Atrial dissociation and uniatrial fibrillation.

Numerous authors have claimed to demonstrate independent rhythms in the 2 atria. Hering' in 1900 first recorded dissociation of the atria in the experimental animal, whereas Wenckebach' in 1906 was first to report it in man. Neither of these authors illustrated his claim with published electrocardiograms. A number of these publications invite special comment. Schrumpf3 published the first illustrative electrocardiogram; his tracing appears reasonably convincing, but Lewis,4 quite properly setting the sceptical pace for all subsequent critics, refused to accept it and pointed out that "it is necessary to be hypercritical in dealing with exceptional curves of this kind, owing to the important conclusions which they would otherwise justify." The 3 tracings published by Bay and Adams5 are further good examples of the double P-wave type. As an argument in favor of the reality of atrial dissociation in their cases, they pointed out that the secondary atrial waves in 2 of their records showed a phasic arrhythmia affecting the normal P waves. Condorelli's tracing of simultaneous fibrillation and sinus rhythm6 affords excellent experimental basis for clinical claims of uniatria]