Editing Myocarditis (section)

== 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 and dysfunction of the heart muscle that is secondary to the inflammation. While myocarditis may develop over periods ranging from hours to months, patients typically present with signs and symptoms that resemble heart failure, including the following:<ref name="NEJM2009" /><ref name=Feldman>{{cite journal | vauthors = Feldman AM, McNamara D | title = Myocarditis | journal = The New England Journal of Medicine | volume = 343 | issue = 19 | pages = 1388–98 | date = November 2000 | pmid = 11070105 | doi = 10.1056/NEJM200011093431908 }}</ref>
{| class="wikitable"
!Symptoms
!Notes
!Signs
!Notes
|-
|[[Chest pain]]
|Often described as sharp or stabbing in nature
|[[Fever]]
|Especially when infectious, e.g., from parvovirus B19
|-
|[[Shortness of breath]]
|Worse when lying down or in a prone position
|[[Heart sounds|Dull heart sounds]]
|Muffling occurs with inflammation, especially with [[pericarditis]]
|-
|[[Palpitations]]
|Feeling like one's heart is beating forcefully
|[[Arrhythmia|Abnormal heart rhythm]]
|Determined using an electrocardiogram
|-
|Dizziness or fainting
|Can reflect inadequate blood flow to the brain
|Damage to heart cells
|Seen as elevated troponin and inflammation on imaging
|}

Since myocarditis is often due to a viral illness, many patients experience symptoms consistent with a recent viral infection including a fever, rash, loss of appetite, abdominal pain, vomiting, [[diarrhea]], [[arthralgia|joint pains]], and easily becoming tired.<ref name=":6">{{cite web |url= https://www.lecturio.com/concepts/myocarditis/| title= Myocarditis|website=The Lecturio Medical Concept Library |access-date= 11 August 2021}}</ref> Additionally, 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.<ref>{{cite news|date=23 July 2020|title=Pericarditis|newspaper=Lecturio|url=https://www.lecturio.com/concepts/pericarditis/|access-date=11 August 2021}}</ref><ref name=":6" />

Children primarily present with the aforementioned symptoms associated with a viral infection.<ref name="Feldman" /> Later stages of the illness can involve the respiratory system and lead to increased work of breathing. These are often mistaken for [[asthma]].<ref name="Feldman" />

Myocarditis can be distinguished as either fulminant or acute based on the severity of symptoms on presentation, as well as the time course over which symptoms develop and persist. This categorization can help predict the treatment, outcomes, and complications of myocarditis.{{cn|date=April 2024}}

Fulminant myocarditis is defined as sudden and severe myocarditis that is associated with signs and symptoms of heart failure while at rest.<ref name="pmid31679645">{{cite journal | vauthors = Sharma AN, Stultz JR, Bellamkonda N, Amsterdam EA | title = Fulminant Myocarditis: Epidemiology, Pathogenesis, Diagnosis, and Management | journal = The American Journal of Cardiology | volume = 124 | issue = 12 | pages = 1954–1960 | date = December 2019 | pmid = 31679645 | doi = 10.1016/j.amjcard.2019.09.017 | s2cid = 204061292 | id = {{ProQuest|2317270452}} }}</ref> More specifically, fulminant myocarditis is characterized by a distinct, rapid onset of severe heart failure symptoms, such as shortness of breath and chest pain, that develop over the course of hours to days. Additionally, treatment requires the use of medications or mechanical devices to improve heart function.<ref name="pmid31679645" /><ref name=":7">{{cite journal | vauthors = Hang W, Chen C, Seubert JM, Wang DW | title = Fulminant myocarditis: a comprehensive review from etiology to treatments and outcomes | journal = Signal Transduction and Targeted Therapy | volume = 5 | issue = 1 | pages = 287 | date = December 2020 | pmid = 33303763 | pmc = 7730152 | doi = 10.1038/s41392-020-00360-y }}</ref>

Acute non-fulminant myocarditis has a less distinct onset in contrast to fulminant myocarditis, and evolves over days to months.<ref name=":7" /><ref name=":8">{{cite journal | vauthors = Ammirati E, Veronese G, Bottiroli M, Wang DW, Cipriani M, Garascia A, Pedrotti P, Adler ED, Frigerio M | display-authors = 6 | title = Update on acute myocarditis | journal = Trends in Cardiovascular Medicine | volume = 31 | issue = 6 | pages = 370–379 | date = August 2021 | pmid = 32497572 | pmc = 7263216 | doi = 10.1016/j.tcm.2020.05.008 }}</ref> While the symptoms of acute myocarditis overlap with those of fulminant myocarditis, they do not typically occur at rest, and treatment does not require the use of mechanical circulatory support.<ref name=":8" />