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.

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.

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.

Bilateral Renal Infarct in a Young Adult: Unveiling an Autoimmune Enigma.

A man in his late 20s presented to the emergency department with sudden-onset abdominal pain. Urinalysis was significant for hematuria and slightly elevated creatinine. A computed tomography (CT) scan with IV contrast revealed bilateral renal infarcts, which was corroborated by a computed tomography angiogram (CTA). Further evaluation by an autoimmune panel demonstrated a positive antinuclear antibody, while echocardiography showed left ventricular non-compaction cardiomyopathy. The workup included consultations with multiple specialities and additional investigations to assess hypercoagulability, vasculitis, and infectious etiologies. Following supportive care, the patient was discharged in stable condition with a plan for outpatient follow-up and further workup, including screening of first-degree family members for left ventricular non-compaction and associated cardiovascular risks. Here we describe a report of a rare case of bilateral renal infarct of possible thromboembolic etiology due to an underlying rare genetic cardiovascular condition.

Left Ventricular Non-compaction and Associated Cardiomyopathy Presenting With Cardiac Failure: A Case Report.

The characteristic structural anomaly of the heart in the left ventricular non-compaction (LVNC) is identified with a prominent layer of the trabecular meshwork, thin compacted myocardium, and intertrabecular recesses within the depths of the left ventricle. Despite growing clinical recognition, the prevalence of LVNC in adults and the full clinical spectrum remain poorly explored. The disease shows heterogeneous phenotypes from an asymptomatic presentation to severe cardiac complications like cardiac failure, arrhythmias, and thromboembolic events. Current diagnostic practices for LVNC lack standardized guidelines, making patient management difficult. We here report a case of an adult patient who presented with features of congestive cardiac failure and on detailed imaging with echocardiogram and magnetic resonance imaging (MRI) was diagnosed to have LVNC. We here also emphasize that there is a great need for refined diagnostic criteria that include genetic, clinical, and imaging data. Cases of LVNC with full-blown phenotypic expression should be used for diagnostic criteria.

Left ventricular function assessment including or excluding trabeculations in left ventricular non-compaction, a preliminary case-control cardiac magnetic resonance study.

Background: Functional assessment of compact myocardium and hypertrabeculations in left ventricular non-compaction (LVNC) is underestimated with regards to the morphological spectrum of disease. We aimed to assess whether measuring concurrently left ventricular (LV) volume, mass and ejection fraction (LVEF) with and without trabeculation inclusion on cine magnetic resonance (cineMR) could help diagnose patients with LVNC by comparison to normal individuals with an excess of myocardial trabeculations. Methods: This retrospective single center magnetic resonance imaging study (Bichat University Hospital) of 67 consecutive patients with echocardiographic hypertrabeculations seen at echocardiography between March 2011 and October 2018 included 30 patients with known LVNC and 16 control subjects with simple hypertrabeculations (non-compact/compact (NC/C) ratio between 1.8 and 2.2, trabeculations involving 10% to 17% of the left ventricle) using steady-state free precession (SSFP) cine sequences in the standard views. LV volumes, mass and LVEF were measured with and without trabeculation inclusion using CVI42 software. Follow-up was studied in 20 patients and 14 controls. Functional parameters were compared using Student's paired t-test. Pearson product moment correlation coefficients were calculated. Bland-Altman analysis determined the inter- and intra-reader functional data reproducibility. Results: When excluding the trabeculations (i.e. non-compacted myocardium) from measurements, LVEF was within normal ranges both in patients and controls, while it increased by 9.8%±1.6% in LVNC and decreased by 10.9%±1.4% in controls when trabeculae were included in the endocardial contours (P<0.0001). The overall myocardial mass remained stable according to the diastolic or systolic phase in LVNC whereas it significantly decreased in controls. Conclusions: Depending whether trabeculations were included or not, LVEF measurements were significantly different between patients with LVNC and controls. These distinctive measurements might be used as an adjunctive clinical tool to help confirm the diagnosis of LVNC.

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.

The impact of fragmented QRS on clinical findings and outcomes in children with dilated cardiomyopathy with or without left ventricular non-compaction.

OBJECTIVE: The aim of this study is to investigate the frequency of fragmented QRS and its associations with clinical findings and prognosis in children diagnosed with dilated cardiomyopathy with or without left ventricular non-compaction. METHODS: This retrospective study was conducted between 2010 and 2020. Patients with dilated cardiomyopathy were classified into two groups according to the presence of left ventricular non-compaction: Dilated cardiomyopathy with left ventricular non-compaction and dilated cardiomyopathy without left ventricular non-compaction. Patients were also divided into two groups according to the presence of fragmented QRS (fragmented QRS group and non-fragmented QRS group). RESULTS: Twenty-three of 44 patients (52.3%) were male. Among left ventricular non-compaction patients, the fragmented QRS group had more complex ventricular arrhythmias (p = 0.003). Patients with fragmented QRS had a significantly higher rate of major adverse cardiac events and/or cardiac death in both cardiomyopathy groups (p = 0.003 and p = 0.005). However, the rate of major adverse cardiac events and/or cardiac death was similar between dilated cardiomyopathy patients with and without left ventricular non-compaction. Multivariate logistic regression analysis showed that the presence of fragmented QRS strongly predicts major adverse cardiac events and/or cardiac death (odds ratio, 31.186; 95% confidence interval, 2.347-414.307). Although the survival rates between cardiomyopathy groups were similar, patients with fragmented QRS had a markedly lower survival rate during the follow-up period, as mean of 15 months (p = 0.001). CONCLUSION: Our study showed that the presence of fragmented QRS may be an important ECG sign predicting an major adverse cardiac event and/or cardiac death in patients with dilated cardiomyopathy. We believe that recognising fragmented QRS could be valuable in forecasting patient prognosis and identifying high-risk patients who require additional support.

Thinning of compact layer and systolic dysfunction in isolated left ventricular non-compaction: A cardiac magnetic resonance study.

BACKGROUND: The Petersen' index reflects an excess of myocardial trabeculation which is not a specific morpho-functional feature of left ventricular non-compaction (LVNC) cardiomyopathy, but a "phenotypic trait" even observed in association with other myocardial diseases and over-loading conditions. The present study was designed to evaluate the relation between a critical thinning of compact layer and the development of systolic dysfunction and LVNC cardiomyopathy. METHODS: We compared CMR morpho-functional features and measurements of LV wall thickness using a 17 segment model of a cohort of patients fulfilling the Petersen criterion for LVNC with LV systolic dysfunction versus those of a cohort of age- and sex-matched controls with LVNC and preserved LV systolic function. All the study patients had an "isolated" LVNC defined as positive Petersen criterion in the absence of other diseases such as hypertrophic and dilated cardiomyopathy, valvular heart disease, or congenital heart disease and over-loading conditions. RESULTS: he study population included 33 patients with "isolated" LVNC: 11 consecutive index patients with a reduced LV ejection fraction (LVNCrEF) and 22 controls with a preserved LVEF (LVNCpEF). The compact myocardial layer was thinner in patients with LVNCrEF than in those with LVNCpEF patients, both in mid-ventricular and apical LV segments. On linear regression analysis, there was a linear correlation between median thickness of mid-ventricular free wall segments and left ventricular ejection fraction (r = 0.51, p = 0.005). On the ROC curves analysis, ≥2 segments with a compact myocardial layer <5 mm in the free wall mid-ventricular segments showed the best accuracy for reduced LVEF (100% sensitivity and 60% specificity; AUC 0.81, p < 0.01). The negative predictive value for LV systolic dysfunction of <2 free wall mid ventricular segments <5 mm was 100%. On quantitative analysis, the mass of papillary muscles was lower in patients with LVNCrEF [1.2 (0.8-1.4) versus 1.6 (1.1-1.8) g/mq; p = 0.08]. CONCLUSIONS: A thinned compact layer of mid-ventricular segments of the LV free wall was associated with a reduced systolic function and "isolated" LVNC cardiomyopathy.

Improving a Deep Learning Model to Accurately Diagnose LVNC.

Accurate diagnosis of Left Ventricular Noncompaction Cardiomyopathy (LVNC) is critical for proper patient treatment but remains challenging. This work improves LVNC detection by improving left ventricle segmentation in cardiac MR images. Trabeculated left ventricle indicates LVNC, but automatic segmentation is difficult. We present techniques to improve segmentation and evaluate their impact on LVNC diagnosis. Three main methods are introduced: (1) using full 800 × 800 MR images rather than 512 × 512; (2) a clustering algorithm to eliminate neural network hallucinations; (3) advanced network architectures including Attention U-Net, MSA-UNet, and U-Net++.Experiments utilize cardiac MR datasets from three different hospitals. U-Net++ achieves the best segmentation performance using 800 × 800 images, and it improves the mean segmentation Dice score by 0.02 over the baseline U-Net, the clustering algorithm improves the mean Dice score by 0.06 on the images it affected, and the U-Net++ provides an additional 0.02 mean Dice score over the baseline U-Net. For LVNC diagnosis, U-Net++ achieves 0.896 accuracy, 0.907 precision, and 0.912 F1-score outperforming the baseline U-Net. Proposed techniques enhance LVNC detection, but differences between hospitals reveal problems in improving generalization. This work provides validated methods for precise LVNC diagnosis.

Clinical and genetic characteristics of catecholaminergic polymorphic ventricular tachycardia combined with left ventricular non-compaction.

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia is an ion channelopathy, caused by mutations in genes coding for calcium-handling proteins. It can coexist with left ventricular non-compaction. We aim to investigate the clinical and genetic characteristics of this co-phenotype. METHODS: Medical records of 24 patients diagnosed with catecholaminergic polymorphic ventricular tachycardia in two Chinese hospitals between September, 2005, and January, 2020, were retrospectively reviewed. We evaluated their clinical and genetic characteristics, including basic demographic data, electrocardiogram parameters, medications and survival during follow-up, and their gene mutations. We did structural analysis for a novel variant ryanodine receptor 2-E4005V. RESULTS: The patients included 19 with catecholaminergic polymorphic ventricular tachycardia mono-phenotype and 5 catecholaminergic polymorphic ventricular tachycardia-left ventricular non-compaction overlap patients. The median age of onset symptoms was 9.0 (8.0,13.5) years. Most patients (91.7%) had cardiac symptoms, and 50% had a family history of syncope. Overlap patients had lower peak heart rate and threshold heart rate for ventricular tachycardia and ventricular premature beat during the exercise stress test (p < 0.05). Sudden cardiac death risk may be higher in overlap patients during follow-up. Gene sequencing revealed 1 novel ryanodine receptor 2 missense mutation E4005V and 1 mutation previously unreported in catecholaminergic polymorphic ventricular tachycardia, but no left ventricular non-compaction-causing mutations were observed. In-silico analysis showed the novel mutation E4005V broke down the interaction between two charged residues. CONCLUSIONS: Catecholaminergic polymorphic ventricular tachycardia overlapping with left ventricular non-compaction may lead to ventricular premature beat/ventricular tachycardia during exercise stress test at lower threshold heart rate than catecholaminergic polymorphic ventricular tachycardia alone; it may also indicate a worse prognosis and requires strict follow-up. ryanodine receptor 2 mutations disrupted interactions between residues and may interfere the function of ryanodine receptor 2.

Left Ventricular Noncompaction Cardiomyopathy and Myocardial Bridging Association: A Coincidence Or a Usual Association?

Left ventricular non compaction (LVNC) is a rare congenital disease. It occurs due to an arrest of the myocardial fibers compaction during embryogenesis. Myocardial bridge (MB) is a coronary anomaly in which the myocardium. covers segments of the coronary arteries. We report a rare case of 62-year-old women who was diagnosed with the association of LVNC and MB revealed by chest pain and dyspnea. Some similar cases were reported in the last two decades suggesting that we may be in front of a usual yet underdiagnosed association. To our knowledge, this is the first case described in the Arab World.

A Rare Case of an Infant With 1p36 Deletion Syndrome Presenting With Systolic Heart Failure Secondary to Severe Dilated Cardiomyopathy.

1p36 deletion syndrome is a common terminal chromosomal deletion syndrome in humans. It is caused by the deletion of genetic material from a specific region in the short arm of chromosome 1. Symptoms range from seizure disorders, abnormalities of tone, visual and auditory disturbances. Cardiac abnormalities like left ventricular non-compaction (LVNC) and dilated cardiomyopathies (DCM) are commonly associated with this syndrome. This case report presents a 15-month-old female with dilated cardiomyopathy associated with 1p36 deletion syndrome, who has been followed from birth. Cardiac function was normal at birth with an ejection fraction of 65%. At three weeks of age, the patient presented with severe tachypnea, cyanosis, poor weight gain, and diaphoresis with feeding. Echocardiogram showed an ejection fraction of 22%. The patient was diagnosed with Modified Ross Heart Failure Class III. The patient was admitted to the cardiovascular intensive care unit where diuretics, phosphodiesterase inhibitors, and ionotropic agents were used to manage the heart failure. The patient relapsed two months later following a severe adenovirus infection. She was readmitted and heart failure medications were optimized. This patient has maintained a steady growth, meeting most milestones with no further relapse. The heterogeneity of 1p36 deletion syndrome presentation poses a diagnostic challenge for most clinicians. Cardiac involvements are very common and infants presenting with signs and symptoms of heart failure need to be screened for chromosomal abnormalities when other causes have been ruled out.

Marfan Syndrome, Giant Ascending Aortic Aneurysm, and Left Ventricular Noncompaction: The Heart in Jeopardy!

Marfan syndrome (MFS) is a heritable connective tissue disorder that is caused by a mutation of the FBN1 gene. It is characterized by cardiovascular, skeletal, and ocular manifestations, with thoracic aortic aneurysms being the main cardiovascular complication. Unconventionally, MFS can present with left ventricular noncompaction (LVNC), which introduces a supplementary aspect of cardiac dysfunction. We herein report the case of a 42-year-old male with MFS who presented with congestive heart failure and cardiogenic shock. His transthoracic echocardiography revealed a giant aortic root aneurysm, causing severe aortic regurgitation and dilated cardiomyopathy, along with LVNC. This case provides a brief overview of this rare medical condition, particularly the natural history of ascending thoracic aortic aneurysm, which is considered a silent complication and the most life-threatening one, combined with LVNC that correspondingly impairs the heart.

Case Report: Non-ossifying fibromas with pathologic fractures in a patient with NONO-associated X-linked syndromic intellectual developmental disorder.

The NONO gene encodes a nuclear protein involved in transcriptional regulation, RNA synthesis and DNA repair. Hemizygous loss-of function, de novo or maternally inherited variants in NONO have been associated with an X-linked syndromic intellectual developmental disorder-34 (OMIM # 300967), characterized by developmental delay, intellectual disability, hypotonia, macrocephaly, elongated face, structural abnormalities of corpus callosum and/or cerebellum, congenital heart defect and left ventricular non-compaction cardiomyopathy. Few patients have been described in the literature and the phenotype data are limited. We report a 17-year-old boy with dolihocephaly, elongated face, strabismus, speech and motor delay, intellectual disability, congenital heart defect (ASD, VSD and Ebstein's anomaly), left ventricular non-compaction cardiomyopathy, bilateral inguinal hernia and cryptorchidism. Additional features included recurrent fractures due to multiple non-ossifying fibromas, thrombocytopenia, and renal anomalies. Exome sequencing revealed a de novo pathogenic variant (NM_001145408.2: c.348+2_ 348+15del) in intron 5 of the NONO gene. Renal anomalies and thrombocytopenia have been rarely reported in patients with NONO-X-linked intellectual disability syndrome, while recurrent fractures due to multiple non-ossifying fibromas have not previously been associated with this syndrome. The phenotypic spectrum of NONO-X-linked intellectual disability syndrome may be broader than currently known.

Prinzmetal angina in a child with actin gene ACTC1 mutation.

Prinzmetal angina is a rare cause of intermittent chest pain in paediatrics. Here, we report the case of a 2-year-old female who presented with episodic chest pain, malaise, diaphoresis, fatigue, and poor perfusion on exam. During her hospitalisation, these episodes were associated with significant low cardiac output as evidenced by lactic acidosis and low mixed venous oxygen saturations. Her workup revealed an actin alpha cardiac muscle 1 (ACTC1) gene mutation and associated left ventricular non-compaction with decreased systolic function. She was started on oral heart failure medications as well as a calcium channel blocker but continued to have episodes which were found to promptly resolve with nitroglycerine. She was ultimately listed for cardiac transplant given her perceived risk of sudden death.

Anomalous origin of the left circumflex artery from the pulmonary artery associated with non-compaction of the left ventricle: usefulness of multimodality imaging-a case report.

Background: The anomalous origin of the left circumflex artery from the pulmonary artery (ACXAPA) is a very rare coronary anomaly. Only a few cases have been reported until today, from incidental findings to autopsy reports after sudden cardiac death. Case summary: We report here for the first time the case of a man, previously monitored for asymptomatic left ventricular non-compaction cardiomyopathy, who presented with non-ST myocardial infarction and was diagnosed with ACXAPA. Complementary tests confirmed ischaemia in the corresponding territory, and the patient was referred to surgery for reimplantation of the circumflex artery. Discussion: Left ventricular non-compaction cardiomyopathy is a rare congenital cardiomyopathy whose association with coronary anomalies, not with ACXAPA, had previously been described until now. A related embryological origin could potentially explain this association. The management of a coronary anomaly should indicate dedicated multimodality cardiac imaging in order to not disregard the association with underlying cardiomyopathy.

Multimodality Imaging and Biomarker Approach to Characterize the Pathophysiology of Heart Failure in Left Ventricular Non-Compaction with Preserved Ejection Fraction.

Left ventricular non-compaction (LVNC) with preserved ejection fraction (EF) is still a controverted entity. We aimed to characterize structural and functional changes in LVNC with heart failure with preserved EF (HFpEF). METHODS: We enrolled 21 patients with LVNC and HFpEF and 21 HFpEF controls. For all patients, we performed CMR, speckle tracking echocardiography (STE), and biomarker assessment for HFpEF (NT-proBNP), for myocardial fibrosis (Galectin-3), and for endothelial dysfunction [ADAMTS13, von Willebrand factor, and their ratio]. By CMR, we assessed native T1 and extracellular volume (ECV) for each LV level (basal, mid, and apical). By STE, we assessed longitudinal strain (LS), globally and at each LV level, base-to-apex gradient, LS layer by layer, from epicardium to endocardium, and transmural deformation gradient. RESULTS: In the LVNC group, mean NC/C ratio was 2.9 ± 0.4 and the percentage of NC myocardium mass was 24.4 ± 8.7%. LVNC patients, by comparison with controls, had higher apical native T1 (1061 ± 72 vs. 1008 ± 40 ms), diffusely increased ECV (27.2 ± 2.9 vs. 24.4 ± 2.5%), with higher values at the apical level (29.6 ± 3.8 vs. 25.2 ± 2.8%) (all p < 0.01); they had a lower LS only at the apical level (-21.4 ± 4.4 vs. -24.3 ± 3.2%), with decreased base-to-apex gradient (3.8 ± 4.7 vs. 6.9 ± 3.4%) and transmural deformation gradient (3.9 ± 0.8 vs. 4.8 ± 1.0%). LVNC patients had higher NT-proBNP [237 (156-489) vs. 156 (139-257) pg/mL] and Galectin-3 [7.3 (6.0-11.5) vs. 5.6 (4.8-8.3) ng/mL], and lower ADAMTS13 (767.3 ± 335.5 vs. 962.3 ± 253.7 ng/mL) and ADAMTS13/vWF ratio (all p < 0.05). CONCLUSION: LVNC patients with HFpEF have diffuse fibrosis, which is more extensive at the apical level, explaining the decrease in apical deformation and overexpression of Galectin-3. Lower transmural and base-to-apex deformation gradients underpin the sequence of myocardial maturation failure. Endothelial dysfunction, expressed by the lower ADAMTS13 and ADAMTS13/vWF ratio, may play an important role in the mechanism of HFpEF in patients with LVNC.