Presumptive Q fever myocarditis associated with Coxiella burnetii infection of a homograft valve in the outflow tract of the right ventricle: review and case report.

A man with pulmonary atresia and a subaortic ventricular septal defect had a radical surgical repair at the age of 16 years with correction of pulmonary atresia by replacement with an aortic valve homograft. This later became infected with Coxiella burnetii. He died at the age of 27 years from renal failure caused by glomerulonephritis and was found to have a most unusual form of widespread focal myocardial degeneration with dystrophic calcification. The diagnosis of Q fever was confirmed by positive serology during life and identification of the organisms in the homograft valve after death, by histology and electron microscopy. A fatal outcome from involvement of the myocardium in Q fever is very rare, and histological evidence of such involvement, other than by embolic infarction, is almost unknown. This would also appear to be the first recorded instance of coxiella colonization of a valve in the pulmonary outflow tract.