Fibroplastic parietal endocarditis with eosinophilia.

A 44-year-old woman with marked eosinophilia, leukocytosis, congestive heart failure, and the murmur of mitral stenosis had a restrictive type of pulse contour at cardiac catheterization. A right atrial angiogram revealed a huge right atrium, a small right ventricle, and a dilated contractile outflow tract consistent with the diagnosis of Loeffler's endocarditis. A marked conduction delay at the atrial level was demonstrated by His bundle electrogram studies.