Pseudo subaortic stenosis--a catheter-induced artifact.

Three cases are reported of valvular aortic stenosis in which artifactual subvalvular chambers were recorded on pressure tracings. The pressure tracings were obtained during withdrawal of multiholed catheters from the left ventricle to the aortic root. Several recent reports have described the coexistence of valvular and subvalvular aortic stenosis. The cases reported here re-emphasize that a multiholed catheter, which is the type commonly used for retrograde left ventricular entry in a patient with valvular aortic stenosis, is unsatisfactory for the detection of coexisting subvalvular obstruction.