Identification of a rare congenital anomaly of the myocardium by two-dimensional echocardiography: persistence of isolated myocardial sinusoids

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.

Determinants of outcome in isolated ventricular noncompaction in childhood

Isolated ventricular noncompaction is now recognized as an important cause of pediatric cardiomyopathy; however, predictors of outcome have yet to be detailed. Echocardiographic features at presentation, including increased noncompacted to compacted segment ratio and enlarged left ventricular dimension, were found to be associated with poor outcomes (heart transplantation, transplant listing, or death).

Comparison of echocardiographic features of noncompaction of the left ventricle in adults versus idiopathic dilated cardiomyopathy in adults

Noncompaction of left ventricular myocardium (NCLV), or "spongy myocardium," in adults represents an arrest in endomyocardial morphogenesis and occurs as an isolated cardiomyopathy. Because NCLV can be readily mistaken for idiopathic dilated cardiomyopathy, echocardiographic features other than the structural features of the myocardial wall need to be carefully defined for distinguishing the 2 conditions. This study was therefore designed to characterize the echocardiographic features that could be useful for differentiating NCLV from idiopathic dilated cardiomyopathy.

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.

Abnormal myocardial strain rate in noncompaction of the left ventricle

A 28-year-old woman presented in the second trimester of pregnancy with palpitations and left heart failure. Transthoracic echocardiography showed features consistent with isolated noncompaction of the left ventricle. Doppler tissue echocardiography with strain-rate imaging revealed unique appearances of paradoxical alternating bands of compression and expansion throughout systole and diastole. These features may be pathognomonic for this disease.

Noncompaction of the ventricular myocardium: the use of contrast-enhanced echocardiography in diagnosis

We describe a case of noncompaction of the ventricular myocardium diagnosed in the preoperative evaluation of a patient undergoing renal transplantation. Ventricular noncompaction is characterized by numerous prominent trabecular recesses with intratrabecular blood from the ventricular cavity. Color Doppler was suggestive of intramyocardial flow. With contrast-enhanced echocardiography the endocardial borders were clearly demarcated, allowing for visualization of trabecular recesses and intratrabecular flow. Contrast-enhanced echocardiography facilitates the diagnosis of noncompaction of the ventricular myocardium, circumventing the need for invasive diagnostic testing.

Isolated ventricular noncompaction is associated with coronary microcirculatory dysfunction

OBJECTIVES

We sought to analyze whether a microcirculatory dysfunction might be associated with isolated ventricular noncompaction (IVNC).

BACKGROUND

In IVNC, which is a cardiomyopathy thus far "unclassified" by the World Health Organization, heart failure and sudden cardiac death are common findings, but the pathophysiologic mechanisms are unknown.

METHODS

In 12 patients with IVNC and 14 control subjects, quantitative evaluation of regional myocardial perfusion (myocardial blood flow [MBF]) and coronary flow reserve (CFR, hyperemic/baseline MBF) was performed using positron emission tomography and (13)N-ammonia. The left ventricular myocardium was divided into nine segments, and the two-dimensional echocardiogram in each patient with IVNC was compared with CFR in each segment. Noncompaction was defined as a two-layered structure with excessive trabeculation.

RESULTS

The CFR in control subjects averaged 4.2+/-0.9, providing a cut-off value > or =2.5, but it was 2.1+/-0.8 in patients with IVNC. A perfusion scan defect was found in 14 of 24 segments with noncompaction, although no defect was found in 76 of 84 normal segments (overall agreement 83%, p < 0.0001 by the chi-square test). In 16 of 21 segments with noncompaction, a decreased CFR was found; but a decreased CFR was also found in 36 of 60 segments without noncompaction (p = NS). In 45 of the 57 segments with wall motion abnormalities, CFR was decreased, but it was preserved in 17 of the 24 segments with normal wall motion (agreement 77%, p < 0.0001).

CONCLUSIONS

In patients with IVNC, a decreased CFR is not confined to noncompacted segments, but extends to most segments with wall motion abnormalities. Thus, coronary microcirculatory dysfunction is associated with IVNC.

Echocardiographic and pathoanatomical characteristics of isolated left ventricular non-compaction: a step towards classification as a distinct cardiomyopathy

AIM

To determine clear cut echocardiographic criteria for isolated ventricular non-compaction (IVNC), a cardiomyopathy as yet "unclassified" by the World Health Organization. The disease is not widely known and its diagnosis mostly missed.

METHODS AND RESULTS

In seven out of a series of 34 patients with IVNC the in vivo echocardiographic characteristics were validated against the anatomical examination of the heart removed after death in four and due to heart transplantation in three patients. Four morphological criteria diagnostic for IVNC were found. (1) Coexisting cardiac abnormalities were absent (by definition). (2) A two layer structure was seen, with a compacted thin epicardial band and a much thicker non-compacted endocardial layer of trabecular meshwork with deep endomyocardial spaces. A maximal end systolic ratio of non-compacted to compacted layers of > 2 is diagnostic. (3) The predominant localisation of the pathology was to mid-lateral (seven of seven patients), apical (six), and mid-inferior (seven) areas. The pathological preparations confirmed the echocardiographic findings. Concomitant regional hypokinesia was not confined to the non-compacted segments. (4) There was colour Doppler evidence of deep perfused intertrabecular recesses.

CONCLUSIONS

Four clear cut echocardiographic diagnostic criteria were established. It is suggested that the WHO classification of cardiomyopathies be reconsidered to include IVNC as a distinct cardiomyopathy.

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.

Echocardiographic features of genetic diseases: part 1. Cardiomyopathy

Introduction To The Series Genetic disorders have characteristic cardiovascular manifestations. These cardiovascular abnormalities often are a major determinant of the morbidity and mortality in this patient population. Some characteristics are unique and can be detected with echocardiography. Drs Alizad and Seward have compiled in this series a review of genetic disorders that have recognizable morphologic and/or functional cardiovascular abnormalities. The following topics will be explored, with examples from the database of the Mayo Clinic Echocardiography Laboratory:Cardiomyopathy Storage disease Shunts Connective tissue Tumors Complex cardiovascular defects Complex genetic disorders Organ system

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.

Clinical features of isolated noncompaction of the ventricular myocardium: long-term clinical course, hemodynamic properties, and genetic background

OBJECTIVES

A nationwide survey was conducted to clarify the clinical features of isolated noncompaction of the ventricular myocardium (INVM) in Japanese children in comparison with features previously described in patients with INVM.

BACKGROUND

Isolated noncompaction of the ventricular myocardium is a rare disorder characterized by an excessively prominent trabecular meshwork. It is accompanied by depressed ventricular function, systemic embolism and ventricular arrhythmia.

METHODS

A questionnaire specifically designed for this study was sent to 150 hospitals in Japan where a pediatric cardiology division exists.

RESULTS

Twenty-seven patients were diagnosed by two-dimensional echocardiography, their ages ranging from one week to 15 years at presentation, with follow-up lasting as long as 17 years. The gross anatomical appearance and the extension of noncompacted myocardium predominantly at the apex observed on two-dimensional echocardiograms were similar to observations reported previously. Dissimilarities included a greater number of asymptomatic patients at initial presentation, a longer clinical course with gradually depressed left ventricular function, no systemic embolism, and rare ventricular tachycardia in the Japanese children. Cardiac catheterization disclosed normal left ventricular end-diastolic volume and increased left ventricular end-diastolic pressure in most cases, consistent with restrictive hemodynamics. A higher incidence of Wolff-Parkinson-White syndrome was found in the children, whereas left bundle branch block was rarer than reported in adults. Familial recurrence was high (44%) and included many women.

CONCLUSIONS

In Japanese children, INVM can be found by screening examinations at asymptomatic stage, and it might have a longer dinical course with gradually depressed left ventricular function and restrictive hemodynamics. The pattern of familial recurrence we observed implies that INVM is a distinctive clinical entity with a heterogeneous genetic background.

Isolated noncompaction of the myocardium in adults

OBJECTIVE

To describe the entity of isolated ventricular noncompaction (IVNC) and present a series of cases of this rare disorder in an adult population.

MATERIAL AND METHODS

We review a 10-year experience with the diagnosis of IVNC and discuss the clinical, echocardiographic, and pathologic features of this condition. Echocardiographic diagnostic criteria included the absence of coexisting cardiac abnormalities, the presence of prominent and excessive trabeculations of one or more ventricular wall segments, and intertrabecular spaces perfused from the ventricular cavity. Pathologic examination focused on regions with exaggerated trabeculations and deep intertrabecular spaces.

RESULTS

IVNC is an unexplained arrest of myocardial morphogenesis previously encountered mainly in pediatric patients. Among 37,555 transthoracic echocardiographic studies performed at our hospital between January 1984 and October 1993, 17 cases of IVNC were identified in adult subjects (14 men and 3 women, 18 to 71 years of age). The mean time from onset of symptoms to correct diagnosis was 3.5 +/- 5.7 years, and the mean duration of follow-up was 30 +/- 28 months. Common clinical symptoms were heart failure, ventricular arrhythmias, and a history of embolic events. Two-dimensional echocardiography revealed 10 patients with left ventricular and 7 (41%) with biventricular IVNC. During a 6-year follow-up period, eight patients died and two underwent heart transplantation.

CONCLUSION

Although the diagnosis of IVNC in an adult population is often delayed because of similarities with more frequently diagnosed conditions, two-dimensional echocardiography will facilitate the diagnosis of IVNC in this subset of patients. Because of the high incidence of heart failure, ventricular arrhythmias, and embolization in adults with IVNC, early diagnosis is important.

Myocardial dysgenesis with persistent sinusoids in a neonate with Noonan's phenotype

Structural cardiac anomalies indicative of primary myocardial maldevelopment are reported in a newborn girl with congenital heart block. The cardiac findings included disordered trabeculation of both ventricles with persistent intramyocardial sinusoids, hypoplastic papillary muscles, and dysplastic atrioventricular valves with partial downward displacement of the septal leaflet of the tricuspid valve. Dilatation of the ascending aorta and craniofacial dysmorphism including webbed neck, hypertelorism, and low-set ears raise the possibility of Noonan syndrome.