'''1953''' Osborn, while experimenting with hypothermic dogs, describes the prominent J (junctional) wave, often known as the "Osborn wave". He found the dogs were more likely to survive if they had an infusion of bicarbonate and supposed the J wave was due to an injury current caused by acidosis. Osborn JJ. Experimental hypothermia: respiratory and blood pH changes in relation to cardiac function. Am J Physiol 1953;175:389.
[[File:Osborn-wave.gif|thumb|150px|right|Osborn wave. 81-year-old black male with BP 80/62 and temperature 89.5 degrees F (
'''1955''' Richard Langendorf publishes the "rule of bigeminy" whereby ventricular bigeminy tends to perpetuate itself. Langendorf R, Pick A, Winternitz M. Mechanisms of intermittent ventricular bigeminy. I. Appearence of ectopic beats dependent upon the length of the ventricular cycle, the "rule of bigeminy." circulation 1955;11:442.