Paroxysmal tachycardia originating from an ectopic focus in the ventricle is a relatively rare type of cardiac arrhythmia. Robinson and Hermann,1 in 1921, found reports of only sixteen cases, not all of which they accepted as proved, and to which they added four additional cases.
This type of paroxysmal tachycardia can be differentiated from that of auricular origin only by the help of the electrocardiograph. Even then, unless the electrocardiogram contains the beginning or the ending of the paroxysm, it is not always possible to determine the exact origin of the rhythm, since it is known that in some instances of paroxysmal auricular tachycardia the ventricular complexes may be aberrant, due to imperfect conduction in the ventricular conduction paths during the rapid rate.2
When the tracing does not contain the first beat of the paroxysm, search should be made for evidence of the P wave, and if it can be