Ross J Jr, Braunwald E, Morrow AG. Clinical and hemodynamic observations in pure mitral
insufficiency. Clinic of Surgery 1958;11-23 Ross J Jr, Braunwald E, Morrow AG. Transseptal left atrial puncture: new technique for the
measurement of left atrial pressure in man. Am J Cardiol 1959;3:653-5
As early as 1952, left atrial pressure was measured intraoperatively. In 1955, Braunwald and his colleagues reported on the simultaneous measurement of the left atrial, left ventricle, and aortic pressures by needle punctures in patients with mitral stenosis. They reported their hemodynamic measurements in 14 patients and in 7 patients they were performed before and after mitral valvulotomy.
In patients without mitral stenosis, the left ventricular mean diastolic pressure ranged between 3 and 10 mmHg. The mean left atrioventricular filling pressure gradient measured between 0 and 1 mmHg.
They also demonstrated the elevation of left atrioventricular filling pressure in patients with mitral stenosis.
Finally, they showed that after mitral valvulotomy, the left atrioventricular filling pressure was significantly reduced. These measurements were extremely important as they enabled surgeons to assess the quality of their procedure. In the summary of this classic article, they commented:
"The elevated left atrioventricular filling pressure gradient is the fundamental hemodynamic expression of mitral stenosis, and its abolition constitutes the chief object of mitral surgery. In the eight patients with mitral stenosis this gradient ranged from 4 to 20 mmHg and following vavulotomy fell significantly in every instance, being almost entirely abolished in three patients."
In 1958, Ross, Braunwald and Morrow reported the results of their hemodynamic studies in patients with pure mitral insufficiency. This was one of the first studies in which both left atrial and ventricular pressure measurements were performed. The authors were able to demonstrate that end diastolic pressure was elevated in both the left atrium and ventricle with no diastolic gradient.
Furthermore, histological studies of the lungs were performed in 4 patients. In patients with pure mitral insufficiency and pulmonary hypertension, "extensive proliferative changes in the pulmonary vasculature" were noted.
In 1959, the same team at the National Heart Institute at Bethesda used for the first time the transseptal approach for left heart catheterization.
Using this technique a long catheter was passed from the saphenous vein to the right atrium and its tip was positioned against the fossa ovalis. Then a long flexible needle was advanced through the catheter and its sharp tip was used to puncture the interatrial septum.
Left atrial and ventricular pressures were measured in 13 patients with mitral valve stenosis or regurgitation.
Wynn A, Matthews MB, McMillan IKR, Daley R. The left auricular pressure pulse in normals and in mitral valve disease. Lancet 1952;2:216
Connolly DC, Tompkins RG, Lev R, Kirklin JW, Wood EH. Pulmonary artery wedge pressures in mitral valve disease; relationship to left atrial pressures. Proc Staff Meet Mayo Clinic 1953;28:72