The relation of regular tachycardias of auricular origin to auricular fibrillation / by Thomas Lewis and H.G. Schleiter.

  • Thomas Lewis
Date:
[1912?]
Catalogue details

Licence: Public Domain Mark

Credit: The relation of regular tachycardias of auricular origin to auricular fibrillation / by Thomas Lewis and H.G. Schleiter. Source: Wellcome Collection.

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    paroxysm of 4 beats only. Fig. 5 is an example of a paroxysm of longer duration. Most of the paroxysms have been similar to that portrayed in this curve. The onset and offset are quite abrupt. The offset is marked by a considerable degree of pulse slowing which vanishes within a few cycles ; this phenomenon has been observed in many previous cases. A single prema- ture contraction interrupts the normal rhythm shortly after it is resumed (in Fig. 5). The premature contractions which interrupt the slow rhythm are of four kinds. Very occasionally the points of origin lie in the ventricle. The electrocardiograms have shown that some of these premature ventricular beats arise in the left or apical portions of the ventricle, some in the right or basal portions of the ventricle ; we do not consider it necessary to reproduce the figures. The majority of the premature beats have arisen in the auricle ; and they originate in two auricular foci, both of which lie at a distance from the pacemaker. The two types are illustrated by Fig. 12 and 15. In Fig. 12 the normal rhythm, to which the first three and the last cycle belong, is interrupted by a single premature contraction, arising in the auricle and represented by P, Rk and 7’ summits. The & and 7' summits of the prema- ture beats are similar to those of the rhythmic beats. The P summit of the premature beat is partly iso-electric, but is mainly a deviation in the upward direction ; it differs from the P summits of the rhythmic beats. The second type of premature auricular contraction is shown in Fig. 15. As in the first type, the ventricular complex is similar to that of the rhythmic beats. On the other hand, the auricular representative is of different form. It consists of a deviation in the downward direction. The short and regular paroxysms, a very large number of which have been observed, have been of one type. They are illustrated by Fig. 13, 14 and 16. They consist of a succession of beats arising in the auricle at the same point from which the second type of single premature beat is shown to arise (Fig. 15). The centre of such a paroxysm is published in Fig. 13, in which the rate is approximately 140 per minute. The cycles consist of a downwardly directed auricular representative P, and the usual summits R and 7, corresponding to the ventricle and of similar form to those of the rhythmic beats. The termination of a similar paroxysm is shown in Fig. 14. Ina very large number of the observed paroxysms, single beats springing from the auricle, but arising in a focus which is distinct from that at which the usual paroxysmal beat originates and from that at which the rhythmic beat of the slow periods arises, interrupt the paroxysm itself. Two examples of this phenomenon are shown, namely, the last cycle but one in Fig. 13 and the last cycle of the paroxysm in Fig. 14. The majority of these interrupting beats are slightly premature in relationship to the rhythm of the paroxysm. This is shown in Fig. 14, but in Fig. 13, the interrupting beat falls at its proper time. A comparison of the interrupting beats with the premature beat of Fig. 12 shows that they arise from the same focus. It has been remarked that they frequently terminate a paroxysm.
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