Isolated ventricular noncompaction mimicking arrhythmogenic right ventricular cardiomyopathy — A study of nine patients

Non-Compaction Ventricle and Associated Cardiovascular and Non-Cardiovascular Diseases; More Attention Is Needed!

Non-compaction of the ventricle (NCV) with a higher tendency to left ventricular involvement (NCLV) is a genetic disorder which can cause arrhythmias and cardiac arrest or remain asymptomatic. It is generally considered an isolated disease most frequently, while a few case reports have reported its association with cardiac anomalies. As the treatment strategies differ for NCV and cardiac anomalies, missed diagnosis of the concomitant cardiac diseases can result in poor response to treatment and prognosis. Here, we present 12 adult patients diagnosed with NCV and associated cardiovascular anomalies. By increasing the clinical suspicion and physician's awareness about the possibility of the presence of other cardiovascular diseases with NCLV and using close examination and follow-up of the patients, we could diagnose this number of patients during 14 months of investigation. This case series emphasizes the need for increased awareness and attention of echocardiographers on the diagnosis of other cardiovascular diseases associated with NCV for a better response to treatment and improved patient prognosis.

Premature ventricular complexes as a first manifestation in left ventricular non-compaction cardiomyopathy: A case report and focused review of the literature

Left ventricular non-compaction (LVNC) cardiomyopathy is an uncommon unclassified or genetic myocardial disorder. Frequent premature ventricular complexes (PVCs) as unique finding in LVNC cardiomyopathy are rare. We report a case of a 36-year-old woman in whom isolated LVNC was diagnosed due to an incidental finding of PVCs in pre-operative consultation.

Non-compact right ventricular myocardium – diagnostic and clinical features: A review

Non-compact right ventricular myocardium is a rare type of cardiomyopathy, it usually results from arrested myocardial development during embryogenesis. This disease can be characterized by excessive prominent trabeculations and deep inter-trabecular recesses in the ventricular wall. It might be a component of biventricular non-compact cardiomyopathy or an isolated form. The article presents a review of the literature on the clinic and radiation diagnostics of non-compact right ventricular myocardium with the presentation of the issues of differential diagnosis.

Three Myocardial Diseases in One Heart: Arrhythmogenic Right Ventricular Cardiomyopathy, Left Ventricular Noncompaction and Myocarditis

Purpose: To evaluate the clinical features, laboratory and instrumental tests results and the effectiveness of complex treatment in a patient with multiple etiologies of dilated cardiomyopathy (DCM) with a high risk of sudden cardiac death. Methods: Female patient was 34 years old. Follow up period was seven years. Since the age of 23 (after a respiratory infection), chest pains and shortness of breath appeared. Coronary arteries were intact. After syncope in 2013, Holter-ECG was performed: 2048 premature ventricular beats (PVBs)/day and episode of sustained ventricular tachycardia (VT, 1 min) were registered. MRI was performed, and a cardioverter defibrillator (ICD) was implanted. Results: ECG showed low QRS voltage and negative T waves in leads V2-V6, III, aVF. In signal-averaged ECG, late potentials were detected. Echocardiography (EchoCG) demonstrated left and right ventricular dilatation, diffuse reduction of left ventricular (LV) contractility and multiple pseudochordae in LV. MRI showed LV noncompaction (LVNC), thickening of the epicardial fat and hypo-/dyskinesia of the anterior wall of the right ventricular (RV), dilatation of both ventricles with decrease of their ejection fraction and subepicardial gadolinium enhancement in the early and late phase in the LV, intraventricular septum and the free walls of the RV. The presence of LVNC was confirmed by cardiac computed tomography (CT). Late contrast enhancement in the middle and subendocardial layer of the LV was observed as well. The level of anticardiac antibodies was high (1:160–1:320). The reasons for statement of a possible diagnosis of myocarditis in this case were the connection of the onset of symptoms with viral infection, high titers of anticardiac antibodies, and early and late subepicardial contrast enhancement by MRI and CT. The endomyocardial biopsy was obtained, and subendocardial lipomatosis, separation of myocardium by fibrous septa, lymphocytic infiltrates (more than 14 cells/mm2) and vasculitis were found. Viral genome in myocardium was not detected. A new splicing mutation in the desmoplakin (DSP) gene was found (NM_004415.4: c.1141-2A>G/N (rs794728111)). Combination of arrhythmogenic right ventricular cardiomyopathy (ARVC), LVNC and myocarditis was diagnosed. Immunosuppressive therapy (prednisone and azathioprine) was prescribed, LV ejection fraction stabilized at the level of 40%. The appropriate shocks of the ICD due to sustainedVT (HR 210/min) with transformation into ventricular fibrillation were recorded twice. For this reason, sotalol was temporarily replaced with amiodarone. After the suppression of myocarditis activity, sustained VT and ICD interventions were not observed. Conclusions: In a young patient with arrhythmogenic syncope and DCM syndrome, a combination of ARVC (two major and three minor criteria, definite diagnosis) and LVNC with the biopsy proved virus-negative chronic myocarditis was diagnosed. DCM as a syndrome can have multiple causes, and the combination of myocarditis and primary cardiomyopathy is not rare. LVNC can be observed in patients with typical desmosomal protein mutations. The use of immunosuppressive therapy led to the stabilization of heart failure and decreased the risk of arrhythmic events.

Arrhythmogenic Noncompaction Cardiomyopathy: Is There an Echocardiographic Phenotypic Overlap of Two Distinct Cardiomyopathies?

The clinical diagnosis of right ventricular (RV) cardiomyopathies is often challenging. It is difficult to differentiate the isolated left ventricular (LV) noncompaction cardiomyopathy (NC) from biventricular NC or from coexisting arrhythmogenic ventricular cardiomyopathy (AC). There are currently few established morphologic criteria for the diagnosis other than RV dilation and presence of excessive regional trabeculation. The gross and microscopic changes suggest pathological similarities between, or coexistence of, RV-NC and AC. Therefore, the term arrhythmogenic right ventricular cardiomyopathy is somewhat misleading as isolated LV or biventricular involvement may be present and thus a broader term such as AC should be preferred. We describe an unusual case of AC associated with a NC in a 27-year-old man who had a history of permanent pacemaker 7 years ago due to second-degree atrioventricular block.

Left ventricular non-compaction cardiomyopathy

Left ventricular non-compaction, the most recently classified form of cardiomyopathy, is characterised by abnormal trabeculations in the left ventricle, most frequently at the apex. It can be associated with left ventricular dilation or hypertrophy, systolic or diastolic dysfunction, or both, or various forms of congenital heart disease. Affected individuals are at risk of left or right ventricular failure, or both. Heart failure symptoms can be induced by exercise or be persistent at rest, but many patients are asymptomatic. Patients on chronic treatment for compensated heart failure sometimes present acutely with decompensated heart failure. Other life-threatening risks of left ventricular non-compaction are ventricular arrhythmias or complete atrioventricular block, presenting clinically as syncope, and sudden death. Genetic inheritance arises in at least 30-50% of patients, and several genes that cause left ventricular non-compaction have been identified. These genes seem generally to encode sarcomeric (contractile apparatus) or cytoskeletal proteins, although, in the case of left ventricular non-compaction with congenital heart disease, disturbance of the NOTCH signalling pathway seems part of a final common pathway for this form of the disease. Disrupted mitochondrial function and metabolic abnormalities have a causal role too. Treatments focus on improvement of cardiac efficiency and reduction of mechanical stress in patients with systolic dysfunction. Further, treatment of arrhythmia and implantation of an automatic implantable cardioverter-defibrillator for prevention of sudden death are mainstays of therapy when deemed necessary and appropriate. Patients with left ventricular non-compaction and congenital heart disease often need surgical or catheter-based interventions. Despite progress in diagnosis and treatment in the past 10 years, understanding of the disorder and outcomes need to be improved.

Right ventricular cardiomyopathies: a multidisciplinary approach to diagnosis

The physiological importance of the right ventricle (RV) has been underestimated over the past years. Finally in the early 1950s through the 1970s, cardiac surgeons recognized the importance of RV function. Since then, the importance of RV function has been recognized in many acquired cardiac heart disease. RV can be mainly or together with left ventricle (LV) affected by inherited or acquired cardiomyopathy. In fact, RV morphological and functional remodeling occurs more common during cardiomyopathies than in ischemic cardiomyopathies and more closely parallels LV dysfunction. Moreover, there are some cardiomyopathy subtypes showing a predominant or exclusive involvement of the RV, and they are probably less known by cardiologists. The clinical approach to right ventricular cardiomyopathies is often challenging. Imaging is the first step to raise the suspicion and to guide the diagnostic process. In the differential diagnosis, cardiologists should consider athlete's heart, congenital heart diseases, multisystemic disorders, and inherited arrhythmias. However, a multiparametric and multidisciplinary approach, involving cardiologists, experts in imaging, geneticists, and pathologists with a specific expertise in these heart muscle disorders is required.

Magnetic resonance assessment of prevalence and correlates of right ventricular abnormalities in isolated left ventricular noncompaction

The aim of the present study was to evaluate the prevalence and correlates of right ventricular (RV) noncompaction (RVNC), RV systolic dysfunction, and RV myocardial fibrosis in patients with isolated left ventricular (LV) noncompaction (LVNC). For this purpose, cine and contrast-enhanced cardiac magnetic resonance imaging (MRI) was used. A total of 56 consecutive patients with isolated LVNC were included in the study. The diagnosis of isolated LVNC was based on the presence of standard cardiac MRI and clinical criteria. For each patient, cine and contrast-enhanced cardiac MR images were analyzed to evaluate the prevalence and correlates of RVNC, RV dysfunction, and late gadolinium enhancement (a surrogate of myocardial fibrosis) involving the RV. Mean age of the patient population was 45 ± 19 years; 35 patients (63%) were men. RVNC was observed in 5 patients (9%). Impaired RV systolic function was observed in 9 patients (16%). Late gadolinium enhancement was not observed in any RV segment. No association was found between wall motion abnormalities and noncompaction at RV segmental level (φ coefficient 0.041, p = 0.26). At multivariate analysis, LV ejection fraction was the only variable independently related to RV ejection fraction (β = 0.62, p <0.001). In conclusion, RV systolic dysfunction is present in a non-negligible proportion of patients with isolated LVNC; LV systolic function is the only variable independently related to RV systolic function.

Ultrastructural findings in noncompaction prevail with neuromuscular disorders

OBJECTIVES

Little is known about the ultrastructural abnormalities of left ventricular hypertrabeculation/noncompaction (LVHT). This literature review aimed to summarize and discuss ultrastructural abnormalities described in LVHT so far.

METHODS

The literature search was conducted via MEDLINE using the search terms 'non-compaction', 'noncompaction', 'left ventricular hypertrabeculation', 'spongy myocardium' in combination with the terms 'ultra-structural', or 'electron microscopy'.

RESULTS

Altogether, 11 studies reporting ultrastructural investigations of LVHT were retrieved. In these 11 studies, data on 13 patients with LVHT were presented. Ultrastructural abnormalities found in these study patients were generally nonspecific and included an increase in the number of mitochondria (n = 3), abnormally shaped mitochondria (n = 2), distorted cristae (n = 3), sarcomeric derangement (n = 3), immature cardiomyocytes (n = 1), lipid-like inclusions (n = 1), enlarged interstitial spaces (n = 1), increased interstitial collagen (n = 1), or increased glycogen (n = 1). The morphological abnormalities were most prominent in patients with a neuromuscular disorder like Barth syndrome or mitochondrial myopathy.

CONCLUSIONS

Only in few patients with LVHT, ultrastructural investigations have been performed so far. Ultrastructural abnormalities in LVHT are nonspecific and most prominent in patients with a neuromuscular disorder. There is a strong need to carry out thorough ultrastructural investigations of LVHT to contribute to the understanding of this still unexplained myocardial abnormality.

Insights from magnetic resonance imaging of left ventricular non-compaction in adults of North African descent

Background

Left ventricular non-compaction (LVNC) is a recently recognized rare disorder. Magnetic resonance imaging (MRI) may help to clarify the uncertainties related to this genetic cardiomyopathy. Despite the fact that many articles have been published concerning the use of MRI in the study of LVNC, there is a lack of data describing the disease in the North African population. The aim of our study is to clarify MRI findings of LVNC in North African patients.

Methods

In our retrospective cohort, twelve patients (7 male, mean age 53 ± 8 years) underwent MRI for suspected LVNC. Correlations were investigated between the number of non-compacted segments per patient and left ventricular ejection fraction (LVEF), then between the number of non-compacted segments and left ventricular end diastolic diameter. The presence or absence of late gadolinium enhancement (LGE) was qualitatively determined for each left ventricular myocardial segment.

Results

Non-compaction was more commonly observed at the apex, the anterior and the lateral walls, especially on their apical and mid-cavity segments. 83% of patients had impaired LVEF. There was no correlation between the number of non-compacted segments per patient and LVEF (r = -0.361; p = 0.263), nor between the number of non-compacted segments per patient and left ventricular end diastolic diameter (r = 0.280; p = 0.377). LGE was observed in 22 left ventricular segments. No association was found between the pattern of fibrosis and non-compaction distribution (OR = 2.2, CI [0.91-5.55], p = 0.076).

Conclusion

The distribution of LVNC in North African patients does not differ from other populations. Ventricular dysfunction is independent from the number of non-compacted segments. Myocardial fibrosis is not limited to non-compacted areas but can extend to compacted segments.

Exercise-induced right ventricular outflow tract tachycardia in a patient with isolated left ventricular noncompaction

Isolated left ventricular noncompaction is a hereditary cardiomyopathy in which a variety of supraventricular and ventricular arrhythmias could be observed. We report a patient with exercise-induced ventricular tachycardia with left bundle branch block morphology that had characteristics of an idiopathic ventricular tachycardia who was subsequently diagnosed as left ventricular noncompaction. Successful remission of arrhythmia was ensured after the introduction of oral beta-blocker therapy.

Left ventricular non-compaction and its cardiac and neurologic implications

Left ventricular non-compaction, also known as left ventricular hypertrabeculation (LVHT), is a morphological abnormality of the left ventricular myocardium, characterised by a meshwork of myocardial strings, interlacing, and orderless in arrangement. LVHT is most frequently located in the apex and the lateral wall and may occur with or without other congenital or acquired cardiac abnormalities. LVHT is believed to be congenital in the majority of the cases but may develop during life in single cases (acquired LVHT). Congenital LVHT is believed to result from defective late-stage embryonic development of the myocardial architecture. The pathogenesis of acquired LVHT remains speculative. LVHT is most frequently found on transthoracic echocardiography and cardiac MRI but may be visualised also with other imaging techniques. In the majority of the cases, LVHT is associated with hereditary cardiac, neuromuscular, non-cardiac/non-muscle disease, or chromosomal aberrations. In the majority of the cases, LVHT is complicated by ventricular arrhythmias, systolic dysfunction, cardiac embolism, or sudden cardiac death. LVHT per se does not require a specific treatment. Only in case of complications, such as ventricular arrhythmias, cardioembolism, or systolic dysfunction, adequate therapy is indicated. Though initially assessed as poor, the prognosis of LVHT has meanwhile improved, most likely due to the increased awareness for the abnormality and the timely administration of adequate therapy.