Myocarditis & Pericarditis Flashcards
list of common causes of acute pericarditis
virus: Coxsackie A and B viruses- most common, echovirus, Adenoviruses
mumps virus,
covid-19
bacteria: streptococcus pneumonia and other, staphylococcus aureus, Neisseria meningitidis, Mycobacteria tuberculosis.
Fungi:
aspergillus, candida species, Blastomyces, Coccidioides, cryptococcus neoformans.
Discuss epidemiology, pathogenesis,clinical presentation and diagnosis of pericarditis in general
Describe TB pericarditis including pathogenic mechanism, pathological findings, diagnosis and the complications that may develop.
pericarditis
inflammation of pericardiac sac.
Pathogenesis
Several mechanisms as follows:
Spread directly from intrathoracic foci of infection, e.g. trauma, thoracic surgery. Most common Streptococcus pneumoniae
Hematogenous spread. Most common is Staphylococcus aureus. E.g. Pneumonia or empyema accompanied by bacteraemia
Extend from subdiaphragmatic suppurative foci. This can be a complication of infective endocarditis extending to the pericardium.
approach to diagnosis of pericaditis
chest pain: improved by sitting up and leaning forward
auscultation: pericardial friction rub. signs associated with cardiac tamponade.
blood cultures and HIV
Chast x-ray, ECG, cardiac biomakers, echordiography
The diagnostic criteria
Typical chest pain
pericardial friction rub
ECG changes : St segment elevation.
new or worsening pericardial effusion.
Pericardial friction rub-
superficial scratchy or squeaking sound best heard with the diaphragm of the stethoscope over the left sternal border
Diagnostic criteria
are consistent with the 2015 European Society of Cardiology guidelines on pericardial diseases
TB pericarditis
Pathogenic mechanism:
via extension of lung or tracheobronchial tree, adjacent lymph nodes, spine, sternum or via miliary spread
Pathologic Findings:
“Fibrinous exudate with polymorphonuclear leukocytes, early granuloma formation with loose organization of macrophages & T cells
Serosanguineous effusion with lymphocytic exudate and high protein concentration; tubercle bacilli present in low concentrations
Absorption of effusion with granulomatous caseation and pericardial thickening with subsequent fibrosis
Constrictive scarring; fibrosing visceral and parietal pericardium contracts on the cardiac chambers and may become calcified, leading to constrictive pericarditis, which impedes diastolic filling.”
Clinical Manifestations
Symptoms – Nonspecific – fever, weight loss, night sweats precede cardiopulmonary complaints
Physical Findings – fever, tachycardia, increased JVP, hepatomegaly, ascites and peripheral edema. Pericardial friction rub and distant heart sounds.
Complications:
constrictive pericarditis, effusive pericarditis and cardiac tamponade
Myocarditis
Definition: inflammatory disease of cardiac muscle.
focal or diffuse involvement of the myocardium
can be acute, subacute or chronic.
causes of myocarditis
most caused by viral infections
bacterial infection as result of bacteremia, direct extension from contiguous foci or toxin.
Viruses
Enteroviruses
adenoviruses
parvovirus B19
human herpes virus
dengue viruses
Coxsackie B virus
Bacteria
brucella
campylobacter
corynebacterium diphtheria
clostridium perfringens
Francisella tularensis.
Fungi
Aspergillus
candida species
Blastomyces
Coccidioides
immits
cryptococcus neoformans.
Parasite
toxoplasma gondii
Trypanosoma rhodesiense
Trypanosoma Cruzi
Approach to diagnosis of myocarditis
Investigations
ECG
CRP
Cardiac markers- serum troponin levels
Chest X-ray
Cardiac imaging – Echocardiogram
Endomyocardial biopsy- should be based upon likelihood that biopsy will change management. Exclude other causes of heart failure
Histology remains gold standard to establish diagnosis of myocarditis
Critical points in diagnosis: when to suspect it? How diagnosis is confirmed?
Differential Diagnosis of Myocarditis
Ischemic Heart Disease
Chest pain, ECG abnormalities and high cardiac markers
Stress Cardiomyopathy
Chest pain, physical signs of HF. Differentiating factor is typical LV apical dysfunction is not seen with myocarditis
Valvular Heart Disease
Congenital Heart Disease
Pulmonary Disease
