Right ventricular pathology in pulmonary thromboembolism and athletes.

Although infrequently observed during routine histologic sampling of the heart at autopsy, right ventricular inflammation is commonly seen in the right ventricular outflow tract in persons dying of pulmonary thromboembolic disease. The lesions are characterised by the presence of a mixed inflammatory cell infiltrate with focal necrosis and occasionally areas of fibrosis and fat infiltration. Very infrequently, these lesions may also be seen in other parts of the right ventricle, and occasionally in the left ventricular myocardium. When taken together with the not infrequent biochemical findings of raised troponin and B-type natriuretic peptide levels in these cases, a strong case can be made that these lesions are the result of right ventricular strain with acute outflow tract dilatation, and not primarily the result of right ventricular ischaemia or right sided myocarditis, as hypothesised in the past.Extreme endurance athletes, including ultra-marathon runners and long distance cyclists have been shown to have transient rises in cardiac enzymes after exercise, thought to be the result of ventricular strain. Such athletes may also have an increased risk of cardiac arrhythmia and sudden death, and a significant proportion of these athletes have right ventricular dysfunction and clinically diagnosed arrhythmogenic right ventricular cardiomyopathy (ARVC).This paper examines whether the cardiac pathology observed in pulmonary thromboembolism, endurance athlete cardiac disease and ARVC have a common mechanism.