Diferencia entre revisiones de «Myocarditis»
(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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*Viral-induced is the most common etiology<ref>Cooper LT Jr. Myocarditis. ''N Engl J Med''. 2009;360(15):1526-38. PMID 19357408</ref> | *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 | *Incidence: estimated 1.5 million cases worldwide annually | ||
*'''Giant cell myocarditis''' is a rapidly fatal variant requiring early recognition | *'''Giant cell myocarditis''' is a rapidly fatal variant requiring early recognition | ||
===Causes=== | ===Causes=== | ||
* | *Viral (most common): | ||
**Enterovirus (Coxsackie B) and adenovirus (historically most common) | **Enterovirus (Coxsackie B) and adenovirus (historically most common) | ||
**Parvovirus B19 and HHV-6 (currently most detected on biopsy) | **Parvovirus B19 and HHV-6 (currently most detected on biopsy) | ||
**Influenza A and B, [[HIV]], [[hepatitis]] B/C, COVID-19 | **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: 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== | ==Clinical Features== | ||
*Typically | *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]]) | *Chest pain or chest pressure/tightness (mimics [[ACS]]) | ||
*Flu-like symptoms: [[fever]], fatigue, [[myalgia]]s, nausea/vomiting | *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 [[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) | *May present with [[sudden cardiac arrest]] (especially in young athletes) | ||
*Pediatric patients: see [[myocarditis (peds)]] | *Pediatric patients: see [[myocarditis (peds)]] | ||
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*Low voltages | *Low voltages | ||
*Prolonged QTc | *Prolonged QTc | ||
*AV block (especially with | *AV block (especially with [[Lyme disease]] or [[sarcoidosis]]) | ||
*Wide QRS / new [[LBBB]] | *Wide QRS / new [[LBBB]] | ||
* | *Normal ECG does NOT rule out myocarditis | ||
===Labs=== | ===Labs=== | ||
* | *Troponin: elevated in ~50% of cases; sensitivity limited | ||
* | *BNP/NT-proBNP: reflects degree of heart failure | ||
*CBC, BMP, LFTs | *CBC, BMP, LFTs | ||
*[[ESR]], [[CRP]] (usually elevated but nonspecific) | *[[ESR]], [[CRP]] (usually elevated but nonspecific) | ||
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===Imaging=== | ===Imaging=== | ||
* | *CXR: cardiomegaly, pulmonary edema, or pleural effusion | ||
* | *Echocardiography (essential in ED): | ||
**Decreased LVEF, global hypokinesis or regional wall motion abnormalities | **Decreased LVEF, global hypokinesis or regional wall motion abnormalities | ||
**Can detect pericardial effusion (myopericarditis) | **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=== | ===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]] | *'''Volume status''': use caution with IV fluids — may worsen [[heart failure]] | ||
**If [[cardiogenic shock]]: consider vasopressors/inotropes (dobutamine, milrinone) | **If [[cardiogenic shock]]: consider vasopressors/inotropes (dobutamine, milrinone) | ||
* | *Dysrhythmia management: | ||
**Avoid class IC antiarrhythmics | **Avoid class IC antiarrhythmics | ||
**Amiodarone for sustained [[VT]] | **Amiodarone for sustained [[VT]] | ||
**Temporary pacing for complete heart block | **Temporary pacing for complete heart block | ||
* | *Anticoagulation consideration if severely reduced LVEF with LV thrombus risk | ||
===Definitive Treatment=== | ===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 | *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> | *'''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 | *Early cardiology consultation | ||
*Consider transfer to center with mechanical circulatory support capability | *Consider transfer to center with mechanical circulatory support capability | ||
==Prognosis== | ==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 | *Overall mortality: ~20% at 1 year, ~50% at 5 years for non-fulminant forms | ||
*Children: ~70% survival rate at 5 years | *Children: ~70% survival rate at 5 years | ||
Revisión actual - 09:24 22 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
