Andre F. Cournand, 92, who shared the 1956 Nobel Prize for medicine for perfecting a method of exploring the heart through catheterization. Cournand followed up on the work of Werner Forssmann, a German scientist who passed a catheter through a vein in his arm and on into his heart. Cournand taught for many years at Columbia University, where he worked with Dickinson W. Richards to penetrate the heart and to push into the lungs to record blood pressure and other cardiovascular and pulmonary ailments. Cournand, Richards and Forssmann shared the then $38,633 Nobel award. In Great Barrington, Mass., on Friday.