• A complete, temporary arrest of cardiac motion was induced and an almost bloodless operative field was obtained by the use of potassium citrate in 37 patients undergoing open-heart surgery. The largest group consisted of 18 children with congenital interventricular septal defect. The heart-lung machine, consisting of a pump and an oxygenator, was connected so as to remove blood from the venae cavae, oxygenate it, and return it to the aorta. The aorta was occuluded 2 or 3 cm. above the heart, and a mixture of 2 ml. of 25% potassium citrate solution with 18 ml. of blood was injected into the aorta proximal to the point of occlusion. The potassium citrate solution was injected until the heart stopped. If 20 ml. was not enough, more was injected. It was found that under these conditions the human heart could resume its normal action after periods of arrest as long as 40 minutes. The flaccidity of the heart facilitated extensive repairs, but distortions and tensions that were produced when large defects were closed sometimes resulted in tears elsewhere after the spontaneous beat was restored. The potassium citrate itself did not seem to introduce any new dangers. Of the 13 patients who died, three had transposition of the great vessels and one had a single ventricle. Twenty-four patients recovered. All of the nine patients who had the tetralogy of Fallot were in the group who recovered.
Kolff WJ, Effler DB, Groves LK, Moraca PP. ELECTIVE CARDIAC ARREST WITH POTASSIUM CITRATE DURING OPEN-HEART OPERATIONSREPORT OF THIRTY-SEVEN CASES. JAMA. 1957;164(15):1653–1660. doi:10.1001/jama.1957.02980150021007