Left atrial calcification.

Abstract

Calcification in the wall of the left atrium, appearing in association with rheumatic heart disease, was first described as a pathologic entity by Oppenheimer (1) in 1912. It was not referred to as a radiologic finding, however, until 1938, when Shanks and his co-workers (2) considered it in the differential diagnosis of intracardiac calcification. Since that time, reports of isolated cases or small series have appeared sporadically in the radiologic literature (3–14). The total number of recorded cases in which the antemortem diagnosis of calcification of the left atrial wall was established by radiologic methods is now 42. The purpose of this paper is to report 5 additional examples seen at the Mayo Clinic since 1953. Since all the cases described, including those comprising the present study, have been associated with rheumatic heart disease of long standing, it may be assumed that left atrial calcification is pathognomonic of that condition. Although minute amounts of calcium may be present in the atrial walls in hyperparathyroidism and in certain other diseases characterized by abnormal deposition of calcium, roentgen evidence of atrial calcification has never, to our knowledge, been noted in these conditions. The calcification may occur in the endocardium or subendocardial region, as originally described by Oppenheimer and later by other authors (6–12); or it may be within a mural thrombus (7–9). Probably the endocardial and subendocardial calcification is the end-result of severe and perhaps repeated episodes of rheumatic endocarditis (9–11), in which circumstances the calcification has occurred in necrotic or devitalized tissue. Calcification occurs in the endocardium and subendocardial region much more frequently than in thrombi. Curry and associates (7) noted that the body of the left atrium and the left auricular appendage are involved in the process with about equal frequency. Among our 5 patients, the calcification was in the endocardium in the body of the left atrium in 4 and in a thrombus in the left auricular appendage in 1. It has been observed (8) that mitral insufficiency, with or without associated mitral stenosis, has been present in the majority of the reported cases of left atrial calcification, and from this it has been concluded that left atrial calcification in patients with rheumatic heart disease may be an indication of inoperability. Among the 5 cases with left atrial calcification which we have observed, however, mitral insufficiency was present in only 1; in the other 4 patients, all of whom underwent operation, the mitral problem was pure stenosis. The roentgenologic manifestation of left atrial calcification is a curvilinear density up to 2 mm. in thickness in the region of the wall of the left atrium. This shell-like calcification may involve a large portion of the wall, in some instances presenting a complete ring-shaped shadow, or it may be small and sickle-shaped (9).