Diferencia entre revisiones de «Myocarditis»
Sin resumen de edición |
(Comprehensive update: expanded causes (checkpoint inhibitors, giant cell), added EM-focused management (avoid NSAIDs, fluid caution, MCS), activity restriction, updated references with PMIDs) |
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{{ | {{Adult patient | pediatric page=Myocarditis (peds)}} | ||
==Background== | ==Background== | ||
[[File: | [[File:Triggers of myocarditis.png|thumb|Triggers of myocarditis. Myocarditis can be induced by both infectious and non-infectious pathogens, with viral infection being the most common cause (red background).]] | ||
*Inflammatory cardiomyopathy caused by damage and necrosis of myocytes | *Inflammatory [[cardiomyopathy]] caused by damage and necrosis of myocytes | ||
*Viral-induced is the most common etiology<ref>Cooper LT Jr. Myocarditis. ''N Engl J Med''. 2009;360(15):1526-38. PMID 19357408</ref> | |||
*Clinical presentation ranges from smoldering heart failure to fulminant cardiogenic shock or sudden death | *Clinical presentation ranges from smoldering [[heart failure]] to fulminant [[cardiogenic shock]] or sudden death | ||
*Maintain | *Maintain '''high index of suspicion in younger patients''' without traditional CAD risk factors | ||
*Incidence: estimated 1.5 million cases worldwide annually | |||
*'''Giant cell myocarditis''' is a rapidly fatal variant requiring early recognition | |||
===Causes=== | ===Causes=== | ||
* | *'''Viral''' (most common): | ||
** | **Enterovirus (Coxsackie B) and adenovirus (historically most common) | ||
** | **Parvovirus B19 and HHV-6 (currently most detected on biopsy) | ||
** | **Influenza A and B, [[HIV]], [[hepatitis]] B/C, COVID-19 | ||
*'''Bacterial''': [[Lyme disease]], beta-hemolytic strep, [[Mycoplasma]], diphtheria | |||
*'''Parasitic''': Chagas disease (most common cause worldwide), toxoplasma, trichinosis | |||
*'''Autoimmune''': [[sarcoidosis]], [[SLE]], giant cell myocarditis | |||
* | *'''Drugs/toxins''': '''cocaine''', doxorubicin, immune checkpoint inhibitors, [[amphetamines]] | ||
* | |||
* | |||
* | |||
===Phases=== | ===Phases=== | ||
*Acute | *'''Acute''': direct cytotoxicity and focal necrosis from viral, autoimmune, or toxins | ||
*'''Subacute''': host immune response (viral molecular mimicry, anti-myocyte antibody production) | |||
*Subacute | *'''Chronic''': diffuse myocardial fibrosis and cardiac dysfunction | ||
*Chronic | |||
==Clinical Features== | ==Clinical Features== | ||
*Typically young patients (20 - 50 years) with few risk factors for CAD | *Typically '''young patients (20-50 years)''' with few risk factors for CAD | ||
* | *'''Preceding viral illness''' in 50-80% of cases (1-2 weeks prior) | ||
* | *Chest pain or chest pressure/tightness (mimics [[ACS]]) | ||
*Flu-like symptoms: [[fever]], fatigue, [[myalgia]]s, nausea/vomiting | |||
* | *'''Tachycardia out of proportion to fever''' | ||
*New-onset [[heart failure]]: fatigue, [[orthopnea]], [[dyspnea]] on exertion | |||
*New onset [[ | *'''Consider this diagnosis in the septic-appearing patient who worsens after IV fluids''' | ||
*Consider this diagnosis in the septic-appearing patient who | *May present with [[sudden cardiac arrest]] (especially in young athletes) | ||
*Pediatric patients: | *Pediatric patients: see [[myocarditis (peds)]] | ||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
*[[Acute coronary syndrome]] (most important to rule out) | |||
*[[Pericarditis]] / [[myopericarditis]] | |||
*[[Takotsubo cardiomyopathy]] (stress cardiomyopathy) | |||
*[[Pulmonary embolism]] | |||
*[[Pneumonia]] | |||
*[[Sepsis]] from other cause | |||
{{Chest pain DDX}} | |||
==Evaluation== | ==Evaluation== | ||
[[File: | [[File:12 lead EKG ST elevation with myocarditis.jpg|thumb|Diffuse ST elevation in a patient with combined myocarditis and pericarditis.]] | ||
* | ===ECG=== | ||
*'''Must be obtained to rule out STEMI''' | |||
* | *Sinus tachycardia (most common finding) | ||
* | *Diffuse ST changes, nonspecific ST-T wave abnormalities | ||
* | *Low voltages | ||
* | *Prolonged QTc | ||
*AV block (especially with '''[[Lyme disease]]''' or '''[[sarcoidosis]]''') | |||
* | *Wide QRS / new [[LBBB]] | ||
* | *'''Normal ECG does NOT rule out myocarditis''' | ||
* | |||
* | ===Labs=== | ||
*[[ | *'''Troponin''': elevated in ~50% of cases; sensitivity limited | ||
* | *'''BNP/NT-proBNP''': reflects degree of heart failure | ||
*CBC, BMP, LFTs | |||
*[[ESR]], [[CRP]] (usually elevated but nonspecific) | |||
*Consider viral serologies, Lyme titer, ANA (if autoimmune suspected) | |||
* | *Blood cultures (if infectious etiology suspected) | ||
===Imaging=== | |||
*'''CXR''': cardiomegaly, pulmonary edema, or pleural effusion | |||
*'''Echocardiography''' (essential in ED): | |||
**Decreased LVEF, global hypokinesis or regional wall motion abnormalities | |||
**Can detect pericardial effusion (myopericarditis) | |||
**'''Fulminant myocarditis may show normal LV dimensions with increased wall thickness''' | |||
*'''Cardiac MRI''' (noninvasive gold standard): myocardial edema and late gadolinium enhancement | |||
*'''Endomyocardial biopsy''': invasive gold standard, reserved for unexplained cardiomyopathy or suspected giant cell myocarditis | |||
==Management== | ==Management== | ||
* | ===ED Management=== | ||
* | *'''IV access, continuous monitoring, 12-lead ECG''' | ||
* | *'''Rule out ACS''': may require coronary angiography if ST elevation or high clinical suspicion | ||
* | *'''Avoid NSAIDs and aspirin''' in acute phase (animal studies suggest increased inflammation) | ||
* | *'''Volume status''': use caution with IV fluids — may worsen [[heart failure]] | ||
** | **If [[cardiogenic shock]]: consider vasopressors/inotropes (dobutamine, milrinone) | ||
** | *'''Dysrhythmia management''': | ||
* | **Avoid class IC antiarrhythmics | ||
** | **Amiodarone for sustained [[VT]] | ||
* | **Temporary pacing for complete heart block | ||
**Cardiac transplant | *'''Anticoagulation''' consideration if severely reduced LVEF with LV thrombus risk | ||
===Definitive Treatment=== | |||
*'''Supportive care''' is mainstay; most viral myocarditis self-resolves | |||
*'''GDMT for heart failure''': ACE-I/ARB, beta-blockers, diuretics (as tolerated by hemodynamics) | |||
*'''Mechanical circulatory support''' (ECMO, VAD) for refractory cardiogenic shock | |||
*'''Giant cell myocarditis''': requires immunosuppression (cyclosporine + corticosteroids) | |||
*Cardiac transplant for end-stage disease | |||
*'''Activity restriction''': no competitive sports for 3-6 months per AHA guidelines<ref>Caforio ALP, et al. Current state of knowledge on aetiology, diagnosis, management, and therapy of myocarditis: a position statement of the ESC. ''Eur Heart J''. 2013;34(33):2636-2648. PMID 23824828</ref> | |||
==Disposition== | ==Disposition== | ||
* | *'''Admit all patients with suspected myocarditis''' to a monitored bed | ||
* | *'''ICU admission''' for hemodynamic instability, arrhythmias, or reduced LVEF | ||
*Early cardiology consultation | |||
*Consider transfer to center with mechanical circulatory support capability | |||
==Prognosis== | ==Prognosis== | ||
*Fulminant myocarditis has best prognosis | *'''Fulminant myocarditis''' paradoxically has the '''best long-term prognosis''' if patient survives the acute phase | ||
* | *Overall mortality: ~20% at 1 year, ~50% at 5 years for non-fulminant forms | ||
*Children | *Children: ~70% survival rate at 5 years | ||
*Most patients with mild disease recover completely | |||
==Complications== | ==Complications== | ||
*[[Ventricular dysrhythmias]] | *[[Ventricular dysrhythmias]] / [[sudden cardiac arrest]] | ||
*[[ | *[[Dilated cardiomyopathy]] | ||
*[[ | *Chronic [[heart failure]] | ||
*LV aneurysm / thrombus formation | |||
==See Also== | ==See Also== | ||
*[[Cardiomyopathy]] | *[[Cardiomyopathy]] | ||
*[[Pericarditis]] | *[[Pericarditis]] | ||
*[[Heart failure]] | |||
*[[Cardiogenic shock]] | |||
*[[Myocarditis (peds)]] | |||
==External Links== | ==External Links== | ||
*[https://www.jacc.org/doi/10.1016/j.jacc.2024.10.080 2024 ACC Expert Consensus on Myocarditis] | |||
==References== | ==References== | ||
<references/> | <references/> | ||
*Ammirati E, et al. Clinical presentation and outcome in a contemporary cohort of patients with acute myocarditis. ''Circulation''. 2018;138(11):1088-1099. PMID 29764898 | |||
*Tschöpe C, et al. Myocarditis and inflammatory cardiomyopathy: current evidence and future directions. ''Nat Rev Cardiol''. 2021;18(3):169-193. PMID 33046850 | |||
*Writing Committee; Drazner MH, et al. 2024 ACC Expert Consensus Decision Pathway on Myocarditis. ''J Am Coll Cardiol''. 2025;85(4):391-431. PMID 39665703 | |||
[[Category:Cardiology]] | [[Category:Cardiology]] | ||
Revisión del 19:35 21 mar 2026
Background
File:Triggers of myocarditis.png
Triggers of myocarditis. Myocarditis can be induced by both infectious and non-infectious pathogens, with viral infection being the most common cause (red background).
- Inflammatory cardiomyopathy caused by damage and necrosis of myocytes
- Viral-induced is the most common etiology[1]
- Clinical presentation ranges from smoldering heart failure to fulminant cardiogenic shock or sudden death
- Maintain high index of suspicion in younger patients without traditional CAD risk factors
- Incidence: estimated 1.5 million cases worldwide annually
- Giant cell myocarditis is a rapidly fatal variant requiring early recognition
Causes
- Viral (most common):
- Bacterial: Lyme disease, beta-hemolytic strep, Mycoplasma, diphtheria
- Parasitic: Chagas disease (most common cause worldwide), toxoplasma, trichinosis
- Autoimmune: sarcoidosis, SLE, giant cell myocarditis
- Drugs/toxins: cocaine, doxorubicin, immune checkpoint inhibitors, amphetamines
Phases
- Acute: direct cytotoxicity and focal necrosis from viral, autoimmune, or toxins
- Subacute: host immune response (viral molecular mimicry, anti-myocyte antibody production)
- Chronic: diffuse myocardial fibrosis and cardiac dysfunction
Clinical Features
- Typically young patients (20-50 years) with few risk factors for CAD
- Preceding viral illness in 50-80% of cases (1-2 weeks prior)
- Chest pain or chest pressure/tightness (mimics ACS)
- Flu-like symptoms: fever, fatigue, myalgias, nausea/vomiting
- Tachycardia out of proportion to fever
- New-onset heart failure: fatigue, orthopnea, dyspnea on exertion
- Consider this diagnosis in the septic-appearing patient who worsens after IV fluids
- May present with sudden cardiac arrest (especially in young athletes)
- Pediatric patients: see myocarditis (peds)
Differential Diagnosis
- Acute coronary syndrome (most important to rule out)
- Pericarditis / myopericarditis
- Takotsubo cardiomyopathy (stress cardiomyopathy)
- Pulmonary embolism
- Pneumonia
- Sepsis from other cause
Evaluation
File:12 lead EKG ST elevation with myocarditis.jpg
Diffuse ST elevation in a patient with combined myocarditis and pericarditis.
ECG
- Must be obtained to rule out STEMI
- Sinus tachycardia (most common finding)
- Diffuse ST changes, nonspecific ST-T wave abnormalities
- Low voltages
- Prolonged QTc
- AV block (especially with Lyme disease or sarcoidosis)
- Wide QRS / new LBBB
- Normal ECG does NOT rule out myocarditis
Labs
- Troponin: elevated in ~50% of cases; sensitivity limited
- BNP/NT-proBNP: reflects degree of heart failure
- CBC, BMP, LFTs
- ESR, CRP (usually elevated but nonspecific)
- Consider viral serologies, Lyme titer, ANA (if autoimmune suspected)
- Blood cultures (if infectious etiology suspected)
Imaging
- CXR: cardiomegaly, pulmonary edema, or pleural effusion
- Echocardiography (essential in ED):
- Decreased LVEF, global hypokinesis or regional wall motion abnormalities
- Can detect pericardial effusion (myopericarditis)
- Fulminant myocarditis may show normal LV dimensions with increased wall thickness
- Cardiac MRI (noninvasive gold standard): myocardial edema and late gadolinium enhancement
- Endomyocardial biopsy: invasive gold standard, reserved for unexplained cardiomyopathy or suspected giant cell myocarditis
Management
ED Management
- IV access, continuous monitoring, 12-lead ECG
- Rule out ACS: may require coronary angiography if ST elevation or high clinical suspicion
- Avoid NSAIDs and aspirin in acute phase (animal studies suggest increased inflammation)
- Volume status: use caution with IV fluids — may worsen heart failure
- If cardiogenic shock: consider vasopressors/inotropes (dobutamine, milrinone)
- Dysrhythmia management:
- Avoid class IC antiarrhythmics
- Amiodarone for sustained VT
- Temporary pacing for complete heart block
- Anticoagulation consideration if severely reduced LVEF with LV thrombus risk
Definitive Treatment
- Supportive care is mainstay; most viral myocarditis self-resolves
- GDMT for heart failure: ACE-I/ARB, beta-blockers, diuretics (as tolerated by hemodynamics)
- Mechanical circulatory support (ECMO, VAD) for refractory cardiogenic shock
- Giant cell myocarditis: requires immunosuppression (cyclosporine + corticosteroids)
- Cardiac transplant for end-stage disease
- Activity restriction: no competitive sports for 3-6 months per AHA guidelines[2]
Disposition
- Admit all patients with suspected myocarditis to a monitored bed
- ICU admission for hemodynamic instability, arrhythmias, or reduced LVEF
- Early cardiology consultation
- Consider transfer to center with mechanical circulatory support capability
Prognosis
- Fulminant myocarditis paradoxically has the best long-term prognosis if patient survives the acute phase
- Overall mortality: ~20% at 1 year, ~50% at 5 years for non-fulminant forms
- Children: ~70% survival rate at 5 years
- Most patients with mild disease recover completely
Complications
- Ventricular dysrhythmias / sudden cardiac arrest
- Dilated cardiomyopathy
- Chronic heart failure
- LV aneurysm / thrombus formation
See Also
External Links
References
- Ammirati E, et al. Clinical presentation and outcome in a contemporary cohort of patients with acute myocarditis. Circulation. 2018;138(11):1088-1099. PMID 29764898
- Tschöpe C, et al. Myocarditis and inflammatory cardiomyopathy: current evidence and future directions. Nat Rev Cardiol. 2021;18(3):169-193. PMID 33046850
- Writing Committee; Drazner MH, et al. 2024 ACC Expert Consensus Decision Pathway on Myocarditis. J Am Coll Cardiol. 2025;85(4):391-431. PMID 39665703
