Further evidence that the pulmonary capillary venous pressure pulse in man reflects cyclic pressure changes in the left atrium.

In four cases of atrial septal defect and in one case of mitral stenosis, the pressure pulse was recorded in the left atrium, in the first four cases through catheters, and in the fifth through a needle introduced through the chest wall. The pressure pulse was compared with pulmonary capillary pressure recorded simultaneously or nearly so. Good agreement was found both in shape and height of the two pressure pulses. •