sentences:  The history of invasive cardiology begins with the development of cardiac catheterization in 1711, when Stephen Hales placed catheters into the right and left ventricles of a living horse.Variations on the technique were performed over the subsequent century, with formal study of cardiac physiology being performed by Claude Bernard in the 1840s.The technique of angiography itself was first developed in 1927 by the Portuguese physician Egas Moniz at the University of Lisbon for cerebral angiography, the viewing of brain vasculature by X-ray radiation with the aid of a contrast medium introduced by catheter.