Myocarditis in Clinical Practice

A special issue of Journal of Clinical Medicine (ISSN 2077-0383). This special issue belongs to the section "Cardiology".

Deadline for manuscript submissions: closed (10 June 2022) | Viewed by 45365

Special Issue Editor


E-Mail Website
Guest Editor
Cellular and Molecular Cardiology Lab, National Institute for Infectious Diseases L. Spallanzani, Rome, Italy
Interests: myocarditis; cardiomyopathies; heart failure; endomyocardial biopsy
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Myocarditis is a major cause of cardiovascular disease, the causes, pathway, and treatment of which are in continuous evolution. It is a clinical syndrome which manifests with three major phenotypes: arrhythmic, infarct-like, and cardiomyopathic, which are sometimes difficult to identify with noninvasive tools, including cardiac magnetic resonance. Endomyocardial biopsy is still the gold standard for diagnosis, providing definitive information vital for prognosis and treatment. Indeed, the histology of endomyocardial tissue can be used to identify the various pathologic patterns of inflammatory lesions, while PCR on frozen samples can discriminate between possible agents. Different forms of myocarditis can thus be used as signals to identify various characteristics, such as infectious, hypersensitivity, granulomatous, giant cells, eosinophilic, associated to connective tissue, metabolic disorders, and virus-negative immune-mediated forms. Each form requires a specific treatment through which a partial or complete recovery are possible.

Finally, up to 15% of patients with myocarditis fail to respond to treatments based on accurate morpho-molecular characterizations. In these circumstances, an unnoticed, or possibly still unknown, infectious agent might be the cause. Metagenomics is a valuable approach for the identification of new agents.

Prof. Andrea Frustaci
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Journal of Clinical Medicine is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • describing epidemiology
  • causes
  • pathways
  • treatment
  • metagenomics

Published Papers (10 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Editorial

Jump to: Research, Review

2 pages, 158 KiB  
Editorial
New Insights in Human Myocarditis
by Andrea Frustaci
J. Clin. Med. 2022, 11(4), 924; https://doi.org/10.3390/jcm11040924 - 10 Feb 2022
Viewed by 1451
Abstract
Myocarditis is an inflammatory heart muscle disease, the incidence of which is likely underestimated, ranging from 10 [...] Full article
(This article belongs to the Special Issue Myocarditis in Clinical Practice)

Research

Jump to: Editorial, Review

8 pages, 12152 KiB  
Article
Hypersensitivity Myocarditis after COVID-19 mRNA Vaccination
by Andrea Frustaci, Romina Verardo, Nicola Galea, Carlo Lavalle, Giulia Bagnato, Rossella Scialla and Cristina Chimenti
J. Clin. Med. 2022, 11(6), 1660; https://doi.org/10.3390/jcm11061660 - 16 Mar 2022
Cited by 21 | Viewed by 3652
Abstract
Background: Myocarditis, even in a severe and lethal form, may occur after COVID-19 mRNA (BNT162b2) vaccination. However, its pathway, morphomolecular characterization and treatment are still unknown. Methods: Routine hematochemical screening, ECG, Holter monitoring, 2D echocardiogram cardiac magnetic resonance (CMR) and invasive cardiac studies [...] Read more.
Background: Myocarditis, even in a severe and lethal form, may occur after COVID-19 mRNA (BNT162b2) vaccination. However, its pathway, morphomolecular characterization and treatment are still unknown. Methods: Routine hematochemical screening, ECG, Holter monitoring, 2D echocardiogram cardiac magnetic resonance (CMR) and invasive cardiac studies (cardiac catheterization, selective coronary angiography, left ventriculography and left ventricular endomyocardial biopsy) are reported from three patients (39F-pt1, 78M-pt2, 52M-pt3) with severe compromise of conduction tissue (junctional rhythm and syncope, pt1) or cardiac function compromise (LVEF ≤ 35%, pt2 and pt3) after COVID-19 mRNA (BNT162b2). Results: Hematochemical data and coronary angiography were normal in the patients studied. Histology showed in all three patients extensive myocardial infiltration of degranulated eosinophils and elevation of serum cationic protein directly responsible for cardiomyocyte damage. These findings demonstrate myocarditis hypersensitivity to some component of the vaccine (spike protein?) acting as a hapten to some macromolecules of cardiomyocytes. Steroid administration (prednisone, 1 mg/kg die for 3 days, followed by 0.33 mg/kg for 4 weeks) was followed by complete recovery of cardiac contractility in pt2 and pt3. Conclusions: Eosinophilic myocarditis is a possible adverse reaction to the mRNA COVID-19 vaccine. Its pathway is mediated by release of cationic protein and responds to short courses of steroid administration. Full article
(This article belongs to the Special Issue Myocarditis in Clinical Practice)
Show Figures

Figure 1

13 pages, 1320 KiB  
Article
More than 50% of Persistent Myocardial Scarring at One Year in “Infarct-like” Acute Myocarditis Evaluated by CMR
by Thibaut Pommier, Thibault Leclercq, Charles Guenancia, Simon Tisserand, Céline Lairet, Max Carré, Alain Lalande, Florence Bichat, Maud Maza, Marianne Zeller, Alexandre Cochet and Yves Cottin
J. Clin. Med. 2021, 10(20), 4677; https://doi.org/10.3390/jcm10204677 - 13 Oct 2021
Cited by 4 | Viewed by 1758
Abstract
Background: Cardiac magnetic resonance (CMR) has emerged as a reference tool for the non-invasive diagnosis of myocarditis. However, its role in follow-up (FU) after the acute event is unclear. The objectives were to assess the evolution of CMR parameters between the acute phase [...] Read more.
Background: Cardiac magnetic resonance (CMR) has emerged as a reference tool for the non-invasive diagnosis of myocarditis. However, its role in follow-up (FU) after the acute event is unclear. The objectives were to assess the evolution of CMR parameters between the acute phase of infarct-like myocarditis and 12 months thereafter and to identify the predictive factors of persistent myocardial scarring at one year. Methods: All patients with infarct-like acute myocarditis confirmed by CMR were included. CMR was performed within 8 days following symptom onset, at 3 months and at one year. One-year FU included ECG, a cardiac stress test, Holter recording, biological assessments, medical history and a quality-of-life questionnaire. Patients were classified according to the presence or absence of complete recovery at one year based on the CMR evaluation. Results: A total of 174 patients were included, and 147 patients had three CMR. At one year, 79 patients (54%) exhibited persistent myocardial scarring on CMR. A multivariate analysis showed that high peak troponin at the acute phase (OR: 3.0—95%CI: 1.16–7.96—p = 0.024) and the initial extent of late gadolinium enhancement (LGE) (OR: 1.1—95%CI: 1.03–1.19—p = 0.006) were independent predictors of persistent myocardial scarring. Moreover, patients with myocardial scarring on the FU CMR were more likely to have premature ventricular contractions during the cardiac stress test (25% versus 9%, p = 0.008). Conclusion: Less than 50% of patients with infarct-like acute myocarditis showed complete recovery at one year. Although major adverse cardiac events were rare, ventricular dysrhythmias at one year were more frequent in patients with persistent myocardial scarring. Full article
(This article belongs to the Special Issue Myocarditis in Clinical Practice)
Show Figures

Figure 1

11 pages, 1447 KiB  
Article
Serum Anti-Heart and Anti-Intercalated Disk Autoantibodies: Novel Autoimmune Markers in Cardiac Sarcoidosis
by Alida L. P. Caforio, Anna Baritussio, Renzo Marcolongo, Chun-Yan Cheng, Elena Pontara, Elisa Bison, Maria Grazia Cattini, Nicoletta Gallo, Mario Plebani, Sabino Iliceto, Gianpietro Semenzato, Lisa Maier and Nabeel Hamzeh
J. Clin. Med. 2021, 10(11), 2476; https://doi.org/10.3390/jcm10112476 - 2 Jun 2021
Cited by 10 | Viewed by 2905
Abstract
Background: Sarcoidosis is an immune-mediated disease. Cardiac involvement, a granulomatous form of myocarditis, is under-recognized and prognostically relevant. Anti-heart autoantibodies (AHAs) and anti-intercalated disk autoantibodies (AIDAs) are autoimmune markers in nonsarcoidosis myocarditis forms. Objective: The aim was to assess serum AHAs and AIDAs [...] Read more.
Background: Sarcoidosis is an immune-mediated disease. Cardiac involvement, a granulomatous form of myocarditis, is under-recognized and prognostically relevant. Anti-heart autoantibodies (AHAs) and anti-intercalated disk autoantibodies (AIDAs) are autoimmune markers in nonsarcoidosis myocarditis forms. Objective: The aim was to assess serum AHAs and AIDAs as autoimmune markers in cardiac sarcoidosis. Methods: This is a cross-sectional study on AHA and AIDA frequency in: 29 patients (aged 46 ± 12, 20 male) with biopsy-proven extracardiac sarcoidosis and biopsy-proven or clinically suspected and confirmed by 18-fluorodeoxyglucose positron emission tomography and/or cardiovascular magnetic resonance (CMR) cardiac involvement; 30 patients (aged 44 ± 11, 12 male) with biopsy-proven extracardiac sarcoidosis without cardiac involvement (no cardiac symptoms, normal 12-lead electrocardiogram, echocardiography and CMR), and control patients with noninflammatory cardiac disease (NICD) (n = 160), ischemic heart failure (IHF) (n = 141) and normal blood donors (NBDs) (n = 270). Sarcoidosis patients were recruited in two recruiting tertiary centers in the USA and Italy. AHAs and AIDAs were detected by indirect immunofluorescence on the human myocardium and skeletal muscle. Results: AHA and AIDA frequencies were higher in sarcoidosis with cardiac involvement (86%; 62%) than in sarcoidosis without cardiac involvement (0%; 0%), NICD (8%; 4%), IHF (7%; 2%) and NBD (9%; 0%) (p = 0.0001; p = 0.0001, respectively). Sensitivity and specificity for cardiac sarcoidosis were 86% and 92% for positive AHAs and 62% and 98% for positive AIDAs, respectively. AIDAs in cardiac sarcoidosis were associated with a higher number of involved organs (p = 0.04). Conclusions: Serum AHAs and AIDAs provide novel noninvasive diagnostic autoimmune markers for cardiac sarcoidosis. Full article
(This article belongs to the Special Issue Myocarditis in Clinical Practice)
Show Figures

Figure 1

11 pages, 965 KiB  
Article
Outcomes of Mechanical Circulatory Support for Giant Cell Myocarditis: A Systematic Review
by Preeyal M. Patel, Abhiraj Saxena, Chelsey T. Wood, Thomas J. O’Malley, Elizabeth J. Maynes, John W. C. Entwistle, H. Todd Massey, Preethi R. Pirlamarla, René J. Alvarez, Leslie T. Cooper, J. Eduardo Rame and Vakhtang Tchantchaleishvili
J. Clin. Med. 2020, 9(12), 3905; https://doi.org/10.3390/jcm9123905 - 1 Dec 2020
Cited by 10 | Viewed by 2173
Abstract
Treatment of giant cell myocarditis (GCM) can require bridging to orthotopic heart transplantation (OHT) or recovery with mechanical circulatory support (MCS). Since the roles of MCS and immunotherapy are not well-defined in GCM, we sought to analyze outcomes of patients with GCM who [...] Read more.
Treatment of giant cell myocarditis (GCM) can require bridging to orthotopic heart transplantation (OHT) or recovery with mechanical circulatory support (MCS). Since the roles of MCS and immunotherapy are not well-defined in GCM, we sought to analyze outcomes of patients with GCM who required MCS. A systematic search was performed in June 2019 to identify all studies of biopsy-proven GCM requiring MCS after 2009. We identified 27 studies with 43 patients. Patient-level data were extracted for analysis. Median patient age was 45 (interquartile range (IQR): 32–57) years. 42.1% (16/38) were female. 34.9% (15/43) presented in acute heart failure. 20.9% (9/43) presented in cardiogenic shock. Biventricular (BiVAD) MCS was required in 76.7% (33/43) of cases. Of the 62.8% (27/43) of patients who received immunotherapy, 81.5% (22/27) used steroids combined with at least one other immunosuppressant. Cyclosporine was the most common non-steroidal agent, used in 40.7% (11/27) of regimens. Immunosuppression was initiated before MCS in 59.3% (16/27) of cases, after MCS in 29.6% (8/27), and not specified in 11.1% (3/27). Immunosuppression started prior to MCS was associated with significantly better survival than MCS alone (p = 0.006); 60.5% (26/43) of patients received bridge-to-transplant MCS; 39.5% (17/43) received bridge-to-recovery MCS; 58.5% (24/41) underwent OHT a median of 104 (58–255) days from diagnosis. GCM recurrence after OHT was reported in 8.3% (2/24) of transplanted cases. BiVAD predominates in mechanically supported patients with GCM. Survival and bridge to recovery appear better in patients on immunosuppression, especially if initiated before MCS. Full article
(This article belongs to the Special Issue Myocarditis in Clinical Practice)
Show Figures

Figure 1

11 pages, 6371 KiB  
Article
Inflammation of Conduction Tissue in Patients with Arrhythmic Phenotype of Myocarditis
by Andrea Frustaci, Romina Verardo, Maria Alfarano and Cristina Chimenti
J. Clin. Med. 2020, 9(11), 3470; https://doi.org/10.3390/jcm9113470 - 29 Oct 2020
Viewed by 1763
Abstract
Background: Myocarditis can manifest with lone ventricular tachyarrhythmias (LVT). Elective inflammation of conduction tissue (CT) is supposed but unproved. Methods: Forty-two of 420 patients with biopsy proven myocarditis presented with LVT. Twelve of them included CT sections in endomyocardial biopsies. Real-time polymerase chain [...] Read more.
Background: Myocarditis can manifest with lone ventricular tachyarrhythmias (LVT). Elective inflammation of conduction tissue (CT) is supposed but unproved. Methods: Forty-two of 420 patients with biopsy proven myocarditis presented with LVT. Twelve of them included CT sections in endomyocardial biopsies. Real-time polymerase chain reaction (PCR) for viral genomes, immunohistochemistry for viral antigens and Toll like receptor 4 (TLR4) were performed. Twelve myocarditis patients with infarct-like or cardiomyopathic phenotype and CT included in tissue section were used as controls. Results: Four of the 12 patients presented non-sustained ventricular tachycardia (nsVT), six with sustained ventricular tachycardia (sVT), two with ventricular fibrillation. CT was inflamed in all LVT patients and not in controls (p < 0.001). PCR was positive for influenza-A virus in two, herpes simplex virus type 2 (HSV2) in one and adenovirus in one with positive CT immunostaining for viral antigens. In eight patients, negative PCR and TLR4 overexpression suggested an immune-mediated pathway. Patients with influenza-A myocarditis and CT infection responded to oseltamivir, those with HSV2 (Herpes Virus 2) and adenovirus infection died. The eight patients with immune-mediated myocarditis were treated with steroids and azathioprine. Seven of them had no more VT(ventricular tachyarrhythmias)during six-month follow-up. Conclusions: Arrhythmic phenotype of myocarditis is associated with CT inflammation/infection. Molecular characterization of CT damage may lead to pharmacologic control of arrhythmias in 75% of cases. Full article
(This article belongs to the Special Issue Myocarditis in Clinical Practice)
Show Figures

Figure 1

15 pages, 2674 KiB  
Article
Evaluation of Myocardial Gene Expression Profiling for Superior Diagnosis of Idiopathic Giant-Cell Myocarditis and Clinical Feasibility in a Large Cohort of Patients with Acute Cardiac Decompensation
by Felicitas Escher, Heiko Pietsch, Ganna Aleshcheva, Philip Wenzel, Friedrich Fruhwald, Christian Stumpf, Dirk Westermann, Johann Bauersachs, Frank Enseleit, Frank Ruschitzka, Herbert Nägele, Karl-Ludwig Laugwitz, Hendrik Haake, Norbert Frey, Johannes Brachmann, Kurt Huber, Rüdiger Christian Braun-Dullaeus, Martin W. Bergmann, Jörg Strotmann, Gerian Grönefeld, Jürgen Krülls-Münch, Ralf Westenfeld, Carsten Skurk, Ulf Landmesser, Burkert Pieske, Ulrich M. Gross, Lars Morawietz and Heinz-Peter Schultheissadd Show full author list remove Hide full author list
J. Clin. Med. 2020, 9(9), 2689; https://doi.org/10.3390/jcm9092689 - 19 Aug 2020
Cited by 8 | Viewed by 2707
Abstract
Aims: The diagnostic approach to idiopathic giant-cell myocarditis (IGCM) is based on identifying various patterns of inflammatory cell infiltration and multinucleated giant cells (GCs) in histologic sections taken from endomyocardial biopsies (EMBs). The sampling error for detecting focally located GCs by histopathology [...] Read more.
Aims: The diagnostic approach to idiopathic giant-cell myocarditis (IGCM) is based on identifying various patterns of inflammatory cell infiltration and multinucleated giant cells (GCs) in histologic sections taken from endomyocardial biopsies (EMBs). The sampling error for detecting focally located GCs by histopathology is high, however. The aim of this study was to demonstrate the feasibility of gene profiling as a new diagnostic method in clinical practice, namely in a large cohort of patients suffering from acute cardiac decompensation. Methods and Results: In this retrospective multicenter study, EMBs taken from n = 427 patients with clinically acute cardiac decompensation and suspected acute myocarditis were screened (mean age: 47.03 ± 15.69 years). In each patient, the EMBs were analyzed on the basis of histology, immunohistology, molecular virology, and gene-expression profiling. Out of the total of n = 427 patient samples examined, GCs could be detected in 26 cases (6.1%) by histology. An established myocardial gene profile consisting of 27 genes was revealed; this was narrowed down to a specified profile of five genes (CPT1, CCL20, CCR5, CCR6, TLR8) which serve to identify histologically proven IGCM with high specificity in 25 of the 26 patients (96.2%). Once this newly established profiling approach was applied to the remaining patient samples, an additional n = 31 patients (7.3%) could be identified as having IGCM without any histologic proof of myocardial GCs. In a subgroup analysis, patients diagnosed with IGCM using this gene profiling respond in a similar fashion to immunosuppressive therapy as patients diagnosed with IGCM by conventional histology alone. Conclusions: Myocardial gene-expression profiling is a promising new method in clinical practice, one which can predict IGCM even in the absence of any direct histologic proof of GCs in EMB sections. Gene profiling is of great clinical relevance in terms of (a) overcoming the sampling error associated with purely histologic examinations and (b) monitoring the effectiveness of therapy. Full article
(This article belongs to the Special Issue Myocarditis in Clinical Practice)
Show Figures

Figure 1

Review

Jump to: Editorial, Research

16 pages, 501 KiB  
Review
“Heart in DRESS”: Cardiac Manifestations, Treatment and Outcome of Patients with Drug Reaction with Eosinophilia and Systemic Symptoms Syndrome: A Systematic Review
by Milan Radovanovic, Djordje Jevtic, Andrew D. Calvin, Marija Petrovic, Margaret Paulson, Libardo Rueda Prada, Lawrence Sprecher, Ivana Savic and Igor Dumic
J. Clin. Med. 2022, 11(3), 704; https://doi.org/10.3390/jcm11030704 - 28 Jan 2022
Cited by 29 | Viewed by 4100
Abstract
Cardiac involvement in drug reaction with eosinophilia and systemic symptoms (DS) is rare but associated with high mortality. The aim of this research was to systematically review case reports by PRISMA guidelines in order to synthetize the knowledge of cardiac manifestations of DS. [...] Read more.
Cardiac involvement in drug reaction with eosinophilia and systemic symptoms (DS) is rare but associated with high mortality. The aim of this research was to systematically review case reports by PRISMA guidelines in order to synthetize the knowledge of cardiac manifestations of DS. We identified 42 cases from 36 case reports. Women were two times more affected than men. Two-thirds of patients had cardiac manifestation in the initial phase of the disease, while in one-third of cases cardiac manifestations developed later (mean time of 70 ± 63 days). The most common inciting medications were minocycline (19%) and allopurinol (12%). In 17% of patients, the heart was the only internal organ affected, while the majority (83%) had at least one additional organ involved, most commonly the liver and the kidneys. Dyspnea (55%), cardiogenic shock (43%), chest pain (38%), and tachycardia (33%) were the most common cardiac signs and symptoms reported. Patients frequently had an abnormal ECG (71.4%), and a decrease in left ventricular ejection fraction was the most common echocardiographic finding (45%). Endomyocardial biopsy or histological examination at autopsy was performed in 52.4%, with the predominant finding being fulminant eosinophilic myocarditis with acute necrosis in 70% of those biopsied. All patients received immunosuppressive therapy with intravenous steroids, while non-responders were more likely to have received IVIG, cyclosporine, mycophenolate, and other steroid-sparing agents (60%). Gender and degree of left ventricular systolic dysfunction were not associated with outcomes, but short latency between drug exposure and the first DRESS symptom onset (<15 days) and older age (above 65 years) was associated with death. This underscores the potential importance of heightened awareness and early treatment. Full article
(This article belongs to the Special Issue Myocarditis in Clinical Practice)
Show Figures

Figure 1

25 pages, 19859 KiB  
Review
Viral Myocarditis—From Pathophysiology to Treatment
by Heinz-Peter Schultheiss, Christian Baumeier, Ganna Aleshcheva, C.-Thomas Bock and Felicitas Escher
J. Clin. Med. 2021, 10(22), 5240; https://doi.org/10.3390/jcm10225240 - 11 Nov 2021
Cited by 29 | Viewed by 9284
Abstract
The diagnosis of acute and chronic myocarditis remains a challenge for clinicians. Characterization of this disease has been hampered by its diverse etiologies and heterogeneous clinical presentations. Most cases of myocarditis are caused by infectious agents. Despite successful research in the last few [...] Read more.
The diagnosis of acute and chronic myocarditis remains a challenge for clinicians. Characterization of this disease has been hampered by its diverse etiologies and heterogeneous clinical presentations. Most cases of myocarditis are caused by infectious agents. Despite successful research in the last few years, the pathophysiology of viral myocarditis and its sequelae leading to severe heart failure with a poor prognosis is not fully understood and represents a significant public health issue globally. Most likely, at a certain point, besides viral persistence, several etiological types merge into a common pathogenic autoimmune process leading to chronic inflammation and tissue remodeling, ultimately resulting in the clinical phenotype of dilated cardiomyopathy. Understanding the underlying molecular mechanisms is necessary to assess the prognosis of patients and is fundamental to appropriate specific and personalized therapeutic strategies. To reach this clinical prerequisite, there is the need for advanced diagnostic tools, including an endomyocardial biopsy and guidelines to optimize the management of this disease. The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has currently led to the worst pandemic in a century and has awakened a special sensitivity throughout the world to viral infections. This work aims to summarize the pathophysiology of viral myocarditis, advanced diagnostic methods and the current state of treatment options. Full article
(This article belongs to the Special Issue Myocarditis in Clinical Practice)
Show Figures

Figure 1

15 pages, 1150 KiB  
Review
Epidemiological Impact of Myocarditis
by Ainoosh Golpour, Dimitri Patriki, Paul J. Hanson, Bruce McManus and Bettina Heidecker
J. Clin. Med. 2021, 10(4), 603; https://doi.org/10.3390/jcm10040603 - 5 Feb 2021
Cited by 54 | Viewed by 13821
Abstract
Myocarditis is an inflammatory disease of the heart muscle with a wide range of potential etiological factors and consequently varying clinical patterns across the world. In this review, we address the epidemiology of myocarditis. Myocarditis was considered a rare disease until intensified research [...] Read more.
Myocarditis is an inflammatory disease of the heart muscle with a wide range of potential etiological factors and consequently varying clinical patterns across the world. In this review, we address the epidemiology of myocarditis. Myocarditis was considered a rare disease until intensified research efforts in recent decades revealed its true epidemiological importance. While it remains a challenge to determine the true prevalence of myocarditis, studies are underway to obtain better approximations of the proportions of this disease. Nowadays, the prevalence of myocarditis has been reported from 10.2 to 105.6 per 100,000 worldwide, and its annual occurrence is estimated at about 1.8 million cases. This wide range of reported cases reflects the uncertainty surrounding the true prevalence and a potential underdiagnosis of this disease. Since myocarditis continues to be a significant public health issue, particularly in young adults in whom myocarditis is among the most common causes of sudden cardiac death, improved diagnostic and therapeutic procedures are necessary. This manuscript aims to summarize the current knowledge on the epidemiology of myocarditis, new diagnostic approaches and the current epidemiological impact of the COVID-19 pandemic. Full article
(This article belongs to the Special Issue Myocarditis in Clinical Practice)
Show Figures

Figure 1

Back to TopTop