MR appearance of isolated noncompaction of the left ventricle

Cardiomyopathies Due to Left Ventricular Noncompaction, Mitochondrial and Storage Diseases, and Inborn Errors of Metabolism

The normal function of the human myocardium requires the proper generation and utilization of energy and relies on a series of complex metabolic processes to achieve this normal function. When metabolic processes fail to work properly or effectively, heart muscle dysfunction can occur with or without accompanying functional abnormalities of other organ systems, particularly skeletal muscle. These metabolic derangements can result in structural, functional, and infiltrative deficiencies of the heart muscle. Mitochondrial and enzyme defects predominate as disease-related etiologies. In this review, left ventricular noncompaction cardiomyopathy, which is often caused by mutations in sarcomere and cytoskeletal proteins and is also associated with metabolic abnormalities, is discussed. In addition, cardiomyopathies resulting from mitochondrial dysfunction, metabolic abnormalities, storage diseases, and inborn errors of metabolism are described.

Evaluation and management of left ventricular noncompaction cardiomyopathy

Left ventricular (LV) noncompaction cardiomyopathy (LVNC) is a form of cardiomyopathy in which trabeculations fail to "compact" with the left ventricular endocardium during fetal cardiac development and is classically associated with subsequent impairment of LV function, significant mortality, ventricular dysrhythmias, and embolic phenomena. As awareness and medical imaging quality have improved, it is becoming easier to identify trabeculations that traverse the LV cavity and serve as a distinguishing feature of this disorder. Differentiating true noncompaction from mild increases in trabeculations requires prudent imaging and clinical correlation. This review seeks to discuss the potential methods of evaluating left ventricular trabeculations, the role of increased trabeculations in cardiovascular disease, and how their presence may affect clinical management.

Left ventricular noncompaction and myocardial fibrosis: a case report

Background

Left ventricular noncompaction (LVNC) is a rare congenital abnormality. It is currently classified as a genetic cardiomyopathy and results from early arrest of endomyocardial morphogenesis. The pathophysiology of left ventricular dysfunction, which becomes apparent beyond the 4^th decade of life, is unclear.

Case report

We report a case of 60-year-old woman who presented with shortness of breath and showed noncompacted endocardium on echocardiography. Cardiac catheterization and viral studies were unremarkable. Histology revealed endomyocardial fibrosis without disarray. She was subsequently diagnosed with LVNC and treated with medications.

Discussion

Cardiologists and other physicians should be aware of LVNC due to its high likelihood of misdiagnosis and associated high complication rates. Early diagnosis, intervention and screening among family members can decrease the morbidity and mortality associated with LVNC.

Is left ventricular noncompaction in children truly an isolated lesion?

Left ventricular noncompaction (LVNC) is a form of cardiomyopathy resulting from a disorder of endomyocardial morphogenesis. It has been associated with significant morbidity and mortality. The aim of this study was to characterize associated cardiac findings in children with LVNC and to identify risk factors associated with increased mortality. From our echocardiography database, we identified 46 patients diagnosed with LVNC between December 1999 and February 2005. The mean age at presentation was 3.6 +/- 5.6 years, and the mean duration of follow-up was 1.9 +/- 2.1 years. Left ventricular ejection fraction was decreased in 24 patients (52%; mean 39.5% +/- 13.1%). Thirty-six patients (78%) had associated cardiac lesions, including atrial septal defect (n = 16 [35%]), ventricular septal defect (n = 17 [37%]), patent ductus arteriosus (n = 14 [30%]), and Ebstein's anomaly (n = 5 [11%]). Electrocardiogram abnormalities were found in 80% of patients; most commonly they included left (n = 15 [43%]) and right ventricular hypertrophy (n = 19 [54%]). Documented arrhythmias included ectopic atrial rhythm (n = 2), junctional rhythm (n = 2), supraventricular tachycardia (n = 2), and ventricular tachycardia (n = 1). Overall mortality was 20%, and there was no association with ejection fraction, morphologic defect, or arrhythmia. Mean age at diagnosis in survivors (4.5 +/- 6.1 years) was higher than nonsurvivors (0.4 +/- 0.7 years) (p < 0.0001). LVNC is a rarely isolated form of cardiomyopathy, and it is associated with significant additional cardiac abnormalities. Although it does not have an invariably fatal course, early presentation in infancy does carry an increased risk of mortality.

Echocardiography in the diagnosis left ventricular noncompaction

Echocardiography is the method of choice to establish a diagnosis and determine a treatment plan for patients with noncompaction of ventricular myocardium (NVM). The 2-dimentional echocardiography, 3-dimentional echocardiography, color Doppler echocardiography and contrast-enhanced echocardiography are of critical importance for diagnosis and family screening of NVM.

Diagnosing left ventricular noncompaction by echocardiography and cardiac magnetic resonance imaging and its dependency on neuromuscular disorders

BACKGROUND

Left ventricular hypertrabeculation (LVHT), also termed noncompaction LVHT, is diagnosed by echocardiography or cardiac magnetic resonance imaging (CMRI), and associated with neuromuscular disorders (NMD). The aim of this study was to assess if LVHT can be diagnosed by CMRI applying echocardiographic definitions.

METHODS AND RESULTS

The CMRI images of 19 echocardiographically diagnosed LVHT patients were re-evaluated (10 female, 14-67 y of age). Left ventricular hypertrabeculation was diagnosed by CMRI in 9 cases. Patients with CMRI-diagnosed LVHT were more often females (67% versus 40%), experienced heart failure more often (100% versus 50%), had an LV end diastolic diameter > 57 mm (67% versus 40%), had an LV fractional shortening < 25% (89% versus 40%), and had a larger extension of LVHT than patients without CMRI-diagnosed LVHT. The prevalence of NMD (87%) did not differ between both groups.

CONCLUSIONS

Echocardiographic definition for CMRI yielded the diagnosis of LVHT in only 47%. When looking for LVHT by CMRI, LV size, function, and extension of LVHT have to be considered.

Angiographic diagnosis, prevalence and outcomes for left ventricular noncompaction in children with congenital cardiac disease

Little is known about the implications of left ventricular noncompaction in children with additional congenital cardiac malformations. With this in mind, we conducted a retrospective review of every left ventricular angiogram performed in a single tertiary referral centre for paediatric cardiology, in Melbourne, Australia, between 1994 and 2000 in children with congenital heart disease, looking specifically for patients with angiographic evidence of noncompaction of the left ventricle. The outcome of patients identified as having noncompaction was compared with that of patients from the same population, stratified by their primary congenital cardiac malformation. Of 1515 children undergoing left ventricular angiography, 31, with 13 being male, were found to have angiographic evidence of left ventricular noncompaction, giving a prevalence of 2% (95% CI: 1.3%-2.8%). Of 69 (22%) children with a functionally single left ventricle, 15 fulfilled the criterions for noncompaction, compared to 16 of 1446 (1.1%) children with a balanced ventricular arrangement (p is less than 0.0001). The presence of noncompaction and a functionally single left ventricle were each associated with a doubling of mortality, the effect being cumulative. Of surviving patients with left ventricular noncompaction, 19% (4%-34%) have left ventricular dysfunction at their latest follow-up. We suggest that the important late sequels of noncompaction justify careful scrutiny for this entity in children with congenital cardiac disease.

Left ventricular noncompaction: A rarity or something else

<zakljucak> Nedovoljno formiran miokard je atipicna forma kardiomiopatije koju treba poznavati i na koju treba misliti pri rutinskim ehokardiografskim pregledima. Novija istrazivanja ukazuju da LVNC ima vecu prevalenciju zahvaljujuci poboljsanju imaging tehnika. Kako su kriterijumi za dijagnozu LVNC prvenstveno ehokardiografski, potrebno je upoznati lekare koji se bave ultrazvucnim pregledima srca sa osnovnim karkteristikama ovog oboljenja, kako bi ga u buducnosti lakse prepoznali. Nedovoljno formiran miokard je udruzen sa drugim nesrcanim oboljenjima, kao sto su neuromuskularna oboljenja. Predlaze se skrining bolesnika, narocito u porodicama sa neuromuskularnim oboljenjima da bi se pronasli bolesnici sa LVNC, kao i skrining bolesnika sa LVNC kako bi se otkrila neuromuskularna oboljenja. Kod familijarnog javljanja bolesti utvrdjena je genetska osnova nasledjivanja. Zbog pretpostavke da postoji dug preklinicki period, potrebno je da se otkriju bolesnici u asimptomatskoj ili oligosimptomatskoj fazi, kako bi se pratili i pravilno tretirali. Iako postoje kontroverze koje se odnose na etiologiju, patogenezu, dijagnosticke kriterijume i prognozu, vecina istrazivaca izrazava stav da i ovu kardiomiopatiju SZO treba da svrsta u poseban entitet.

Pitfalls in the diagnosis of left ventricular hypertrabeculation/non-compaction

Left ventricular hypertrabeculation/non-compaction (LVHT) is a cardiac abnormality, characterised by >3 trabeculations apically to the papillary muscles and intertrabecular spaces. LVHT may occur with other cardiac abnormalities, heart failure, electrocardiographic abnormalities and neuromuscular disorders. This study gives an overview about (1) patients with LVHT in whom LVHT was initially overlooked and (2) cardiac conditions that may lead to falsely diagnosed LVHT. In 50 reported cases, LVHT has been overlooked and misdiagnosed as dilated (n = 20), hypertrophic (n = 14) or restrictive cardiomyopathy (n = 2), endocardial fibroelastosis (n = 5), endomyocardial fibrosis (n = 1), myocarditis (n = 3), thrombus (n = 2), localised left ventricular hypertrophy (n = 1), left ventricular mass (n = 1) or myocardial/pericardial disease (n = 1). In 14 patients, LVHT was diagnosed only by transoesophageal echocardiography (n = 1), computed tomography (n = 2) ventriculography (n = 2), magnetic resonance imaging (n = 3) or pathoanatomic findings (n = 6). Falsely diagnosed LVHT comprises false tendons, aberrant bands, thrombi, apical hypertrophic cardiomyopathy, fibroma, obliterative processes, intramyocardial haematoma, cardiac metastases and intramyocardial abscesses. Echocardiographers should be more aware of LVHT and consider its differential diagnoses.

Echocardiography in the diagnosis and management of isolated left ventricular noncompaction: case reports and review of the literature

Isolated left ventricular noncompaction (IVNC) is a congenital cardiomyopathy characterized by a loosened spongy myocardium. Recognition of this condition is extremely important because of its high mortality and morbidity due to progressive heart failure, thromboembolic events, and ventricular arrhythmias. However, IVNC is commonly misdiagnosed because of the lack of knowledge about this rare disorder. We report 2 patients with the characteristic echocardiographic presentation for IVNC. Echocardiography is the procedure of choice to confirm the diagnosis and perform follow-up in patients with IVNC; therefore, it is important to make echocardiographers more familiar with this condition.

Familial biventricular myocardial noncompaction associated with Ebstein's malformation

BACKGROUND

Noncompaction of the ventricular myocardium is a rare congenital cardiomyopathy characterized by numerous excessively prominent trabeculations and deep intertrabecular recesses. Noncompaction of the ventricular myocardium is most often an isolated cardiac malformation presenting as a sporadic disease. Associated cardiac anomalies are present in some patients. We report a family with three adult males from consecutive generations having a biventricular form of noncompaction of the myocardium. Two of the patients have an associated Ebstein's malformation of the tricuspid valve.

METHODS

Clinical evaluation and follow-up, electrocardiography, echocardiography, heart catheterization, coronary angiography, contrast cineventriculography, and magnetic resonance imaging.

RESULTS AND CONCLUSIONS

The association of noncompaction of the ventricular myocardium and Ebstein's malformation has not been reported so far. We believe that both defects were caused by a developmental arrest of the right ventricular myocardium. Echocardiography is the diagnostic modality of choice in patients and in the male relatives, irrespective of their clinical status. Thromboembolic events, cardiac rhythm disorders and heart failure mandate treatment. Anticoagulation treatment and implantation of cardioverter-defibrillator pacemaker have to be strongly considered in these patients.

Isolated Left Ventricular Noncompaction of the Myocardium as a Cause of Embolic Superior Mesenteric Artery Occlusion

Isolated noncompaction of the left ventricular (LV) myocardium is a rare congenital disorder resulting from an arrest of the compaction process of the myocardial trabeculae during normal embryogenesis. It is characterized by the presence of prominent LV myocardial trabeculations and deep intertrabecular recesses that are in continuity with the LV cavity. The most common clinical presentation includes progressive LV dysfunction, life-threatening tachyarrhythmias, and the risk for severe cardioembolic events. We describe a case where isolated noncompaction of the LV myocardium was diagnosed after an embolic occlusion of the superior mesenteric artery in a 40-year-old Caucasian woman.

Isolated noncompaction involving the left ventricular apex in adults

We present a series of 9 adults in 2 families with isolated noncompaction of the ventricular myocardium involving the left ventricular apex. Three of these patients had been previously misdiagnosed as having dilated cardiomyopathy, apical hypertrophic cardiomyopathy, or apical mural thrombus. Phenotypic variation was observed with gradation of severity of noncompaction and left ventricular systolic dysfunction between first-degree relatives.

Left ventricular hypertrabeculation/noncompaction

In normal human hearts the left ventricle (LV) has up to 3 prominent trabeculations and is, thus, less trabeculated than the right ventricle. Rarely, more than 3 prominent trabeculations can be found at autopsy and by various imaging techniques in the LV. For this abnormality, different synonyms are used such as spongy myocardium, LV noncompaction, and LV hypertrabeculation (LVHT). In this review it is stated that: (1) LVHT has a higher prevalence than previously thought and the prevalence of LVHT seems to increase with the improvement of cardiac imaging; (2) because LVHT is most frequently diagnosed primarily by echocardiography, echocardiographers should be aware and trained to recognize this abnormality; (3) LVHT is frequently associated with other cardiac and extracardiac, particularly neuromuscular, disorders; (4) there are indications that the cause of LVHT is usually a genetic one and quite heterogeneous; and (5) controversies exist about diagnostic criteria, nomenclature, prognosis, origin, pathogenesis, and the necessity to classify LVHT as a distinct entity and cardiomyopathy by the World Health Organization.

Isolated noncompaction cardiomyopathy presenting with paroxysmal supraventricular tachycardia--case report and literature review

Isolated noncompaction cardiomyopathy is an exceedingly rare congenital cardiomyopathy. A case of isolated noncompaction cardiomyopathy is reported and the literature on the subject collected through a comprehensive literature search is reviewed. Fewer than 100 cases of this condition have been reported. Isolated noncompaction cardiomyopathy is caused by a defect in cardiac morphogenesis resulting in an arrest of compaction of loose interwoven meshwork of myocardial fibers during intrauterine life, which results in severe systolic dysfunction as well as undue hypertrophy of the involved walls of the ventricles. Although the most frequent sites involved are left ventricular apex and inferior wall, involvement of other left ventricular walls and right ventricle has also been reported. Etiology of the isolated noncompaction of myocardium is not clear. Familial cases have been reported and the mode of inheritance is heterogeneous. In X-linked form of the disease, a locus has been found on Xq28, and mutations have been reported in G4.5 gene. The age of onset of symptoms ranges from infancy to the geriatric age. Patients with isolated noncompaction cardiomyopathy have a high incidence of heart failure, arrhythmias, and thromboembolism. The most common presentation is congestive heart failure. Arrhythmias include atrial arrhythmias, ventricular tachycardia, and sudden cardiac death. The patient reported in this article presented with paroxysmal supraventricular tachycardia. Echocardiography is the procedure of choice to establish diagnosis. Due to the lack of associated cardiac anomalies, antenatal detection is difficult. The treatment is that for congestive heart failure, arrhythmias, and thromboembolism. The end-stage congestive heart failure is managed with heart transplantation and potential life-threatening ventricular tachyarrhythmias with an implantable cardioverter defibrillator. Prognosis is poor and the common causes of death are intractable heart failure and sudden cardiac death.

Two-layered appearance of noncompaction of the ventricular myocardium on magnetic resonance imaging

A 60-year-old man with isolated noncompaction of the ventricular myocardium was evaluated by magnetic resonance imaging (MRI), which clearly showed excessively prominent trabeculations and deep intertrabecular recesses that correlated well with the findings on echocardiography and contrast enhanced computed tomography. On the T2-weighted and contrast enhanced MRI scans, the noncompacted myocardium was separated into 2 layers: a subendocardial and an endocardial layer. A difference in signal intensity may reflect myocardial damage that leads to ventricular dysfunction or arrhythmia.

MRI of subendocardial perfusion deficits in isolated left ventricular noncompaction

Ventricular noncompaction is a rare unclassified cardiomyopathy due to intrauterine arrest of compaction of the loose interwoven meshwork. It is characterized by markedly irregular endocardial surfaces with prominent trabeculations and intertrabecular recesses. Patients are asymptomatic or present with depressed ventricular function, ventricular arrhythmia, and systemic embolism. Areas of restricted myocardial perfusion have been previously documented by scintigraphy and positron emission tomography. This report documents a case of isolated left ventricular noncompaction with subendocardial perfusion deficits on MRI.

Isolated non-compaction of the left ventricle: a rare indication for transplantation

This report describes the diagnostic difficulty encountered in a young female patient presenting with neurologic symptoms, atrial fibrillation and severe left ventricular systolic dysfunction, eventually leading to cardiac transplantation. The scrutiny used in the evaluation of the particular aspect of the left ventricle, and the integration of the information obtained from echocardiography, angiography and magnetic resonance imaging, led to the diagnosis of a rare and mostly unknown cause of cardiac failure. The correct identification of this entity is mandatory because enhanced risk of thromboembolism and malignant arrhythmia should be anticipated. A review of the literature revealed only 6 patients in whom isolated non-compaction of the left ventricle was treated by heart transplantation.

Isolated noncompaction of the ventricular myocardium: ultrafast computed tomography and magnetic resonance imaging

This study was undertaken to evaluate the feasibility of ultrafast computed tomography (CT) and magnetic resonance imaging (MRI) for anatomical and pathophysiological diagnosis of isolated noncompaction of the left ventricular myocardium (INVM) compared with other imaging modalities including thallium myocardial imaging. Six patients, three sets of siblings, ranging in age from 13 to 18 years, were included in this study. Two-dimensional echocardiograms revealed numerous prominent trabeculations and deep intertrabecular recesses in one or more ventricular wall segments in all cases. Thallium-201 myocardial imaging disclosed a hypoperfusion area corresponding to the zones where noncompacted ventricular myocardium was localized. Ultrafast CT showed early defects of varying degrees and rate enhancement of the noncompacted ventricular myocardium, implying fibrosis in this area. MRI disclosed inner zones of noncompacted myocardium distinguishable from thin outer zones of compacted myocardium. T2-weighted imaging revealed high intensity areas at the apex of the left ventricle, suggesting disturbed microcirculation due to fibrosis, thrombus formation, and hypokinesis. Cine MRI revealed hypokinesis of the noncompacted ventricular wall during the cardiac cycle. In conclusion, ultrafast CT and MRI provide high-resolution imaging of noncompacted myocardium, and also pathophysiological details regarding this rare disease.

Noncompaction of the ventricular myocardium

Noncompaction of the ventricular myocardium is a rare congenital cardiomyopathy resulting from an arrest in normal endomyocardial embryogenesis. The characteristic echocardiographic findings consist of multiple, prominent myocardial trabeculations and deep intertrabecular recesses communicating with the left ventricular cavity. The disease uniformly affects the left ventricle, with or without concomitant right ventricular involvement, and results in systolic and diastolic ventricular dysfunction and clinical heart failure. Noncompaction was initially described in children. However, recent studies have characterized this disease in the adult population, in whom this process may be more prevalent than currently appreciated. We describe an illustrative case of isolated noncompaction of the ventricular myocardium in a 57-year-old woman with the typical clinical and echocardiographic features of the disease. The literature on the topic is reviewed.