| Myocarditis |
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Histopathological image of myocarditis at autopsy in a patient with acute onset of congestive heart failure
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| Classification and external resources |
| Specialty |
Cardiology |
| ICD-10 |
I09.0, I51.4 |
| ICD-9-CM |
391.2, 422, 429.0 |
| DiseasesDB |
8716 |
| MedlinePlus |
000149 |
| eMedicine |
article/156330 article/890740 article/1612533 |
| Patient UK |
Myocarditis |
| MeSH |
D009205 |
Myocarditis or inflammatory cardiomyopathy is inflammation of heart muscle. The consequences of myocarditis vary widely. It can cause a mild disease without any symptoms that resolves itself, or it may cause chest pain, heart failure, or sudden death. An acute myocardial infarction-like syndrome with normal coronary arteries has a good prognosis. Heart failure, even with a dilated left ventricle, may have a good prognosis. Ventricular arrhythmias and high-degree heart block have a poor prognosis. Loss of right ventricular function is a strong predictor of death.[1]
Myocarditis is most often due to infection by common viruses, such as parvovirus B19, less commonly nonviral pathogens such as Borrelia burgdorferi (Lyme disease) or Trypanosoma cruzi, or as a hypersensitivity response to drugs.[1] Myocarditis is often an autoimmune reaction. Streptococcal M protein and coxsackievirus B have regions that are similar to the myosin protein found in the heart muscle. During and after the infection, the immune system may attack cardiac myosin.[1] Myocarditis may or may not include death (necrosis) of heart tissue. It may include dilated cardiomyopathy.[1] A definitive diagnosis requires a heart biopsy.[1]
Cardiomyopathy, including myocarditis, resulted in 443,000 deaths in 2013 up from 294,000 in 1990.[2]
Contents
- 1 Definition
- 2 Signs and symptoms
- 3 Causes
- 3.1 Infections
- 3.2 Toxins
- 3.3 Immunologic
- 3.4 Physical agents
- 4 Diagnosis
- 5 Treatment
- 6 Epidemiology
- 7 History
- 8 References
- 9 External links
Definition
The definition of myocarditis varies, but the central feature is an infection of the heart, with an inflammatory infiltrate, and damage to the heart muscle, without the blockage of coronary arteries that define a heart attack (myocardial infarction) or other common noninfectious causes.[3]
Signs and symptoms
The signs and symptoms associated with myocarditis are varied, and relate either to the actual inflammation of the myocardium or to the weakness of the heart muscle that is secondary to the inflammation. Signs and symptoms of myocarditis include the following:[4]
- Chest pain (often described as "stabbing" in character)
- Congestive heart failure (leading to swelling, shortness of breath and liver congestion)
- Palpitations (due to abnormal heart rhythms)
- Sudden death (in young adults, myocarditis causes up to 20% of all cases of sudden death)[5]
- Fever (especially when infectious, e.g. in rheumatic fever)
- Symptoms in infants and toddlers tend to be more nonspecific, with generalized malaise, poor appetite, abdominal pain, and/or chronic cough. Later stages of the illness will present with respiratory symptoms with increased work of breathing, and is often mistaken for asthma.
Since myocarditis is often due to a viral illness, many patients give a history of symptoms consistent with a recent viral infection, including fever, rash, diarrhea, joint pains, and easily becoming tired.
Myocarditis is often associated with pericarditis, and many people with myocarditis present with signs and symptoms that suggest myocarditis and pericarditis at the same time.
Causes
A large number of causes of myocarditis have been identified, but often a cause cannot be found. In Europe and North America, viruses are common culprits. Worldwide, however, the most common cause is Chagas' disease, an illness endemic to Central and South America that is due to infection by the protozoan Trypanosoma cruzi.[4]
Infections
- Viral (adenovirus, parvovirus B19, coxsackie virus, HIV, enterovirus, rubella virus, polio virus, cytomegalovirus, human herpesvirus 6 and possibly hepatitis C)
- Protozoan (Trypanosoma cruzi causing Chagas disease and Toxoplasma gondii)
- Bacterial (Brucella, Corynebacterium diphtheriae, gonococcus, Haemophilus influenzae, Actinomyces, Tropheryma whipplei, Vibrio cholerae, Borrelia burgdorferi, leptospirosis, and Rickettsia, Mycoplasma pneumoniae)
- Fungal (Aspergillus)
- Parasitic (ascaris, Echinococcus granulosus, Paragonimus westermani, schistosoma, Taenia solium, Trichinella spiralis, visceral larva migrans, and Wuchereria bancrofti)
Bacterial myocarditis is rare in patients without immunodeficiency.
Toxins
- Drugs, including alcohol, anthracyclines and some other forms of chemotherapy, and antipsychotics, e.g. clozapine, also some designer drugs such as mephedrone[6]
Immunologic
- Allergic (acetazolamide, amitriptyline)
- Rejection after a heart transplant
- Autoantigens (scleroderma, systemic lupus erythematosus, sarcoidosis, systemic vasculitis such as Churg-Strauss syndrome, and granulomatosis with polyangiitis, Kawasaki disease)
- Toxins (arsenic, toxic shock syndrome toxin, carbon monoxide, or snake venom)
- Heavy metals (copper or iron)
Physical agents
- Electric shock, hyperpyrexia, and radiation
Diagnosis
Endomyocardial biopsy specimen with extensive eosinophilic infiltrate involving the endocardium and myocardium (hematoxylin and eosin stain)
Myocarditis refers to an underlying process that causes inflammation and injury of the heart. It does not refer to inflammation of the heart as a consequence of some other insult. Many secondary causes, such as a heart attack, can lead to inflammation of the myocardium and therefore the diagnosis of myocarditis cannot be made by evidence of inflammation of the myocardium alone.[7]
Myocardial inflammation can be suspected on the basis of electrocardiographic (ECG) results, elevated C-reactive protein (CRP) and/or Erythrocyte sedimentation rate (ESR), and increased IgM (serology) against viruses known to affect the myocardium. Markers of myocardial damage (troponin or creatine kinase cardiac isoenzymes) are elevated.[4]
The ECG findings most commonly seen in myocarditis are diffuse T wave inversions; saddle-shaped ST-segment elevations may be present (these are also seen in pericarditis).[4]
The gold standard is still biopsy of the myocardium, in general done in the setting of angiography. A small tissue sample of the endocardium and myocardium is taken, and investigated by a pathologist by light microscopy and—if necessary—immunochemistry and special staining methods. Histopathological features are myocardial interstitium with abundant edema and inflammatory infiltrate, rich in lymphocytes and macrophages. Focal destruction of myocytes explains the myocardial pump failure.[4]
Cardiac magnetic resonance imaging (cMRI or CMR) has been shown to be very useful in diagnosing myocarditis by visualizing markers for inflammation of the myocardium.[8] Recently, consensus criteria for the diagnosis of myocarditis by CMR have been published.[9]
Treatment
As most viral infections cannot be treated with directed therapy, symptomatic treatment is the only form of therapy for those forms of myocarditis.[10] In the acute phase, supportive therapy, including bed rest, is indicated. For symptomatic patients, digoxin and diuretics provide clinical improvement. For patients with moderate to severe dysfunction, cardiac function can be supported by use of inotropes such as Milrinone in the acute phase, followed by oral therapy with ACE inhibitors (Captopril, Lisinopril) when tolerated. People who do not respond to conventional therapy are candidates for bridge therapy with left ventricular assist devices. Heart transplantation is reserved for patients who fail to improve with conventional therapy.[11]
In several small case series and randomized control trials, systemic corticosteroids have shown to have beneficial effects in people with proven myocarditis.[11] However, data on the usefulness of corticosteroids should be interpreted with caution, since 58% of adults recover spontaneously, while most studies on children lack control groups.[10] Studies have shown no benefit for the use of herbal medicine on all cause mortality in viral myocarditis.[12]
A 2015 Cochrane review found no evidence of benefit of using intravenous immunoglobulin (IVIG) in adults and tentative benefit in certain children.[13] It is not recommended routinely until there is better evidence.[13]
Epidemiology
The exact incidence of myocarditis is unknown. However, in series of routine autopsies, 1–9% of all patients had evidence of myocardial inflammation. In young adults, up to 20% of all cases of sudden death are due to myocarditis.[4]
Among patients with HIV, myocarditis is the most common cardiac pathological finding at autopsy, with a prevalence of 50% or more.[1]
History
Cases of myocarditis have been documented as early as the 1600s,[14] but the term "myocarditis", implying an inflammatory process of the myocardium, was introduced by German physician Joseph Friedrich Sobernheim in 1837.[15] However, the term has been conflated with other cardiovascular conditions, such as hypertension and ischemic heart disease.[16] Following admonition regarding the indiscriminate use of myocarditis as a diagnosis from authorities such as British cardiologist Sir Thomas Lewis and American cardiologist and a co-founder of the American Heart Association Paul White, myocarditis was under-diagnosed.[16]
Although myocarditis is clinically and pathologically clearly defined as "inflammation of the myocardium", its definition, classification, diagnosis, and treatment are subject to continued controversy, but endomyocardial biopsy has helped define the natural history of myocarditis and clarify clinicopathological correlations.[17]
References
- ^ a b c d e f Leslie T. Cooper, Jr., (April 9, 2009) Myocarditis, N. Engl. J. Med. 360(15) 1526-38
- ^ GBD 2013 Mortality and Causes of Death, Collaborators (17 December 2014). "Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013.". Lancet. doi:10.1016/S0140-6736(14)61682-2. PMID 25530442.
- ^ Kenneth L. Baughman, Special Report: Diagnosis of Myocarditis; Death of Dallas Criteria. Circulation. 2006;113:593-595 Free full text
- ^ a b c d e f Feldman AM, McNamara D (November 2000). "Myocarditis". N. Engl. J. Med. 343 (19): 1388–98. doi:10.1056/NEJM200011093431908. PMID 11070105.
- ^ Eckart RE, Scoville SL, Campbell CL et al. (December 2004). "Sudden death in young adults: a 25-year review of autopsies in military recruits". Ann. Intern. Med. 141 (11): 829–34. doi:10.7326/0003-4819-141-11-200412070-00005. PMID 15583223.
- ^ Nicholson PJ, Quinn MJ, Dodd JD (December 2010). "Headshop heartache: acute mephedrone 'meow' myocarditis". Heart (British Cardiac Society) 96 (24): 2051–2. doi:10.1136/hrt.2010.209338. PMID 21062771.
- ^ Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; & Mitchell, Richard N. (2007). Robbins Basic Pathology (8th ed.). Saunders Elsevier. pp. 414-416 ISBN 978-1-4160-2973-1
- ^ Skouri HN, Dec GW, Friedrich MG, Cooper LT (2006). "Noninvasive imaging in myocarditis". J. Am. Coll. Cardiol. 48 (10): 2085–93. doi:10.1016/j.jacc.2006.08.017. PMID 17112998.
- ^ Friedrich MG, Sechtem U, Schulz-Menger J, Holmvang G, Alakija P, Cooper LT, White JA, Abdel-Aty H, Gutberlet M, Prasad S, Aletras AH, Laissy JP, Paterson I, Filipchuk NG, Kumar A, Pauschinger M, Liu P (2009). "Cardiovascular Magnetic Resonance in Myocarditis: A JACC White Paper". J. Am. Coll. Cardiol. 53 (17): 1475–87. doi:10.1016/j.jacc.2009.02.007. PMC 2743893. PMID 19389557.
- ^ a b Hia, CP; Yip, WC; Tai, BC; Quek, SC (June 2004). "Immunosuppressive therapy in acute myocarditis: an 18 year systematic review". Archives of Disease in Childhood 89 (6): 580–4. doi:10.1136/adc.2003.034686. PMC 1719952. PMID 15155409.
- ^ a b Aziz, KU; Patel, N; Sadullah, T; Tasneem, H; Thawerani, H; Talpur, S (October 2010). "Acute viral myocarditis: role of immunosuppression: a prospective randomised study". Cardiology in the young 20 (5): 509–15. doi:10.1017/S1047951110000594. PMID 20584348.
- ^ Liu, ZL; Liu, ZJ; Liu, JP; Kwong, JS (28 August 2013). "Herbal medicines for viral myocarditis.". The Cochrane database of systematic reviews 8: CD003711. PMID 23986406.
- ^ a b Robinson, J; Hartling, L; Vandermeer, B; Klassen, TP (20 May 2015). "Intravenous immunoglobulin for presumed viral myocarditis in children and adults.". The Cochrane database of systematic reviews 5: CD004370. PMID 25992494.
- ^ P. Schölmerich. (1983.) "Myocarditis — Cardiomyopathy Historic Survey and Definition", International Boehringer Mannheim Symposia, 1:5.
- ^ Joseph Friedrich Sobernheim. (1837.) Praktische Diagnostik der inneren Krankheiten mit vorzueglicher Ruecksicht auf pathologische Anatomic. Hirschwald, Berlin, 117.
- ^ a b Eckhardt G. J. Olsen. (1985.) "What is myocarditis?", Heart and Vessels, 1(1):S1-3.
- ^ Jared W. Magnani; G. William Dec. (2006.) "Myocarditis", Circulation, 113:876-890.
External links
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Cardiovascular disease I00–I52, 390–429
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| Ischaemic |
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Coronary disease
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- Coronary artery disease (CAD)
- Coronary artery aneurysm
- Coronary artery dissection
- Coronary thrombosis
- Coronary vasospasm
- Myocardial bridge
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Active ischemia
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- Angina pectoris
- Prinzmetal's angina
- Stable angina
- Acute coronary syndrome
- Myocardial infarction
- Unstable angina
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Sequelae
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- hours
- Hibernating myocardium
- Myocardial stunning
- days
- weeks
- Aneurysm of heart / Ventricular aneurysm
- Dressler syndrome
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| Layers |
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Pericardium
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- Pericarditis
- Acute
- Chronic / Constrictive
- Pericardial effusion
- Cardiac tamponade
- Hemopericardium
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Myocardium
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- Myocarditis
- Cardiomyopathy: Dilated (Alcoholic), Hypertrophic, and Restrictive
- Loeffler endocarditis
- Cardiac amyloidosis
- Endocardial fibroelastosis
- Arrhythmogenic right ventricular dysplasia
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Endocardium /
valves
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Endocarditis
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- infective endocarditis
- Subacute bacterial endocarditis
- non-infective endocarditis
- Libman–Sacks endocarditis
- Nonbacterial thrombotic endocarditis
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Valves
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- mitral
- regurgitation
- prolapse
- stenosis
- aortic
- tricuspid
- pulmonary
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Conduction /
arrhythmia |
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Bradycardia
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- Sinus bradycardia
- Sick sinus syndrome
- Heart block: Sinoatrial
- AV
- Intraventricular
- Bundle branch block
- Right
- Left
- Left anterior fascicle
- Left posterior fascicle
- Bifascicular
- Trifascicular
- Adams–Stokes syndrome
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Tachycardia
(paroxysmal and sinus)
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Supraventricular
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- Atrial
- Junctional
- AV nodal reentrant
- Junctional ectopic
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Ventricular
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- Accelerated idioventricular rhythm
- Catecholaminergic polymorphic
- Torsades de pointes
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Premature contraction
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- Atrial
- Junctional
- Ventricular
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Pre-excitation syndrome
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- Lown–Ganong–Levine
- Wolff–Parkinson–White
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Flutter / fibrillation
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- Atrial flutter
- Ventricular flutter
- Atrial fibrillation
- Ventricular fibrillation
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Pacemaker
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- Ectopic pacemaker / Ectopic beat
- Multifocal atrial tachycardia
- Pacemaker syndrome
- Parasystole
- Wandering pacemaker
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Long QT syndrome
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- Andersen–Tawil
- Jervell and Lange-Nielsen
- Romano–Ward
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Cardiac arrest
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- Sudden cardiac death
- Asystole
- Pulseless electrical activity
- Sinoatrial arrest
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Other / ungrouped
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- hexaxial reference system
- Right axis deviation
- Left axis deviation
- QT
- T
- ST
- Osborn wave
- ST elevation
- ST depression
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| Cardiomegaly |
- Ventricular hypertrophy
- Left
- Right / Cor pulmonale
- Atrial enlargement
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| Other |
- Cardiac fibrosis
- Heart failure
- Diastolic heart failure
- Cardiac asthma
- Rheumatic fever
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Index of the heart
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| Description |
- Anatomy
- Physiology
- Development
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| Disease |
- Injury
- Congenital
- Neoplasms and cancer
- Other
- Symptoms and signs
- Blood tests
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| Treatment |
- Procedures
- Drugs
- glycosides
- other stimulants
- antiarrhythmics
- vasodilators
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Inflammation
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| Acute |
| Plasma derived mediators |
- Bradykinin
- complement
- coagulation
- Factor XII
- Plasmin
- Thrombin
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| Cell derived mediators |
| preformed: |
- Lysosome granules
- biogenic amines
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| synthesized on demand: |
- cytokines
- eicosanoids
- Leukotriene B4
- Prostaglandins
- Nitric oxide
- Kinins
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| Chronic |
- Macrophage
- Epithelioid cell
- Giant cell
- Granuloma
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| Processes |
| Traditional: |
- Rubor
- Calor
- Tumor
- Dolor (pain)
- Functio laesa
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| Modern: |
- Acute-phase reaction/Fever
- Vasodilation
- Increased vascular permeability
- Exudate
- Leukocyte extravasation
- Chemotaxis
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| Specific locations |
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