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

Viral Myocarditis-Incidence, Diagnosis and Management

Viral myocarditis has an incidence rate of 10 to 22 per 100,000 individuals. The presentation pattern of viral myocarditis can range from nonspecific symptoms of fatigue and shortness of breath to more aggressive symptoms that mimic acute coronary syndrome. After the initial acute phase presentation of viral myocarditis, the virus may be cleared, resulting in full clinical recovery; the viral infection may persist; or the viral infection may lead to a persistent autoimmune-mediated inflammatory process with continuing symptoms of heart failure. As a result of these 3 possibilities, the diagnosis, prognosis, and treatment of viral myocarditis can be extremely unpredictable and challenging for the clinician. Herein, the incidence, etiology, definition and classification, clinical manifestation, diagnosis, pathogenesis, prognosis, and treatment of viral myocarditis are reviewed, and how acute clinical care teams might differentiate between viral myocarditis and other acute cardiac conditions is discussed.

Sudden cardiac death in young athletes: preparticipation screening for underlying cardiovascular abnormalities and approaches to prevention

The study of sudden cardiac death (SCD) in athletes has received more interest in the medical and lay press over the past few years. Professional athletes represent ideals of fitness and health, and the sudden death of prominent athletes can come as a shock. Underlying occult cardiovascular disorders are the most common cause of SCD in athletes. Unfortunately, because these disorders rarely present clinically, their initial manifestation is often a fatal event. Due to this, much attention has turned to both primary and secondary prevention. Primary prevention includes preparticipation screening and secondary prevention includes having automatic external defibrillators available at sporting events. This article summarizes the most common causes of athletic-related cardiac arrest and evaluates the screening methods used to screen for these conditions. The general sentiment is that we need to more effectively identify athletes who are at risk for SCD, but how to do so using an efficient screening system and in a cost-effective manner have not been determined.

Update on myocarditis

Myocarditis is an inflammatory disease of the heart frequently resulting from viral infections and/or post-viral immune-mediated responses. It is one of the important causes of dilated cardiomyopathy worldwide. The diagnosis is presumed on clinical presentation and noninvasive diagnostic methods such as cardiovascular magnetic resonance imaging. Endomyocardial biopsy remains the gold standard for in vivo diagnosis of myocarditis. The therapeutic and prognostic benefits of endomyocardial biopsy results have recently been demonstrated in several clinical trials. Although remarkable advances in diagnosis, understanding of pathophysiological mechanisms, and treatment of acute myocarditis were gained during the last years, no standard treatment strategies could be defined as yet, apart from standard heart failure therapy and physical rest. In severe cases, mechanical support or heart transplantation may become necessary. There is some evidence that immunosuppressive and immunomodulating therapy are effective for chronic, virus-negative inflammatory cardiomyopathy. Further investigations by controlled, randomized studies are needed to definitively determine their role in the treatment of myocarditis.

Can cocaine abuse exacerbate the cardiac toxicity of human immunodeficiency virus?

Both cocaine use and human immunodeficiency virus (HIV) infection alone have been associated with an increased incidence of cardiac dysfunction. Concomitant exposure to cocaine and HIV infection may exacerbate the cardiac toxicity of either agent alone, a hypothesis that is examined in this review article. A possible unifying hypothesis based on enhancement of adrenergic stimulation is proposed.

Special feature for the Olympics: effects of exercise on the immune system: infections and exercise in high-performance athletes

The elite athlete has a potentially increased sensitivity to respiratory infections, rendering protective measures particularly important. Some other infections that may appear in clusters in the sports setting, such as gastroenteritis, leptospirosis, herpes simplex and viral hepatitis, also require special precautionary attention. Strenuous exercise during ongoing infection and fever may be hazardous and should always be avoided. In addition, early symptoms of infection warrant caution until the nature and severity of the infection become apparent. Because myocarditis may or may not be accompanied by fever, malaise or catarrhal symptoms, athletes should be informed about the symptoms suggestive of this disease. Although sudden unexpected death resulting from myocarditis is rare, exercise should be avoided whenever myocarditis is suspected. Guidelines are suggested for the management and counselling of athletes suffering from infections, including recommendations on when to resume training. Acute febrile infections are associated with decreased performance resulting from muscle wasting, circulatory deregulation and impaired motor coordination, which require variable amounts of time to become normalized once the infection is over.