History

Fact Explanation
Fever The main aspect of this disease is inflammation of the myocardium. There are many different viral etiologies, but the commoner ones are Adenovirus, Coxsackie virus HCV and HIV [2] (EV), Epstein-Barr Virus, Human Herpesvirus 6 (HHV 6), parvovirus B19 (PVB19) and cytomegalovirus. [3] Fever is a nonspecific symptom but it is seen in some patients.[2] It can be due to either the inflammatory mediators or due to the viral products itself.
Myalgias This is also a nonspecific symptom but it is commonly seen in viral infections.[2]
Chest pain This is due to the inflammation of the myocardium. Acute focal myocarditis can resemble a myocardial infarction, with acute onset of chest pain. [1]
Dyspnoea This is a very common symptom. [1] It is due to the functional left ventricular impairment. Sometimes severe dyspnoea is due to advanced heart failure. These patients have severe global left ventricular dysfunction. [2]
Palpitations This can be present in a lesser number of patients.(about 18%) and is due to cardiac arrhythmia.[1]
Recent history of upper respiratory tract infections Some of the viruses present with a prior respiratory tract infection ( usually 3 weeks previously). [2] Along with respiratory symptoms there can be symptoms such as diarrhea (viral gastroenteritis). [3]
Fulminant hemodynamic collapse Abrupt onset of hemodynamic collapse, [1,2] is a serious complication resulting in shock.
References
  1. SCHULTZ JC, HILLIARD AA, COOPER LT JR, RIHAL CS. Diagnosis and Treatment of Viral Myocarditis Mayo Clin Proc [online] 2009 Nov, 84(11):1001-1009 [viewed 23 June 2014] Available from: doi:10.1016/S0025-6196(11)60670-8
  2. MAGNANI JW, DEC GW. Myocarditis: current trends in diagnosis and treatment. Circulation [online] 2006 Feb 14, 113(6):876-90 [viewed 23 June 2014] Available from: doi:10.1161/CIRCULATIONAHA.105.584532
  3. DENNERT R., CRIJNS H. J., HEYMANS S.. Acute viral myocarditis. European Heart Journal [online] 2008 July, 29(17):2073-2082 [viewed 23 June 2014] Available from: doi:10.1093/eurheartj/ehn296

Examination

Fact Explanation
Febrile patient Fever is a nonspecific symptom but it is seen in some patients with viral infection.[1,2]. It can be due to either the inflammatory mediators or due to the viral products itself.
Variations in pulse: sinus tachycardia This is a common sign.[1,5] Factors contributing are fever and release of catecholamines in response to pain.
Variations in pulse: irregularly irregular pulse This is due to atrial fibrillation, [3] arrhythmias occur due to myocyte necrosis, replacement fibrosis , proarrhythmic effects of cytokines and inflammatory mediators. [6]
Variations in pulse: bradycardia This is due to the presence of atrioventricular blocks. [3]
Variations in pulse: absent pulse This occurs due to appearance of pulseless VT or VF. [3] Arrhythmias occur due to myocyte necrosis, replacement fibrosis or proarrhythmic effects of cytokines and inflammatory mediators. [6]
Low blood pressure This occurs in severe heart failure or fulminant myocarditis resulting in shock. Heart failure occurs due to inflammation and necrosis of the myocardium resulting in reduced ventricular function.
Edema This is a feature of advanced congestive cardiac failure (edema is the result of back pressure on the venous system). [4] Heart failure occurs due to inflammation and necrosis of the myocardium resulting in reduced ventricular function.
Diminished first heart sound This is present in some patients [1,5].It can be due different pathophysiologies such as mitral regurgitation or atrial fibrillation.
Murmurs of mitral or tricuspid insufficiency This is seen in some patients. [1] This occurs due to weakening of the roots and cusps of the valves due to inflammation, resulting in blood flow into atria in systole and increased flow in diastole. This produces turbulence and is auscultated as a pansystolic murmur.
Gallop rhythm This occurs only in a few patients. [1] This is audible in the presence of S3, S4 [5] or both. Gallop rhythm can be an indicator of heart failure.
Pericardial friction rub This is a rare feature. If it is present, it is pathognomic of pericarditis. [1]
References
  1. DENNERT R, CRIJNS HJ, HEYMANS S. Acute viral myocarditis Eur Heart J [online] 2008 Sep, 29(17):2073-2082 [viewed 23 June 2014] Available from: doi:10.1093/eurheartj/ehn296
  2. MAGNANI JW, DEC GW. Myocarditis: current trends in diagnosis and treatment. Circulation [online] 2006 Feb 14, 113(6):876-90 [viewed 23 June 2014] Available from: doi:10.1161/CIRCULATIONAHA.105.584532
  3. PROVIDêNCIA R, BOTELHO A, CACHULO MDO C, ANTUNES A, MOTA P, LEITãO-MARQUES AM. Viral myocarditis--new advances. Rev Port Cardiol [online] 2008 May, 27(5):707-22 [viewed 23 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/18717218
  4. MAHRHOLDT H., WAGNER A., DELUIGI C. C., KISPERT E., HAGER S., MEINHARDT G., VOGELSBERG H., FRITZ P., DIPPON J., BOCK C. -T., KLINGEL K., KANDOLF R., SECHTEM U.. Presentation, Patterns of Myocardial Damage, and Clinical Course of Viral Myocarditis. Circulation [online] 2006 October, 114(15):1581-1590 [viewed 23 June 2014] Available from: doi:10.1161/​CIRCULATIONAHA.105.606509
  5. SCHULTZ JC, HILLIARD AA, COOPER LT JR, RIHAL CS. Diagnosis and Treatment of Viral Myocarditis Mayo Clin Proc [online] 2009 Nov, 84(11):1001-1009 [viewed 24 June 2014] Available from: doi:10.1016/S0025-6196(11)60670-8
  6. PIERONI,Maurizio. SMALDONE,Costantin. BELLOCCI,Fulvio .Myocarditis Presenting with Ventricular Arrhythmias: Role of Electroanatomical Mapping-Guided Endomyocardial Biopsy in Differential Diagnosis.[online] December [viewed 24 June 2014] Available from: doi:10.5772/22123

Differential Diagnoses

Fact Explanation
Bacterial Myocarditis There is a wide range of of bacterial infections that can cause myocarditis. Differentiating symptoms and signs vary according to each pathogen. Following are some examples: 1.Chlamydia[1], (pneumonia with skin manifestations and meningoencephalitis) 2.Corynebacterium diphtheriae [1](fever, cough, respiratory distress, pseudomembrane of the throat) 3.Legionella[1]( pneumonia with hepatitis, CNS manifestations) 4.Mycobacterium tuberculosis,[1](Chronic cough, haemoptysis,loss of appetite, loss of weight) 5.Mycoplasma[1](pneumonia with skin involvement, haemolysis) 6.Staphylococcus,[1] (pneumonia, septic foci,skin lesions such as furuncles) 7. Streptococcus pneumoniae[1](pneumonia with high fever, and sepsis) 8.Rheumatic carditis is due to Group A beta haemolytic streptococci. (Arthritis, skin manifestations,[6] chorea can be seen)
Fungal myocarditis Following fungi can cause myocarditis; Actinomyces, Aspergillus, Blastomyces, Candida, Coccidioides, Cryptococcus, Histoplasma, Nocardia, Sporothrix. [1] Fungal myocarditis occurs in disseminated disease. Especially in immunocompromised patients(HIV). Recurrent antibiotics use, corticosteroids and cytotoxic agents, invasive medical procedures are risk factors. [3]
Rickettsial disease There is vasculitis, endocarditis is more common but myocarditis may also present in Q fever caused by Coxiella burnetii. [3]
Tripanozoma cruzi (Chagas’ disease) There is organomegaly and volvulus. History living in an endemic part of South America should be sought.
Toxoplasma gondii This can cause myocarditis in recipients of cardiac transplants. [3]
Autoimmune diseases There are different types of autoimmune diseases. Differentiation depends on specific disease. Following are some examples: 1.Celiac disease [1] (features of anemia, diarrhoea) 2. Crohn's disease [1] (chronic diarrhea, ocular manifestations, arthritis) 3.. Kawasaki disease [1], (fever, lymphadenopathy, strawberry tongue, scaling rash) 4. Systemic Lupus Erythematosus, [1] (skin manifestations-discoid rash, photosensitivity, arthritis)
Hypersensitivity reactions to drugs This is very acute and it occurs following the administration of a drug. Past history of reaction to that drug or drug class may be present. Urticarial rash may be observed in some patients. [6] Following are some examples: Penicillins, ,tetracyclines, sulfonamides, benzodiazepines,diuretics, methyldopa, vaccines, tricyclic antidepressants.[1]
Toxic reactions to drugs Following drugs show toxicity even when administered according to the recommended doses: Amphetamines, catecholamines, cyclophosphamide, phenytoin, trastuzumab, anthracyclines, 5-fluorouracil [1]
Toxic chemicals Ethanol, arsenic, copper, iron [1] can cause myocarditis in some patients.
Peripartum myocarditis This is an idiopathic disease in healthy women seen during the latter part of pregnancy and postpartum.[2,4]
Myocardial Infarction This can be a differential diagnosis in some occasions. [2] Especially for there is a past history of hypertension, diabetes and hyperlipidemia. There is a central tightening pain with radiation to the arm or jaw. It lasts more than 20 minutes and does not relieve with GTN.
Cardiac sarcidosis This is another differential diagnosis.[5] There is fever, skin manifestations and lymphadenopathy. [6]
References
  1. KINDERMANN INGRID, BARTH CHRISTINE, MAHFOUD FELIX, UKENA CHRISTIAN, LENSKI MATTHIAS, YILMAZ ALI, KLINGEL KARIN, KANDOLF REINHARD, SECHTEM UDO, COOPER LESLIE T., BöHM MICHAEL. Update on Myocarditis. Journal of the American College of Cardiology [online] 2012 February, 59(9):779-792 [viewed 23 June 2014] Available from: doi:10.1016/j.jacc.2011.09.074
  2. DENNERT R, CRIJNS HJ, HEYMANS S. Acute viral myocarditis Eur Heart J [online] 2008 Sep, 29(17):2073-2082 [viewed 23 June 2014] Available from: doi:10.1093/eurheartj/ehn296
  3. CALABRESE F, THIENE G. Myocarditis and inflammatory cardiomyopathy: microbiological and molecular biological aspects. Cardiovasc Res [online] 2003 Oct 15, 60(1):11-25 [viewed 23 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/14522403
  4. OAKLEY C. Myocarditis, pericarditis and other pericardial diseases Heart [online] 2000 Oct, 84(4):449-454 [viewed 23 June 2014] Available from: doi:10.1136/heart.84.4.449
  5. JCS JOINT WORKING GROUP. Guidelines for diagnosis and treatment of myocarditis (JCS 2009): digest version. Circ J [online] 2011, 75(3):734-43 [viewed 24 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/21304213
  6. SCHULTZ JC, HILLIARD AA, COOPER LT JR, RIHAL CS. Diagnosis and Treatment of Viral Myocarditis Mayo Clin Proc [online] 2009 Nov, 84(11):1001-1009 [viewed 24 June 2014] Available from: doi:10.1016/S0025-6196(11)60670-8

Investigations - for Diagnosis

Fact Explanation
ECG Changes include ST-segment elevation in ≥2 contiguous leads, T-wave inversions, widespread ST-segment depressions and pathological Q waves[1], [2][3][4]. There can be low voltage QRS complexes present as well.
Echocardiogram There is a variation of features. Changes in thickness, systolic and diastolic dysfunction, regional wall motion abnormalities. This is useful in distinguishing fulminant myocarditis from subacute myocarditis. [1],[2],[3],[4]
Chest X-ray It shows some cardiac enlargement in severe conditions. [4]
Cardiac enzymes Elevated troponin (Troponin I and T) levels have proven to be a more reliable predictor of myocardial injury than levels of creatine kinase -MB.[1],[2],[3],[4]
Viral antibody titres Viral etiology is diagnosed when seroconversion (low IgG, raised IgM, and IgA) occurs along with the cardiac symptoms[1],[4]
Cardiovascular magnetic resonance imaging This is a highly sensitive test so it is very useful It is used to distinguish between ischaemic and non-ischaemic cardiomyopathy.[1],[3],[4]
Endomyocardial biopsy Histology, viral diagnosis using PCR on a biopsy speciment can be done in specialized centers.[1] [3][4]
References
  1. DENNERT R., CRIJNS H. J., HEYMANS S.. Acute viral myocarditis. European Heart Journal [online] 2008 July, 29(17):2073-2082 [viewed 23 June 2014] Available from: doi:10.1093/eurheartj/ehn296
  2. MAGNANI JW, DEC GW. Myocarditis: current trends in diagnosis and treatment. Circulation [online] 2006 Feb 14, 113(6):876-90 [viewed 23 June 2014] Available from: doi:10.1161/CIRCULATIONAHA.105.584532
  3. SCHULTZ JC, HILLIARD AA, COOPER LT JR, RIHAL CS. Diagnosis and Treatment of Viral Myocarditis Mayo Clin Proc [online] 2009 Nov, 84(11):1001-1009 [viewed 24 June 2014] Available from: doi:10.1016/S0025-6196(11)60670-8
  4. JCS JOINT WORKING GROUP. Guidelines for diagnosis and treatment of myocarditis (JCS 2009): digest version. Circ J [online] 2011, 75(3):734-43 [viewed 24 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/21304213

Management - General Measures

Fact Explanation
Limit physical activity Exercise during active viral infection may increase viral replication, exertion may also precipitate heart failure. [1],[2]
Analgesia Fever and pain management is important.In initial stages NSAIDS should not be used.[5]
Cardiac monitoring This is important because patients can develop sudden arrhythmias.[3][4]
Regular temperature monitoring This indicates improvement of the condition.
Oxygen If the patient is severe respiratory distress this is helpful.
Fluid restriction This is to minimize edema and to reduce the load on myocardium. [5]
Low salt diet Sodium is an osmotically active particle that retains water so salt restriction is indicated. [5]
References
  1. DENNERT R., CRIJNS H. J., HEYMANS S.. Acute viral myocarditis. European Heart Journal [online] 2008 July, 29(17):2073-2082 [viewed 23 June 2014] Available from: doi:10.1093/eurheartj/ehn296
  2. JCS JOINT WORKING GROUP. Guidelines for diagnosis and treatment of myocarditis (JCS 2009): digest version. Circ J [online] 2011, 75(3):734-43 [viewed 24 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/21304213
  3. PROVIDêNCIA R, BOTELHO A, CACHULO MDO C, ANTUNES A, MOTA P, LEITãO-MARQUES AM. Viral myocarditis--new advances. Rev Port Cardiol [online] 2008 May, 27(5):707-22 [viewed 23 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/18717218
  4. JCS JOINT WORKING GROUP. Guidelines for diagnosis and treatment of myocarditis (JCS 2009): digest version. Circ J [online] 2011, 75(3):734-43 [viewed 24 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/21304213
  5. SCHULTZ JC, HILLIARD AA, COOPER LT JR, RIHAL CS. Diagnosis and Treatment of Viral Myocarditis Mayo Clin Proc [online] 2009 Nov, 84(11):1001-1009 [viewed 24 June 2014] Available from: doi:10.1016/S0025-6196(11)60670-8

Management - Specific Treatments

Fact Explanation
Heart failure treatment Symptomatic management of heart failure is important.[1] This involves the following: 1. Diuretics[1][4]-(Ex Furosemide is a loop diuretic and it prevents sodium reabsorption in the thick ascending limb) 2. Beta receptor-blockers[1][4]- (Blocks the effects of catecholamines on cardiac muscle) 3.Angiotensin converting enzyme-inhibitors or angiotensin II receptor blockers. [1],[4] Blocks the effects of angiotensin and reduces the after-load on the heart. In severe myocarditis and symptomatic hypotension, IV inotropes such as phosphodiesterase inhibitors ( milrinone) or adrenergic agonists ( dobutamine or dopamine) are indicated. [4]
Arrhythmia management This depend on the type and severity of arrhythmia. Cardioversion can be achieved either with pharmacological agents or with electro- cardioversion. Rate control is by the following: 1.Digoxin- a cardiac glycoside with negative chronotropic and positive inotropic action 2.beta receptor-blockers- Blocks the effects of catecholamines on cardiac muscle Anticoagulation is indicated in atrial fibrillation.[4] External pacing(temporary) is needed in bradyarrhythmias. [3]
Mechanical support with intra-aortic balloon pump or LV assist device This can help in the recovery process. recovery or heart transplantation may be necessary in severe cases.[3]
Antiviral therapy Antivirals are helpful in inhibiting viral proliferation, (preventing interaction of viruses with their cellular receptor) [1],[2] and help to minimize myocardial damage.
interferon-b Enteroviral and Adenoviral[1] clearance and improvement of left ventricular function has been identified with this option.[2]
References
  1. DENNERT R., CRIJNS H. J., HEYMANS S.. Acute viral myocarditis. European Heart Journal [online] 2008 July, 29(17):2073-2082 [viewed 23 June 2014] Available from: doi:10.1093/eurheartj/ehn296
  2. PROVIDêNCIA R, BOTELHO A, CACHULO MDO C, ANTUNES A, MOTA P, LEITãO-MARQUES AM. Viral myocarditis--new advances. Rev Port Cardiol [online] 2008 May, 27(5):707-22 [viewed 24 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/18717218
  3. JCS JOINT WORKING GROUP. Guidelines for diagnosis and treatment of myocarditis (JCS 2009): digest version. Circ J [online] 2011, 75(3):734-43 [viewed 24 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/21304213
  4. SCHULTZ JC, HILLIARD AA, COOPER LT JR, RIHAL CS. Diagnosis and Treatment of Viral Myocarditis Mayo Clin Proc [online] 2009 Nov, 84(11):1001-1009 [viewed 24 June 2014] Available from: doi:10.1016/S0025-6196(11)60670-8