The use of echocardiography in diagnosing culture-negative endocarditis.

We reviewed M-mode and two-dimensional echocardiographic findings in 11 patients with abacteremic endocarditis to study the application of echocardiography in this setting. All patients had negative blood cultures but underwent surgery that confirmed the presence of active infective endocarditis. The infection involved native valves in five patients and prosthetic valves in six patients. Valvular masses were identified in eight patients. The other three patients, who had prosthetic aortic valves, had diastolic mitral valve vibration characteristic of aortic regurgitation. One of these also showed dehiscence of the prosthesis. Three patients had poorly defined clinical illnesses and echocardiography was a prime element in the diagnosis because valvular masses were identified. The operation was facilitated by knowledge of the mass indicated by echocardiography in these eight cases. Also, the surgical approach was affected by knowledge of dehiscence and perivalvular abscess formation in two cases each.