This experimental study demonstrates that atrial flutter can arise from either a rapidly firing ectopic focus or a circus movement depending on the induction method, and these mechanisms can only be differentiated using direct cardiac leads.
The mechanism of atrial flutter induced by the local application of aconitine or by the Rosenblueth-Garcia Ramos method was studied in dogs. The results were analyzed from a pharmacologic and electrocardiographic point of view. It was concluded that aconitine-induced flutter is due to a single, rapidly firing ectopic focus and electrically-induced flutter to a circus movement. Although they can be differentiated electrocardiographically by means of direct cardiac leads, they cannot be differentiated by esophageal or limb leads.
Lanari et al. (1956) studied this question.