Recurrent parietal thromboendocarditis.

A rare condition, which generally occurs in young adults and may, simulate coronary disease, is discussed. The patients are afebrile, with low blood pressures, fast weak pulses and marked irregularities in cardiac rhythm. They are unresponsive to therapy and may survive initial attacks only to succumb to a recurrence. In the portions of the endocardium uninvolved by mural thrombi, there is marked collagenized subendocardial thickening devoid of elastic tissue. The etiology is unknown.