptomatic patients diagnosed during family screening on one end to patients with depressed systolic function, heart failure, thromboembolic complications, and cardiac arrhythmias on the other (Kim et al in J Am Coll Cardiol 53: 2009, 2009). Further, the progression of the condition is highly variable. Hence, these patients require close follow-up, and management for each patient needs to be individualized and periodically reevaluated. Here, we present a series of five cases that have been followed in our practice and present our experience. A literature review of this rare form of congenital cardiomyopathy is also presented.

Naturally Occurring Biventricular Noncompaction in an Adult Domestic Cat

A definitively diagnosed case of left ventricular noncompaction (LVNC) has not been previously reported in a non-human species. We describe a Maine Coon cross cat with echocardiographically and pathologically documented LVNC. The cat was from a research colony and was heterozygous for the cardiac myosin binding protein C mutation associated with hypertrophic cardiomyopathy (HCM) in Maine Coon cats (A31P). The cat had had echocardiographic examinations performed every 6 months until 6 years of age at which time the cat died of an unrelated cause. Echocardiographic findings consistent with LVNC (moth-eaten appearance to the inner wall of the mid- to apical region of the left ventricle (LV) in cross section and trabeculations of the inner LV wall that communicated with the LV chamber) first were identified at 2 years of age. At necropsy, pathologic findings of LVNC were verified and included the presence of noncompacted myocardium that consisted of endothelial-lined trabeculations and sinusoids that constituted more than half of the inner part of the LV wall. The right ventricular (RV) wall also was affected. Histopathology identified myofiber disarray, which is characteristic of HCM, although heart weight was normal and LV wall thickness was not increased.

[Heart transplantation for the treatment of isolated left ventricular myocardial noncompaction. First case in Mexico]

BACKGROUND

Myocardial noncompaction of the left ventricle is a congenital cardiomyopathy characterised by left ventricular hypertrabeculation and prominent intertrabecular recesses. The incidence ranges from 0.15% to 2.2%. Clinical manifestations include heart failure, arrhythmias, and stroke. Prognosis is fatal in most cases. Heart transplantation is a therapeutic option for this cardiomyopathy, and few had been made worldwide.

CLINICAL CASE

The case is presented of a 20 year-old male with noncompacted myocardium of the left ventricle, who had clinical signs of heart failure. His functional class was IV on the New York Heart Association scale. He was successfully transplanted. Its survival to 15 months is optimal in class I New York Heart Association, and endomyocardial biopsies have been reported without evidence of acute rejection.

CONCLUSION

It is concluded that heart transplantation modified the natural history and improved survival in patients with this congenital heart disease.

Interobserver Agreement of the Echocardiographic Diagnosis of LV Hypertrabeculation/Noncompaction

OBJECTIVES

The aim of the study was to assess interobserver agreement (IOA) between 3 observers from 2 laboratories.

BACKGROUND

IOA of left ventricular hypertrabeculation/noncompaction (LVHT) in adults has only been studied within single echocardiographic laboratories.

METHODS

Echocardiographic recordings with and without LVHT were selected and anonymized. The "not-LVHT" cases were matched for age and systolic function. Each observer reviewed the recordings, blinded to the initial diagnosis and the other observers' results. Pre-defined criteria for LVHT were: 1) >3 prominent trabeculae at end-diastole, distinct from papillary muscles, false tendons, or aberrant bands; 2) a noncompacted part of a 2-layered myocardial structure formed by these trabeculations; 3) a ratio of >2:1 of noncompacted to compacted layer at end-systole; and 4) perfusion of the intertrabecular spaces from the ventricular cavity. IOA was estimated using the kappa measure of concordance.

RESULTS

Cine-loops of 100 patients (42 women, ages 16 to 92 years), 50 from each center, and 51 with LVHT as the initial diagnosis, were reviewed. The left ventricular end-diastolic diameter was 32 to 78 mm, and ejection fraction, 4% to 88%. The observers agreed about presence (n = 29) or absence (n = 36) of LVHT and disagreed in 35 cases. Agreement was higher among the 2 observers from the same laboratory (kappa 0.793 [95% confidence interval (CI): 0.672 to 0.915]) than from different laboratories (kappa 0.628 [95% CI: 0.472 to 0.784], kappa 0.669 [95% CI: 0.521 to 0.818]). The observers agreed with the initial report of LVHT-presence in 53% and of absence in 67%. By reviewing the discordant cases, consensus was achieved about LVHT presence (n = 8) or absence (n = 16); in 11 cases, the diagnosis remained questionable. Discordance was due to poor image quality, lack of views in different apical planes, aberrant bands and chordae tendineae, abnormally sized or inserting papillary muscles, and localized calcifications of the endocardium.

CONCLUSIONS

IOA was substantial for diagnosing LVHT. However, even the application of pre-defined criteria yielded disagreement in 35% of cases; and after mutual review, there were still 11% questionable cases.

Mismatch between the origin of premature ventricular complexes and the noncompacted myocardium in patients with noncompaction cardiomyopathy patients: involvement of the conduction system?

BACKGROUND

Noncompaction cardiomyopathy (NCCM) is considered to be the result of an arrest in the normal myocardial embryogenesis. The histological, developmental, and electrophysiological explanation of ventricular arrhythmias in NCCM is still unknown. The aim of this study was to determine the origin of premature ventricular contractions (PVCs) in NCCM and to identify any predominant arrhythmic foci.

METHODS

Retrospective data from our NCCM registry including 101 patients were analyzed. A total number of 2069 electrocardiograms (ECGs) were studied to determine the origin of PVCs. Echocardiographic data were analyzed in patients with PVCs in all 12 leads. Segments affected by noncompaction (NC) were compared with the origin of PVCs.

RESULTS

PVCs were documented in 250 ECGs from 55 (54%) patients. Thirty-five ECGs recorded PVCs on all 12 leads and the origin of 20 types of PVCs could be determined. Ninety-five percent of PVCs did not originate from left ventricular NC myocardial areas and two PVCs (10%) had a true myocardial origin. All other PVCs originated from structures such as the outflow tracts (8/20), the fascicles (7/20), especially the posteromedial fascicle (6/20), and the mitral and tricuspid annulus (3/20).

CONCLUSIONS

Our data suggest that PVCs in NCCM mainly originate from the conduction system and related myocardium.

Prominent left ventricular trabeculations in competitive athletes: A proposal for risk stratification and management

BACKGROUND

Recently, an unexpectedly large prevalence of Left Ventricular Non Compaction (LVNC) has been reported in athletes, raising the question of the appropriateness of current diagnostic criteria. We sought to describe prevalence and clinical characteristics of athletes with suspected LVNC in a large cohort of Olympic athletes.

METHODS

Over 29months, 2501 consecutive athletes underwent a cardiac evaluation including physical examination, ECG, exercise test and echocardiography. Additional investigations (Cardiac Magnetic Resonance and/or genetic testing) were selectively performed in athletes with abnormal ECGs, ventricular arrhythmias, borderline LV dysfunction or positive family history.

RESULTS

Of the 2501 athletes, 36 (1.4%) showed prominent trabeculations suggestive for LVNC. Of these, 3 (0.1%) were considered to be affected by LVNC, based on presence of LV dysfunction (ejection fraction<50%) and/or positive family history and genetic testing; these athletes were cautiously restricted from competitions and entered a clinical follow-up program. The remaining 33 athletes, in the absence of LV impairment or familial cardiac diseases, were considered normal (n=24) or unlikely affected (n=9), regardless of the extent of the trabeculations.

CONCLUSIONS

In a large athlete population, a marked LV trabecular pattern was seen in 1.4%. Only a small subset of these athletes (0.1%) showed familial, clinical and morphologic changes supporting the diagnosis of LVNC. In the vast majority of the athletes, the increased trabeculations were not associated with LV dysfunction and/or positive family history, likely representing a morphologic LV variant, deprived of clinical significance.

Left ventricular noncompaction cardiomyopathy in end-stage heart failure patients undergoing orthotopic heart transplantation

BACKGROUND

Previous studies reported that left ventricular noncompaction (LVNC) is a cardiomyopathy, familial or sporadic, arising from arrest of the normal process of trabecular remodeling during embryonic development. The diagnosis is usually made by echocardiography, but to date, there has been little research on the occurrence and clinicopathological features of LVNC in the explanted hearts of orthotopic heart transplant (OHT) recipients.

DESIGN

The clinical, echocardiographic, and pathologic findings were reviewed for evidence of LVNC, diagnosed by echocardiographic criteria, in 105 patients with end-stage heart failure (HF) undergoing OHT. Analyses of multiple sections of the explanted hearts were carried out. The hearts were evaluated for grades (0, negative; 1, mild/occasional foci; 2, moderate/multiple foci; 3, severe/extensive, diffuse) of fibrosis, reactive and replacement, hypertrophy, myocytolysis in left ventricle, right ventricle, interventricular septum, and atria. Absolute measurements of noncompacted and compacted portions of the left ventricle wall and noncompacted/compacted ratios were calculated.

RESULTS

Isolated LVNC was observed in 0 of 54 ischemic cardiomyopathy and in 4 of 51 (7.8%) nonischemic cardiomyopathy patients - 2 men and 2 women, with a mean age±SEM of 34.2±6.9years. The echocardiogram disclosed marked left ventricular dilatation, prominent trabeculations, and left ventricle ejection fraction <20%. Mural thrombi were seen in 3 of 4 (75%) patients. The heart weight mean±SEM was 468±55.3 g (range, 340-600g); noncompacted myocardium was 22±5.8mm, compacted myocardium was 13.2±3.5mm, and noncompacted/compacted ratio was 1.7/1±0.2. The total scores of hypetrophy, myocytolysis, and fibrosis were as follows: left ventricle, 7.7±0.2; right ventricle, 6.2±0.5; interventricular septum, 6.7±0.2; and atria, 7.5±0.3.

CONCLUSIONS

LVNC is an unusual form of nonischemic cardiomyopathy in patients suffering from end-stage HF undergoing OHT. The variability in the noncompacted/compacted ratio and discordance between the echocardiographic and pathological findings points to the need for further clarification of diagnostic imaging and diagnostic criteria for LVNC. Further studies in larger series, correlating the anatomoclinical and genetic variables, also would improve our understanding of LVNC as a cause of advanced HF leading to OHT.

Noncompaction Cardiomyopathy: Case Presentation with Cardiac Magnetic Resonance Imaging Findings and Literature Review

Left ventricular noncompaction cardiomyopathy is a very rare condition, yet believed to be often overlooked. It is thought to be caused by the developmental arrest in embryogenesis and characterized by an increase in the noncompacted, trabeculated myocardium adjacent to compacted myocardium in the left ventricular. The clinical presentations of this type of cardiomyopathy are of variable severity. Echocardiography used to be the diagnostic modality, but recent reports suggest that cardiac magnetic resonance imaging has higher sensitivity and specificity by showing a ratio of the noncompacted myocardium to compacted myocardium of >2.3.

A Striking Coronary Artery Pattern in a Grown-Up Congenital Heart Disease Patient

Left ventricular noncompaction (LVNC) is a myocardial disorder probably due to the arrest of normal embryogenesis of the left ventricle. It could be isolated or associated with other extracardiac and cardiac abnormalities, including coronary artery anomalies. Despite the continuous improvement of imaging resolution quality, this cardiomyopathy still remains frequently misdiagnosed, especially if associated with other heart diseases. We report a case of LVNC association with both malposition of the great arteries and a very original coronary artery pattern.

The Current Approach to Diagnosis and Management of Left Ventricular Noncompaction Cardiomyopathy: Review of the Literature

Isolated left ventricular noncompaction (LVNC) is a genetic cardiomyopathy characterized by prominent ventricular trabeculations and deep intertrabecular recesses, or sinusoids, in communication with the left ventricular cavity. The low prevalence of patients with this cardiomyopathy presents a unique challenge for large, prospective trials to assess its pathogenesis, management, and outcomes. In this paper we review the embryology and genetics of LVNC, the diagnostic approach, and propose a management approach based on the current literature available.