The estimation of aortic insufficiency

Thirty patients were investigated to determine the degree of aortic insufficiency present in them, using the test of Braunwald and Morrow in which indicator dye is injected at descending levels in the aorta and regurgitant dye is recorded by oximetry at the right ear. In the presence of aortic insufficiency regurgitant dye was demonstrated from as low as the second lumbar level, while in normal subjects none was demonstrated on injection distal to the fifth thoracic level. In the older patients the level was more proximal than in the younger for similar regurgitant flows. In most patients the test correlated well with the clinical impression of the severity of the lesion. However, tachycardia, bradycardia a reduced forward flow secondary to failure, aortic stenosis, or mitral stenosis or insufficiency will modify the level from which regurgitation occurs. Estimation of forward flow would permit estimation of the percentage regurgitation and allow a more accurate assessment of aortic insufficiency. Preoperative and postoperative estimation permitted objective assessment of successful corrective surgery.