RT Journal A1 LUNDY CJ, WOODRUFF LW T1 EXperimental heart block JF Archives of Internal Medicine JO Archives of Internal Medicine YR 1929 FD February 1 VO 43 IS 2 SP 184 OP 186 DO 10.1001/archinte.1929.00130250040003 UL http://dx.doi.org/10.1001/archinte.1929.00130250040003 AB In the course of our experimental work on the heart, a new method was devised for increasing the intra-auricular and intraventricular pressures of the intact dog. This was done by tying a balloon on the tip of a properly bent glass rod (2 mm. in diameter) and inserting the rod into the right auricle or ventricle by way of the right jugular and innominate veins. This apparatus was connected with a mercury manometer and a pressure bottle which permitted raising the intra-auricular pressure to any desired amount. It was found unnecessary to use heparin to prevent coagulation, as clotting of blood was observed only once in twenty-five experiments. After a few trials, we were able to put the balloon into the right auricle, the right ventricle and the inferior or superior vena cavae at will. Control electrocardiograms were taken before and after tracheotomy, after tying the right jugular vein, after