Persisting myocardial sinusoids of both ventricles as an isolated anomaly: echocardiographic, angiographic, and pathologic anatomical findings

From cold-blooded reptiles to embryological remnants: Persistent myocardial sinusoids

In nature, basically 2 types of myocardial vascular patterns exist: the sinusoidal and the coronary type. In the sinusoidal type, the sinusoid is completely fed by blood coming directly from the ventricle through a spongy sinusoidal network. This pattern is found in cold-blooded animals and in the early embryologic development of human (warm-blooded) hearts. A 61-year-old man with atrial fibrillation developed severe tachymyopathy with a severely reduced left-ventricular ejection fraction (LVEF) of 20%. The patient had no history of prior heart surgery or other cardiac interventions. He was referred for a computed tomography (CT) scan for assessment of pulmonary vein anatomy prior to their isolation. Incidentally, a focal myocardial defect of the midventricular infero-septal wall with tail-like extension into the right ventricular cavity was detected. In a cardiac magnetic resonance (CMR) scan there was no evidence of a myocardial infarction or fibrosis. In the absence of a ventricular septal defect by CT, CMR and echocardiography the diagnosis of a persistent myocardial sinusoid was evident. In this case, we used state-of-the art methods for pathology visualization, illustrating the effectiveness of CT and CMR in the precise detection and differential diagnosis of myocardial anomalies including a multi-coloured 3D-printed model that may further enhance visuospatial appreciation of those anomalies.

Correlation between pathoanatomic findings, imaging modalities, and genetic findings in patients with left ventricular hypertrabeculation/noncompaction

Introduction: Left ventricular hypertrabeculation, also named 'noncompaction' (LVHT) is a cardiac abnormality which is detected by pathoanatomic investigation or during cardiac surgery. Imaging techniques visualize LVHT by ventriculography, echocardiography, cardiac magnetic resonance imaging (CMRI) and computed tomography (CT).Areas covered: We aimed to assess 1) how often the definition of LVHT was validated against a criterion standard, 2) if inter- and intra-observer agreement was assessed, and 3) how often LVHT was associated with genetic diseases. A literature search disclosed 58 cases whose hearts were investigated pathoanatomically and by ≥1 imaging technique. Echocardiography was most frequently (95%) compared with pathoanatomy, followed by cMRI (31%), ventriculography (7%) and CT (5%). Intra- and inter-observer agreement was more frequently assessed for cMRI definitions and yielded more consistent results than for echocardiographic definitions. Since genetic findings were only reported from 4 of the 58 cases, no association with imaging findings could be carried out.Expert opinion: Correlation between pathoanatomic investigations with imaging techniques will hopefully contribute to reliable and uniformly accepted definitions of LVHT. Most probably, the echocardiographic definition of LVHT will be a synthesis of the currently used definitions, integrating short axis and four-chamber views. A refinement of cMRI definitions, considering pathoanatomic and echocardiographic investigations, seems necessary to avoid overdiagnosis.

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.

State-of-the art review: Noncompaction cardiomyopathy in pediatric patients

Noncompaction cardiomyopathy (NCCM) is a disease characterized by hypertrabeculation, commonly hypothesized due to an arrest in compaction during fetal development. In 2006, NCCM was classified as a distinct form of cardiomyopathy (CMP) by the American Heart Association. NCCM in childhood is more frequently familial than when diagnosed in adulthood and is associated with other congenital heart diseases (CHDs), other genetic CMPs, and neuromuscular diseases (NMDs). It is yet a rare cardiac diseased with an estimated incidence of 0.12 per 100.000 in children up to 10 years of age. Diagnosing NCCM can be challenging due to non-uniform diagnostic criteria, unawareness, presumed other CMPs, and presence of CHD. Therefore, the incidence of NCCM in children might be an underestimation. Nonetheless, NCCM is the third most common cardiomyopathy in childhood and is associated with heart failure, arrhythmias, and/or thromboembolic events. This state-of-the-art review provides an overview on pediatric NCCM. In addition, we discuss the natural history, epidemiology, genetics, clinical presentation, outcome, and therapeutic options of NCCM in pediatric patients, including fetuses, neonates, infants, and children. Furthermore, we provide a simple classification of different forms of the disease. Finally, the differences between the pediatric population and the adult population are described.

Long-Term Survival of Patients With Left Ventricular Noncompaction

Background

The prognosis of left ventricular noncompaction (LVNC) remains elusive despite its recognition as a clinical entity for >30 years. We sought to identify clinical and imaging characteristics and risk factors for mortality in patients with LVNC.

Methods and Results

339 adults with LVNC seen between 2000 and 2016 were identified. LVNC was defined as end‐systolic noncompacted to compacted myocardial ratio >2 (Jenni criteria) and end‐diastolic trough of trabeculation‐to‐epicardium (X):peak of trabeculation‐to‐epicardium (Y) ratio <0.5 (Chin criteria) by echocardiography; and end‐diastolic noncompacted:compacted ratio >2.3 (Petersen criteria) by magnetic resonance imaging. Median age was 47.4 years, and 46% of patients were female. Left ventricular ejection fraction <50% was present in 57% of patients and isolated apical noncompaction in 48%. During a median follow‐up of 6.3 years, 59 patients died. On multivariable Cox regression analysis, age (hazard ratio [HR] 1.04; 95% CI, 1.02–1.06), left ventricular ejection fraction <50% (HR, 2.37; 95% CI, 1.17–4.80), and noncompaction extending from the apex to the mid or basal segments (HR, 2.11; 95% CI, 1.21–3.68) were associated with all‐cause mortality. Compared with the expected survival for age‐ and sex‐matched US population, patients with LVNC had reduced overall survival (P<0.001). However, patients with LVNC with preserved left ventricular ejection fraction and patients with isolated apical noncompaction had similar survival to the general population.

Conclusions

Overall survival is reduced in patients with LVNC compared with the expected survival of age‐ and sex‐matched US population. However, survival rate in those with preserved left ventricular ejection fraction and isolated apical noncompaction was comparable with that of the general population.

Acute on Chronic Heart Failure Secondary to Left Ventricular Noncompaction

Left ventricular noncompaction (LVNC) is a rare cardiomyopathy characterized by hypertrabeculations and intertrabecular recesses most often seen in the left ventricle (LV). The patient may be asymptomatic or present with heart failure, arrhythmia, and sudden death. We discuss a previously healthy 7-year-old male who presented to the Emergency Department (ED) multiple times over a three-week period. His complaints evolved over the course of his illness, initially presenting with fatigue and suicidal ideation, followed by diffuse abdominal pain. Prior to his ICU admission, he had been discharged from the ED twice, due to well appearance and reassuring lab findings. He returned to the ED a final time with severe venous congestion and cardiogenic shock with acute hepatic injury. Echocardiogram revealed LV apical hypertrabeculation with a severe dilated cardiomyopathy and biventricular failure along with a large thrombus in the left ventricular cavity. Congestive heart failure and anticoagulation therapy was initiated, and the patient went on to biventricular assist device (BiVAD) placement and cardiac transplant. Although LVNC is rare, pediatric heart failure does present to the general pediatrician and has high morbidity and mortality. The presenting symptoms can be obscure and pose a challenge to pediatricians. This case report and review will assist in familiarizing the general pediatrician with pediatric heart failure presentation, treatment, and course.

Epidemiology of the inherited cardiomyopathies

In the absence of contemporary, population-based epidemiological studies, estimates of the incidence and prevalence of the inherited cardiomyopathies have been derived from screening studies, most often of young adult populations, to assess cardiovascular risk or to detect the presence of disease in athletes or military recruits. The global estimates for hypertrophic cardiomyopathy (1/500 individuals), dilated cardiomyopathy (1/250) and arrhythmogenic right ventricular cardiomyopathy (1/5,000) are probably conservative given that only individuals who fulfil diagnostic criteria would have been included. This caveat is highly relevant because a substantial minority or even a majority of individuals who carry disease-causing genetic variants and are at risk of disease complications have incomplete and/or late-onset disease expression. The genetic literature on cardiomyopathy, which is often focused on the identification of genetic variants, has been biased in favour of pedigrees with higher penetrance. In clinical practice, an abnormal electrocardiogram with normal or non-diagnostic imaging results is a common finding for the sarcomere variants that cause hypertrophic cardiomyopathy, the titin and sarcomere variants that cause dilated cardiomyopathy and the desmosomal variants that cause either arrhythmogenic right ventricular cardiomyopathy or dilated cardiomyopathy. Therefore, defining the genetic epidemiology is also challenging given the overlapping phenotypes, incomplete and age-related expression, and highly variable penetrance even within individual families carrying the same genetic variant.

Biventricular imaging markers to predict outcomes in non-compaction cardiomyopathy: a machine learning study

Aims

Left ventricular non‐compaction cardiomyopathy (LVNC) is a genetic heart disease, with heart failure, arrhythmias, and embolic events as main clinical manifestations. The goal of this study was to analyse a large set of echocardiographic (echo) and cardiac magnetic resonance imaging (CMRI) parameters using machine learning (ML) techniques to find imaging predictors of clinical outcomes in a long‐term follow‐up of LVNC patients.

Methods and results

Patients with echo and/or CMRI criteria of LVNC, followed from January 2011 to December 2017 in the heart failure section of a tertiary referral cardiologic hospital, were enrolled in a retrospective study. Two‐dimensional colour Doppler echocardiography and subsequent CMRI were carried out. Twenty‐four hour Holter monitoring was also performed in all patients. Death, cardiac transplantation, heart failure hospitalization, aborted sudden cardiac death, complex ventricular arrhythmias (sustained and non‐sustained ventricular tachycardia), and embolisms (i.e. stroke, pulmonary thromboembolism and/or peripheral arterial embolism) were registered and were referred to as major adverse cardiovascular events (MACEs) in this study. Recruited for the study were 108 LVNC patients, aged 38.3 ± 15.5 years, 48.1% men, diagnosed by echo and CMRI criteria. They were followed for 5.8 ± 3.9 years, and MACEs were registered. CMRI and echo parameters were analysed via a supervised ML methodology. Forty‐seven (43.5%) patients had at least one MACE. The best performance of imaging variables was achieved by combining four parameters: left ventricular (LV) ejection fraction (by CMRI), right ventricular (RV) end‐systolic volume (by CMRI), RV systolic dysfunction (by echo), and RV lower diameter (by CMRI) with accuracy, sensitivity, and specificity rates of 75.5%, 77%, 75%, respectively.

Conclusions

Our findings show the importance of biventricular assessment to detect the severity of this cardiomyopathy and to plan for early clinical intervention. In addition, this study shows that even patients with normal LV function and negative late gadolinium enhancement had MACE. ML is a promising tool for analysing a large set of parameters to stratify and predict prognosis in LVNC patients.

Multiple diffuse coronary cameral fistulas from the left anterior descending artery and right coronary artery to both the right and left ventricle associated with left ventricular noncompaction: A rare combination

Diffuse and multiple coronary cameral fistulas are very rare and with very few case reports of its association with left ventricular noncompaction are published. Here, we report a 6-year-old child of multiple diffuse coronary cameral fistulas to both the right and left ventricle in association with the left ventricular noncompaction. A possible common embryological link between the two uncommon entities is also discussed.

Left ventricular noncompaction - Risk stratification and genetic consideration

Left ventricular noncompaction (LVNC) is a cardiomyopathy characterized by two layered structures composed of prominent trabecular meshwork and deep intertrabecular recesses. LVNC was thought to be rare; however, heightened awareness has resulted in an increased detection of the morphological features of LVNC in routine clinical practice especially in the adult population. Although LVNC was classified as an independent primary cardiomyopathy of genetic origin by the American Heart Association in 2006, its definition, diagnostic criteria and clinical implications are still being debated. Clinical manifestations are highly variable, even in the same family, ranging from no symptoms to disabling congestive heart failure, life-threatening arrhythmias, systemic thromboemboli, and sudden cardiac death. Among phenotypic subtypes of LVNC, children with isolated LVNC with normal cardiac function had the best outcomes: children with LVNC and dilated cardiomyopathy had the worst outcomes. Myocardial dysfunction or ventricular arrhythmias are predictors of mortality in adults with LVNC. LVNC, like other forms of inherited cardiomyopathy, is genetically heterogeneous and can be inherited as an autosomal dominant or X-linked recessive disorder. It has been linked to mutations in many genes, including ZASP, TAZ/G4.5, and those encoding sarcomeric, Z-disc, cytoskeleton proteins, and mitochondria. Disturbance of the NOTCH signaling pathway has been reported to be part of genetic pathway for LVNC as well. Although there are an increasing number of reports, genotype-phenotype correlations have been challenging and investigations are ongoing. Patients with mutations are more likely to have major adverse cardiovascular events, further, LV systolic dysfunction in mutation carriers makes them at high risk for cardiac events. Treatments focus on improvement in cardiac function and reduction of mechanical stress in patients with systolic dysfunction and on treatment of arrhythmia and implantation of an automatic implantable cardioverter-defibrillator for prevention of sudden death. Given that 20-40% of cases may be familial, family screening is recommended.

Cardiac Segmental Strain Analysis in Pediatric Left Ventricular Noncompaction Cardiomyopathy

BACKGROUND

Left ventricular noncompaction cardiomyopathy (LVNC) is characterized by prominent left ventricular trabeculations, often leading to myocardial dysfunction and death or heart transplantation. Although diagnostic echocardiographic criteria exist for LVNC, segmental speckle-tracking strain patterns have not been described in pediatric LVNC. The objectives of this study were to characterize segmental noncompaction, evaluate segmental speckle-tracking strain, and characterize peak strain values in children with LVNC with adverse clinical outcomes.

METHODS

Echocardiographic noncompaction/compaction ratios and segmental radial, circumferential, and longitudinal strain were measured retrospectively in children with LVNC (January 2000 to June 2013). Segmental strain of the cohort was compared with that in control subjects matched by age and body surface area.

RESULTS

One hundred one pediatric patients with LVNC were included (median age 2.8 years; range, 0-19.4 years); 71 patients survived (benign group) and 30 patients did not survive or required heart transplantation (adverse group). The adverse group was younger at diagnosis (P = .03), with lower ejection fractions (P < .0001) compared with the benign group. Both groups demonstrated increased noncompaction/compaction ratios within apical segments, with significantly increased involvement in antero- and inferolateral midpapillary segments in the adverse group (P < .005). Radial, circumferential, and longitudinal strain of nearly all left ventricular segments were significantly decreased in the adverse compared with the benign group and in pediatric LVNC patients compared with control subjects. Global radial (7.4 ± 9.7% vs 19.6 ± 16.5%, P < .0001), circumferential (-8.4 ± 7.0% vs -18.9 ± 6.9%, P < .0001), and longitudinal (-7.1 ± 5.2% vs -11.8 ± 5.3%, P < .0001) strain were all significantly decreased in the adverse group compared with the benign group.

CONCLUSIONS

Segmental radial, circumferential, and longitudinal strain are decreased in pediatric patients with LVNC compared with control subjects and lowest in those with adverse compared with benign outcomes. LVNC appears to be a global disease affecting deformation in all regions, including compacted myocardial segments.

Thickness and Ratio of Noncompacted and Compacted Layers of the Left Ventricular Myocardium Evaluated in 56 Normal Fetuses by Two-Dimensional Echocardiography

The thickness and ratio of noncompacted and compacted layers of the left ventricular (LV) myocardium in the normal fetus were investigated by fetal echocardiography. We aimed to investigate the compaction process of the LV myocardium during the normal gestation period and provide reference for echocardiographic diagnosis of a fetus with ventricular myocardium noncompaction. A total of 56 pregnant women in the gestational period of 23–30 weeks were included. Complete fetal echocardiography was performed with system ultrasonographic examination to exclude congenital heart malformation or extracardiac malformation. All 56 fetuses showed normal development. In the short-axis view of the fetal heart, the LV wall was divided into an upper and lower section at the level of the papillary muscle. Each section was then further divided into four segments, namely, anterior, posterior, lateral, and inferior wall. Thus, the LV wall was divided into eight segments. The thickness of the ventricular noncompacted and compacted layers and the ratio of the ventricular noncompacted to compacted layers of these segments at end-systole were measured and calculated. In echocardiography, the fetal LV myocardium is a two-layered structure: the endocardial noncompact myocardium (NC) with higher echo and the epicardium compact myocardium (C) with lower echo. The noncompacted layer is thinner than the compacted layer in the anterior wall, but thicker than the compacted layers in the posterior, lateral, and inferior wall. With respect to the upper and lower sections of the LV myocardium, the noncompacted layer in each segment of the upper section is thinner than that in each segment of the lower section, whereas the compacted layer of the upper section is thicker than that of the lower section. This study suggests that the densification of the fetal LV myocardium occurs gradually from base to apex and from the anterior to lateral, posterior, and inferior walls. This finding aids in further understanding the process of myocardial densification and provides a diagnostic reference for noncompaction of noncompaction cardiomyopathy (NCCM).

Understanding left ventricular hypertrabeculation/noncompaction: pathomorphologic findings and prognostic impact of neuromuscular comorbidities

INTRODUCTION

When >3 trabeculations associated with interventricular recesses are found, this is termed 'left ventricular hypertrabeculation/noncompaction' (LVHT). Cardiac-imaging methods detect LVHT in all ages, isolated or associated with extracardiac, especially neuromuscular disorders (NMDs). Many issues about LVHT are unclear. The review gives an update about pathomorphologic findings in patients >14 years and the role of NMDs in LVHT. Areas covered: A PubMed-search for the terms "noncompaction" or "non-compaction" or "hypertrabeculation" AND "autopsy" or 'biopsy' or 'ultrastructure' or 'electron microscopy' AND 'neuromuscular' or 'myopathy' or 'neuropathy' was carried out from 1985 to July 2018. Expert commentary: Macroanatomic (n = 65), histopathologic (n = 59) and ultrastructural (n = 7) reports were found. A comparison with echocardiography was described in 45 cases. Measurements of non-compacted and compacted layer were only given from hearts investigated in short-axis cuts after formaldehyde-fixation. Endocardial, subendocardial and interstitial fibrosis were frequent findings. When LVHT-patients were systematically investigated, a NMD was found in 80%, most frequently mitochondrial disorders, Barth syndrome, zaspopathy, and myotonic dystrophy type 1. LVHT does not seem to be a special type of cardiac involvement of NMDs. NMDs affect prognosis in LVHT as well as LVHT affects prognosis in patients with Duchenne muscular dystrophy.

[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.

Left Ventricular Noncompaction Cardiomyopathy in Pediatric Patients: A Case Series of a Clinically Heterogeneous Disease

Left ventricular noncompaction is a rare form of cardiomyopathy, which results from multiple trabeculations in the left ventricular myocardium. The clinical presentation is highly variable, and spectrum includes asymptomatic patients diagnosed during family screening on one end to patients with depressed systolic function, heart failure, thromboembolic complications, and cardiac arrhythmias on the other (Kim et al in J Am Coll Cardiol 53: 2009, 2009). Further, the progression of the condition is highly variable. Hence, these patients require close follow-up, and management for each patient needs to be individualized and periodically reevaluated. Here, we present a series of five cases that have been followed in our practice and present our experience. A literature review of this rare form of congenital cardiomyopathy is also presented.

Left ventricular noncompaction-A rare form of cardiomyopathy: Revelation modes and predictors of mortality in adults through 23 cases

Objectives

To describe modes of clinical presentation and echocardiographic, angiographic, and rhythmic features, and prognostic characteristics of left ventricular noncompaction cardiomyopathy (LVNC) in North African adults, through one of the first series in Morocco.

Background

LVNC is a rare congenital disorder, described for the first time by Engberding in 1984. The suspected diagnosis in thromboembolic, hemodynamic, or rhythm events requires both echocardiography and cardiovascular magnetic resonance (CMR). Its therapeutic management is not yet well codified but akin to that proposed for dilated cardiomyopathy.

Patients and design

This study included a retrospective, descriptive, and analytical cohort of 23 cases of cardiomyopathy with LVNC diagnosed in the Noninvasive Explorations Laboratory at the Military Hospital of Rabat, Morocco, between January 2009 and October 2014. The echocardiographic criteria for LVNC include the absence of any coexisting cardiac anomalies. The characteristic appearance of numerous excessively prominent trabeculations and deep intertrabecular recesses and intertrabecular spaces filled by direct blood flow from the ventricular cavity, as visualized on color Doppler imaging with noncompacted/compacted ratio > 2 according to Jenni criteria. Twenty-three adults fulfilled the diagnostic criteria and were followed prospectively.

Results

At diagnosis, the mean age was 47 ± 13 years with a male predominance at 65.2%. Of them, 56.5% had a left bundle branch block and 21.7% were in atrial fibrillation. Left ventricular end-diastolic diameter was 67.7 ± 6.6 mm and ejection fraction was at 27 ± 8%. Apex and/or midventricular segments of both the inferior and lateral wall were involved in more than 80% of patients with an average of 4.8 noncompacted segments. CMR was performed in 12 patients and was decisive for the diagnosis. Major complications were heart failure in 31% of patients, ventricular tachycardia in three patients, and thromboembolic events in one patient. Twenty eight point six percent of patients started a long-term anticoagulant therapy. One patient underwent implantation of a double-room pacemaker. Automated defibrillators were implanted in two patients. There were three deaths: one sudden death and two end-stage heart failure.

Conclusion

LVNC should be looked for at any dilated cardiomyopathy particularly in young patients. It requires a careful echocardiographic examination and sometimes CMR to confirm the diagnosis. It is characterized by severe systolic and diastolic dysfunction that would provide poor prognosis.

A Rare Case of Renal Infarct due to Noncompaction Cardiomyopathy: A Case Report and Literature Review

Left ventricular noncompaction cardiomyopathy is a rare myocardial disorder which results from failure of left ventricle to compact in embryogenesis. We present a case of a 53-year-old female who came because of abdominal pain and was found to have renal infarct secondary to noncompaction cardiomyopathy.

Noncompaction Cardiomyopathy: Case Presentation with Cardiac Magnetic Resonance Imaging Findings and Literature Review

Left ventricular noncompaction cardiomyopathy is a very rare condition, yet believed to be often overlooked. It is thought to be caused by the developmental arrest in embryogenesis and characterized by an increase in the noncompacted, trabeculated myocardium adjacent to compacted myocardium in the left ventricular. The clinical presentations of this type of cardiomyopathy are of variable severity. Echocardiography used to be the diagnostic modality, but recent reports suggest that cardiac magnetic resonance imaging has higher sensitivity and specificity by showing a ratio of the noncompacted myocardium to compacted myocardium of >2.3.

Noncompaction cardiomyopathy: Manifestation as a surgical pitfall – rare but real

Objectives

Noncompaction cardiomyopathy is characterized by hyper-trabeculation of the myocardium. The patients present with heart failure and variable combination of arrhythmias and thromboembolism. Although several articles have shed light on the medical aspect of this disease, none have highlighted its surgical relevance. A death following ligation of a patent ductus arteriosus prompted us to evaluate the surgical aspects of this disease.

Methods

Autopsy records from 2003 to 2012 were reviewed, and cases identified as noncompaction cardiomyopathy were retrieved and analyzed. Cases with obligatory hyper-trabeculation were excluded.

Results

Thirteen patients were found to have noncompaction cardiomyopathy in 9427 autopsies performed. Their ages ranged from 4 months to 55 years; 10 were children, and all 3 adults were over 45 years of age. Only one patient had an antemortem diagnosis of noncompaction cardiomyopathy on echocardiography. There were 7 postoperative deaths.

Conclusions

Although noncompaction cardiomyopathy is rare, missing its diagnosis in a patient operated on for another indication can spell disaster postoperatively. As the clinical picture is nonspecific and the disease is not very well known, it needs vigilance on the part of the echocardiographer and surgeon.

[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.

Left ventricular non-compaction: prevalence in congenital heart disease

INTRODUCTION

Left ventricular non-compaction cardiomyopathy (LVNC) is a rare cardiomyopathy, originally described as an isolated disease without other structural cardiac abnormalities. The aim of this study was to explore the prevalence of LVNC among adults with different types of congenital heart disease.

METHODS

From our databases we identified adults with congenital heart disease who fulfilled diagnostic criteria for LVNC. We report frequencies of associated congenital cardiac defects and the prevalence of LVNC among patients with different congenital heart defects.

RESULTS

From a total of 202 patients with LVNC, 24 patients (12%; mean age 32 ± 11 years, 19 males) had additional congenital cardiac defects. Associated defects were left ventricular outflow tract abnormalities in 11 patients (46%), including 7 uni- or bicuspid aortic valves; two aortic coarctations; one diffuse aortic hypoplasia and one subaortic stenosis, Ebstein anomaly in 6 patients (25%), tetralogy of Fallot in two (8%), and double outlet right ventricle in one patient (4%). In our cohort, the prevalence of LVNC was highest among patients with Ebstein anomaly (6/40, 15%), followed by aortic coarctation (2/60, 3%), tetralogy of Fallot (3/129, 2%) and uni- or bicuspid aortic valves (7/963, 1%).

CONCLUSION

In adults, various forms of congenital heart disease are associated with LVNC, particularly stenotic lesions of the left ventricular outflow tract, Ebstein anomaly, and tetralogy of Fallot. In the future, studying these patients in more depth may provide a better understanding of the interplay between genetic and hemodynamic factors that lead to the phenotype of LVNC.

Left ventricular noncompaction: a 25-year odyssey

Left ventricular noncompaction (LVNC) is a cardiomyopathy associated with sporadic or familial disease, the latter having an autosomal dominant mode of transmission. The clinical features associated with LVNC vary from asymptomatic to symptomatic patients, with the potential for heart failure, supraventricular and ventricular arrhythmias, thromboembolic events, and sudden cardiac death. Echocardiography is the diagnostic modality of choice, revealing the pathognomonic features of a thick, bilayered myocardium; prominent ventricular trabeculations; and deep intertrabecular recesses. Widespread use and advances in the technology of echocardiography and cardiac magnetic resonance imaging are increasing awareness of LVNC, and cardiac magnetic resonance imaging is improving the ability to stage the severity of the disease and potential for adverse clinical consequences. Study of LVNC through research in embryology, imaging, and genetics has allowed enormous strides in the understanding of this heterogeneous disease over the past 25 years.

Predictors of adverse outcome in adolescents and adults with isolated left ventricular noncompaction

Isolated left ventricular noncompaction is a rare form of primary cardiomyopathy. Although increasingly diagnosed, data on the outcomes are limited. To define the predictors of adverse outcomes, we performed a retrospective analysis of a prospectively defined cohort of consecutive patients (age >14 years) diagnosed with left ventricular noncompaction at a single center. The baseline characteristics included presentation with a cardiovascular complication (i.e., decompensated heart failure, systemic embolic event, or sustained ventricular arrhythmia). The primary end point was survival free from cardiovascular death or transplantation. The predictors of survival were evaluated using the Kaplan-Meier method and Cox proportional hazards analysis. A total of 115 patients were included, 77% of whom were symptomatic at diagnosis. Compared to the asymptomatic patients, the symptomatic patients were significantly older and had larger left ventricular cavities and worse left ventricular ejection fraction. Of the 115 patients, 49 (43%) presented with a cardiovascular complication. During a median follow-up of 2.7 years (range 0.1 to 19.4), none of the asymptomatic patients died or underwent transplantation compared to 31% (27 of 88) of the symptomatic patients (p = 0.001). The major determinants of cardiovascular death or transplantation were presentation with a cardiovascular complication (hazard ratio 20.6, 95% confidence interval 4.9 to 87.5, p <0.0001) or New York Heart Association class III or greater (hazard ratio 8.8, 95% confidence interval 3.2 to 24.0, p <0.0001). Left ventricular dilation and systolic dysfunction were less strong predictors. In conclusion, in patients with left ventricular noncompaction, New York Heart Association class III or greater and cardiovascular complications at presentation are strong predictors for adverse outcome.

Long-term myocardial recovery after mitral valve replacement in noncompaction cardiomyopathy

Isolated noncompaction of the left ventricle is a congenital cardiomyopathy, which has been described recently, with literature limited to case reports and case series. Even though various complications have been reported with noncompaction cardiomyopathy, among them severe mitral regurgitation has been reported recently in a few cases. There is no great evidence in the literature about its management, apart from some cases of mitral valve repair and replacement in young patients. We are reporting a case of an elderly lady with isolated left ventricular noncompaction cardiomyopathy associated with severe mitral regurgitation treated with mitral valve replacement with one and half year of follow up demonstrating significant myocardial recovery.

Examination of isolated ventricular noncompaction (hypertrabeculation) as a distinct entity in adults

Three patients (2 women) 36, 45, and 49 years of age underwent cardiac transplantation for what was diagnosed clinically as nonischemic dilated cardiomyopathy. Examination of the transthoracic echocardiogram and explanted heart in each disclosed marked hypertrabeculation involving the free wall of the very dilated left ventricle, a finding consistent with what has been termed "isolated ventricular noncompaction" (IVNC). Although these 3 cases anatomically fulfilled the echocardiographic definition of IVNC, review of previous publications containing gross photographs of the heart suggests that IVNC is overdiagnosed at least morphologically.

Isolated left ventricular noncompaction mimicking ventricular mass

Isolated left ventricular noncompaction is an inherited cardiomyopathy characterized by multiple prominent trabeculations with deep intertrabecular recesses. The diagnosis is often missed because echocardiography poses inherent problems of poor echo window in assessment of the LV apex, which is most commonly involved in noncompaction. We report a case in which conventional 2D echocardiography failed to demonstrate multiple prominent trabeculations. Contrast echocardiography confirmed the presence of multiple trabeculations with deep intertrabecular recesses. This report emphasizes the importance of contrast echocardiography in the diagnosis of ventricular noncompaction.

Isolated left ventricular noncompaction cardiomyopathy diagnosed by transesophageal echocardiography

Isolated noncompaction of the ventricular myocardium has often been misdiagnosed as other cardiomyopathies because it is a relatively recently described cardiomyopathy with literature limited to case reports and case series and little awareness among physicians. We are reporting a case of isolated left ventricular noncompaction cardiomyopathy that was misdiagnosed for over two decades.

Left ventricular non-compaction revisited: a distinct phenotype with genetic heterogeneity?

Non-compaction of the left ventricular myocardium (LVNC) has gained increasing recognition during the last 25 years. There is a morphological trait of the myocardial structure with a spectrum from normal variants to the pathological phenotype of LVNC, which reflects the embryogenic structure of the human heart due to an arrest in the compaction process during the first trimester. It must be cautioned not to overdiagnose LVNC: the morphological spectrum of trabeculations, from normal variants to pathological trabeculations with the morphological feature of LVNC must be carefully considered. The classical triad of complications are heart failure, arrhythmias, including sudden cardiac death, and systemic embolic events. Non-compaction of the left ventricular myocardium can occur in isolation or in association with congenital heart defects (CHDs), genetic syndromes, and neuromuscular disorders among others. The clinical spectrum is wide and the outcome is more favourable than in previously described populations with a negative selection bias. Familial occurrence is frequent with autosomal dominant and X-linked transmissions. Different mutations in sarcomere protein genes were identified and there seems to be a shared molecular aetiology of different cardiomyopathic phenotypes, including LVNC, hypertrophic and dilated cardiomyopathies. Thus, genetic heterogeneity, with an overlap of different phenotypes, and the variability of hereditary patterns, raise the questions whether there is a morphological trait from dilated/hypertrophic cardiomyopathy to LVNC and what are the triggers and modifiers to develop either dilated, hypertrophic cardiomyopathy, or LVNC in patients with the same mutation. The variety in clinical presentation, the genetic heterogeneity, and the phenotype of the first transgenetic animal model of an LVNC-associated mutation question the hypothesis that LVNC be a distinct cardiomyopathy: it seems to be rather a distinct phenotype or phenotypic, morphological expression of different underlying diseases than a distinct cardiomyopathy.

The treatment of noncompaction of ventricular myocardium

AIMS

Critically reexamine and place in perspective the most appropriate therapeutic strategies for patients noncompaction of ventricular myocardium.

RESULTS

Specific treatments are not available for the majority of patients with noncompaction of ventricular myocardium currently. Treatment of patients with noncompaction of ventricular myocardium could be similar to patients with other cardiomyopathies, especially dialated cardiomyopathy, and therefore, the primary aims of treatment are to control symptoms, disease progression, and complications, which should include appropriate treatment for heart failure, management of arrhythmias, and oral anticoagulation to prevent systemic emboli.

CONCLUSION

Among the many challenges facing clinicians treating patients with noncompaction of ventricular myocardium are the detection of early disease, the identification of the predominant mechanism of left ventricular dysfunction, and the development of treatments that target the initiating mechanism of disease. Nevertheless, there have been major advances in our understanding of the genetic basis of noncompaction of ventricular myocardium, and recent advances in the drug therapy and nondrug therapy of noncompaction of ventricular myocardium have substantially improved the outlook for many patients. The rapid pace of current research and the development of new treatments for the management of both early and late disease augur well for the future.

Isolated non-compaction cardiomyopathy

BACKGROUND

Isolated non-compaction cardiomyopathy (NCCM) was first described in 1984. This disorder, a primary genetic cardiomyopathy, is now attracting increased attention.

METHOD

The current state of the epidemiology, pathogenesis, pathophysiology, clinical features, diagnosis, treatment, and prognosis of NCCM are discussed on the basis of a review of selected literature as well as the authors' personal experience.

RESULTS

The pathogenesis of NCCM is thought to involve a genetically determined disturbance of the myocardial compaction process during fetal endomyocardial morphogenesis. It is not accompanied by any other cardiac anomalies. Echocardiography is the diagnostic method of choice. The diagnosis is based on the following echocardiographic criteria: the presence of at least 4 prominent trabeculations and deep intertrabecular recesses, blood flow from the ventricular cavity into the intertrabecular recesses, and a typical bilaminar structure of the affected portion of the left ventricular myocardium. NCCM can also be diagnosed with magnetic resonance imaging of the heart. The clinical severity of NCCM is variable; its manifestations include heart failure, thromboembolic events, and arrhythmias. The treatment is symptom-based. Patients with symptomatic NCCM have a poor prognosis.

CONCLUSION

NCCM 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.

Measurement of trabeculated left ventricular mass using cardiac magnetic resonance imaging in the diagnosis of left ventricular non-compaction

AIMS

To describe a method for measuring trabeculated left ventricular (LV) mass using cardiac magnetic resonance imaging and to assess its value in the diagnosis of left ventricular non-compaction (LVNC).

METHODS AND RESULTS

Between January 2003 and 2008, we prospectively included 16 patients with LVNC. During the mean period, we included 16 patients with dilated cardiomyopathy (DCM), 16 patients with hypertrophic cardiomyopathy (HCM), and 16 control subjects. Left ventricular volumes, LV ejection fraction, and trabeculated LV mass were measured in the four different populations. The percentage of trabeculated LV mass was almost three times higher in the patients with LVNC (32 +/- 10%), compared with those with DCM (11 +/- 4%, P < 0.0001), HCM (12 +/- 4%, P < 0.0001), and controls (12 +/- 5%, P < 0.0001). A value of trabeculated LV mass above 20% of the global mass of the LV predicted the diagnosis of LVNC with a sensitivity of 93.7% [95% confidence interval (CI), 71.6-98.8%] and a specificity of 93.7% (95% CI, 83.1-97.8%; kappa = 0.84).

CONCLUSION

The method described is reproducible and provides an assessment of the global amount of LV trabeculation. A trabeculated LV mass above 20% of the global LV mass is highly sensitive and specific for the diagnosis of LVNC.

Isolated left ventricular noncompaction cardiomyopathy accompanied by severe mitral regurgitation

Isolated left ventricular noncompaction cardiomyopathy (IVNC) is a cardiomyopathy thought to be caused by arrest of normal embryogenesis of the endocardium and myocardium. This abnormality is often associated with other congenital cardiac defects. A 21-year-old man presented to the emergency department with worsening exertional dyspnea during the previous 2 months. Two-dimensional and Doppler echocardiography revealed an enlarged left atrium (LA) and a markedly dilated left ventricle (LV) with preserved LV systolic function, severe mitral valve regurgitation, and prolapse due to chordae rupture. The myocardium of the LV and right ventricle (RV) had excessively prominent trabeculations and deep intertrabecular recesses. He is the first patient in Korea who has undergone mitral valve replacement surgery because of severe mitral valve regurgitation and prolapse due to chordae rupture accompanied by IVNC.

Isolated left ventricular noncompaction syndrome

Isolated left ventricular noncompaction (ILVNC) is a rare congenital cardiomyopathy characterized by prominent trabeculae, deep intertrabecular recesses, and thickened myocardium with 2 distinct layers (compacted and noncompacted). Clinical characteristics, outcomes, and appropriate therapies remain poorly defined. Data were collected on patients diagnosed with ILVNC by echocardiographic criteria at the Mayo Clinic from 2001 through 2006. These data were entered prospectively into a clinical database and retrospectively analyzed. All-cause mortality, stroke, and development of atrial fibrillation (AF) were compared to community and nonischemic dilated cardiomyopathic (DC) controls. Implantable cardioverter-defibrillator (ICD) therapies were examined. Thirty patients with confirmed ILVNC were included in analyses (mean age at diagnosis 39 +/- 19.5 years, 60% men). Three patients with ILVNC died during follow-up (mean 2.5 +/- 1.2 years) compared to 5 DC and 1 community controls. No mortality difference was observed among these groups (p = 0.42 and 0.054, respectively). No ILVNC deaths were observed in patients with normal LV ejection fraction. New-onset AF was diagnosed in 2 patients with ILVNC, and none was observed in DC controls. Stroke occurred in 2 DC controls and none was observed in patients with ILVNC. ICDs were implanted in 11 patients with ILVNC. No appropriate therapies were identified during follow-up, but 2 patients underwent inappropriate therapies related to AF. In conclusion, mortality in patients with ILVNC is similar to that in DC patients. Deaths were observed only in patients with decreased LV ejection fraction, suggesting that ICD therapy may be reserved for this subgroup. New-onset AF may lead to inappropriate ICD discharges.