Comprehensive Assessment of Endomyocardial Fibrosis with Cardiac MRI: Morphology, Function, and Tissue Characterization

Advanced myocardial characterization and function with cardiac CT

Non-invasive imaging with characterization and quantification of the myocardium with computed tomography (CT) became feasible owing to recent technical developments in CT technology. Cardiac CT can serve as an alternative modality when cardiac magnetic resonance imaging and/or echocardiography are contraindicated, not feasible, inconclusive, or non-diagnostic. This review summarizes the current and potential future role of cardiac CT for myocardial characterization including a summary of late enhancement techniques, extracellular volume quantification, and strain analysis. In addition, this review highlights potential fields for research about myocardial characterization with CT to possibly include it in clinical routine in the future.

Imaging of Cardiac Fibrosis: How Far Have We Moved From Extracellular to Cellular?

Cardiovascular disease is the leading cause of morbidity and mortality worldwide. Myocardial fibrosis plays an important role in adverse outcomes such as heart failure and arrhythmias. As the pathological response and degree of scarring, and therefore clinical presentation varies from patient to patient, early detection of fibrosis is crucial for identifying the appropriate treatment approach and forecasting the progression of a disease along with the likelihood of disease-related mortality. Current imaging modalities provides information about either decreased function or extracellular signs of fibrosis. Targeting activated fibroblasts represents a burgeoning approach that could offer insights prior to observable functional alterations, presenting a promising focus for potential anti-fibrotic therapeutic interventions at cellular level. In this article, we provide an overview of imaging cardiac fibrosis and discuss the role of different advanced imaging modalities with the focus on novel non-invasive imaging of activated fibroblasts.

How the trabecular layer impacts on left ventricular function

The ventricular trabecular layer is crucial in embryonic life. In adults, the proportion of trabecular-to-compact myocardium varies substantially between individuals, within individuals over time, and yet exhibits almost no correlation to pump function since most individuals with excessive trabeculation are asymptomatic. The question of how functional is the myocardium of the trabecular layer, relative to the myocardium of the compact layer, has been difficult to answer but it is often assumed to be inferior. An answer is now emerging from recent advances and it can improve our understanding of how the trabecular layer impacts on pathogenicity. This narrative review concerns natural variation in trabeculation, tissue organization, transcriptomics, immunohistochemistry, vascularization, electrical propagation, diastolic function and compliance, systolic function, and ejection fraction. There are no overt transcriptional differences in the adult stage, and the myocardium is equally equipped with sarcomeric proteins, mitochondria, and vascular supply. The similar structural features are consistent with myocardium with a similar stroke work per gram tissue, along with a high ejection fraction of the trabecular layer. In conclusion, the myocardium of the trabecular and compact layers is highly similar and this offers a logical explanation for the reproducible observations that most individuals with excessive trabeculation are asymptomatic.

A non-invasive osteopontin-targeted phase changeable fluorescent nanoprobe for molecular imaging of myocardial fibrosis

Due to the elevated fatality rate of cardiovascular diseases, myocardial fibrosis emerges as a prominent pathological alteration in the majority of heart ailments and their associated pathologies, thereby augmenting the likelihood of sudden cardiac death. Consequently, the prompt and obligatory identification of myocardial fibrosis assumes paramount importance in averting malignant incidents among patients afflicted with cardiac disorders. Herein, with higher expression osteopontin (OPN) found in cardiac fibrosis tissue, we have developed a dual-modality imaging probe, namely OPN targeted nanoparticles (OPN@PFP-DiR NPs), which loaded perfluoropentane (PFP) for ultrasound (US) and 1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbocyanine iodide (DiR) for near-infrared fluorescence (NIR) of molecular imaging, to investigate the molecular features of cardiac fibrosis using US and NIR imaging. Subsequently, the OPN@PFP-DiR NPs were administered intravenously to a mouse model of myocardial infarction (MI). The US and NIR molecular imaging techniques were employed to visualize the accumulation of the nanoparticles in the fibrotic myocardium. Hence, this research presents a valuable noninvasive, cost-effective, and real-time imaging method for evaluating cardiac fibrosis, with promising clinical applications.

Endomyocardial fibrosis with ischaemic stroke

A Caucasian man in his mid-50s presented to the emergency department with sudden onset right-sided weakness and dysarthria. CT angiogram demonstrated a small volume of left middle cerebral artery territory infarction after which the patient underwent successful thrombolysis. Initial ECG showed diffuse T wave inversion. He was admitted to an acute stroke ward where 72 hours of telemetry demonstrated normal sinus rhythm without arrhythmia. Transthoracic echocardiogram showed a reduced ejection fraction of 47% in the absence of any regional wall motion abnormality. An echogenic mass was noted in the apical inferior septal wall. Cardiac MRI demonstrated circumferential mid to apical endocardial thickening with characteristic appearances consistent with endomyocardial fibrosis (EMF). Furthermore, a visible hypointensity in the apex confirmed left ventricular thrombus adherent to the area of EMF. The patient was started on anticoagulation and heart failure therapy. He has recovered from the ischaemic stroke and is currently under outpatient surveillance.

Focus on Paediatric Restrictive Cardiomyopathy: Frequently Asked Questions

Restrictive cardiomyopathy (RCM) is characterized by restrictive ventricular pathophysiology determined by increased myocardial stiffness. While suspicion of RCM is initially raised by clinical evaluation and supported by electrocardiographic and echocardiographic findings, invasive hemodynamic evaluation is often required for diagnosis and management of patients during follow-up. RCM is commonly associated with a poor prognosis and a high incidence of heart failure, and PH is reported in paediatric patients with RCM. Currently, only a few therapies are available for specific RCM aetiologies. Early referral to centres for advanced heart failure treatment is often necessary. The aim of this review is to address questions frequently asked when facing paediatric patients with RCM, including issues related to aetiologies, clinical presentation, diagnostic process and prognosis.

Endomyocardial fibrosis and apical calcification: A case report with unusual presentations of apical hypertrophic cardiomyopathy

RATIONALE

Apical hypertrophic cardiomyopathy (ApHCM) is a phenotypic variant of hypertrophic cardiomyopathy. Endomyocardial fibrosis and endocardial calcification are especially rare in ApHCM.

PATIENT CONCERNS

The main symptoms was chest tightness, palpitation, shortness of breath, and fatigue. Echocardiography and imaging examinations found apical hypertrophy along with endocardial calcification and endomyocardial fibrosis. Abnormal structural changes led to thrombosis and made the left ventricle a flat shape resembling an "apple."

DIAGNOSES

The typical presentations, hypertrophic apex on echocardiography and an elevated N-terminal pro-brain natriuretic peptide level indicated the diagnosis of ApHCM and heart failure with preserved ejection fraction.

INTERVENTIONS

Optimal medical therapy including the administration of ApHCM, heart failure and atrial fibrillation to improve symptoms and life quality.

OUTCOMES

Since discharge, the patient could perform normal daily activities and had no discomfort based on the optimal medical therapy.

LESSONS

We report a ApHCM patients with unusual presentations of endomyocardial fibrosis and apical calcification. This case highlights the importance of understanding the specific pathological changes of ApHCM for treatment and prognosis.

Diastology with Cardiac MRI: A Practical Guide

Diastolic filling of the ventricle is a complex interplay of volume and pressure, contingent on active energy-dependent myocardial relaxation and myocardial stiffness. Abnormal diastolic function is the hallmark of the clinical entity of heart failure with preserved ejection fraction (HFpEF), which is now the dominant type of heart failure and is associated with significant morbidity and mortality. Although echocardiography is the current first-line imaging modality used in evaluation of diastolic function, cardiac MRI (CMR) is emerging as an important technique. The principal role of CMR is to categorize the cause of diastolic dysfunction (DD) and distinguish other entities that manifest similarly to HFpEF, particularly infiltrative and pericardial disorders. CMR also provides prognostic information and risk stratification based on late gadolinium enhancement and parametric mapping techniques. Advances in hardware, sequences, and postprocessing software now enable CMR to diagnose and grade DD accurately, a role traditionally assigned to echocardiography. Two-dimensional or four-dimensional velocity-encoded phase-contrast sequences can measure flow and velocities at the mitral inflow, mitral annulus, and pulmonary veins to provide diastolic functional metrics analogous to those at echocardiography. The commonly used cine steady-state free-precession sequence can provide clues to DD including left ventricular mass, left ventricular filling curves, and left atrial size and function. MR strain imaging provides information on myocardial mechanics that further aids in diagnosis and prognosis of diastolic function. Research sequences such as MR elastography and MR spectroscopy can help evaluate myocardial stiffness and metabolism, respectively, providing additional insights on diastolic function. The authors review the physiology of diastolic function, mechanics of diastolic heart failure, and CMR techniques in the evaluation of diastolic function. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Immunoglobulin G4-Related Myocarditis with Eosinophilic Infiltration: A Case Report

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a fibroinflammatory disorder that can involve any organ system; however, myocarditis is extremely rare. A 52-year-old male with dyspnea and chest discomfort underwent cardiac MRI that revealed edema and nodular, patchy, mesocardial and subendoardial delayed enhancement of left ventricle, suggesting myocarditis. Laboratory findings revealed elevated serum IgG4 and eosinophilia. Cardiac biopsy confirmed eosinophilic myocarditis with IgG4-positive cells. Here, we present an unusual case of IgG4-RD manifesting as eosinophilic myocarditis.

Complications of Endomyocardial fibrosis and their physiological compromise: A review

Endomyocardial fibrosis (EMF) is an endemic idiopathic cardiomyopathy denoted by restricted and fibrous myocardium and endocardium. Apical fibrosis may cause thickening of the myocardium and extend from the ventricular apices through to the valves, thereby, restricting inflow. EMF is a critical condition that is predominant in the young population. However, it may also be associated with older individuals. Identified areas recorded with cases include the under-developed populations i.e. the tropics of Africa- Uganda, Mozambique; South Asia, and South America. Unlike in the preceded years, further studies are currently on focus to completely evaluate this medical condition. Additionally, this review encompasses the complications that arise from EMF as studied and reported from case studies, clinical trials, experiments and research including heart failure, atrioventricular valves regurgitations, arrhythmias, serous cavities'effusions, circulatory shock, stroke, myocardial ischemic syndromes, hepatic and end-organ dysfunctions. Complications like heart failure may be very fatal to its victims. Moreover, left ventricular thrombosis may probably impose systemic or cerebral thromboembolism, which would risk the probability of a stroke. All in all, suggestions in the management strategies that have proved effective and advances in cardiac transplantation and of recently proposed therapeutic targets equally take part of this review and may form a foundation to diminishing the remaining inch of EMF and its outcomes.

Endomyocardial Fibrosis, Apical Hypertrophy, or Both?

• Endomyocardial fibrosis and apical HCM can coexist. • These conditions can appear similar on TTE. • CMR is a useful tool to distinguish between the 2 conditions. • Serial TTE can be used to monitor response to treatment of EMF.

Endomyocardial fibrosis of the right ventricle in a patient with schistosomiasis: a case report

Background

Endomyocardial fibrosis (EMF) is a rare and underdiagnosed cause of restrictive cardiomyopathy. Its aetiology is not yet defined and could be caused by the influence of different clinical factors that seem to combine with genetic aspects of individuals susceptible to an inflammatory process that leads to formation of fibrosis.

Case summary

We describe a case of a 50-year-old man from the northeastern region of Brazil, where there is high prevalence of schistosomiasis. He presented to our centre with symptoms of right heart failure. The echocardiogram showed normal left ventricular ejection fraction. Right ventricular had normal systolic function but in the apical region was filled with a homogeneous and hypoechoic image causing obliteration and restriction of the apex. The late gadolinium enhancement with cardiac magnetic resonance showed diffuse and heterogeneous subendocardial fibrosis in the right ventricle apex consistent with EMF, but declined endocardiectomy.

Discussion

This report presents an interesting case of EMF and schistosomiasis simultaneously. The hypothesis of parasitosis as a probable cause of EMF was raised by helminth-induced hypereosinophilia. Complementary imaging tests such as magnetic resonance imaging and echocardiography, in addition to clinical and epidemiological suspicion, are essential for its diagnosis. Early surgical resolution becomes crucial for long-term survival.

Role of Cardiovascular Magnetic Resonance to Assess Cardiovascular Inflammation

Cardiovascular inflammatory diseases still represent a challenge for physicians. Inflammatory cardiomyopathy, pericarditis, and large vessels vasculitis can clinically mimic a wide spectrum of diseases. While the underlying etiologies are varied, the common physio-pathological process is characterized by vasodilation, exudation, leukocytes infiltration, cell damage, and fibrosis. Cardiovascular magnetic resonance (CMR) allows the visualization of some of these diagnostic targets. CMR provides not only morphological and functional assessment but also tissue catheterization revealing edema, hyperemia, tissue injury, and reparative fibrosis through T2 weighted images, early and late gadolinium enhancement, and parametric mapping techniques. Recent developments showed the role of CMR in the identification of ongoing inflammation also in other CV diseases like myocardial infarction, atherosclerosis, arrhythmogenic and hypertrophic cardiomyopathy. Future developments of CMR, aiming at the specific assessment of immune cell infiltration, will give deeper insight into cardiovascular inflammatory diseases.

Endomyocardial fibrosis in a non‐tropical patient who presented with chest pain mimicking ACS and left ventricular thrombus, case report

Endomyocardial fibrosis (EMF) is a disease known to cause restrictive cardiomyopathy. It shows a high prevalence in tropical countries. Several triggering factors have been proposed. However, the pathogenesis is still a mystery. The disease is progressive, and the outcome is generally unfavorable. The most common symptom is heart failure. However, an atypical presentation may be expected. Our case presented with symptoms suggestive of ischemia and missed diagnosis initially as ischemic cardiomyopathy. This report aims to increase the attention and awareness of this disease. We present a case of a 53‐year‐old man referred to the emergency department for sudden chest pain, left‐sided and non‐radiating lasted for several minutes, awoke him from sleep with no associated symptoms. He is known to have Diabetes type‐2 and hypertension on oral therapy. Cardiac markers were within the normal limit. The patient was discharged home with an appointment at the cardiology outpatient clinic. Echocardiography was done and revealed mildly reduced left ventricular (LV) systolic function, Ejection Fraction of 46%, asymmetric LV hypertrophy affecting the apical segments with aneurysm, and calcified apical thrombus. CT coronary angiography was done with non‐significant Left Anterior Descending artery lesions and left ventricular hypertrophy affecting the apex with calcified apical thrombus. Further investigation by cardiac MRI revealed apical thrombus and late apical uptake suggesting Endomyocardial Fibrosis of possible eosinophilic etiology. The patient continued to have attacks of similar chest pain, for which stress cardiac MRI was done and was negative for ischemia. Another diagnostic workup was done, including hematological and serological tests such as Antinuclear Antibodies and Schistosoma Antibodies. The patient was kept on valsartan and Bisoprolol with oral anticoagulant (vitamin K antagonist) and Rosuvastatin. EMF may have a heterogeneous presentation and should be considered in a patient with calcific apical thrombus without previous history of cardiac problem, even in the non‐tropical region.

Early diagnosis of cardiomyopathies by cardiac magnetic resonance. Overview of the main criteria

Cardiomyopathies (CMPs) are diseases of the heart muscle. They include a variety of myocardial disorders that manifest with various structural and functional phenotypes and are frequently genetic. Myocardial disease caused by known cardiovascular causes (such as hypertension, ischemic heart disease, or valvular disease) should be distinguished from CMPs for classification and management purposes. Identification of various CMP phenotypes relies primarily upon echocardiographic evaluation. In selected cases, cardiac magnetic resonance imaging (CMR) or computed tomography may be useful to identify and localize fatty infiltration, inflammation, scar/fibrosis, focal hypertrophy, and better visualize the left ventricular apex and right ventricle.  CMR imaging has emerged as a comprehensive tool for the diagnosis and follow-up of patients with CMPs. The accuracy and reproducibility in evaluating cardiac structures, the unique ability of non-invasive tissue characterization and the lack of ionizing radiation, make CMR very attractive as a potential "all-in-one technique". Indeed, it provides valuable data to confirm or establish the diagnosis, screen subclinical cases, identify aetiology, establish the prognosis. Additionally, it provides information for setting a risk stratification (based on evaluation of proved independent prognostic factors as ejection fraction, end-systolic-volume, myocardial fibrosis) and follow-up. Last, it helps to monitor the response to the therapy. In this review, the pivotal role of CMR in the comprehensive evaluation of patients with CMP is discussed, highlighting the key features guiding differential diagnosis and the assessment of prognosis.

Follow-up CMR in a case of Loeffler endocarditis

The typical finding of hypereosinophilic syndrome (Eosinophilic myocarditis) in the delayed enhancement (DE) cardiac magnetic resonance (CMR) is the "double V" sign, which includes (a) normal myocardium, (b) thickened enhanced endomyocardial layer, and (c) overlying apical thrombus. Corticosteroids may result in significant improvement of myocardial involvement.