I came across a brilliant short publication in a 1952 issue of a Hungarian weekly medical journal which is on the Medline and is referred to in Index Medicus [1]. The publication is clearly one of if not the ancestor of the percutaneous balloon interventions of our day, including balloon valvuloplasty, angioplasty, and hemodynamic monitoring. Mezey et al.
[1] built a catheter device which had a separated smaller distal and a bigger proximal fluid inflatable rubber balloon tightly folded on its tip. Both balloons were connected to separate manometers. They inserted the deflated device through a jugular vein cut down of anesthetized dogs. The smaller distal balloon was inflated in the superior caval vein to monitor the balloon position through manometer readings. They floated the balloon into the right ventricle, where they inflated the proximal, bigger balloon and then pulled the inflated balloon back, thus performing, to my knowledge, the first (tricuspid) valvuloplasty. The success of the procedure was verified by autopsy. The authors predicted that their refined method would be suitable for dilatation of stenotic valves and vessels. However, they did not follow through with that. Interestingly, two of the authors, in their late sixties, are practicing medicine in North America: Dr. Pinter, the principal investigator, is an endocrinologist in Montreal, Canada, and Dr. Bogdan is a gynecologist in Hinsdale, Illinois.