The Road to Cardiac Catheterization

Werner Forssmann and the experiments on himself

Radiograph of cardiac catheterization by Werner Forssmann, 1929

There are many types of inventors, but medical device inventors are unique because their ideas need to work in the human body. This often requires the inventor to try the device on their own body, a leap of faith requiring a certain personality type.

In my world the best-known example of self-experimentation is the development of cardiac catheterization by the German, Werner Forssmann. At the time, surgery on the heart or even touching the heart was considered a fatal move. The great surgeon Theodor Billroth said in 1880, “A surgeon who tries to suture a heart wound deserves to lose the esteem of his colleagues.”

Surgery on the heart was approached as fatalistic. The influential English physician Sir Stephen Paget said in 1896, “Surgery of the heart has probably reached the limits set by nature to all surgery. No new method and no new discovery can overcome the natural difficulties that attend a wound of the heart.”

It was into this world of firm belief that the heart should not be touched that Forssmann strode. He had read of the work of French physiologists who performed experiments on the veins and right side of the heart of horses measuring right-sided heart pressure and examining right-sided venous waveforms. He believed that this could be done in humans. He became obsessed with the idea of putting a catheter into the heart.
He did not come from a medical family, and he was not of financial means. For that reason, he needed to find paying jobs in a system where most professors were wealthy, and most students were poor and were unpaid.

In 1929 he developed a friendship with an operating room nurse called Gerda Ditzen. He explained that he wanted to go from his right elbow through the veins to his heart with the catheter and then take an x-ray. She volunteered to have this done. Together they accumulated the equipment to do this and at night they went to the basement of the radiology department where he tied her to a table. It seems she assumed that he would do the procedure on her.

However, he anaesthetized the veins over his own left elbow and cut down reaching a large vein. He passed a needle into this vein and then through that he passed a urinary catheter tube. He advanced this gently into the right side of his own heart. When he thought he had the catheter in position he understood he would need documentation. He told Gerda what he had done, and she was furious with him.

They walked to the x-ray department and had an x-ray taken of his arm and chest showing the catheter in the right side of his heart. Gerda, the x-ray technician, took the x-ray but then ran to report this alarming behavior. His boss, Schneider, urged Forssmann to write a scientific paper describing his achievement and technique. This was published in October 1929. There was an outcry and Forssmann found it extremely difficult to find a job. No one wanted to work with him. He continued to perform experiments on himself including nine further attempts to catheterize the right side of the heart.

Because he had tied off all his arm veins, he started to go through his groin blood vessels, both the femoral artery and the femoral vein. One of his colleagues attempted to pass a needle through a space between his ribs into his aorta. Fortunately, they failed. His wife implored him to stop as they now had three children, and he agreed. Since he had been blackballed and was unemployable in German academic medicine, he became a urologist in a small town in Germany.

Decades later his papers were read by two American physicians, Andre Cournand and Dickenson Richards, at Columbia University. They realized his techniques could be used in understanding heart failure. They perfected the technique in the 1930s and 40s initially in animals and then in patients with heart failure and high blood pressure. Neither physician experimented on themselves.

In 1956 Frossman, who was by now living in complete obscurity in a small farming town in Germany, received notification that he, Cournand, and Richards were to receive the Nobel Prize for medicine. The Chair of the Nobel committee paid tribute to Forssmann’s courage in doing “by no means harmless” experiments on himself. He said “it must’ve required firm conviction of the value of the method to induce self-experimentation of the kind carried out by Forssmann. His disappointment must have been all the more bitter. Forssmann was not given the necessary support. In fact, on the contrary, he was subjected to criticism of such exaggerated severity that it robbed him of any inclination to continue. This criticism was based on an unsubstantiated belief in the dangers of the intervention thus affording proof that even in our enlightened times a valuable suggestion may remain unexploited on the grounds of preconceived opinions.”