History
Physicians must maintain a high index of suspicion to diagnose patients with myocardial abscess. Many of the clinical features of this condition reflect the symptoms and signs of the clinical setting, most commonly bacteremia and infective endocarditis, which predisposes to development of the abscess.
Infective endocarditis is associated with the following:
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Significant clinical deterioration, including worsening CHF and alteration of heart sounds and murmurs (eg, new-onset valvular regurgitation [100% of cases]) [12]
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Poor response to antibiotics, with persistent fever and other signs of infection despite adequate antibiotic coverage
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Development of conduction defects or progression of heart block, such as bundle-branch block and atrioventricular block (45%) [2]
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Sudden onset of complete heart block or Mobitz type II block (highly specific)
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Type of valve involvement, eg, aortic valve endocarditis (40%-85% incidence)
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Severe recurrent ventricular arrhythmias
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Pericarditis (uncommon)
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Infection of the prosthetic valves (bioprosthetic or mechanical)
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Right-sided endocarditis in patients with congenital heart disease
Myocardial abscess must be considered in patients who have longstanding persistent bacteremia and who do not respond to antibiotic therapy. In the setting of infective endocarditis, clinical features can persist or even worsen with development of a myocardial abscess. Other, less common settings to consider for the development of myocardial abcess include acute MI in the setting of sepsis or penetrating chest injuries complicated by sepsis.
One must bear in mind a certain constellation of symptoms that may raise the suspicion for myocardial abscess. For example, fever is the most common symptom, presenting in 80-85% of patients. It is absent in some patients who are elderly; those who have CHF, severe debility, or chronic renal failure; and in patients with coagulase-negative staphylococcal infection and abscess. Another characteristic symptom is chills, which occurs in 42-75% of cases.
Other signs and symptoms include the following:
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Anorexia
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Weight loss
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Malaise
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Dyspnea
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Cough
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Stroke
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Headache
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Nausea/vomiting
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Myalgia
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Arthralgia
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Chest pain
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Abdominal pain
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Back pain
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Confusion
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Sweats.
Physical
Physical examination findings commonly encountered in myocardial abscess are primarily due to the underlying infective endocarditis. These include the following:
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Fever
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Tachycardia
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Murmur, especially changing or new murmur
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Neurological abnormalities
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Embolic event
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Splenomegaly
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Clubbing
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Peripheral manifestations
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Osler nodes
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Splinter hemorrhages
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Petechiae
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Janeway lesions
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Retinal lesions (Roth spots)
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Widening pulse pressure, especially with involvement of the aortic valve and progression of aortic regurgitation.
Causes
Causes of myocardial abscess associated with endocarditis may include the following:
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Native valve endocarditis
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Prosthetic valve endocarditis - bioprosthesis, mechanical prosthesis
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Myocardial (muscle) infection - ventricular septal wall, left ventricular posterior wall.
Causes of myocardial abscess associated with septicemia may include the following:
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Bronchopneumonias
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Genitourinary infections
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Other infections.
Miscellaneous causes of myocardial abscess may include the following:
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Complications of acute MI
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Trauma and deep penetrating wounds
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Mechanical interventions - Catheterization, angioplasty, stent
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Infection associated with left ventricular aneurysm
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Infection associated with atrial myxoma (exceedingly rare)
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Myocarditis and suppuration associated with HIV
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Transplanted heart infection
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Asymptomatic
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Other
Complications
The following are potential complications of myocardial abscess:
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Myocardial perforation
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Significant clinical deterioration
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Worsening CHF
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Worsening heart sounds and murmurs
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New-onset valvular regurgitation (100% of cases) [12]
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Poor response to antibiotics
-
Development of conduction defects or progression of heart block, such as bundle-branch block and atrioventricular block (45%) [2]
-
Sudden onset of complete heart block or Mobitz type II block (highly specific)
-
Type of valve involvement, eg, aortic valve endocarditis (40%-85%)
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Miscellaneous (severe recurrent ventricular arrhythmias, pericarditis [uncommon], infection of the prosthetic valves, right-sided endocarditis in patients with congenital heart disease).
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Myocardial abscess. Transesophageal echocardiogram exhibiting aortic valvular endocarditis and aortic root abscess.
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Myocardial abscess. Complete heart block seen on a 12-lead electrocardiogram in a patient with myocardial abscess involving the prosthetic aortic valve ring.
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Myocardial abscess. Color Doppler imaging showing flow into the aortic root abscess.
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Myocardial abscess. Aortic valvular ring abscess seen by transesophageal echocardiography.
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Myocardial abscess (gross).
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Myocardial abscess (opened).
