Left Heart Catheterization

The modern era in the study of circulatory dynamics in man began in 1941, when Cournand and Ranges demonstrated the practicability and safety of catheterization of the right side of the heart.1The ability to record pressure pulses in the chambers of the right heart and pulmonary artery and the opportunity to sample blood from these areas furnished the basis for precise and detailed study of the lesser circulation in the normal and various pathologic states. It soon became clear, however, that the principal hemodynamic abnormalities associated with many diseases were manifest in the left heart and only indirect information as to their nature and severity could be obtained at right heart catheterization. The usefulness of right heart catheterization was extended by the demonstration that the pressure transmitted to the tip of a catheter wedged in a peripheral pulmonary artery often closely approximated that in the left atrium.2