Isolated non-compaction cardiomyopathy

LEFT VENTRICULAR NONCOMPACTION CARDIOMYOPATHY: A SCOPING REVIEW

Introduction

There has been an upsurge in the reporting of cases of Left Ventricular Noncompaction (LVNC) cardiomyopathy in medical literature in the last 35 years due to advances in medical imaging.The condition was first described in 1926 and the first reported case by echocardiography was in 1984. The American Heart Association considers LVNC a primary cardiomyopathy of genetic origin, while the European Society of Cardiology and the World Health Organization grouped it as an unclassified cardiomyopathy. Its variability in terms of genetic profile, phenotypic expression, clinical presentation, and histopathological findings makes it somewhat a variant of other cardiomyopathies.

Case presentation

Patients with LVNC cardiomyopathy may not have any symptoms or may present with ventricular arrhythmias, heart failure, thromboembolism, or sudden death. LVNC cardiomyopathy diagnosis is typically made by echocardiography, although there are higher resolution cardiac imaging techniques. Management will depend on the patient's clinical presentation. Due to its genetic association, there is a need to screen living relatives once the diagnosis is made in an individual.

Conclusion

The aim of this paper is to review current knowledge on this condition.

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.

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.

Case report: Prenatal diagnosis of fetal non-compaction cardiomyopathy with bradycardia accompanied by de novo CALM2 mutation

We herein report what appears to be the first case of fetal non-compaction cardiomyopathy in both ventricles accompanied by a mutation in the calmodulin gene (CALM2). A 25-year-old woman was referred to our hospital at 25⁺¹ weeks of gestation for evaluation of fetal defects. Prenatal echocardiography showed biventricular non-compaction cardiomyopathy with sinus bradycardia. After termination of the pregnancy, fetal biventricular non-compaction cardiomyopathy was confirmed by autopsy and histopathologic examination. Additionally, whole-exome sequencing of genomic DNA demonstrated a de novo heterozygous mutation (c.389A > G; p.D130G) in CALM2, whereas the parents were normal. In this case report, we highlight the importance of prenatal ultrasound and genetic testing in fetal non-compaction cardiomyopathy with arrhythmia.

Noncompaction Cardiomyopathy-History and Current Knowledge for Clinical Practice

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

Effects of Race, Cardiac Mass, and Cardiac Load on Myocardial Function Trajectories from Childhood to Young Adulthood: The Augusta Heart Study

Background

The overall goal of this longitudinal study was to determine if the Black population has decreased myocardial function, which has the potential to lead to the early development of congestive heart failure, compared with the White population.

Methods and Results

A total of 673 subjects were evaluated over a period of 30 years including similar percentages of Black and White participants. Left ventricular systolic function was probed using the midwall fractional shortening (MFS). A longitudinal analysis of the MFS using a mixed effect growth curve model was performed. Black participants had greater body mass index, higher blood pressure readings, and greater left ventricular mass compared with White participants (all P<0.01). Black participants had a 0.54% decrease of MFS compared with White participants. As age increased by 1 year, MFS increased by 0.05%. As left ventricular mass increased by 1 g, MFS decreased by 0.01%. As circumferential end systolic stress increased by 1 unit, MFS decreased by 0.04%. The MFS trajectories for race differed from early age to young adulthood.

Conclusions

Changes in myocardial function mirror the race‐dependent variations in blood pressure, afterload, and cardiac mass, suggesting that myocardial function depression occurs early in childhood in populations at high cardiovascular risk such as Black participants.

Reduced Systolic Function and Not Genetic Variants Determine Outcome in Pediatric and Adult Left Ventricular Noncompaction Cardiomyopathy

Background: Left ventricular noncompaction cardiomyopathy (LVNC CMP) is a genetic cardiomyopathy. Genotype-phenotype correlation and clinical outcome of genetic variants in pediatric and adult LVNC CMP patients are still unclear. Methods: The retrospective multicenter study was conducted in unrelated index patients with LVNC CMP, diagnosed between the years 1987 and 2017, and all available family members. All index patients underwent next-generation sequencing for genetic variants in 174 target genes using the Illumina TruSight Cardio Sequencing Panel. Major adverse cardiac events (MACE) included mechanical circulatory support, heart transplantation, survivor of cardiac death, and/or all-cause death as combined endpoint. Results: Study population included 149 LVNC CMP patients with a median age of 27.8 (9.2-44.8) years at diagnosis; 58% of them were symptomatic, 18% suffered from non-sustained and sustained arrhythmias, and 17% had an implantable cardioverter defibrillator (ICD) implanted. 55/137 patients (40%) were ≤ 18 years at diagnosis. A total of 134 variants were identified in 87/113 (77%) index patients. 93 variants were classified as variant of unknown significance (VUS), 24 as likely pathogenic and 15 as pathogenic. The genetic yield of (likely) pathogenic variants was 35/113 (31%) index patients. Variants occurred most frequently in MYH7 (n=19), TTN (n = 10) and MYBPC3 (n = 8). Altogether, sarcomere gene variants constituted 42.5% (n = 57) of all variants. The presence or absence of (likely) pathogenic variants or variants in specific genes did not allow risk stratification for MACE. Reduced left ventricular (LV) systolic function and increased left ventricular end-diastolic diameter (LVEDD) were risk factors for event-free survival in the Kaplan-Meier analysis. Through multivariate analysis we identified reduced LV systolic function as the main risk factor for MACE. Patients with reduced LV systolic function were at a 4.6-fold higher risk for MACE. Conclusions: Genetic variants did not predict the risk of developing a MACE, neither in the pediatric nor in the adult cohort. Multivariate analysis emphasized reduced LV systolic function as the main independent factor that is elevating the risk for MACE. Genetic screening is useful for cascade screening to identify family members at risk for developing LVNC CMP.

[Left ventricular noncompaction]

This paper provides a literature review on left ventricular noncompaction (noncompact cardiomyopathy). It details the historical aspects, epidemiology, ethology, pathophysiology, clinical features, diagnosis, treatment, and prognosis of this abnormality.

Presyncope – not always an orthostatic problem

A 41-year-old female was brought to the ER after a presyncope and absence episode while riding a bike. She recalled no prodromi. Her physical and neurological examinations were unremarkable; past medical, family, substance, and travel history bland. She reported a constant tiredness, sporadic slight cephalgia, responsive to acetaminophen, and a recent syncope while jogging, resulting in a fall, circumstances of which she could not recall. Non-compaction cardiomyopathy is a type of cardiomyopathy that was first described 25 years ago. Its molecular genetic basis is not yet fully clear, and the same is true of its diagnosis, treatment, and prognosis. Further study of these matters is needed.

Right ventricular free wall dyskinesis in the setting of left ventricular non compaction: a case report

Background

Left ventricular non compaction is a relatively rare congenital disorder characterized by prominent trabeculations and intertrabecular recesses with the potential for thromboembolism, arrhythmias, and sudden cardiac death as adverse effects. Echocardiography has traditionally been employed as the primary mode of imaging; however, with the advent of cardiac magnetic resonance as a more precise imaging technique, the disorder known as left ventricle non compaction is becoming more broadly defined with increasing recognition of right ventricle (RV) involvement.

Case presentation

This report describes a 52-year-old Caucasian female with new onset atrial fibrillation with an unusual finding of left ventricular non compaction and right ventricular dysfunction on transthoracic echocardiogram with preserved left ventricular ejection fraction. Cardiac magnetic resonance imaging demonstrated a disproportionately affected right ventricle, with apical free wall dyskinesis.

Conclusions

This case illustrates the unique occurrence of left ventricular non compaction with preserved ejection fraction alongside RV free wall dyskinesis and RV systolic dysfunction. The significance of this is yet unknown given the paucity of existing literature. This report serves to highlight the vast heterogeneity within left ventricular non compaction as we are better able to delineate this disorder using increasingly sophisticated imaging techniques.

Revisiting Non-Compaction Cardiomyopathy Through a Case with Cyanosis and Complete Heart Block

Left ventricular non-compaction or “spongy myocardium”, is a rare congenital cardiomyopathy that should be considered as a possible diagnosis because of its potential complications. Echocardiography is the diagnostic tool of choice, and cardiomagnetic resonance (CMR) can confirm or rule out this disease. Herein, we report the case of an 8-month-old female child who presented with congestive cardiac failure (CCF) and symptomatic complete heart block (CHB). An echocardiogram established the diagnosis as non-compaction cardiomyopathy (NCCM). An associated double outlet right ventricle with ventricular septal defect and valvular pulmonary stenosis was found. Cardiac magnetic resonance study confirmed the findings. This singular case report of NCCM highlights the importance of clinical awareness of this rare abnormality, its varied presentation and associated cardiac anomalies. The article revisits NCCM and focuses on the practical issues for a proper echodiagnosis.

A novel method for quantification of left ventricular noncompaction using two-dimensional echocardiography in children

OBJECTIVE

Although there are several echocardiographic criteria, there is not yet a general consensus about the diagnosis of left ventricular noncompaction. The current criteria are mostly based on the areas with maximal noncompaction in the heart. The echocardiographer may miss this maximal point leading to a misdiagnosis. Accordingly, we suggested a new method to measure the percentage of myocardial noncompaction using two-dimensional echocardiography.

METHODS

In this study, the new method was examined on 4 noncompaction and 26 dilated cardiomyopathies, and 25 normal subjects. The percentage of noncompaction was measured at 3 levels (apical, papillary muscle and mitral valve) and averaged.

FINDINGS

The mean percentages of myocardial noncompaction were 3.59±2.27, 8.86±5.52 and 34.7±26.1 in the control, dilated cardiomyopathy and noncompaction groups, respectively. A value of 17% or greater could distinguish left ventricular noncompaction from dilated cardiomyopathy with 92% specificity and 100% sensitivity and from normal subjects with 100% specificity and sensitivity. This percentage had a statistically significant association with noncompacted to compacted myocardial thickness ratio (P<0.001).

CONCLUSION

This method showed good correlations with the existing echocardiographic and magnetic resonance criteria. However, it is not dependent on finding the area of maximal involvement. Being comparable to magnetic resonance imaging in accuracy, it is easier to perform and more available.

[Cardiac magnetic resonance tomography in the diagnostics of restrictive and unclassified cardiopathies]

CLINICAL/METHODICAL ISSUE

Besides ischemic heart disease cardiomyopathies are common causes of heart failure and sudden cardiac death.

STANDARD RADIOLOGICAL METHODS

The diagnostic spectrum in cardiomyopathies comprises non-invasive and invasive examination techniques.

METHODICAL INNOVATIONS

The exact verification of certain cardiomyopathies necessitates knowledge of the latest classification of cardiomyopathies as well as dedicated examination protocols.

PERFORMANCE

Modern imaging modalities, such as echocardiography and cardiac magnetic resonance imaging (MRI) have emerged as useful imaging tools in the investigation of patients suspected of having many different types of cardiomyopathies.

ACHIEVEMENTS

Based on a better understanding of the underlying pathophysiology several diagnostic criteria have been defined using cardiac MRI. In particular there is an increasing importance of cardiac MRI in the description of patients with restrictive and unclassified cardiomyopathies.

PRACTICAL RECOMMENDATIONS

Echocardiography still remains the modality of choice in the diagnostics of unclear left ventricular heart failure. Further diagnostic work-up should include cardiac MRI in case of any lack of clarity.

Ethnic differences in ventricular hypertrabeculation on cardiac MRI in elite football players

PURPOSE

Left ventricular (LV) trabeculation may be more pronounced in ethnic African than in Caucasian (European) athletes, leading to possible incorrect diagnosis of left ventricular non-compaction cardiomyopathy (LVNC). This study investigates ethnic differences in LV hypertrabeculation amongst elite athletes with cardiac magnetic resonance (CMR) and electrocardiography (ECG).

METHODS

38 elite male football (soccer) players (mean age 23.0, range 19-34 years, 28/38 European, 10/38 African) underwent CMR and ECG. Hypertrabeculation was assessed using the ratio of non-compacted to compacted myocardium (NC/C ratio) on long-axis and short-axis segments. ECGs were systematically rated.

RESULTS

No significant differences were seen in ventricular volumes, wall mass or E/A ratio, whereas biventricular ejection fraction (EF) was significantly lower in African athletes (European/African athletes LVEF 55/50 %, p = 0.02; RVEF 51/48 %, p = 0.05). Average NC/C ratio was greater in African athletes but only significantly at mid-ventricular level (European/African athletes: apical 0.91/1.00, p = 0.65; mid-ventricular 0.89/1.45, p < 0.05; basal 0.40/0.46, p = 0.67). ECG readings demonstrated no significant group differences, and no correlation between ECG anomalies and hypertrabeculation.

CONCLUSIONS

A greater degree of LV hypertrabeculation is seen in healthy African athletes, combined with biventricular EF reduction at rest. Recognition of this phenomenon is necessary to avoid misdiagnosis of LVNC.

[Isolated noncompaction cardiomyopathy with special emphasis on arrhythmia complications]

Isolated noncompaction cardiomyopathy (NCCM) is a rare genetically determined myocardial disease caused by abnormal fetal development of the myocardium resulting in a thin compacted and a thicker noncompacted layer of the affected left ventricular (LV) wall. The genetic basis of NCCM is heterogenous. Diagnosis can be made using echocardiography or magnetic resonance imaging. The diagnostic criteria for NCCM are still under discussion. Afflicted patients may present with various symptoms caused by arrhythmias, heart failure and cardioembolic events. Severely reduced LV function as well as left bundle branch block and atrial fibrillation were shown to be linked to worse outcomes. Treatment in patients with NCCM should be targeted at individual symptoms and clinical findings. Therapy includes pharmacological treatment, and in individual cases ablation or device therapy, as well as consideration for heart transplantation in selected cases. Aside from regular clinical follow-up of patients with NCCM screening of first degree family members with assessment of medical history, physical examination, ECG recording, and echocardiography are recommended.

The first reported case of non-compacted cardiomyopathy in a preterm infant with Ebstein's anomaly

Non-compaction of the ventricular myocardium is a congenital dysfunction of ventricular morphogenesis caused by the arrest of normal embryogenesis of the ventricles. It is considered as a rare disease and can involve both ventricles but commonly the left ventricle. It is classified into isolated non-compaction of the ventricles and non-compaction associated with other congenital heart defects. Its association with Ebstein's anomaly is very rare. We are reporting a rare case of severe heart failure and complex cardiac anomaly including biventricular non-compaction cardiomyopathy, Ebstein's anomalies and large patent ductus arteriosus with severe persistent pulmonary hypertension in a 31-weeks-old preterm infant. The infant recovered smoothly and continued to be asymptomatic and off medications throughout his 2 years follow-up period. Up to our knowledge, this is the youngest and first patient yet reported to have this disease at this age with good recovery.