Dressler's syndrome
Synonyms and keywords: Postmyocardial infarction syndrome; PMIS; Post-cardiac injury syndrome

# Overview
Dressler's syndrome or post-myocardial infarction syndrome is a form of pericarditis that occurs in the setting of myocardial infarction. It typically occurs 2 to 10 weeks after myocardial infarction. Dressler's syndrome results from an autoimmune inflammatory reaction to myocardial neo-antigens. Possible complications include pericardial effusion, cardiac tamponade, and constrictive pericarditis; however, the prognosis is usually favorable with early treatment. The diagnostic criteria of Dressler's syndrome depend on pleuritic chest pain, pericardial friction rub, ECG changes, and echocardiography-detected pericardial effusion. The recommended medical treatments include aspirin and colchicine.

# Historical Perspective
- Dressler's syndrome was first characterized by William Dressler in 1956.
- It should not be confused with the Dressler's syndrome of hemoglobinuria, named after Lucas Dressler who characterized it in 1854.

# Classification
- There is no established system for the classification of Dressler's syndrome.

# Pathophysiology
- Although the exact cause remains unknown, Dressler's syndrome is believed to result from an autoimmune inflammatory reaction to myocardial neo-antigens, as well as injury to the mesothelial pericardial cells.
- It usually occurs within weeks or months of the infarction due to antimyocardial antibodies; this begins with myocardial injury that releases cardiac antigens and stimulates antibody formation.
- The immune complexes that are generated as anti-actin and actomyosin antibodies deposit onto the pericardium and causes inflammation.
- The autoimmune response and syndrome may also develop secondary to pulmonary embolism.

## Gross Pathology
Gross pathological examination may show the following findings: 
- Fine granular layer on the epicardial surface with a bread and butter appearance.
- Because Dressler's syndrome is more common with transmural infarctions, the causing infarction is likely to be seen.

## Microscopic Pathology
Microscopic examination of the myocardial tissue sections may show: 
- Plurifocal signs of myocardial sclerosis may be detected.
- Lymphocytic perimyofibrillar microinfiltrations may be seen.
- Localized lipofuscin pigment deposits in the myocytes.

# Causes
The common causes of Dressler's syndrome include: 
- Surgeries associated with myocardial damage
Coronary artery bypass grafting and
Aortic valve replacement.
- Coronary artery bypass grafting and
- Aortic valve replacement.
- Myocardial infarction
- Pulmonary embolism

# Differentiating Dressler's Syndrome from other Diseases
- Dressler's syndrome typically occurs 2 to 10 weeks after a myocardial infarction has occurred.
- This differentiates Dressler's syndrome from:
- Post myocardial infarction pericarditis that occurs in 17,000 to 25,000 in every 100,000 cases of acute myocardial infarction between days 2 and 4 after the myocardial infarction.
- Post myocardial infarction pericarditis that occurs in 17,000 to 25,000 in every 100,000 cases of acute myocardial infarction between days 2 and 4 after the myocardial infarction.
- Pulmonary embolism, another identifiable cause of pleuritic (and non-pleuritic) chest pain in people who have been hospitalized and/or undergone surgical procedures within the preceding weeks.
- Pulmonary embolism, another identifiable cause of pleuritic (and non-pleuritic) chest pain in people who have been hospitalized and/or undergone surgical procedures within the preceding weeks.
- Dressler's syndrome should be differentiated from:
- Congestive Heart Failure: Another complication of MI that may occur in a more acute setting.
Acute anemia (e.g., hemorrhage): shares the same symptoms as malaise, dyspnea, and palpitations.
Uremia: may lead to pericarditis that must be differentiated from Dressler's syndrome.
- Congestive Heart Failure: Another complication of MI that may occur in a more acute setting.
- Acute anemia (e.g., hemorrhage): shares the same symptoms as malaise, dyspnea, and palpitations.
- Uremia: may lead to pericarditis that must be differentiated from Dressler's syndrome.

# Epidemiology and Demographics
- Incidence: In the setting of myocardial infarction, Dressler's syndrome was classically reported to occur in about 3 to 4% of MI cases.
- However, the incidence has markedly decreased in the reperfusion era (between 0.5 to 2%), presumably because of smaller infarct sizes.
- Age: Dressler's syndrome occurs more often in younger age groups.
- Gender: There is no gender predilection for Dressler's syndrome.
- Race: There is no racial predilection for Dressler's syndrome.
- Mortality rate: The prognosis is usually favorable with early treatment with a low mortality rate.

# Risk Factors
- The risk of Dressler's syndrome increases with the size of the infarction.
- Further, a former episode of Dressler's syndrome increases the risk of relapse upon recurrent MI (the most important risk factor).
- Epidemiological studies showed a higher risk ratio of Dressler's syndrome with: 
- Cardiac surgeries associated with greater myocardial damage as aortic valve replacement
Younger age
Prior treatment with prednisone
B-negative blood type
Halothane anesthesia
Viral infections that have been associated with Dressler's syndrome (based on the seasonal variations in incidence and elevated blood levels of viral components in Dressler's Syndrome patients), including: 
Coxsackie B virus
Adenovirus
Cytomegalovirus
- Cardiac surgeries associated with greater myocardial damage as aortic valve replacement
- Younger age
- Prior treatment with prednisone
- B-negative blood type
- Halothane anesthesia
- Viral infections that have been associated with Dressler's syndrome (based on the seasonal variations in incidence and elevated blood levels of viral components in Dressler's Syndrome patients), including: 
Coxsackie B virus
Adenovirus
Cytomegalovirus
- Coxsackie B virus
- Adenovirus
- Cytomegalovirus

# Screening
- There is insufficient evidence to recommend routine screening for Dressler's syndrome.

# Natural History, Complications, and Prognosis

## Natural History
- Dressler's syndrome typically occurs 2 to 10 weeks after a myocardial infarction has occurred.
- The symptoms for Dressler's syndrome starts mild and then progress to reach the full clinical profile.
- The condition is usually acute; however, some patients may develop chronic pericardial inflammation.
- The prognosis is usually favorable with early treatment.
- Untreated or poorly treated patients may develop cardiac tamponade (acute) or constrictive pericarditis (chronic).

## Complications
The complications of Dressler's syndrome may include: 
- Pericardial effusion may result from the accumulation of fluids as a result of inflammation in the pericardial sac.
- Cardiac tamponade can occur if the accumulation of fluids in the pericardium is large enough and rapid enough.
- Constrictive pericarditis can occur if there is a chronic inflammatory response.

## Prognosis
- The prognosis for patients with Dressler's syndrome is usually favorable, even those requiring pericardial drainage.
- However, the latter patients have a higher risk for fluid reaccumulation and repeat pericardiocentesis.
- Otherwise, constrictive pericarditis would occur leading to the need for pericardial stripping.

# Diagnosis

## Diagnostic Study of Choice
"2017 Revised ESC Guidelines for the Management of ST-Elevation Myocardial Infarction (DO NOT EDIT)
Diagnostic criteria do not differ from those for acute pericarditis including two of the following criteria: (i) pleuritic chest pain (8590% of cases); (ii) pericardial friction rub ( 33% of cases); (iii) ECG changes ( 60% of cases), with new widespread ST-segment elevation, usually mild and progressive, or PR depression in the acute phase; and (iv) pericardial effusion ( 60% of cases and generally mild)".

## History and Symptoms
The syndrome consists of a persistent low-grade fever and chest pain which is usually pleuritic in nature.The symptoms enlisted below tend to occur after a few weeks or even months after myocardial infarction and tend to subside in a few days: 
- Malaise
- Irritability
- Lack of appetite
- Difficulty breathing (with or without hypoxia)
- Palpitations
- Pain in the joints

## Physical Examination
Physical examination of patients with Dressler's syndrome may show:
- Pericardial friction rub: This characteristic sign may disappear secondary to either improvement in or worsening of accumulation of pericardial fluid
- Tachycardia
- Pulsus paradoxus (>10 mmHg decrease in blood pressure with inspiration and decreased pulse amplitude on the radial artery).
- Signs of pneumonitis (e.g., a cough, decreased oxygen saturation, and fever).
- Minimal respiratory symptoms to significant respiratory distress with large pleural effusions.

## Laboratory Findings
The laboratory work-up of patients with Dressler's syndrome may include: 
- Blood culture: can differentiate between inflammatory and infectious pericarditis (should be negative in Dressler's syndrome)
- Leucocytosis (with a leftward shift)
- Elevated acute phase reactants (e.g., ESR and CRP)
- High serum titers of anti-cardiac antibodies
- The pericardial fluid may be examined for cell count, culture, total proteins, and triglyceride levels

## Electrocardiogram
An ECG may demonstrate: 
- ST segment elevation
- T-wave inversion (as with pericarditis).
- PR depression
- Variations in the amplitude or directionality of QRS from beat to beat and/or a low voltage QRS

## X-ray
The findings of chest x-ray in Dressler's syndrome may include: 
- Flattening of the costophrenic angles
- Enlargement of the cardiac silhouette (non-specific chamber enlargement).

## Echocardiography or Ultrasound
- Echocardiography is used to:
Confirm the presence of pericardial fluid and evaluate the potential risk of cardiac tamponade.
Evaluate ventricular contractility and the potential risk of congestive heart failure.
- Confirm the presence of pericardial fluid and evaluate the potential risk of cardiac tamponade.
- Evaluate ventricular contractility and the potential risk of congestive heart failure.

## CT scan
The findings of CT scan in Dressler's syndrome may include: 
- Pericardial effusion of varying size, which may be simple (serous) or more often complex (hemopericardium)
- Myocardial thinning of the infarcted region
- Stents in the coronary arteries (e.g., post PCI) may be present

## MRI
The findings of MRI in Dressler's syndrome may include:
- Fluid collections in the pericardium (may become loculated).
- Intense late post-gadolinium enhancement of entire pericardium.
- Regional thinning and akinesis of the infarcted myocardium.

## Other Imaging Findings
There are no other imaging findings associated with Dressler's syndrome.

## Other Diagnostic Studies
There are no other diagnostic studies associated with Dressler's syndrome.

# Treatment

## Medical Therapy
Dressler's syndrome is typically treated with high dose (up to 650 mg PO q 4 to 6 hours) enteric-coated aspirin. Acetaminophen can be added for pain management as this does not affect the coagulation system. Anticoagulants should be discontinued if the patient develops a pericardial effusion.
"2017 Revised ESC Guidelines for the Management of ST-Elevation Myocardial Infarction (DO NOT EDIT)
- Anti-inflammatory therapy is recommended in post-STEMI pericarditis as in post-cardiac injury pericardial syndromes for symptom relief and reduction of recurrences.
- Aspirin is recommended as first choice of anti-inflammatory therapy post-STEMI at a dose of 5001000 mg every 68 h for 12 weeks, decreasing the total daily dose by 250500 mg every 12 weeks in keeping with 2015 ESC Guidelines for the diagnosis and management of pericardial diseases.
- Colchicine is recommended as first-line therapy as an adjunct to aspirin/non-steroidal anti-inflammatory drug therapy (3 months) and is also recommended for the recurrent forms (6 months).
- Corticosteroids are not recommended due to the risk of scar thinning with aneurysm development or rupture.
- Pericardiocentesis is rarely required, except for cases of haemodynamic compromise with signs of tamponade".

### 2013 Revised ACCF/AHA Guidelines for the Management of ST-Elevation Myocardial Infarction

### Management of Pericarditis After STEMI

## Surgery
- No surgical intervention is recommended in the management of Dressler's syndrome.
- Pericardiocentesis is rarely required, except for cases of hemodynamic compromise with signs of tamponade.

## Primary Prevention
Despite the lack of guidelines on the prevention of Dressler's syndrome, MI patients with the aforementioned risk factors should be followed closely in the few weeks after the ischemic event for the early detection of signs of pericarditis.

## Secondary Prevention
- Recurrence of Dressler's syndrome is common and relapses were reported up to 1 year following the event.
- Some researchers suggest that intravenous immunoglobulin therapy has some benefit in resistant cases.