Auricular fibrillation and its relationship to clinical irregularity of the heart / by Thomas Lewis.

  • Lewis, Thomas, Sir, 1881-1945.
Date:
[1910?]
Catalogue details

Licence: In copyright

Credit: Auricular fibrillation and its relationship to clinical irregularity of the heart / by Thomas Lewis. Source: Wellcome Collection.

    9/80 (page 311)
    the arterial pulse alone, laid more stress upon its characteristics and s})oke of it under the title pulsus irregularis perpetuus*. He appears to claim’' to have implied, by the use of this term, a specific type of rhythm, but the facts brought forward in his paper failed to carry conviction of an irregularity sui generis. The recognition of its specificity has been arrived at gradually and the facts supporting the conclusion have been contributed largely by Mackenzie. In particular, the emphasis which he laid upon its frequent association with the ventricular form of venous ])ulse in 1904’’’’, and the ])romi- nence given to this observation in a later paper, based upon an examination of 500 cases”', must be noticed. Hut in reality it is only since the galvanometric examination of the heart has been available that the probability of its specific nature has grown to certainty. In his papers of 1904-5, Mackenzie”’’'*'”® brought forward several new and important facts, and most striking amongst them, in the light of our present knowledge, were evidences that the auricle is active. Formerly regarding the auricle as paralysed, because no sign of activity could be found, he attempted at this time to separate a special group of cases in which auricular activity was considered probable. Auricular activity was assumed, (1) because the auricle was found hypertro])hied at autopsy ; and (2) because certain instances were observed in which the normal rhythm reasserted itself. It is to these papers more especially that we are indebted for the observation that in all cases of complete irregularity of the heart there is an entire failure of signs of the normal auricular contraction during diastole ; and further, for the first record of cases of this nature, in which it is probable that little dilatation of the right heart and little triscuspid regurgitation is present. His earlier view that the condition results from auricular distension as a consequence of valve incomjietence was at least ])artially abandoned, and the rhythm was ascribed as the cause rather than the result of the eventual dilatation. In 1904 Mackenzie jmstulated the view which he has since held, that in many cases the seat of the rhythm is in the junctional fibres lying between auricle and ventricle, and by conceiving the simultaneous contraction of auricle and ventricle in response to impulses from this single source attempted to explain the absence of every sign of normal auricular contraction which he had demonstrated to be one of the chief features of such cases. In 1906 Hering’® realised the correctness of Mackenzie’s assertion that the completely irregular pulse when once established is not of necessity perpetual. In 1907 Theopold®^ described cases confirming the view that the rhythm is not a secondary j)henomenon to tricuspid leakage. In 1907-8 Mackenzie”^*”” adopted the hypothesis of the nodal origin of the rhythm more generally, holding the node of Tawara'j* to be the seat of * The qualification “ perpetual ” has since been discarded. t A specially differentiated structure at the auricular side of the junctional tissues betueen auricle and ventricle.