A progressive pericardial effusion caused by psittacosis

Myocarditis

Viruses are the most common cause of myocarditis in economically advanced countries.

Enteroviruses and adenoviruses are the most common etiologic agents.

Viral myocarditis is a triphasic process. Phase 1 is the period of active viral replication in the myocardium during which the symptoms of myocardial damage range from none to cardiogenic shock. If the disease process continues, it enters phase 2, which is characterized by autoimmunity triggered by viral and myocardial proteins. Heart failure often appears for the first time in phase 2. Phase 3, dilated cardiomyopathy, is the end result in some patients. Diagnostic procedures and treatment should be tailored to the phase of disease.

Viral myocarditis is a significant cause of dilated cardiomyopathy, as proved by the frequent presence of viral genomic material in the myocardium, and by improvement in ventricular function by immunomodulatory therapy.

Myocarditis of any etiology usually presents with heart failure, but the second most common presentation is ventricular arrhythmia. As a result, myocarditis is one of the most common causes of sudden death in young people and others without preexisting structural heart disease.

Myocarditis can be definitively diagnosed by endomyocardial biopsy. However, it is clear that existing criteria for the histologic diagnosis need to be refined, and that a variety of molecular markers in the myocardium and the circulation can be used to establish the diagnosis.

Treatment of myocarditis has been generally disappointing. Accurate staging of the disease will undoubtedly improve treatment in the future. It is clear that immunosuppression and immunomodulation are effective in some patients, especially during phase 2, but may not be as useful in phases 1 and 3. Since myocarditis is often selflimited, bridging and recovery therapy with circulatory assistance may be effective. Prevention by immunization or receptor blocking strategies is under development.

Giant cell myocarditis is an unusually fulminant form of the disease that progresses rapidly to heart failure or sudden death. Rapid onset of disease in young people, especially those with other autoimmune manifestations, accompanied by heart failure or ventricular arrhythmias, suggests giant cell myocarditis.

Peripartum cardiomyopathy in economically developed countries is usually the result of myocarditis.

[Acute pericarditis with effusion as a form of presentation of psittacosis]

Psittacosis is an uncommon cause of acute pericarditis and pericardial effusion. However, some isolated cases have been reported. We present a case which the first clinical feature of psittacosis was acute pericarditis. Severe pericardial effusion associated with a pulmonary infiltrate and an epidemiologic history of contact with avian species suggested the diagnosis of psittacosis, confirmed by serological test.

Infectious and lymphocytic myocarditis: epidemiology and factors relevant to sports medicine

Myocarditis is a disease entity of permanent actuality and of special concern in the sports setting. This is because the probability of complications or sequelae increases if exercise is imposed. Myocarditis may pass unrecognized by the sufferer or be easily overlooked by the physician, especially in athletes, where electrocardiographic changes often exist normally. Furthermore, although the immune system of the conditioned individual may be more efficient than that of the sedentary individual, very strenuous and frequently repeated or long-lasting exercise may cause immunosuppression and an increased susceptibility to respiratory tract infections (RTI). Several causative agents of RTI can give rise to myocarditis as well. The true incidence of proven infectious myocarditis in society is unknown. Histopathologically defined myocarditis (lymphocytic myocarditis), on the other hand, has been found in about 1% of unselected routine autopsies. In general, the long-term prognosis in myocarditis is favorable but exercise stress may cause long-term sequelae or sudden death. It is thus essential to refrain from strenuous exercise during RTI.

Chlamydial infections of the heart

Chlamydiae are common human pathogens, causing a broad spectrum of infectious diseases. Chlamydial infections involving the heart have been described in numerous previous reports. These organisms are documented to cause endocarditis, myocarditis and pericarditis. Furthermore, Chlamydia pneumoniae, the recently discovered respiratory pathogen, has also been implicated in coronary artery disease. For the first time the literature on involvement of the heart in chlamydial infections is reviewed. Information on the discovery of Chlamydia species is also included and the problem of the species determination of Chlamydia in interpretation of the older literature is mentioned.