In 1940, after several years of debate and experimentation, two Columbia researchers inserted a urological catheter into a patient's heart to accurately determine, for the first time ever, the amount of blood the heart pumped into the lungs.
Though this was not the first time a catheter had been inserted into the heart of a living person, research Drs. Dickinson Richards and Andre Cournand conducted with the catheter stimulated widespread use of the technique, changing cardiopulmonary research and patient treatment forever. For their discoveries about heart catheterization and the circulatory system, the two were awarded the Nobel Prize in Medicine in 1956, along with Dr. Werner Forssmann of Germany who inserted the first catheter into his own heart.
Physicians now routinely use heart catheters in hundreds of diagnostic and therapeutic procedures, but in the 1930s Drs. Cournand and Richards, physician scientists at Columbia's First Medical Division of Bellevue Hospital, used catheters to try to understand the relationship among the heart, the lungs, and the circulatory system. It was known that the three systems were interconnected, but it was unclear how changes in one affected the others.
To understand the system they needed to know a fundamental quantity: how much blood the heart sent through the lungs every minute. Drs. Cournand and Richards, like other researchers, knew they could calculate this amount if they could measure the oxygen concentration in the blood when it reached the right atrium. The oxygen concentration could then be used in an equation (the Fick principle) with two other pieces of information that were easily attainable to calculate the output of the heart.
For several years, Drs. Cournand and Richards avoided using a catheter to measure the concentration directly and used indirect methods to estimate the amount from exhaled air. Ultimately, the indirect methods proved to be inadequate.
Though Dr. Forssmann had inserted a catheter into his own heart in 1929, threading catheters into human hearts was still considered too dangerous.
When Drs. Cournand and Richards decided in 1936 that they needed to use the catheter, Dr. Cournand traveled to Paris to one of the few places in the world where catheters were used in human hearts. He reviewed about 100 cases in which the catheter was placed near the right atrium to inject a contrast material to view the heart.
Persuaded the technique was safe, the two investigators spent the next four years experimenting in dogs and in one chimpanzee, threading the catheter through a vein in the arm and into the heart. In 1941, they published their first paper detailing safe catheter use in the hearts of 14 people, including five with heart disease. They took blood samples from the right atrium through the catheter, measured oxygen content, and calculated the volume of blood pumped by the heart into the lungs every minute. Not long after they also connected a manometer to the catheter and measured pressure of the blood in the right atrium, which allowed them to calculate the volume of blood in the entire system.
With a catheter, the two researchers and their colleagues discovered what the normal pressures and gas concentrations are in the entire circulatory system, how changes in one part of the system affect the others, and how disease alters the system.
Some of the first patients to benefit from the technique were wounded soldiers. Large blood loss can lead to shock, a failure of the circulatory system to deliver blood to the body. With the catheter, the two found shock became critical when patients lose more than 50 percent of their blood and the system reduces blood flow to structures other than the brain and heart. Injecting any liquid would return circulation to normal, but whole blood was preferable so patients wouldn't become anemic.
After World War II, Drs. Cournand and Richards developed other techniques to diagnose congenital heart defects that allowed surgeons to correct them and provided direct descriptions of heart diseases that until then were characterized only with stethoscopes and electrocardiograms.
Once Drs. Cournand and Richards (who died in 1988 and 1973, respectively) showed heart catheterization was safe, other researchers adapted the technique for additional research and diagnostic purposes.
By the 1980s, many clinicians began to treat heart disease via catheters with the development of balloon angioplasty to open up clogged arteries. Some of these advances in diagnostic and interventional techniques were pioneered by other P&S faculty.
"By introducing cardiac catheterization, Drs. Richards and Cournand elucidated the physiology of the systemic and pulmonary circulation in health and disease," says Dr. Allan Schwartz, Hatch Professor of Clinical Medicine and chief of the Division of Cardiology in the Department of Medicine. "And they placed Columbia on the road to a distinguished history of leadership in the discipline of cardiovascular disease."