Diagnosis if dissecting aortic aneurysm by left atrial angiography.

T HE diagnosis of dissecting aortic aneu- rysm is made in most instances using a transaxillary or transfemoral approach to retrograde aortography.24'5 Employing this technique, entry into the false lumen may occur, in which case injection of a large bolus of dye may be hazardous.4 Further- more, passage of the catheter into the false lumen will prevent its advancement into the left ventricle for the purpose of obtain- ing hemodynamic measurements. Two cases are reported in which retro- grade aortography was inadequate, and the study was completed by dye injection into the left atrium and left ventricle after passage of the catheter across the atrial septum. REPORT OF CASES