Echocardiographic detection and clinical significance of left atrial vegetations in active infective endocarditis

Abstract

Involvement of the mural endocardium during infective endocarditis (IE) was commonly reported in early series of patients, 1,2 but little new information has been added since antibiotic therapy dramatically reduced the mortality of this condition. Mural vegetations are thought to develop in 2 ways. The more common involves growth of a vegetation at the site of a “jet lesion,” that is, the impact site of a regurgitant stream. Much less common is isolated, primary mural endocarditis—through 1978 there had been only 22 reported cases. 3 Two-dimensional echocardiography can detect vegetations of IE in 43 to 100% of patients. 4 Some investigators have suggested that the detection of vegetations by echocardiography may identify a subgroup of patients at higher risk for embolic complications. 4–6 Others have included it as a minor criterion for surgical intervention in active IE. 7 Mural vegetations have not been well characterized echocardiographically, nor has their clinical significance been studied in detail. We report 6 patients with IE and left atrial (LA) masses demonstrated by 2-dimensional echocardiography. Doppler color flow imaging revealed a regurgitant stream striking endocardium at the base of the vegetation in all patients. Transesophageal echocardiography proved an excellent technique to study the location and size of vegetations attached to the posterior LA wall, which is difficult to visualize by standard 2-dimensional echocardiography.