Isolated left ventricular non-compaction: Clinical characterisation of a teenage male.

Isolated Left Ventricular Non-compaction (LVNC) is a type of cardiomyopathy that usually has a genetic origin. Its diagnosis is based on finding such as deep intertrabecular recesses or sinusoids and ventricular trabeculations communicating with the left ventricular cavity. LVNC was first clinically recognised almost four decades ago, yet its diagnostic and management challenges persist. In this report, we present the case of an 18-year-old boy, who presented at the National Institute of Cardiovascular Diseases, Karachi, in March 2023, with complaints of dizziness, pedal oedema, and shortness of breath. Echocardiography revealed signs suggestive of LVNC, which were confirmed conclusively on Cardiovascular Magnetic Resonance (CMR) (NC/C ratio>2.4). The patient underwent implantable cardioverter defibrillator (ICD) placement, was discharged after a smooth post-procedure recovery, and is doing well on follow-ups. Hence, ICD and guideline-directed medical therapy as a combination have turned out to have satisfactory outcomes in decreasing morbidity and providing mortality benefits for such patients.

A review regarding the article 'Advances and Challenges in the Diagnosis and Management of Left Ventricular Noncompaction in Adults.'

Left ventricular noncompaction (LVNC) is a rare genetic and congenital disorder characterized by the excessive formation of blood-filled trabeculae and intertrabecular recesses in the uncompressed inner endocardial wall associated with a thin, compact wall, the mesocardium. Although LVNC was described for the first time as long ago as 1984, our understanding of the disease with regard to its genetic pattern, diagnosis, clinical presentation, and treatment is still scanty. LVNC can be present as an isolated condition or associated with congenital heart disease, genetic syndromes, or neuromuscular disease. This suggests that LVNC is not a distinct form of cardiomyopathy, but rather a morphological expression of different diseases. Recognition of the disease is of fundamental importance because its clinical manifestations are variable, ranging from the absence of any symptom to congestive heart failure, lethal arrhythmias, and thromboembolic events. The main cardiac symptoms associated with LVNC are related to HF, occurring in up to half of the patients. Atrial fibrillation can affect 25 % of adult patients and ventricular tachyarrhythmias up to around 50 %. There is a possible association between bradycardia and Wolff-Parkinson-White syndrome in pediatric patients with LVNC. Other frequent manifestations are related to thromboembolic events, such as stroke, pulmonary embolism, and mesenteric ischemia. In asymptomatic patients, LVNC is identified by echocardiography or when the patient is subjected to family screening. However, when the disease is identified during the fetal period, the presence of systemic diseases, such as mitochondrial alterations and metabolic disorders, is frequently reported.

Advances and challenges in the diagnosis and management of left ventricular noncompaction in adults: A literature review.

In the realm of cardiovascular health, isolated left ventricular noncompaction (LVNC) stands out for its distinct morphological features and the clinical challenges it presents, particularly in adults. This literature review explores the intricacies of LVNC, aiming to unravel its epidemiological spread, diagnostic hurdles, and therapeutic strategies. Despite technological advancements in cardiac imaging that have improved the recognition of LVNC, a significant gap persists alongside a fragmented understanding of its pathogenesis. The studies scrutinized reveal a broad spectrum of prevalence rates influenced by diverse diagnostic tools and demographic variables. This variation underscores the complexity of accurately identifying LVNC and the resultant implications for clinical management. The review succinctly addresses the need for precise guidelines to navigate the diagnosis of LVNC and outlines the imperative for tailored clinical management approaches that cater to the wide array of patient presentations, from asymptomatic cases to those with severe cardiac dysfunction. By highlighting the critical gaps in current literature-namely the absence of standardized diagnostic criteria and a comprehensive pathogenic model-the review sets the stage for future research directions. These endeavors are essential for enhancing diagnostic accuracy, refining management protocols, and ultimately improving patient outcomes in this complex subset of cardiomyopathy, thus contributing significantly to the advancement of cardiovascular medicine.

Noncompaction Cardiomyopathy: Issues, Contradictions, and Search for Effective Diagnostic Criteria. Literature Review. Part 1.

Active research of noncompaction cardiomyopathy (NCM) has been going on for more than 30 years. A significant amount of information has been accumulated that is familiar to a much larger number of specialists than in the most recent past. Despite this, numerous issues remain unresolved, ranging from classification (congenital or acquired, nosology or morphological phenotype) to the ongoing search for clear diagnostic criteria that separate NCM from physiological hypertrabecularity and secondary noncompaction myocardium with the background of existing chronic processes. Meanwhile, a high risk of adverse cardiovascular events in a certain group of people with NCM is quite high. These patients need timely and often quite aggressive therapy. This review of sources of scientific and practical information is devoted to the current aspects of the classification, extremely diverse clinical picture, extremely complex genetic and instrumental diagnosis of NCM, and the possibilities of its treatment. The purpose of this review is to analyze current ideas about the controversial problems of noncompaction cardiomyopathy. The material for its preparation is the numerous sources of databases Web Science, PubMed, Google Scholar, eLIBRARY. As a result of their analysis, the authors tried to identify and summarize the main problems of the NCM and identify the ways to resolve them.

Noncompaction Cardiomyopathy: Issues, Contradictions and Search for Effective Diagnostic Criteria. Literature Review. Part 2.

Active research of noncompaction cardiomyopathy (NCM) has been going on for more than 30 years. A significant amount of information has been accumulated that is familiar to a much larger number of specialists than in the most recent past. Despite this, numerous issues remain unresolved, ranging from classification (congenital or acquired, nosology, or morphological phenotype) to the ongoing search for clear diagnostic criteria that separate NCM from physiological hypertrabecularity and secondary noncompaction myocardium with the background of existing chronic processes. Meanwhile, a high risk of adverse cardiovascular events in a certain group of people with NCM is quite high. These patients need timely and often quite aggressive therapy. This review of sources of scientific and practical information is devoted to the current aspects of the classification, extremely diverse clinical picture, extremely complex genetic, and instrumental diagnosis of NCM, and the possibilities of its treatment. The purpose of this review is to analyze current ideas about the controversial problems of noncompaction cardiomyopathy. The material for its preparation is the numerous sources of databases Web Science, PubMed, Google Scholar, eLIBRARY. As a result of their analysis, the authors tried to identify and summarize the main problems of the NCM and identify the ways to resolve them.

Excessive Trabeculation of the Left Ventricle: JACC: Cardiovascular Imaging Expert Panel Paper.

Excessive trabeculation, often referred to as "noncompacted" myocardium, has been described at all ages, from the fetus to the adult. Current evidence for myocardial development, however, does not support the formation of compact myocardium from noncompacted myocardium, nor the arrest of this process to result in so-called noncompaction. Excessive trabeculation is frequently observed by imaging studies in healthy individuals, as well as in association with pregnancy, athletic activity, and with cardiac diseases of inherited, acquired, developmental, or congenital origins. Adults with incidentally noted excessive trabeculation frequently require no further follow-up based on trabecular pattern alone. Patients with cardiomyopathy and excessive trabeculation are managed by cardiovascular symptoms rather than the trabecular pattern. To date, the prognostic role of excessive trabeculation in adults has not been shown to be independent of other myocardial disease. In neonates and children with excessive trabeculation and normal or abnormal function, clinical caution seems warranted because of the reported association with genetic and neuromuscular disorders. This report summarizes the evidence concerning the etiology, pathophysiology, and clinical relevance of excessive trabeculation. Gaps in current knowledge of the clinical relevance of excessive trabeculation are indicated, with priorities suggested for future research and improved diagnosis in adults and children.

The Electrocardiogram in the Diagnosis and Management of Patients With Left Ventricular Non-Compaction.

PURPOSE OF THE REVIEW: Left ventricular non-compaction (LVNC) is characterised by prominent left ventricular trabeculae and deep inter-trabecular recesses. Although considered a distinct cardiomyopathy, prominent trabeculations may also be found in other cardiomyopathies, in athletes or during pregnancy. Clinical presentation includes heart failure symptoms, systemic embolic events, arrhythmias and sudden cardiac death. Currently, LVNC diagnosis relies on imaging criteria, and clinicians face several challenges in the assessment of patients with prominent trabeculations. In this review, we summarise the available information on the role of the ECG in the diagnosis and management of LVNC. RECENT FINDINGS: ECG abnormalities have been reported in 75-94% of adults and children with LVNC. The lack of specificity of these ECG abnormalities does not allow (in isolation) to diagnose the condition. However, when considered in a set of diagnostic criteria including family history, clinical information, and imaging features, the ECG may differentiate between physiological and pathological findings or may provide clues raising the possibility of specific underlying conditions. Finally, some ECG features in LVNC constitute ominous signs that require a stricter patient surveillance or specific therapeutic measures. The ECG remains a cornerstone in the diagnosis and management of patients with cardiomyopathies, including LVNC.

Informe de caso de miocardiopatía no compactada en una mujer de 34 años / Case report of left ventricular noncompaction cardiomyopathy in a 34-year-old woman

Introducción: la miocardiopatía no compactada (MCNC) es una miocardiopatía no clasificada por la Organización Mundial de la Salud. Se describe como una enfermedad congénita muy rara, donde se observan trabeculaciones endomiocárdicas que aumentan en número y prominencia. Esta miocardiopatía conlleva un alto riesgo de arritmias malignas, fenómeno tromboembólico y disfunción ventricular izquierda. Objetivo: reportar el caso de una mujer de 34 años, diagnosticada previamente con obesidad mórbida, que acudió a consulta externa para una evaluación cardiovascular prequirúrgica. El electrocardiograma mostró el ventrículo izquierdo (VI) ligeramente dilatado y llamativa trabeculación del mismo. Resultados: se confirma el diagnóstico de MCNC a través de una imagen de resonancia magnética. Se autoriza su cirugía y se recomiendan cambios en su estilo de vida y cambio de medicación para riesgos de fallo cardíaco. En el último ecocardiograma, los diámetros del VI muestran mejoría con respecto al primero. Conclusiones: la presencia de trabeculaciones en el VI debe considerarse un dato clínico de sospecha de MCNC. Se deben realizar más investigaciones sobre las causas de esta miocardiopatía no clasificada para desarrollar mejores formas terapéuticas, sin embargo, ha sido probada la eficacia de los bloqueadores de los receptores de la angiotensina II en el manejo farmacoterapéutico de esta condición

Introduction: Left ventricular non-compaction cardiomyopathy (LVNC) is a cardiomyopathy not classified by the World Health Organization. It is described as a very rare congenital disease where endomyocardial trabeculations that increase in number and prominence are observed. This cardiomyopathy carries a high risk of malignant arrhythmias, thromboembolic events and left ventricular dysfunction. Objective: To report the case of a 34-year-old woman, previously diagnosed with morbid obesity, who came to the outpatient clinic for a preoperative cardiovascular evaluation. The electrocardiogram showed a slightly dilated left ventricle (LV) and striking trabeculation. Results: The diagnosis of LVNC was confirmed by magnetic resonance imaging. Surgery was authorized and lifestyle changes and change of medication for heart failure risks were recommended. On the last echocardiogram, LV diameters show improvement from the first. Conclusions: The presence of trabeculations in the LV should be considered as clinical data of suspected LVNC. Further investigations on the causes of this unclassified cardiomyopathy should be performed to develop better therapeutic ways, however, the efficacy of angiotensin II receptor blockers in the pharmacotherapeutic management of this condition has been proven

Ventricular non-compaction review.

Left ventricular non-compaction cardiomyopathy (LVNC) is a rare and unclassified cardiomyopathy that carries the potential to cause heart failure, arrhythmias, and embolic events within adults. The diagnosis of this cardiomyopathy can be based off a variety of echocardiographic, cardiac magnetic resonance (CMR), and computed tomography (CT) imaging criteria; none of which have been standardized to establish a firm diagnosis. This is further complicated by the observation from prior studies that LVNC may present as different forms of cardiomyopathy, each with its own subset of nuances that may change treatment strategies. Management of such cardiomyopathy has been debated in terms of anticoagulation, electrophysiologic studies to prevent arrhythmia, as well as heart failure prevention. Not enough data exists in regard to establishing firm guidelines for management. The following article aims to provide a comprehensive review in regard to the etiologies, pathogenesis, diagnostic criteria, management, and treatment of LVNC.

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.

Clinical outcomes in patients with left ventricle trabeculation or noncompaction.

Trabeculation exhibits highly varied presentations, whereas noncompaction (NC) is a specific disease entity based arithmetically on wall thickness. We aimed to evaluate the clinical implications of trabeculation and its relevance to outcomes. A total of 296 patients (age 63 ± 12 years; 64% men) with trabeculation who underwent echocardiography were retrospectively identified between January 2011 and December 2012. Analyses were conducted on distinguished trabeculation which was divided into NC (maximum noncompacted/compacted ratio ≥ 2.0) or hypertrabeculation (HT) (ratio < 2.0). We evaluated features of trabeculation and explored cardiovascular (CV) outcome events (coronary revascularization, hospitalization for worsening heart failure (HF), stroke, nonsustained ventricular tachycardia (VT), implantation of an implantable cardioverter defibrillator (ICD), and CV death). Over a mean of 4.2 years, CV outcome events occurred in 122 (41%) patients who were older and exhibited an increased frequency of diabetes mellitus, stroke, implantation of ICD, HF and dilated cardiomyopathy. The frequencies of NC or HT, the trabeculation ratio and its manifestation were similar among patients with and without events. NC/HT with concomitant apical hypocontractility and worsening systolic function were univariable predictors of adverse events. On multivariable analysis, concomitant apical hypocontractility on NC/HT remained significant (hazard ratio 8.94, 95% confidence interval 2.9-27.2, p < 0.001) together with old age, HF and increased E/e' ratio. NC/HT with concomitant apical hypocontractility provided clues about the current medical illness and aided in risk stratification.

[Non-compaction and restrictive cardiomyopathy in pediatrics: Two types of myocardial diseases that are important to recognize]. / Miocardiopatía no compactada y restrictiva en pediatría: Dos tipos de enfermedades del miocardio que son importantes saber reconocer.

Left ventricular non-compaction (LVNC) and restrictive cardiomyopathies (RCM) are rare diseases with high morbidity and mortality in the pediatric age group, particularly the restrictive. They can be diagnosed at any age even in fetal life, in isolation or association with other cardiomyopathies or congenital heart disease. The causes may be genetic, neuromuscular, metabolic, storage, or idiopathic disorders. The main morphological characteristic of LVNC is the presence of a non-compact myocar dium with numerous prominent trabeculations and deep recesses, which may results in myocardial dysfunction, malignant arrhythmias and thromboembolism. On the other hand, in RCM there is an abnormal myocardial stiffness, which generates a restrictive ventricular filling and atrial dilatation secondary. Clinically it manifested by severe diastolic dysfunction, pulmonary hypertension, arrhyth mias and sudden death. For both cardiomyopathies, the Doppler color echocardiography, electro cardiography and Holter monitoring of arrhythmias are the gold standard for diagnosis and follow up. Cardiac resonance adds information on functional assessment and quantification of myocardial fibrosis. The therapy is oriented to improve symptoms and quality of life. Patients with severe forms of LVNC and RCM may require extracorporeal ventricular support and cardiac transplantation, even in early stages of the disease. The pediatrician plays an important role in the early recognition of these pathologies for timing to referral as well as in the follow-up and screening for complications. The objective of this review is to update the clinical, genetic, diagnostic, therapeutic issues and prognostic of the LVNC and RCM.

Prognostic value of plasma big endothelin-1 in left ventricular non-compaction cardiomyopathy.

OBJECTIVE: To determine the prognostic role of big endothelin-1 (ET-1) in left ventricular non-compaction cardiomyopathy (LVNC). METHODS: We prospectively enrolled patients whose LVNC was diagnosed by cardiac MRI and who had big ET-1 data available. Primary end point was a composite of all-cause mortality, heart transplantation, sustained ventricular tachycardia/fibrillation and implanted cardioverter defibrillator discharge. Secondary end point was cardiac death or heart transplantation. RESULTS: Altogether, 203 patients (median age 44 years; 70.9% male) were divided into high-level (≥0.42 pmol/L) and low-level (<0.42 pmol/L) big ET-1 groups according to the median value of plasma big ET-1 levels. Ln big ET-1 was positively associated with Ln N-terminal pro-brain natriuretic peptide, left ventricular diameter, but negatively related to age and Ln left ventricular ejection fraction. Median follow-up was 1.9 years (IQR 0.9-3.1 years). Kaplan-Meier analysis showed that, compared with patients with low levels of big ET-1, those with high levels were at greater risk for meeting both primary (p<0.001) and secondary (p<0.001) end points. The C-statistic estimation of Ln big ET-1 for predicting the primary outcome was 0.755 (95% CI 0.685 to 0.824, p<0.001). After adjusting for confounding factors, Ln big ET-1 was identified as an independent predictor of the composite primary outcome (HR 1.83, 95% CI 1.27 to 2.62, p=0.001) and secondary outcome (HR 1.93, 95% CI 1.32 to 2.83, p=0.001). CONCLUSIONS: Plasma big ET-1 may be a valuable index to predict the clinical adverse outcomes in patients with LVNC.

[Left ventricular non-compaction : diagnosis and management]. / Non-compaction du ventricule gauche : diagnostic et prise en charge.

Isolated left ventricular non-compaction (LVNC) is a congenital disorder characterized by prominent myocardial trabeculations and deep intertrabecular recesses. Although LVNC is diagnosed by echocardiography and cardiac magnetic resonance, there is no evidence-based imaging diagnostic criteria. Affected individuals are at risk of left ventricular failure, life-threatening arrhythmias and cardio-embolism. The diagnosis may be difficult in the atypical forms. The management remains controversial and depends on the clinical manifestations. Familial forms exist, ordering for genetic counseling. The aim of this article is to optimize the knowledge and the management of LVNC by reminding the diagnostic criteria used.

La non-compaction du ventricule gauche (NCVG) est une malformation congénitale caractérisée par la présence de trabéculations proéminentes et des récessus intertrabéculaires profonds. Bien que la NCVG puisse être diagnostiquée par l'échocardiographie ou l'imagerie par résonance magnétique (IRM) cardiaque, il n'y a actuellement pas de critère permettant un diagnostic formel. Les patients atteints sont à risque de présenter une insuffisance cardiaque, des arythmies malignes et des événements thrombo-emboliques. Le diagnostic peut être difficile dans les formes atypiques. La gestion thérapeutique est controversée et dépend de la présentation clinique. Les formes familiales existent, justifiant un conseil génétique. Cet article a pour objectif d'optimaliser les connaissances et la prise en charge de la NCVG en rappelant les critères diagnostiques actuels.

A significance of school screening electrocardiogram in the patients with ventricular noncompaction.

Left ventricular noncompaction (LVNC) is a hereditary cardiomyopathy and is associated with high morbidity and mortality. However, the role and significance of school screening for LVNC have not been fully elucidated. In this multicenter, retrospective cohort study, a total of 105 children with LVNC were included from 2000 to 2017. At the initial presentation, 44 patients (41.9%) were diagnosed by school screening. One (1.0%) patient underwent heart transplantation and four (3.8%) patients died during the study. Electrocardiogram data showed a high prevalence of fragmented QRS (33.4%) and J wave (15.7%). Treatments were needed in eight (18.2%) patients who were detected by school screening. The multivariable proportional hazards model showed T-wave abnormality on electrocardiogram in first graders was independent risk factors for major adverse cardiac events (odds ratio 4.94, p value = 0.0007). Moreover, dilation of the left atrium on chest X-ray and low ejection fraction on echocardiogram at the initial treatment were independent risk factors for treatment (odds ratio 1.7 × 107 and 22.3, p = 0.0362 and 0.0028, respectively). This study is the first report focusing on school screening in a large pediatric cohort with LVNC. With the use of abnormalities in electrocardiogram, school screening may be a good detector of and predictor for LVNC.

Bridging the gap between hypertrabeculation phenotype, noncompaction phenotype and left ventricular noncompaction cardiomyopathy.

Left ventricular noncompaction (LVNC) is an increasingly recognised cardiomyopathy characterised by excessive trabeculation and deep intertrabecular recesses in direct communication with the left ventricular cavity. In LVNC, hypertrabeculation has been associated with heart failure, ventricular arrhythmia, and systemic thromboembolism. However, hypertrabeculation alone is not sufficient to define a subject as at risk for such complications and thus should not be sufficient to diagnose LVNC. Despite several studies having investigated parameters to predict adverse cardiovascular events, physicians have no effective tools to differentiate between clinically silent hypertrabeculation and LVNC. The aim of this paper was to review literature on LVNC diagnostic criteria and to provide an easy and accessible diagnostic algorithm to distinguish between hypertrabeculation phenotype, non-compaction phenotype and LVNC cardiomyopathy.

Co-Phenotype of Left Ventricular Non-Compaction Cardiomyopathy and Atypical Catecholaminergic Polymorphic Ventricular Tachycardia in Association With R169Q, a Ryanodine Receptor Type 2 Missense Mutation.

BACKGROUND: Left ventricular non-compaction (LVNC) is a cardiomyopathy characterized by prominent trabeculae and intertrabecular recesses. We present the cases of 3 girls with the sameryanodine receptor type 2(RYR2) mutation who had phenotypes of both catecholaminergic polymorphic ventricular tachycardia (CPVT) and LVNC .Methods and Results:Clinical characteristics and genetic background of the 3 patients were analyzed retrospectively. Age at onset was 5, 6, and 7 years, respectively. Clinical presentation included syncope during exercise in all 3 patients and cardiac arrest in 2 patients. LVNC diagnosis was confirmed on echocardiography according to previously defined criteria. Exercise stress testing provoked ventricular arrhythmia in two of the patients. Beta-blockers (n=3) and flecainide (n=2) were given, and an implantable cardioverter defibrillator was used in 1 patient. Genotyping identified the sameRYR2-R169Q missense mutation and no other CPVT- or LVNC-related gene mutations. Functional analysis of the mutation using HEK293 cells with single-cell Ca2+imaging and [3H]ryanodine binding analysis, indicated a gain of function: a reduced threshold for overload-induced Ca2+release from the sarcoplasmic reticulum and increased fractional Ca2+release. CONCLUSIONS: The rare association of LVNC and CPVT phenotypes withRYR2mutations is less likely to be coincidental. Screening for life-threatening arrhythmias using exercise or pharmacologic stress tests is recommended in LVNC patients to prevent sudden cardiac death in those with preserved LV function.

Isolated right ventricular noncompaction caused ventricular tachycardia and pulmonary embolism.

Isolated ventricular noncompaction is an unclassified cardiomyopathy due to intrauterine arrest of compaction of the loose interwoven meshwork. Its mortality and morbidity are high, including heart failure, thromboembolic events, and ventricular arrhythmias. Isolated right ventricular noncompaction was reported rarely, especially that causes pulmonary embolism and ventricular tachycardia. We describe a case of isolated noncompaction of the right ventricular causing pulmonary embolism and ventricular tachycardia.

Clinical and genetic insights into non-compaction: a meta-analysis and systematic review on 7598 individuals.

BACKGROUND: Left ventricular non-compaction has been increasingly diagnosed in recent years. However, it is still debated whether non-compaction is a pathological condition or a physiological trait. In this meta-analysis and systematic review, we compare studies, which investigated these two different perspectives. Furthermore, we provide a comprehensive overview on the clinical outcome as well as genetic background of left ventricular non-compaction cardiomyopathy in adult patients. METHODS AND RESULTS: We retrieved PubMed/Medline literatures in English language from 2000 to 19/09/2018 on clinical outcome and genotype of patients with non-compaction. We summarized and extensively reviewed all studies that passed selection criteria and performed a meta-analysis on key phenotypic parameters. Altogether, 35 studies with 2271 non-compaction patients were included in our meta-analysis. The mean age at diagnosis was the mid of their fifth decade. Two-thirds of patients were male. Congenital heart diseases including atrial or ventricular septum defect or Ebstein anomaly were reported in 7% of patients. Twenty-four percent presented with family history of cardiomyopathy. The mean frequency of neuromuscular diseases was 5%. Heart rhythm abnormalities were reported frequently: conduction disease in 26%, supraventricular tachycardia in 17%, and sustained or non-sustained ventricular tachycardia in 18% of patients. Three important outcome measures were reported including systemic thromboembolic events with a mean frequency of 9%, heart transplantation with 4%, and adequate ICD therapy with 15%. Nine studies investigated the genetics of non-compaction cardiomyopathy. The most frequently mutated gene was TTN with a pooled frequency of 11%. The average frequency of MYH7 mutations was 9%, for MYBPC3 mutations 5%, and for CASQ2 and LDB3 3% each. TPM1, MIB1, ACTC1, and LMNA mutations had an average frequency of 2% each. Mutations in PLN, HCN4, TAZ, DTNA, TNNT2, and RBM20 were reported with a frequency of 1% each. We also summarized the results of eight studies investigating the non-compaction in altogether 5327 athletes, pregnant women, patients with sickle cell disease, as well as individuals from population-based cohorts, in which the presence of left ventricular hypertrabeculation ranged from 1.3 to 37%. CONCLUSION: The summarized data indicate that non-compaction may lead to unfavorable outcome in different cardiomyopathy entities. The presence of key features in a multimodal diagnostic approach could distinguish between benign morphological trait and manifest cardiomyopathy.

Meta-Analysis of the Prognostic Role of Late Gadolinium Enhancement and Global Systolic Impairment in Left Ventricular Noncompaction.

OBJECTIVES: The objective of this meta-analysis was to assess the predictive value of late gadolinium enhancement (LGE) and global systolic impairment for future major adverse cardiovascular events in left ventricular noncompaction (LVNC). BACKGROUND: The prognosis of patients with LVNC, with and without left ventricular dysfunction and LGE, is still unclear. METHODS: A systematic review of published research and a meta-analysis reporting a combined endpoint of hard (cardiac death, sudden cardiac death, appropriate defibrillator firing, resuscitated cardiac arrest, cardiac transplantation, assist device implantation) and minor (heart failure hospitalization and thromboembolic events) events was performed. RESULTS: Four studies with 574 patients with LVNC and 677 with no LVNC and an average follow-up duration of 5.2 years were analyzed. In patients with LVNC, LGE was associated with the combined endpoint (pooled odds ratio: 4.9; 95% confidence interval: 1.63 to 14.6; p = 0.005) and cardiac death (pooled odds ratio: 9.8; 95% confidence interval: 2.44 to 39.5; p < 0.001). Preserved left ventricular systolic function was found in 183 patients with LVNC: 25 with positive LGE and 158 with negative LGE. In LVNC with preserved ejection fraction, positive LGE was associated with hard cardiac events (odds ratio: 6.1; 95% confidence interval: 2.1 to 17.5; p < 0.001). No hard cardiac events were recorded in patients with LVNC, preserved ejection fraction, and negative LGE. CONCLUSIONS: Patients with LVNC but without LGE have a better prognosis than those with LGE. When LGE is negative and global systolic function is preserved, no hard cardiac events are to be expected. Currently available criteria allow diagnosis of LVNC, but to further define the presence and prognostic significance of the disease, LGE and/or global systolic impairment must be considered for better risk stratification.