MYOCARDIAL IRRITAr.II.ITV— TIEGNAUKR and COVINO 351 



Thus far it seemed clear llial certain measures almost completely prexented ven- 

 tricular fibrillation in moderately hypothermic dogs stimulated by maneuvers which 

 in control subjects invariably were associated with fibrillation. Such measures in- 

 clude procaine blockacle of the supericjr vena caval-atrial junction, sympathetic in- 

 terruption or blockade, and vagal stimulation. 



These experiences ])roved of some value in the treatment of ventricular fibrilla- 

 tion induced by coronary air enibob'>m in iiioderateK' ]i\])otliermic dogs.'' It was our 

 experience that conversion could be successfully accomplished in all animals by 

 making the fil)rillation strong with the intracardiac injection of a weak solution of 

 epinephrine, clani])ing the ascending aorta, elinn'nating the air from the coronaries 

 l)y massage, and, if necessary, l)y incising terminal branches of arteries with en- 

 trapped air, and by the application of three successive electric shocks using 170 

 volts and a duration of one-tenth of a second. In 10 control animals fil)rillation oc- 

 curred in all (table IV). In one, fibrillation recurred once and in two others, three 

 times. In one of the latter, procaine blockade preceded the final successful con- 

 version. In six animals, injection was carried out after the onset of fibrillation and 

 in none did fibrillation recur. In four animals, procaine blockade was accomplished 

 before the expected onset of fibrillation. Fibrillation did not occur in one and it did 

 not return after conversion in the other three. When the same experiments were 

 repeated with the added procedure of right ventriculotomy and placement of 

 sutures in the septum, fibrillation developed in all (table \'). The fibrillation did 

 not recur, however, in any animal treated by procaine injection before the expected 



TABLE IV 



Experiences with Treatment of Coronary Air Embolism and Ventricular Fibrillation 

 iN THE Hypothermic Dog by Cardiac Massage, Intracardiac Epinephrine, and 



Electric Shock 



(Surgery, Nov., 1955) 



Sinoauricular node injection prior to expected onset of fibrillation 



" One had injection of the sinoauricular node after fibrillation recurred 4 times. 



