André Cournand

Cournand refined cardiac catheterization—originally attempted by Werner Forssmann in 1929—into a safe, reliable clinical procedure for measuring pressures and oxygen content inside the heart's chambers. Working at Bellevue Hospital and Columbia University, he and Dickinson Richards systematically used the technique to diagnose congenital heart defects and study pulmonary circulation. Their work made catheterization a standard diagnostic tool in cardiology.

Cournand shared the 1956 Nobel Prize in Physiology or Medicine with Dickinson W. Richards, his Columbia University colleague, and Werner Forssmann, the German physician who first performed cardiac catheterization on himself in 1929. Forssmann's self-experimentation had been largely ignored for over two decades before Cournand and Richards validated and expanded on his technique.

In 1929, Forssmann inserted a catheter into a vein in his own arm and guided it into his right atrium, capturing the procedure on X-ray. Cournand and Richards encountered Forssmann's published report years later and realized the technique could be used to safely access the heart for diagnostic purposes. They developed specialized catheters and protocols that reduced the risks that had made Forssmann's colleagues dismiss the procedure as dangerous.

Cournand conducted his catheterization research at Columbia University's First Medical Division at Bellevue Hospital in New York City, where he worked with Dickinson Richards throughout the 1940s. He had emigrated from France to the United States in 1930 for what was intended to be a one-year fellowship, but remained at Columbia for his entire career. Bellevue's large patient population provided ample clinical material for their cardiac studies.