1 From the Mayo Clinic and Mayo Foundation: Section of Medicine, and the Mayo Graduate School of Medicine (University of Minnesota), Rochester, Minnesota.
Ten patients with the electrocardiographic diagnosis of atrial flutter were investigated by exploration with electrodes within the esophagus and the right atrium. The records obtained were studied in regard to the timing of the intrinsic deflection and the contour of the atrial waves, as recorded at various sites. In four patients, atrial activation progressed in sequence cephalad in the left atrial wall and caudad in the right atrium. This process continued through two thirds of the total atrial cycle, favoring "circus movement" as the underlying mechanism. In six other patients, activation was believed to originate low in the left atrium, with simultaneous spread of excitation of both atrial walls in a general cephalad direction and terminating within the first half (usually the first third) of the atrial cycle. This pattern is compatible with, but not conclusive of, an ectopic focal mechanism. Serial records in one patient are presented in which transformation of one type into a second type of atrial flutter is suggested. It is likely that at least two mechanisms are present in human atrial flutter.
© 1969 American Heart Association, Inc.
Studies in Human Atrial Flutter with the Use of Proximity Electrodes
Key Words: Circus-movement hypothesis • Right intra-atrial electrocardiogram • Right intra-atrial esophageal potential-difference curve • Ectopic unifocal impulse formation • Esophageal electrocardiogram