The Unity of Paroxysmal Tachycardia and Auricular Flutter

It is difficult in the common electrocardiogram of paroxysmal tachycardia to identify the auricular wave and to place it in relation to the ventricular complex. Accordingly the cardio- graphic classification for paroxysmal tachycardia based on the position of the P wave (deformed and preceding the R wave in the auricular type, succeeding or coinciding with the R in the auriculo-ventricular or nodal variety, and normal in the ventricular type) has not always been easy to follow in practice. Again, the record has often resembled that customarily called auricular flutter. As a rule the rhythm is readily distinguished from sinus tachycardia. Fortunately the treatment of paroxysmal tachycardia has not suffered from failure to under- stand its exact mechanism, since attention has usually been directed to the underlying heart condition, and digitalis and quinidine have been given a trial for the correction of the arrhythmia. Nonetheless, the actual mechanism of the attack has engaged the diligent search of many investigators, and a contribution to this subject is worth while.