Noncompaction Cardiomyopathy-History and Current Knowledge for Clinical Practice

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.

Exploring the Unknown: Appreciating the Challenges of Non-compaction Cardiomyopathy

Left ventricular non-compaction cardiomyopathy (LVNC), or non-compaction cardiomyopathy (NCCM), is defined by pronounced left ventricular trabeculations and deep intertrabecular recesses connecting with the ventricular cavity. Patients with NCCM can be asymptomatic or have severe complications, including heart failure, arrhythmias, thromboembolism, and sudden cardiac death. Our case discusses a patient with shortness of breath who was found to have a newly decreased ejection fraction. The workup revealed non-ischemic cardiomyopathy and cardiac MRI showed hyper-trabeculations consistent with NCCM. The patient was started on oral anticoagulation and guideline-directed medical therapy (GDMT) and discharged with an event monitor. NCCM stands as a relatively rare and enigmatic condition, often veiled in ambiguity. The absence of standardized diagnostic and management protocols further complicates its clinical landscape. While echocardiography is the primary diagnostic tool, its tendency for under-diagnosis poses a significant challenge. Conversely, advanced imaging modalities like cardiac MRI may lead to instances of overdiagnosis. Treatment approaches are non-specific, incorporating GDMT, anticoagulation, implantable cardioverter-defibrillator placement, and genetic testing paired with counseling. Prioritizing genetic research is crucial to uncover tailored therapeutic interventions. Establishing consensus guidelines and refining diagnostic accuracy are pivotal steps toward mitigating the risks associated with under and over-diagnosis.

Utilities and Limitations of Cardiac Magnetic Resonance Imaging in Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is one of the most common types of non-ischemic cardiomyopathy. DCM is characterized by left ventricle (LV) dilatation and systolic dysfunction without coronary artery disease or abnormal loading conditions. DCM is not a single disease entity and has a complex historical background of revisions and updates to its definition because of its diverse etiology and clinical manifestations. In cases of LV dilatation and dysfunction, conditions with phenotypic overlap should be excluded before establishing a DCM diagnosis. The differential diagnoses of DCM include ischemic cardiomyopathy, valvular heart disease, burned-out hypertrophic cardiomyopathy, arrhythmogenic cardiomyopathy, and non-compaction. Cardiac magnetic resonance (CMR) imaging is helpful for evaluating DCM because it provides precise measurements of cardiac size, function, mass, and tissue characterization. Comprehensive analyses using various sequences, including cine imaging, late gadolinium enhancement imaging, and T1 and T2 mapping, may help establish differential diagnoses, etiological work-up, disease stratification, prognostic determination, and follow-up procedures in patients with DCM phenotypes. This article aimed to review the utilities and limitations of CMR in the diagnosis and assessment of DCM.

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.

Non-Compaction Ventricle and Associated Cardiovascular and Non-Cardiovascular Diseases; More Attention Is Needed!

Non-compaction of the ventricle (NCV) with a higher tendency to left ventricular involvement (NCLV) is a genetic disorder which can cause arrhythmias and cardiac arrest or remain asymptomatic. It is generally considered an isolated disease most frequently, while a few case reports have reported its association with cardiac anomalies. As the treatment strategies differ for NCV and cardiac anomalies, missed diagnosis of the concomitant cardiac diseases can result in poor response to treatment and prognosis. Here, we present 12 adult patients diagnosed with NCV and associated cardiovascular anomalies. By increasing the clinical suspicion and physician's awareness about the possibility of the presence of other cardiovascular diseases with NCLV and using close examination and follow-up of the patients, we could diagnose this number of patients during 14 months of investigation. This case series emphasizes the need for increased awareness and attention of echocardiographers on the diagnosis of other cardiovascular diseases associated with NCV for a better response to treatment and improved patient prognosis.

Advances in symptomatic therapy for left ventricular non-compaction in children

Left ventricular non-compaction is a complex cardiomyopathy and the third largest childhood cardiomyopathy, for which limited knowledge is available. Both pathogenesis and prognosis are still under investigation. Currently, no effective treatment strategy exists to reduce its incidence or severity, and symptomatic treatment is the only clinical treatment strategy. Treatment strategies are constantly explored in clinical practice, and some progress has been made in coping with the corresponding symptoms because the prognosis of children with left ventricular non-compaction is usually poor if there are complications. In this review, we summarized and discussed the coping methods for different left ventricular non-compaction symptoms.

Left Ventricular Noncompaction Cardiomyopathy in an Elderly Patient: A Case Report and Literature Review

Isolated left ventricular noncompaction cardiomyopathy (LVNC), also known as spongy myocardium, is an extremely rare congenital disorder belonging to unclassified cardiomyopathies by the World Health Organization and classified as a genetic cardiomyopathy by the American Heart Association. Adult prevalence is 0.017-0.26% in observational echocardiographic studies. The disease occurs due to the intrauterine arrest of normal myocardial compaction, leading to left ventricular dysfunction. Reported mortality is high, ranging from 35 to 47% over a 42- to 72-month follow-up period. Knowledge regarding proper diagnosis, morbidity, and prognosis is limited; thus, this disease is subdiagnosed. Our aim is to highlight a diagnostic approach to LVNC in an elderly patient and to stress specific diagnostic signs that make the disease more recognizable. We are reporting a case of noncompaction cardiomyopathy in a 62-year-old male without any significant past medical history who was referred to our clinic for arrhythmia evaluation. The patient had several brief episodes of palpitations over the past two months. On physical examination, he presented a blowing systolic murmur at the apex and an irregularly irregular rhythm. The 12-lead electrocardiogram (ECG) demonstrated atrial fibrillation and ST-T segment depression in the V4-V6 leads. A transthoracic echocardiogram (TTE) showed signs of dilated cardiomyopathy, severe eccentric left ventricular hypertrophy, decreased contractility with an ejection fraction (EF) <30%, moderate mitral and tricuspid regurgitations, and moderate pulmonary hypertension. Multiple prominent trabeculations were noticed in the middle and apical segments of the left ventricle. The noncompacted to compacted myocardium ratio was >2.5:1. Cardiac catheterization excluded ischemic heart disease. Cardiac magnetic resonance (CMR) imaging confirmed the diagnosis of LVNC. The patient started treatment with carvedilol, ramipril, verospiron, torasemide, and rivaroxaban. An implantable cardioverter-defibrillator (ICD) was recommended. In conclusion, the diagnosis of LVNC in the adult population is often delayed because of similarities with more frequently diagnosed diseases. TTE is the initial diagnostic test of choice. Additional imaging modalities (contrast echocardiography, CMR) can help confirm the diagnosis. Early diagnosis is crucial because of the high incidence of life-threatening complications related to heart failure, thromboembolic events, and ventricular arrhythmias. Additional prospective studies are needed to improve the management and outcomes of this rare cardiomyopathy.

Left ventricular noncompaction: a disorder with genotypic and phenotypic heterogeneity-a narrative review

Background and Objective

Left ventricular noncompaction (LVNC) is a cardiomyopathy characterized by excessive trabecular formation and deep recesses in the ventricular wall, with a bilaminar structure consisting of an endocardial noncompaction layer and an epicardial compacted layer. Although genetic variants have been reported in patients with LVNC, understanding of LVNC and its pathogenesis has not yet been fully elucidated. We addressed the latest findings on genes reported to be associated with LVNC morphogenesis and possible pathologies to understand the diverse spectrum between genotype and phenotype in LVNC. Also, the latest findings and issues related to the diagnosis of LVNC were summarized.

Methods

This article is written as a commentary narrative review and will provide an update on the current literature and available data on common forms of LVNC published in the past 30 years in English through to May 2022 using PubMed.

Key Content and Findings

Familial forms of LVNC are frequent, and autosomal dominant mode of inheritance has been predominantly observed. Several of the candidate causative genes are also mutated in other cardiomyopathies, suggesting a possible shared molecular and/or cellular etiology. The most common gene functions were sarcomere function whereas genes in mice LVNC models were involved in heart development. Echocardiography and cardiac magnetic resonance imaging (CMR) are useful for diagnosis although there are no unified criteria due to overdiagnosis of imaging, poor consistency between techniques, and lack of association between trabecular severity and adverse clinical outcomes.

Conclusions

This review reflects the current lack of clarity regarding the pathogenesis and significance of LVNC and showed the complexity of imaging diagnostic criteria, interpretation of the role of LVNC as a cause, and uncertainty regarding the specific genetic basis of LVNC.

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.

Left Ventricular Noncompaction in Children: The Role of Genetics, Morphology, and Function for Outcome

Left ventricular noncompaction (LVNC) is a ventricular wall anomaly morphologically characterized by numerous, excessively prominent trabeculations and deep intertrabecular recesses. Accumulating data now suggest that LVNC is a distinct phenotype but must not constitute a pathological phenotype. Some individuals fulfill the morphologic criteria of LVNC and are without clinical manifestations. Most importantly, morphologic criteria for LVNC are insufficient to diagnose patients with an associated cardiomyopathy (CMP). Genetic testing has become relevant to establish a diagnosis associated with CMP, congenital heart disease, neuromuscular disease, inborn error of metabolism, or syndromic disorder. Genetic factors play a more decisive role in children than in adults and severe courses of LVNC tend to occur in childhood. We reviewed the current literature and highlight the difficulties in establishing the correct diagnosis for children with LVNC. Novel insights show that the interplay of genetics, morphology, and function determine the outcome in pediatric LVNC.

Molecular genetic testing in athletes: Why and when a position statement from the Italian society of sports cardiology

Molecular genetic testing is an increasingly available test to support the clinical diagnosis of inherited cardiovascular diseases through identification of pathogenic gene variants and to make a preclinical genetic diagnosis among proband's family members (so-called "cascade family screening"). In athletes, the added value of molecular genetic testing is to assist in discriminating between physiological adaptive changes of the athlete's heart and inherited cardiovascular diseases, in the presence of overlapping phenotypic features such as ECG changes, imaging abnormalities or arrhythmias ("grey zone"). Additional benefits of molecular genetic testing in the athlete include the potential impact on the disease risk stratification and the implications for eligibility to competitive sports. This position statement of the Italian Society of Sports Cardiology aims to guide general sports medical physicians and sports cardiologists on clinical decision as why and when to perform a molecular genetic testing in the athlete, highlighting strengths and weaknesses for each inherited cardiovascular disease at-risk of sudden cardiac death during sport. The importance of early (preclinical) diagnosis to prevent the negative effects of exercise on phenotypic expression, disease progression and worsening of the arrhythmogenic substrate is also addressed.

Non-Compaction Cardiomyopathy and Multiple Sclerosis: Associated or Independent Diseases? A Case Report

Non-compaction cardiomyopathy (NCCM) is associated with neuromuscular disorders; however, there has been little investigation on its association with other neurological diseases, such as multiple sclerosis. We present the case of a 46-year-old woman with a history of multiple sclerosis who developed heart failure and was diagnosed with non-compaction cardiomyopathy.

Imaging Features of Pediatric Left Ventricular Noncompaction Cardiomyopathy in Echocardiography and Cardiovascular Magnetic Resonance

Background: Left ventricular noncompaction (LVNC) is a distinct cardiomyopathy characterized by the presence of a two-layer myocardium with prominent trabeculation and deep intertrabecular recesses. The diagnosis of LVNC can be challenging because the diagnostic criteria are not uniform. The aim of our study was to evaluate echocardiographic and CMR findings in a group of children with isolated LVNC. Methods: From February 2008 to July 2021, pediatric patients under 18 years of age at the time of diagnosis with echocardiographic evidence of isolated LVNC were prospectively enrolled. The patients underwent echocardiography and contrast-enhanced cardiovascular magnetic resonance (CMR) with late gadolinium enhancement to assess myocardial noncompaction, ventricular size, and function. Results: A total of 34 patients, with a median age of 11.9 years, were recruited. The patients were followed prospectively for a median of 5.1 years. Of the 31 patients who met Jenni’s criteria in echocardiography, CMR was performed on 27 (79%). Further comprehensive analysis was performed in the group of 25 patients who met the echocardiographic and CMR criteria for LVNC. In echocardiography, the median NC/C ratio in systole was 2.60 and in diastole 3.40. In 25 out of 27 children (93%), LVNC was confirmed by CMR, according to Petersen’s criteria, with a median NC/C ratio of 3.27. Conclusions: (1) Echocardiography precisely identifies patients with LVNC. (2) Echocardiography is a good method for monitoring LV systolic function, but CMR is indicated for the precise assessment of LV remodeling and RV size and function, as well as for the detection of myocardial fibrosis.

Left and Right Ventricular Morphology, Function and Myocardial Deformation in Children with Left Ventricular Non-Compaction Cardiomyopathy: A Case-Control Cardiovascular Magnetic Resonance Study

Background: Left ventricular non-compaction (LVNC) is a rare cardiomyopathy typically involving the left ventricle (LV); however, the right ventricle (RV) can also be affected. This case-control study aimed to assess the morphology and function of LV and RV in children with LVNC. Methods: Sixteen children (13 ± 3 years, six girls) with LVNC were compared with 16 sex- and age-matched controls. LV and RV morphology and function were evaluated in cardiovascular magnetic resonance (CMR) studies. Additionally, LV and RV global radial (GRS), circumferential (GCS), and longitudinal strain (GLS) were assessed using tissue-tracking analysis. Results: Patients with LVNC did not differ from the healthy controls in terms of age, height, weight, and body surface area (BSA). In total, 4/16 subjects with LVNC had mid-wall late gadolinium enhancement (LGE). Compared to the control group, patients with LVNC had higher end-diastolic volume (EDV) indexed for body surface area (BSA), lower ejection fraction (EF), and lower LV strain parameters (all p < 0.05). Children with LVNC also presented with thicker RV apical trabeculation, whereas there were no differences in RV EF and EDV/BSA between the groups. Nevertheless, children with LVNC had impaired RV GRS and GCS (both p < 0.05). Conclusions: LVNC in pediatric patients is associated with LV enlargement and impaired LV systolic function. Additionally, children with LVNC have increased RV trabeculations and subclinical impairment of RV myocardial deformation.