Ventricular Noncompaction Research Articles

Determination of Genotype and Phenotypes in Pediatric Patients With Biventricular Noncompaction.

Left ventricular noncompaction (LVNC) is a hereditary type of cardiomyopathy characterized by prominent trabeculations. Detailed characteristics of biventricular noncompaction (BiVNC) remain unknown. This study aimed to elucidate the clinical characteristics and genetic landscape of BiVNC. We recruited children with left ventricular noncompaction from Japanese multi-institutional centers from 2013 to 2021. Left ventricular noncompaction was classified as BiVNC, congenital heart disease, arrhythmia, dilated cardiomyopathy, or normal function. In these patients, cardiomyopathy-associated genes were screened. A total of 234 patients (127 male; mean age, 4 months [range, 0-6.6 years]) were enrolled in this study, of whom 25 had BiVNC; 55, normal function; 84, dilated cardiomyopathy; 38, congenital heart disease; and 32, arrhythmia. BiVNC was diagnosed during the perinatal period in 10 patients, in whom the prevalence was higher than that in other patients. A total of 14 patients in the group with BiVNC had congenital heart disease, but not necessarily right heart lesions. Left ventricular dyskinesis was frequently observed in the lateral wall (24%) and apex (28%). Eleven pathogenic variants were found in 11 patients with BiVNC (44.0%). The group with BiVNC had a higher ratio of mitochondrial and developmental gene variants than the other groups. Among all groups, the group with BiVNC had the worst survival rate (P=0.0009). Pediatric patients with BiVNC had a high rate of ventricular dyskinesis and poor outcome. A comprehensive and careful screening for disease-causing genes and phenotype may help identify specific patients with left ventricular noncompaction and mortality-related cardiac phenotypes.

ABLE-SCORE: a simplified risk score for major adverse cardiovascular outcomes in patients with left ventricular noncompaction

Abstract Background Left ventricular noncompaction (LVNC) is a heterogeneous entity with life-threatening complications and variable prognosis [1,2]. However, there are limited prediction models available to identify individuals at high risk of adverse outcomes, and the current risk score in LVNC is comparatively complex for clinical practice [3,4]. Purpose To develop and validate a simplified risk score to predict major adverse cardiovascular events (MACE) in LVNC. Methods This multicenter longitudinal cohort study consecutively enrolled morphologically diagnosed LVNC patients between January 2009 and December 2020 at a single national-level medical center (derivation cohort n=300; internal validation cohort n=129), and between January 2014 and December 2022 at two national-level medical centers (external validation cohort n=95). The derivation/internal validation cohorts and the multicenter external validation cohort were followed annually until December 2022 and December 2023, respectively. MACE was defined as a composite of all-cause mortality, heart transplantation/left ventricular assist device implantation, cardiac resynchronization therapy, malignant ventricular arrhythmia, and thromboembolism. A simplified risk score, the ABLE-SCORE, was developed based on independent risk factors for MACE in the multivariable Cox regression predictive model, and underwent both internal and external validation to confirm its discrimination (Harrell’s C-index), calibration (calibration plots), and clinical applicability (decision curve analysis). Results A total of 524 LVNC patients (43.5 ± 16.6 years, 65.8% male) were included in the study. At the end of the follow-up, 97 (32.3%), 38 (29.5%), and 20 (21.1%) individuals in the derivation, internal validation, and external validation cohort experienced at least one endpoint of MACE. The ABLE-SCORE was established using four easily accessible clinical variables: age at diagnosis, N-terminal pro-brain natriuretic peptide levels, left atrium enlargement and left ventricular ejection fraction≤40% measured by echocardiography. The risk score showed excellent performance in discrimination, with Harrell’s C-index of 0.821 (95%CI 0.772-0.869), 0.786 (95%CI 0.703-0.869), and 0.750 (95%CI 0.644-0.856) in the derivation, internal validation, and external validation cohort, respectively. Calibration plots of the three datasets suggested accurate agreement between the predicted and observed 5-year risk of MACE in LVNC. According to decision curve analysis, the ABLE-SCORE displayed greater net benefit than the currently existing risk score for MACE in LVNC [3], indicating its strength in clinical applicability. Conclusions Derived from readily available laboratory and echocardiographic variables, a simplified and efficient risk score for MACE was developed and validated using a large LVNC cohort, making it a reliable and convenient tool for the risk stratification and clinical management of patients with LVNC.Development of the ABLE-SCOREValidation of the ABLE-SCORE

Characterisation of the novel SCN5A-P1891A variant, implicated in left ventricular noncompaction cardiomyopathy in a Finnish family, using human induced pluripotent stem cell-derived cardiomyocytes

Abstract Introduction Left ventricular noncompaction (LVNC) is a heterogenous cardiomyopathy characterised by an extensively trabeculated left ventricle (LV). Several genetic variants that perturb trabeculae compaction, and thus LV maturation, have been reported [1]. However, the precise mechanisms underpinning this have proven contentious with, for example, differentially aberrant cardiomyocyte proliferation implicated in the development of LVNC [2,3]. Purpose In this study, we investigate a novel SCN5A variant, P1891A, which is associated with LVNC in a Finnish family. We ascertain the effects of this variant through the characterisation of variant-carrying human induced pluripotent stem cell-derived cardiomyocytes (P1891A-hiPSC-CMs). Methods We isolated dermal fibroblasts from a symptomatic member of a Finnish family carrying the SCN5A-P1891A variant; derived P1891A-hiPSCs via nucleofection with reprogramming plasmids [4]; and differentiated these into hiPSC-CMs alongside healthy control-hiPSCs. We determined the action potential (AP) and sodium- (INa) and calcium-current (ICa) densities of hiPSC-CMs via patch-clamp. We investigated gene expression in hiPSC-CMs through qPCR and employed Multiple Approaches Combined (MCA) proteomics [5] in SCN5A-transfected HEK293-like cells to elucidate protein-protein interactions (PPI). We subjected hiPSC-CMs to mechanical stretch [6] to examine their stress response and assessed their proliferation capacity via high-content analysis for the percentage of BrdU positive hiPSC-CMs following mitogenic stimulation (5 µM CHIR99021 and 1 µM SB203580). Finally, we ascertained contractile kinetics and apparent contractile force using fibrin hydrogel-based engineered heart tissues (EHTs) [7]. Results The P1891A-hiPSC-CMs demonstrated elevated INa density alongside enhanced arrhythmogenicity relative to healthy control hiPSC-CMs although, AP kinetics and ICa density were unperturbed (Fig. 1). Under baseline conditions, P1891A-hiPSC-CMs exhibited higher SCN5A gene expression and proteomics revealed a reduction in PPI. Baseline proliferation was unchanged; however, aged P1891A-hiPSC-CMs had enhanced proliferative capacity following mitogenic stimulation. Further, the P1891A-hiPSC-CMs displayed impaired tolerance to mechanical stretch as evidenced by upregulated NPPB and ACTA1 expression. In the context of the EHT, P1891A-hiPSC-CMs yielded disparate phenotypes. Whilst a subset compacted fully and yielded weaker contractile parameters relative to healthy control EHTs, the majority of P1891A-hiPSC-CM EHTs failed to fully compact thereby recapitulating the LVNC phenotype (Fig. 2). Conclusions This study presents a unique aetiology of LVNC and links, for the first time, SCN5A mutations with enhanced human cardiomyocyte proliferation. The ability to recapture the noncompaction phenotype in EHTs presents a powerful model for future mechanistic research and drug development.

Morphological, electrophysiological, and molecular alterations in foetal noncompacted cardiomyopathy induced by disruption of ROCK signalling.

Left ventricular noncompaction cardiomyopathy is associated with heart failure, arrhythmia, and sudden cardiac death. The developmental mechanism underpinning noncompaction in the adult heart is still not fully understood, with lack of trabeculae compaction, hypertrabeculation, and loss of proliferation cited as possible causes. To study this, we utilised a mouse model of aberrant Rho kinase (ROCK) signalling in cardiomyocytes, which led to a noncompaction phenotype during embryogenesis, and monitored how this progressed after birth and into adulthood. The cause of the early noncompaction at E15.5 was attributed to a decrease in proliferation in the developing ventricular wall. By E18.5, the phenotype became patchy, with regions of noncompaction interspersed with thick compacted areas of ventricular wall. To study how this altered myoarchitecture of the heart influenced impulse propagation in the developing and adult heart, we used histology with immunohistochemistry for gap junction protein expression, optical mapping, and electrocardiography. At the prenatal stages, a clear reduction in left ventricular wall thickness, accompanied by abnormal conduction of the ectopically paced beat in that area, was observed in mutant hearts. This correlated with increased expression of connexin-40 and connexin-43 in noncompacted trabeculae. In postnatal stages, left ventricular noncompaction was resolved, but the right ventricular wall remained structurally abnormal through to adulthood with cardiomyocyte hypertrophy and retention of myocardial crypts. Thus, this is a novel model of self-correcting embryonic hypertrabeculation cardiomyopathy, but it highlights that remodelling potential differs between the left and right ventricles. We conclude that disruption of ROCK signalling induces both morphological and electrophysiological changes that evolve over time, highlighting the link between myocyte proliferation and noncompaction phenotypes and electrophysiological differentiation.

Prevalence, Clinical Manifestations, and Adverse Outcomes of Left Ventricular Noncompaction in Adults: A Systematic Review and Meta-Analysis.

Left ventricular noncompaction (LVNC) is recognized within the spectrum of adult cardiomyopathies for its unique pathophysiologic features and clinical challenges. This condition exhibits a wide range of clinical manifestations, from asymptomatic states to severe cardiovascular complications, making its diagnosis and management challenging. This study aimed to synthesize current data on the prevalence, diagnostic methods, clinical outcomes, and treatment efficacy of LVNC in adults to address gaps in understanding and management strategies. A systematic review and meta-analysis of research from 2000 to March 2024 was conducted, focusing on studies involving adults diagnosed with LVNC. This approach aimed to collect data on the prevalence of LVNC, the diagnostic accuracy of different imaging modalities, clinical manifestations, and the impact of different treatment strategies. The study showed a prevalence of LVNC of 0.5%, with cardiovascular magnetic resonance outperforming echocardiography in diagnosis with a detection rate of 1.3%. Mortality and heart transplantation rates were 12% and 7%, respectively. Significant predictors of adverse outcomes included New York Heart Association (NYHA) class III or IV, ventricular tachycardia, and reduced left ventricular ejection fraction (LVEF), guiding a nuanced approach in tailoring therapeutic strategies to optimize patient care and outcomes. This study advances the understanding of LVNC by refining diagnostic criteria and evaluating management strategies, highlighting the superiority of cardiovascular magnetic resonance. It identifies predictors of adverse outcomes and assesses treatment efficacy, urging precision in diagnosis and tailored treatments. Its comprehensive analysis and methodological rigor make it a key resource advocating a multidisciplinary approach to improve patient outcomes in LVNC.

Cardiomyopathy-Associated Chronic HeartFailure in Infants Aged

There have been few large-scale studies on the outcomes of cardiomyopathy-associated heart failure (HF) in infants aged <1 year. This study aimed to assess longitudinal echocardiographic outcomes of infants with HF secondary to cardiomyopathy who survived for >1 year. A prospective observational study following 327 infant patients up to 5 years in 2 large pediatric heart centers in Northern China between January 2010 and December 2018. A total of 236 (72.2%) patients had reduced left ventricular ejection fraction (LVEF) (HF with reduced ejection fraction group; LVEF <40%), 91 (27.8%) patients had midrange LVEF (HF with midrange ejection fraction group; LVEF ≥40% but <55%). LVEF improved significantly within the first year and remained stable in years 2 through 5 for both groups. The HF with midrange ejection fraction group had a higher rate of LVEF normalization (hazard ratio, 1.65; P<0.001). Baseline LVEF ≥40%, baseline left ventricular end-diastolic diameter Z score <7.8, the absence of left bundle-branch block, and the absence of β-blocker use were 4 independent favorable predictors for future LVEF normalization. A total of 62.4% of enrolled patients were diagnosed with left ventricular noncompaction. No significant difference in LVEF normalization was found among the different types of cardiomyopathy studied. A significant number of infants with cardiomyopathy who survived >1 year were found to improve with medical therapies during the first year of diagnosis. Poorer outcomes were associated with decreased LVEF and increased heart size at diagnosis baseline, the presence of left bundle-branch block and use of β blockers. The Northern Chinese pediatric population may have a high proportion of left ventricular noncompaction.

Left Ventricular Non-Compaction: Evolving Concepts

Left ventricular non-compaction (LVNC) is a rare heart muscle disease defined by the presence of prominent left ventricular trabeculation, deep intertrabecular recesses, and a thin compact layer. Several hypotheses have been proposed regarding its pathogenesis, with the most recently accepted one being that compact layer and trabeculated layers develop independently according to an “allometric growth”. The current gold-standard diagnostic criteria (in particular, the Petersen index non-compaction/compaction ratio &gt; 2.3) reflect an excess of myocardial trabeculation, which is not a specific morpho-functional feature of LVNC cardiomyopathy but merely a “phenotypic trait”, even described in association with other myocardial disease and over-loading conditions. Accordingly, the European Society of Cardiology (ESC) guidelines have definitively abolished the term ‘LVNC cardiomyopathy’. Recently, evolving perspectives led to the restoration of LVNC cardiomyopathy by distinguishing “hypertrabeculation phenotype” and “non-compaction phenotype”. It has been proposed that the disease-specific pathophysiologic mechanism is a congenitally underdevelopment of the compact layer accounting for an impairment of the left ventricular systolic function. Future prospective research should focus on the clinical and prognostic relevance of compact layer thinning rather than excessive trabeculation, which could significantly influence the management of patients with LVNC. The review aims to update current knowledge on the pathogenesis, genetics, and diagnostic criteria of LVNC, offering modern insights for future perspectives.

Lack of Bridge to Recovery in Pediatric Dilated Cardiomyopathy With Left Ventricular Noncompaction

BackgroundThis study assessed the possibility of a bridge to recovery using the Berlin Heart EXCOR and the histologic characteristics of pediatric patients with dilated cardiomyopathy accompanied by a left ventricular noncompaction phenotype. MethodsOf the 17 pediatric patients with dilated cardiomyopathy who underwent Berlin Heart EXCOR implantation between 2013 and 2020, 6 were diagnosed with left ventricular noncompaction association. The patients were classified into 2 groups: the dilated cardiomyopathy group and dilated cardiomyopathy with the left ventricular noncompaction phenotype group. The histologic characteristics of the left ventricular myocardium and left ventricular function after Berlin Heart EXCOR implantation were compared. ResultsCardiac recovery was not observed in the dilated cardiomyopathy with left ventricular noncompaction group. In contrast, 6 patients (55%) in the dilated cardiomyopathy group achieved cardiac recovery, and the Berlin Heart EXCOR was explanted. The degree of myocardial fibrosis was significantly higher in the dilated cardiomyopathy with the left ventricular noncompaction phenotype group than in the dilated cardiomyopathy group (P < .05). The final follow-up left ventricular ejection fraction and end-diastolic diameter during Berlin Heart EXCOR support improved significantly compared with the preimplantation variables in the dilated cardiomyopathy group (both P < .001); the dilated cardiomyopathy with left ventricular noncompaction phenotype group showed no improvements (P = .84 and P = .37, respectively). ConclusionsThe left ventricular noncompaction phenotype associated with dilated cardiomyopathy may adversely affect the rate of cardiac recovery with Berlin Heart EXCOR.

Abstract Or125: Numb Family Proteins regulate left ventricular compaction by modulating autophagic process

Background: Left ventricular noncompaction (LVNC) is a type of cardiomyopathy, which patients manifest clinical features of heart failure, arrhythmias, thrombotic events, and sudden death. We previously found that the ablation of Numb(Nb) , and its homologue Numbl(Nl) at early stage, causes LVNC defects resulting in embryonic lethality. In this study, we found that mice with Nb and Nl deletion at later stage survive to adulthood and develop toLVNC cardiomyopathy. Method: We applied aMHC-Cre to delete and generate Nb and Nl double knockout (ADKO); examine the structure and functions of the ADKO hearts via echocardiography (ECHO); determine the heart arrhythmia via telemetry; determine the Nb subcellular localization via a Nb overexpression line (R26-Flag:mCherry:Numb); and determine the mechanistic function of NFPs in autophagy via autophagic reporter, electron microscopy, and molecular and biochemical assays. Results: The cTnT-Cre mediated Nb and Nl deletion causes LVNC and embryonic lethality, while the ADKO can survive to adulthood and died between eight- and twelve-month-old. The ADKO hearts display LVNC by two months of age, a reduced systolic function by four months old, and left ventricular remodeling and dilatation starting at six months old. ADKO hearts manifest major clinical features of LVNC, including arrhythmias and thrombosis. ADKO hearts exhibit significant accumulation of damaged mitochondria, autophagosomes and autophagolysosomes compared to controls. Biochemical analyses reveal elevated levels of p62 and a higher ratio of LC3II/LC3I in ADKO hearts. NFP null cells and ADKO hearts exhibit abnormal autophagic flux, characterized by arrested at autophagolysosome, increased expression of Lamp1 and Lamp2, but reduced levels of cathepsin D. Mass spectrometry analyses reveal Numb's interaction with proteins involved in endocytosis and autophagy. Consistently, Numb localizes to autophagosomes and autophagolysosomes. Conclusion: NFPs regulate left ventricular compaction at both embryonic and postnatal stages, suggesting that LVNC can be both congenital and acquired. As LVNC mice progress, they develop dilated cardiomyopathy (DCM) at later stage, suggesting that LVNC can occur independently at early stage, and is associated with DCM at later stage. Deletion of NFPs in cardiomyocytes disrupts endocytosis and autophagic flux. Our studies suggest that NFPs mediated endocytosis and autophagy are essential for left ventricular compaction.

Pathophysiological and Pedigree Analysis of Left Ventricular Noncompaction in Japanese Macaques (Macaca fuscata).

Left ventricular noncompaction (LVNC) involving genetic mutation is categorized as an unclassified cardiomyopathy, and its diagnostic criteria have not been standardized. This could be because precise animal models of LVNC have not been created in any laboratory animal species. This study aimed to analyze the pathophysiology and familial tendency of LVNC in Japanese macaques. Two Japanese macaques with LVNC, and their parents who were suspected of having cardiac disease, were examined. One macaque with LVNC was examined using chest radiography, echocardiography, cardiac biomarkers, cardiac MRI, and pathologic examination, and the other macaque was examined using chest radiography, echocardiography, and cardiac biomarkers. Their common father and the mother of one of the macaques with LVNC were tested for chest radiography and cardiac biomarkers. Echocardiography revealed a meshwork with trabeculation and deep intertrabecular recesses in all their left ventricular walls. The 2 macaques with LVNC demonstrated a layered appearance of the myocardium, consisting of noncompacted myocardium on the endocardial side and compacted myocardium on the epicardial side, with a noncompacted/compacted ratio of 6.0 and 5.8, respectively. One of the 2 macaques with LVNC (case 1) had elevated levels of troponin I, troponin T, atrial natriuretic peptide, and brain natriuretic peptide. The second macaque with LVNC (case 2) showed blood flow in the intertrabecular recesses on echocardiography. The common father (case 3) of the 2 macaques with LVNC and the mother (case 4) of one of the macaques with LVNC had elevated levels of troponin I and troponin T. In case 1, histopathologic examination revealed fibrous thickening of the endocardium, fibrosis of the myocardial interstitium, myocardial disarray, vacuolar degeneration, anisonucleosis, and necrosis of myocardial cells. This suggests that Japanese macaques could serve as a reliable animal model of human LVNC.

A Case of Pregnant Woman with Severe Mitral Regurgitation Demonstrating Left Ventricular Non-compaction

A Case of Pregnant Woman with Severe Mitral Regurgitation Demonstrating Left Ventricular Non-compaction

Adverse Events in Patients With Left Ventricular Noncompaction: Risk Stratification and Treatment Options

Adverse Events in Patients With Left Ventricular Noncompaction: Risk Stratification and Treatment Options

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 findings such as deep intertrabecular recesses or sinusoids and ventricular trabeculations communicating with the left ventricular cavity. LVNC was first clinically recognised almost four decades back, 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&gt;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. ---Continue

Left Ventricular Noncompaction: Often Forgotten Cause of Heart Failure

Left ventricular (LV) noncompaction is a form of genetic cardiomyopathy characterized by hypertrabeculations with deep intertrabecular recesses of the LV myocardium. The diagnosis can be confirmed by echocardiography and magnetic resonance imaging. These patients can be asymptomatic or may present with heart failure, arrhythmias, or thromboembolic episodes. The management is guideline directed. When associated with congenital heart defects or correctable valvular lesions, surgical management should be advised. Familial screening and counseling of first-degree relatives are essential. In this review, an attempt has been made to give an overview of this condition.

Rare case of super-response to Cardiac Resynchronization Therapy in Macedonian patient with Dilated Left Ventricular Non-Compaction Cardiomyopathy

Background: Left ventricular non-compaction (LVNC) is rare cardiomyopathy with increased and prominent endomyocardial trabeculations also known as spongy myocardium. It is often found in association with a dilated cardiomyopathy (DCM) and has high incidence of Heart failure (HF). Cardiac resynchronization therapy (CRT) is currently recommended by the available guidelines for selected patients with Heart failure with reduced ejection fraction (HFrEF). Aim: Our case report aims to highlight the therapeutic benefits and superresponse to CRT in a patient with Left ventricular non-compaction cardiomyopathy and HFrEF. Case report: 55-year-old Macedonian male patient with HFrEF, Left bundle branch block (LBBB) remained symptomatic (NYHA III) despite optimal medical treatment (OMT). Echocardiography and CMR findings were in addition to dilated and left ventricular non-compaction cardiomyopathy. Cardiac resynchronization therapy was indicated and 18 months after implantation of CRT-P device we have achieved complete and utter reversibility of systolic myocardial function (EF from 23% to 53%), left ventricular internal diameter was reduced from 90mm to 64mm, left ventricular end systolic volume (LVESV) was reduced from 319ml to 98ml and patient quality of life significantly improved. Conclusion: Cardiac resynchronization therapy is a safe and valuable method of treatment for patients with HFrEF due to dilated left ventricular non-compaction cardiomyopathy.

Long-term prognostic value of thyroid hormones in left ventricular noncompaction

PurposeThyroid function is closely related to the prognosis of cardiovascular diseases. This study aimed to explore the predictive value of thyroid hormones for adverse cardiovascular outcomes in left ventricular noncompaction (LVNC).MethodsThis longitudinal cohort study enrolled 388 consecutive LVNC patients with complete thyroid function profiles and comprehensive cardiovascular assessment. Potential predictors for adverse outcomes were thoroughly evaluated.ResultsOver a median follow-up of 5.22 years, primary outcome (the combination of cardiovascular mortality and heart transplantation) occurred in 98 (25.3%) patients. For secondary outcomes, 75 (19.3%) patients died and 130 (33.5%) patients experienced major adverse cardiovascular events (MACE). Multivariable Cox analysis identified that free triiodothyronine (FT3) was independently associated with both primary (HR 0.455, 95%CI 0.313–0.664) and secondary (HR 0.547, 95%CI 0.349–0.858; HR 0.663, 95%CI 0.475–0.925) outcomes. Restricted cubic spline analysis illustrated that the risk for adverse outcomes increased significantly with the decline of serum FT3. The LVNC cohort was further stratified according to tertiles of FT3 levels. Individuals with lower FT3 levels in the tertile 1 group suffered from severe cardiac dysfunction and remodeling, resulting in higher incidence of mortality and MACE (Log-rank P < 0.001). Subgroup analysis revealed that lower concentration of FT3 was linked to worse prognosis, particularly for patients with left atrial diameter ≥ 40 mm or left ventricular ejection fraction ≤ 35%. Adding FT3 to the pre-existing risk score for MACE in LVNC improved its predictive performance.ConclusionThrough the long-term investigation on a large LVNC cohort, we demonstrated that low FT3 level was an independent predictor for adverse cardiovascular outcomes.Graphical

Role of TBX20 Truncating Variants in Dilated Cardiomyopathy and Left Ventricular Noncompaction.

Less than 40% of patients with dilated cardiomyopathy (DCM) have a pathogenic/likely pathogenic genetic variant identified. TBX20 has been linked to congenital heart defects; although an association with left ventricular noncompaction (LVNC) and DCM has been proposed, it is still considered a gene with limited evidence for these phenotypes. This study sought to investigate the association between the TBX20 truncating variant (TBX20tv) and DCM/LVNC. TBX20 was sequenced by next-generation sequencing in 7463 unrelated probands with a diagnosis of DCM or LVNC, 22 773 probands of an internal comparison group (hypertrophic cardiomyopathy, channelopathies, or aortic diseases), and 124 098 external controls (individuals from the gnomAD database). Enrichment of TBX20tv in DCM/LVNC was calculated, cosegregation was determined in selected families, and clinical characteristics and outcomes were analyzed in carriers. TBX20tv was enriched in DCM/LVNC (24/7463; 0.32%) compared with internal (1/22 773; 0.004%) and external comparison groups (4/124 098; 0.003%), with odds ratios of 73.23 (95% CI, 9.90-541.45; P<0.0001) and 99.76 (95% CI, 34.60-287.62; P<0.0001), respectively. TBX20tv was cosegregated with DCM/LVNC phenotype in 21 families for a combined logarythm of the odds score of 4.53 (strong linkage). Among 57 individuals with TBX20tv (49.1% men; mean age, 35.9±20.8 years), 41 (71.9%) exhibited DCM/LVNC, of whom 14 (34.1%) had also congenital heart defects. After a median follow-up of 6.9 (95% CI, 25-75:3.6-14.5) years, 9.7% of patients with DCM/LVNC had end-stage heart failure events and 4.8% experienced malignant ventricular arrhythmias. TBX20tv is associated with DCM/LVNC; congenital heart defect is also present in around one-third of cases. TBX20tv-associated DCM/LVNC is characterized by a nonaggressive phenotype, with a low incidence of major cardiovascular events. TBX20 should be considered a definitive gene for DCM and LVNC and routinely included in genetic testing panels for these phenotypes.

Impact of Cardiac Magnetic Resonance on the Diagnosis of Left Ventricular Noncompaction-A 15-Year Experience.

The aim of this study was to assess the impact of cardiac magnetic resonance (CMR) on the diagnosis in patients with known or suspected left ventricular noncompaction (LVNC). We retrospectively reviewed the medical charts of 12,811 consecutive patients who had CMR studies between 2008 and 2022 in a large tertiary center. We included patients referred for CMR because of known or suspected LVNC. The study sample consisted of 333 patients, 193 (58.0%) male, median age 39.0 (26.8-51.0) years. Among 74 patients fulfilling the echocardiographic LVNC criteria, the diagnosis was confirmed in 54 (73.0%) cases. In 259 patients with ultrasound-based suspicion of LVNC, CMR led to an LVNC diagnosis in 82 (31.7%) patients. In both groups, CMR led to a new diagnosis in 89 cases (10 (13.5%) and 79 (30.5%)). A quantity of 38 (5.4%) patients were diagnosed with dilated cardiomyopathy, 11 (1.4%) patients were diagnosed with hypertrophic cardiomyopathy, and 21 (4.1%) patients were diagnosed with unclassified cardiomyopathy. In four patients with suspected LVNC, a myocardial trabeculation was a secondary result of dilatation due to coronary heart disease. In five cases, valvular heart disease was found. Four patients were diagnosed with athlete's heart. Other diagnoses (arrhythmogenic right ventricular cardiomyopathy, peripartum cardiomyopathy, hypokinetic non-dilated cardiomyopathy, sarcoidosis, amyloidosis, and ventricular septum defect) were found in six patients. CMR is a valuable tool in the evaluation of cardiac muscle and in differentiating LVNC and other cardiac diseases.

Difficulties in selecting antiarrhythmic therapy in a patient with left ventricular noncompaction and atrial septal defect: a case report

Introduction. Left ventricular noncompaction (LVNC) is a rare heterogeneous pathology characterized by a two-layered structure with a predominance of non-compact layer in the form of multiple trabeculations and pockets between them, communicating with the left ventricular cavity. One of the rare LVNC phenotypes is a combination with congenital heart defects, including atrial septal defect (ASD).Brief description. The article presents a case report describing the difficulties of selecting antiarrhythmic therapy in a patient with LVNC and ASD, complicated by arrhythmias due to heart failure. The diagnosis of LVNC was confirmed by the Petersen criterion using magnetic resonance imaging.Discussion. Cardiac arrhythmias in patients with LVNC and congenital heart defects, as a result of both anatomical and hemodynamic causes of electrical heart instability, constitute a danger of thromboembolism and sudden cardiac death, and also contribute to heart failure progression. The case is of interest due to the rare combination of LVNC and ASD, complicated by frequent episodes atrial fibrillation and premature ventricular contractions in the form of parasystoles, as well as difficulties in selecting antiarrhythmic therapy. Pulmonary vein cryoballoon ablation eliminated the source of atrial fibrillation. Ventricular ectopic activity was stopped using the anticonvulsant drug carbamazepine.

Left Ventricular Non-Compaction in Children: Aetiology and Diagnostic Criteria.

Left ventricular non-compaction (LVNC) is a heterogeneous myocardial disorder characterized by prominent trabeculae protruding into the left ventricular lumen and deep intertrabecular recesses. LVNC can manifest in isolation or alongside other heart muscle diseases. Its occurrence among children is rising due to advancements in imaging techniques. The origins of LVNC are diverse, involving both genetic and acquired forms. The clinical manifestation varies greatly, with some cases presenting no symptoms, while others typically manifesting with heart failure, systemic embolism, and arrhythmias. Diagnosis mainly relies on assessing heart structure using imaging tools like echocardiography and cardiac magnetic resonance. However, the absence of a universally agreed-upon standard and limitations in diagnostic criteria have led to ongoing debates in the scientific community regarding the most reliable methods. Further research is crucial to enhance the diagnosis of LVNC, particularly in early life stages.