医学英语学习材料 心肌炎

Nuclear imaging
Technetium-99m pyrophosphate is avidly tacken up by the necrotic myocardium whether the necrosis is due to myocarditis or MI
Diagnosis
‘Common cold or mumps’+symptoms
Pathology and pathogenesis
Myocardium fiber damage may be due to direct
virus-mediated destruction and through immunologic cell-mediated mechanism
Pathology and pathogenesis
Pathology and pathogenesis
Dilatation of cardiac chambers, varying degree of LVH, areas of endocardial thickening, replacement of fibrous tissue,
celluar infiltration (monocelluar type, mainly with lymphocytes) and destruction of myocardial cells.
Dilatation of cardiac chambers
Heart failure
Abnormal ECG, arrhythmia Other heart diseases are excluded Laboratory examination
Prognosis
Viral myocarditis is generally a mild benign disease ending in complete recovery.
Dilated cardiomyopathy may be the result of chronic active myocarditis.
Management
Intensive care Bed rest (14 days), avoid moderate physical exertion for 6 to 8 weeks in uncomplicated cases. Heart failure: digitalis, diuretics, vasodilators Antiarrhythmia, pacing Corticosteroids
Laboratory examinations
Elevation of cardiac enzymes Elevated Erythrocyte Sedimentation Rate
Slight to moderate leukocytosis
Complement-fixing protein (+)
ห้องสมุดไป่ตู้
Antibody in paired acute(less than 1 month)
and convalescent ( two weeks or longer)
Supplementary examination
Endomyocardial biopsy
Evidence of recent damage to myocardial fibers, inflammatory cells, evidence of repair
Clinical manifestation
Preceding or accompanying viral infection
Tachycardia disproportionate to the fever and palpitation may be the first indications of myocarditis. Various arrhythmias and conduction disturbances.
Clinical manifestation
Chest pain is found in about two third and is
present also in those without evidence of pericarditis.
A pericardial rub is heard in about one third of patients.
Appearance or worsening of dyspnea with
various severity of heart failure.
Clinical manifestation
Signs
Arrhythmias,heart block
Dilatation of cardiac chambers, signs of heart failure Heart murmur (MI, TI), gallop rhythm (S3)
Introduction
Myocarditis is a focal or diffuse involvement of the heart muscle in an inflammatory process. It can result from a variety of common or rare infections, drugs, chemicals, or physical agents. A wide variety of viruses and viral diseases can result in myocarditis. Coxsackie virus B is the most frequent cause of human myocarditis.
Clinical manifestation
Subclinical Abnormal ECG, Abnormal chest film, Unexpected sudden death
Clinical manifestation
Clinical
Palpitation, tachycardia Arrhythmia, conduction defects Chest pain: pleuopericardial, vague, ischemic Dyspnea, heart failure Fulminant heart failure Collapse: heart block, tamponade, shock Embolism: systemic, pulmonary Mitraltricuspid valve regurgitation Chronic severe heart failure-chronic active myocarditis
Pathologic changes generally depend on the
duration of the process.
The lesion may involve not only the interstitium and cardiac muscle but also specialized tissue such as the conduction system.
In newborns, however, mortality is high and may be about 50%.
Mortality may be as high as 33% in patients with heart failure. Undiagnosed myocarditis has been the cause in 14% to 17% of unexplained sudden death.
Others
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Chest film
Normal or dilated heart chambers, pulmonary congestion
Electrocardiogram
ST-T changes
Decreased amplititude of R waves Abnormal Q waves Cardiac conduction defect Arrhythmias