Pseudoaneurysm of the aorta is a rare complication of cardiac or aortic surgery.' It may present as chest pain,2 as a mediastinal mass, or as an abnormal pulsation of the right sternal border or suprasternal notch.' Although aortography has been the method of choice for diagnosis, in some cases noninvasive methods may allow a definitive diagnosis. We present two cases of pseudoaneurysm of the aorta diagnosed by noninvasive techniques.
CASE REPORTS Patient 1
A 66-ywald white female underwent aortic valve replacement for symptomatic aortic stenosis in March 1982. A prosthetic valve was inserted, followed by an uncomplicated postoperative course. She remained asymptomatic but in February 1985 was found on routine chest x-ray to have a large mediastinal mass (Fig. 1). Physical examination revealed normal vital signs as well as peripheral and central pulses. Her chest was clear to auscultation. Palpation of the precordium revealed no abnormal pulsations or thrills. First and second heart sounds were normal. A crisp metallic aortic valve-closing sound was present. A fourth sound was heard at the apex. A grade IWI systolic ejection murmur was heard at the base.
Echocardiography of the heart showed mild concentric left ventricular hypertrophy. Pulsed