Neuromuscular implications in left ventricular hypertrabeculation/noncompaction

Case report: A rare case of left ventricular noncompaction in two Chinese siblings with becker muscular dystrophy caused by deletion of exons 10 to 12 in the DMD gene

Background

Becker muscular dystrophy (BMD) is an inherited X-linked recessive condition resulting from mutations of the DMD gene encoding dystrophin. Left ventricular noncompaction (LVNC) is a rare cardiomyopathy morphologically characterized by abnormal myocardial trabeculae and deep recesses in the left ventricle. LVNC in BMD patients has only rarely been reported.

Case report

In the present study, we identified a deletion mutation in exons 10 to 12 (EX10_12 del) of the DMD gene (reference sequence NM_004006.2) in two Chinese siblings with BMD and LVNC by high throughput targeted next-generation sequencing (NGS) and quantitative polymerase chain reaction (qPCR). The proband was a 22-year-old man admitted with dyspnea, abdominal distention, and polyserositis. It is noteworthy that both the proband and his younger brother manifested progressive muscular atrophy and creatine kinase (CK) elevation. Light and electron microscopy examination of muscle biopsies showed the typical features of dystrophinopathies. Cardiac magnetic resonance imaging and echocardiography demonstrated that both brothers had an enlarged left ventricle, LVNC, and reduced left ventricular ejection fraction. Finally, the proband underwent heart transplantation at age 26 with an event-free follow-up over 4 years post-transplantation.

Conclusion

This case further enriches our knowledge of the symptoms, genotype, cardiac performance, management, and prognosis of BMD patients complicated by LVNC. It is recommended that early comprehensive cardiac evaluation should be considered for patients with BMD to exclude LVNC, as this may have a significant impact on their prognosis.

Pronounced QT Prolongation During General Anesthesia in a Child with Left Ventricular Noncompaction Cardiomyopathy: A Case Report

We report the case of an 8-year-old boy with left ventricular noncompaction cardiomyopathy (LVNC) and QT prolongation who experienced further prolongation of the QTc during general anesthesia for extraction of a maxillary mesiodens. Pronounced prolongation of the QTc was observed after induction of general anesthesia with thiamylal and during emergence. No notable fluctuations in blood pressure, heart rate, and estimated continuous cardiac output were observed. We considered it likely that the QT prolongation was triggered by thiamylal and increased sympathetic nervous system activity. During general anesthesia for children with LVNC and QT prolongation, it is necessary to monitor intraoperative hemodynamic fluctuations and prepare for the possible occurrence of arrhythmias.

Characterization of cardiac involvement in children with LMNA-related muscular dystrophy

Introduction: LMNA-related muscular dystrophy is a rare entity that produce "laminopathies" such as Emery-Dreifuss muscular dystrophy (EDMD), limb-girdle muscular dystrophy type 1B (LGMD1B), and LMNA-related congenital muscular dystrophy (L-CMD). Heart failure, malignant arrhythmias, and sudden death may occur. No consensus exists on cardiovascular management in pediatric laminopathies. The aim was to perform an exhaustive cardiologic follow-up in pediatric patients diagnosed with LMNA-related muscular dystrophy. Methods: Baseline cardiac work-up consisted of clinical assessment, transthoracic Doppler echocardiography, 12-lead electrocardiogram, electrophysiological study, and implantation of a long-term implantable cardiac loop recorder (ILR). Results: We enrolled twenty-eight pediatric patients diagnosed with EDMD (13 patients), L-CMD (11 patients), LGMD1B (2 patients), and LMNA-related mild weakness (2 patients). Follow-up showed dilated cardiomyopathy (DCM) in six patients and malignant arrhythmias in five (four concomitant with DCM) detected by the ILR that required implantable cardioverter defibrillator (ICD) implantation. Malignant arrhythmias were detected in 20% of our cohort and early-onset EDMD showed worse cardiac prognosis. Discussion: Patients diagnosed with early-onset EDMD are at higher risk of DCM, while potentially life-threatening arrhythmias without DCM appear earlier in L-CMD patients. Early onset neurologic symptoms could be related with worse cardiac prognosis. Specific clinical guidelines for children are needed to prevent sudden death.

The Electrocardiogram in the Diagnosis and Management of Patients With Left Ventricular Non-Compaction

PURPOSE OF THE REVIEW

Left ventricular non-compaction (LVNC) is characterised by prominent left ventricular trabeculae and deep inter-trabecular recesses. Although considered a distinct cardiomyopathy, prominent trabeculations may also be found in other cardiomyopathies, in athletes or during pregnancy. Clinical presentation includes heart failure symptoms, systemic embolic events, arrhythmias and sudden cardiac death. Currently, LVNC diagnosis relies on imaging criteria, and clinicians face several challenges in the assessment of patients with prominent trabeculations. In this review, we summarise the available information on the role of the ECG in the diagnosis and management of LVNC.

RECENT FINDINGS

ECG abnormalities have been reported in 75-94% of adults and children with LVNC. The lack of specificity of these ECG abnormalities does not allow (in isolation) to diagnose the condition. However, when considered in a set of diagnostic criteria including family history, clinical information, and imaging features, the ECG may differentiate between physiological and pathological findings or may provide clues raising the possibility of specific underlying conditions. Finally, some ECG features in LVNC constitute ominous signs that require a stricter patient surveillance or specific therapeutic measures. The ECG remains a cornerstone in the diagnosis and management of patients with cardiomyopathies, including LVNC.

Left Ventricular Noncompaction: Diagnostic Approach, Prognostic Evaluation, and Management Strategies

Left ventricular noncompaction cardiomyopathy is a heart disease with relevant potential complications including heart failure, life-threatening arrhythmias, and embolic events. In order to prevent adverse outcomes, it is crucial to appropriately recognize and manage this cardiomyopathy. In this paper, we report the main clinical presentations and imaging modalities used for diagnosis, including echocardiography and magnetic resonance imaging. We highlight the role of a comprehensive functional cardiac evaluation and the possible prognostic implications of both systolic and diastolic dysfunction. Furthermore, we summarize clinical factors and imaging findings which have prognostic significance. Finally, we discuss the main management strategies based on phenotypic expressions which are aimed at treating symptoms and preventing complications.

Echocardiographic and clinical markers of left ventricular ejection fraction and moderate or greater systolic dysfunction in left ventricular noncompaction cardiomyopathy

BACKGROUND

Left ventricular noncompaction (LVNC) is associated with progressive LV systolic dysfunction and dilated cardiomyopathy. We aimed to investigate the echocardiographic and clinical characteristics associated with LV ejection fraction (LVEF) and moderate or greater systolic dysfunction in patients with LVNC.

METHODS

Our institutional echocardiography database was retrospectively reviewed between 2008 and 2014, and 62 patients with LVNC were identified. Forty-three (69%) had moderate or greater LV systolic dysfunction (LVEF ≤ 40%) and were compared with 19 (31%) patients with preserved or mildly reduced LVEF (>40%). Linear regression analyses were utilized to identify markers associated with LVEF.

RESULTS

The mean age was 63 ± 17 years and noncompacted-to-compacted ratio was 2.3 ± 0.5, and was larger in patients with LVEF ≤ 40% (2.4 vs 2.1; P = .02). Patients with LVEF ≤ 40% were older, had more congestive heart failure, significant QRS interval prolongation, and greater LV remodeling and worse mean global longitudinal strain (GLS). Multivariate regression analysis revealed increased age (standardized regression coefficient (β) = -0.17; P = .04) and QRS duration (β = -0.13; P = .08), congestive heart failure (β = -0.18; P = .04), and worsened GLS (β = -0.40; P = .001) were independently associated with decreased LVEF in the cohort (overall model fit R2  = 0.71; P < .0001). Increased age (β = -0.49; P = .01) and QRS duration (β = -0.50; P = .002), and worsened GLS (β = -0.33; P = .04), were also associated with a lower LVEF in patients with LVEF > 40%.

CONCLUSIONS

The independent markers associated with LVEF and moderate or greater LV systolic dysfunction in patients with LVNC, in particular GLS and QRS duration, may detect high-risk candidates for more aggressive clinical surveillance and medical therapy.

Combination of mitochondrial myopathy and biventricular hypertrabeculation/noncompaction

Left ventricular hypertrabeculation/noncompaction (LVHT/LVNC), characterized by prominent trabeculations and intertrabecular recesses within the left ventricle, is a cardiac abnormality of unclear etiology. Although the left ventricle is the most commonly affected site, a few cases of biventricular involvement have also been reported. We report a 31-year-old woman who presented with mild cardiac symptoms and progressive bilateral limb muscle weakness following exercise which she had also been experiencing for about 5 years. Abnormal serum levels of creatine kinase, lactic acid and pyruvic acid, combined with the results of modified lactate stress test, needle EMG and muscle biopsy indicated that she had mitochondrial myopathy. The transthoracic echocardiography, together with magnetic resonance imaging (MRI), revealed biventricular hypertrabeculation.

Successful management of Barth syndrome: a systematic review highlighting the importance of a flexible and multidisciplinary approach

This review describes and summarizes the available evidence related to the treatment and management of Barth syndrome. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards were used to identify articles published between December 2004 and January 2015. The Cochrane Population, Intervention, Control, Outcome, Study Design (PICOS) approach was used to guide the article selection and evaluation process. Of the 128 articles screened, 28 articles matched the systematic review inclusion criteria. The results of this review indicate the need for a flexible and multidisciplinary approach to manage the symptoms most commonly associated with Barth syndrome. It is recommended that a comprehensive care team should include individuals with Barth syndrome, their family members and caregivers, as well as medical, rehabilitative, nutritional, psychological, and educational professionals. The evidence for specific treatments, therapies, and techniques for individuals with Barth syndrome is currently lacking in both quality and quantity.

Cardiomyopathy in neurological disorders

According to the American Heart Association, cardiomyopathies are classified as primary (solely or predominantly confined to heart muscle), secondary (those showing pathological myocardial involvement as part of a neuromuscular disorder) and those in which cardiomyopathy is the first/predominant manifestation of a neuromuscular disorder. Cardiomyopathies may be further classified as hypertrophic cardiomyopathy, dilated cardiomyopathy, restrictive cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, or unclassified cardiomyopathy (noncompaction, Takotsubo-cardiomyopathy). This review focuses on secondary cardiomyopathies and those in which cardiomyopathy is the predominant manifestation of a myopathy. Any of them may cause neurological disease, and any of them may be a manifestation of a neurological disorder. Neurological disease most frequently caused by cardiomyopathies is ischemic stroke, followed by transitory ischemic attack, syncope, or vertigo. Neurological disease, which most frequently manifests with cardiomyopathies are the neuromuscular disorders. Most commonly associated with cardiomyopathies are muscular dystrophies, myofibrillar myopathies, congenital myopathies and metabolic myopathies. Management of neurological disease caused by cardiomyopathies is not at variance from the same neurological disorders due to other causes. Management of secondary cardiomyopathies is not different from that of cardiomyopathies due to other causes either. Patients with neuromuscular disorders require early cardiologic investigations and close follow-ups, patients with cardiomyopathies require neurological investigation and avoidance of muscle toxic medication if a neuromuscular disorder is diagnosed. Which patients with cardiomyopathy profit most from primary stroke prevention is unsolved and requires further investigations.

Noncompaction of the ventricular myocardium and hydrops fetalis in cobalamin C disease

Cobalamin C disease (cblC), a form of combined methylmalonic acidemia and hyperhomocysteinemia caused by mutations in the MMACHC gene, may be the most common inborn error of intracellular cobalamin metabolism. The clinical manifestations of cblC disease are diverse and range from intrauterine growth retardation to adult onset neurological disease. The occurrence of structural heart defects appears to be increased in cblC patients and may be related to the function of the MMACHC enzyme during cardiac embryogenesis, a concept supported by the observation that Mmachc is expressed in the bulbis cordis of the developing mouse heart. Here we report an infant who presented with hydrops fetalis, ventricular dysfunction, and echocardiographic evidence of LVNC, a rare congenital cardiomyopathy. Metabolic evaluations, complementation studies, and mutation analysis confirmed the diagnosis of cblC disease. These findings highlight an intrauterine cardiac phenotype that can be displayed in cblC disease in association with nonimmune hydrops.

Correlation of trabeculae and papillary muscles with clinical and cardiac characteristics and impact on CMR measures of LV anatomy and function

OBJECTIVES

The goal of this study was to assess the relationship of left ventricular (LV) trabeculae and papillary muscles (TPM) with clinical characteristics in a community-based, free-living adult cohort and to determine the effect of TPM on quantitative measures of LV volume, mass, and ejection fraction (EF).

BACKGROUND

Hypertrabeculation has been associated with adverse cardiovascular events, but the distribution and clinical correlates of the volume and mass of the TPM in a normal left ventricle have not been well characterized.

METHODS

Short-axis cine cardiac magnetic resonance images, obtained using a steady-state free precession sequence from 1,494 members of the Framingham Heart Study Offspring cohort, were analyzed with software that automatically segments TPM. Absolute TPM volume, TPM as a fraction of end-diastolic volume (EDV) (TPM/EDV), and TPM mass as a fraction of LV mass were determined in all offspring and in a referent group of offspring free of clinical cardiovascular disease and hypertension.

RESULTS

In the referent group (mean age 61 ± 9 years; 262 men and 423 women), mean TPM was 23 ± 3% of LV EDV in both sexes (p = 0.9). TPM/EDV decreased with age (p < 0.02) but was not associated with body mass index. TPM mass as a fraction of LV mass was inversely correlated with age (p < 0.0001), body mass index (p < 0.018), and systolic blood pressure (p < 0.0001). Among all 1,494 participants (699 men), LV volumes decreased 23%, LV mass increased 28%, and EF increased by 7.5 EF units (p < 0.0001) when TPM were considered myocardial mass rather than part of the LV blood pool.

CONCLUSIONS

Global cardiac magnetic resonance LV parameters were significantly affected by whether TPM was considered as part of the LV blood pool or as part of LV mass. Our cross-sectional data from a healthy referent group of adults free of clinical cardiovascular disease demonstrated that TPM/EDV decreases with increasing age in both sexes but is not related to hypertension or obesity.

Oculopharyngodistal myopathy--a possible association with cardiomyopathy

Oculopharyngodistal myopathy is an uncommon myopathy characterised clinically by cranial and distal limb muscle weakness. Here we describe two siblings with autosomal dominant oculopharyngodistal myopathy apparently associated with dilated cardiomyopathy, which in one case progressed to ventricular hypertrabeculation/non-compaction. Electrocardiographic screening was normal and the cardiomyopathy was detected only with echocardiography. Our findings suggest that patients with oculopharyngodistal myopathy should be screened for cardiomyopathy (with both electrocardiography and echocardiography).

Noncompaction syndrome of the myocardium: pathophysiology and imaging pearls

Patients with noncompaction syndrome of the myocardium may present with cardiac arrhythmia, thromboembolic events, or left ventricular failure. Associations with other diseases, including neurologic or other cardiac syndromes, have been noted. Noncompaction syndrome of the myocardium is primarily diagnosed by echocardiography; however, CT scanning and magnetic resonance imaging are useful tools for determining severity and the patient's prognosis. With these methods, high-resolution images of the myocardium are obtained that enable better recognition of the areas over which the trabeculae are distributed. Early diagnosis can improve the patient's survival by premature heart transplantation or implantation of a defibrillator. Also, as there are many reports of occurrence of this syndrome in several members of the same family (mainly X-linked inheritance), upon accurate and early diagnosis, the patient's family can be further screened.

Left ventricular noncompaction

According to the World Health Organization classification of cardiomyopathies, left ventricular noncompaction is still an unclassified cardiomyopathy. In 2006, the American Heart Association classified this entity as a primary cardiomyopathy of genetic origin. In 2008, the European Society of Cardiology updated the classification scheme similar to the World Health Organization classification. At present, there is no consensus on the diagnostic criteria, and diagnosis is based on the morphologic features identified by cardiac imaging studies or at autopsy. Due to lack of standardization of the diagnostic criteria and little awareness of this condition among clinicians, the true prevalence of this disease is not clear. There is no specific therapy for this condition. However, it seems prognosis is much better than initially reported. The current status of diagnosis, prognosis, and management of isolated noncompaction in adults is discussed in this review.

Myopathy, left ventricular noncompaction, and tetralogy of fallot

Left ventricular hypertrabeculation, also termed noncompaction (LVHT) is a cardiac abnormality characterized by excessive trabeculations of the left ventricular cavity. LVHT may be associated with extracardiac abnormalities, most frequently neuromuscular disorders (NMDs). LVHT associated with tetralogy of Fallot (ToF), so far, has been reported in 2 cases, but no indication for the presence of NMDs are given.We present a 47-year old female who underwent 2 cardiac surgeries because of ToF, and was admitted because of heart failure. She was diagnosed with echocardiographic LVHT. A myopathy was diagnosed by biopsy.

Cardiac and neuromuscular implications of left bundle branch block in left ventricular hypertrabeculation/noncompaction

BACKGROUND

Left bundle branch block (LBB) is frequently found in left ventricular hypertrabeculation/noncompaction (LVHT).

OBJECTIVES

To compare LVHT patients with and without LBB regarding LVHT location and extension, left ventricular function, symptoms, electrocardiographic findings, prevalence of neuromuscular disorders (NMDs) and mortality during follow-up.

METHODS

The charts of patients who underwent transthoracic echocardiographic examination at the Krankenanstalt Rudolfstiftung (Wien, Austria) between June 1995 and November 2006 were examined.

RESULTS

LVHT was diagnosed in 102 patients (30 women) with a mean (+/- SD) age of 53+/-16 years (range 14 to 94 years). A specific NMD was diagnosed in 21 patients and an NMD of unknown etiology was diagnosed in 47. The neurological investigation was normal in 14 patients and 20 patients refused the investigation. The 24 patients with LBB were older (61 versus 51 years of age; P<0.01), and suffered from exertional dyspnea (96% versus 59%; P<0.01) and heart failure (79% versus 46%; P<0.01) more often than patients without LBB. LBB patients had less frequent tall QRS complexes (8% versus 47%; P<0.01) and ST-T wave abnormalities (4% versus 50%; P<0.01) than patients without LBB. Patients with LBB had a larger left ventricular end-diastolic diameter (73 mm versus 61 mm; P<0.01), worse left ventricular fractional shortening (15% versus 26%; P<0.01) and more extensive LVHT (1.8 versus 1.5 ventricular segments; P<0.05). The prevalence of NMDs did not differ between patients with and without LBB. Survival did not differ between patients with and without LBB during follow-up.

CONCLUSIONS

LBB is associated with increased age, decreased systolic function and increased extension of LVHT. Whether LBB is a prognostic factor in LVHT remains speculative.

Primary myopathies and the heart

Myopathies are frequently not confined to the skeletal muscles but also involve other organs or tissues. One of the most frequently affected organ in addition to the skeletal muscle is the heart (cardiac involvement, CI). CI manifests as impulse generation or conduction defects, focal or diffuse myocardial thickening, dilation of the cardiac cavities, relaxation abnormality, hypertrophic, dilated, restrictive cardiomyopathy, apical form of hypertrophic cardiomyopathy, noncompaction, Takotsubo phenomenon, secondary valve insufficiency, intra-cardiac thrombus formation, or heart failure with systolic or diastolic dysfunction. CI occurs in dystrophinopathies, Emery-Dreifuss muscular dystrophy, facioscapulohumeral muscular dystrophy, limb girdle muscular dystrophies, laminopathies, congenital muscular dystrophies, myotonic dystrophies, congenital myopathies, metabolic myopathies, desminopathies, myofibrillar myopathy, Barth syndrome, McLeod syndrome, Senger's syndrome, and Bethlem myopathy. Patients with myopathy should be cardiologically investigated as soon as their neurological diagnosis is established, since supportive cardiac therapy is available, which markedly influences prognosis and outcome of CI in these patients.

Cerebrovascular events in left ventricular hypertrabeculation/noncompaction with and without myopathy

Little is known about frequency, morphology, and causes of stroke in patients with left-ventricular hypertrabeculation/noncompaction (LVHT). Aim of this study was to find out how many LVHT-patients suffer from stroke, which abnormalities are found on cerebral imaging, and if stroke LVHT-patients differ from non-stroke LVHT-patients with regard to cardiac and neuromuscular abnormalities.

METHOD AND MATERIALS

Records of all included patients were reviewed for stroke diagnosed upon history, clinical examination, or cerebral CT/MRI (CCT, cMRI).

RESULTS

Among 104 LVHT-patients included, stroke was diagnosed in 16 (15%). Of these two had a transitory ischemic attack and one a prolonged ischemic deficit. Among 36 patients undergoing a CCT (n=32), cMRI (n=9), or both (n=5) territorial stroke was found in 7, lacunar stroke in 2, and intracerebral bleeding in 1. Other imaging findings were atrophy (n=7), microangiopathy (n=4), leucencephalopathy (n=3), basal-ganglia-calcification (n=2), or non-specific hypodensities (n=2). Imaging studies without vascular lesions were found in 2 patients. At least one classical risk factor for stroke was found in 15 patients. Stroke-patients did not differ from non-stroke-patients regarding cardiac or neuromuscular findings.

CONCLUSIONS

If systematically looked for, stroke is a frequent feature of LVHT. A causal relation between LVHT and stroke, however, is rather the exception than the rule.

Large recesses associated with left ventricular noncompaction: An unusual presentation of the disease

Left ventricular noncompaction (LVNC) represents an arrest of myocardial morphogenesis, resulting in persistence of multiple prominent ventricular trabeculations and deep intertrabecular recesses. We report a case of a 30-year-old patient who was referred to our hospital due to familial history of cardiomyopathy. The patient underwent transthoracic echocardiography, cardiac catheterization and contrast ventriculography and cardiac magnetic resonance imaging. All imaging techniques showed the characteristic pattern of noncompaction together with two unusually large recesses in the inferior wall of myocardium. This unusual form of LVNC may have an impact on the clinical course of the disease and may require anticoagulation therapy.

Noncompaction and neuromuscular disease with positive troponin-T in a nonagenerian

In a 94-year-old male with a history of atrial fibrillation, aortic stenosis, heart failure, apical thrombus, arterial hypertension, aneurysm of the abdominal aorta, and a urinary bladder carcinoma, cardiologic investigations revealed pulmonary rales, enlarged heart, absolute arrhythmia, and positive troponin-, myocardial thickening, enlarged cardiac cavities, hypocontractility, aortic stenosis, slight aortic insufficiency, severe mitral insufficiency, and surprisingly left ventricular hypertrabeculation. Upon neurological investigations, a polyneuropathy was suspected but a myopathy not completely excluded. The presented case shows that LVHT occurs also in nonagenarians and is associated with neuromuscular disease and positive troponin-T, in the absence of ischemic heart disease or severe renal failure. The cause of troponin-T-positivity remains multi-factorial.