On defective closure of the tricuspid foramen as a frequent cause of dropsy / by Peyton Blakiston.

  • Blakiston, Peyton, 1801-1878.
Date:
[1841]
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Licence: Public Domain Mark

Credit: On defective closure of the tricuspid foramen as a frequent cause of dropsy / by Peyton Blakiston. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    exist between writers on diseases of the heart, as to the sufficiency of the proofs of regurgitation through the tricuspid foramen, both as drawn from observa- tion during hfe and autopsy after death. Thus pulsations of the jugular veins, synchronous or nearly so with the sys- tole of the ventricles, which have been considered by most writers as indica- tive of such regurgitation, are looked upon by Dr. Hope as produced by the force of the rightventricular systole, and altogether independent of the complete- ness or incompleteness of the tricuspid valves. It must be borne in mind, however, that considerable hypertrophy of the right ventricle is notunfrequently found in the bodies of persons who during life-time presented no appearance of jugular pulsation. And were it possi- ble that the ventricle could ever contract ■with such force as to communicate a shock to the valves and blood above them, which should run up the jugu- lar veins, it could only be in cases of extreme hypertrophy of the right ven- tricle, and therefore would be of rare occurrence, and would be accompanied by signs of such hypertrophy. When, therefore, pulsations or ob- scure fluctuations of the jugular veins are observed, unaccompanied by any very strong heaving impulse of the heart, it is, I think, highly probable th;.t regurgitation takes place through the tricuspid foramen. A perusal of the cases brought forward in this paper will be found very much to favour this view, inasmuch as in all those where venous pulsations or undulations were observed during life-time, the triciispid foramen was found incomplete, either from its dilatation or the imperfect ac- tion of its valves, or from both causes. That the force of pulsation of the jugular veins is a measure of the power of the right ventricle, and not a measure of the degree of regurgitation and ob- struction to the circulation, I readily admit; for in all cases the stronger be the force of the right ventricle which throws the blood back upon the veins, the stronger will be the pulsation pro- pagated up them. Not so as regards the obstruction to the circulation, which depends on the relative proportion be- tween the power of the two ventricles. If both be hypcrtrophied, ihe pulsation or shock will be great, and if both be attenuated the pulsationwill be'weak, while the obstruction to the circulation is the same in each case ; for the ve- nous current and that of the regurgi- tating fluid, being both mainly derived from ventricular contraction, whenTthc one is strong it is opposed by the other equally strong; and when one is weak, by the other equally weak : the ob- struction is therefore the same in each case, and it is perfectly independent of the shock. or pulsation. This js strikingly illustrated in Case XIII., where the pulsation of the jugular veins was most vehement, but the effect on the circulation slight. If the proportion between the power of the two ventricles be altered, the effect on the circulation is altered; thus, if the right ventricle be hypcrtrophied and the left attenuated, a weak venous cur- rent is opposed by a powerful current of regurgitation, and the circulation is powerfully obstructed; if, on the other hand, the left ventricle be hypertro- phied and the right attenuated, a strong venous current is opposed by a weak current of regurgitation, and a feeble resistance is offered to the circulation. While, therefore, pulsations of the jugular veins may, in certain cases, Jje considered as indicative of regurgi- tation through the tricuspid foramen, their absence affords no proof of the non-existence of such regurgitation. It has been proposed to test the com- pleteness of the tricuspid valves after death by the manner in which they retain fluid in the right ventricle, which has either been forced or injected into it through the pulmonary artery. Mr. King has seldom found the valves to retain fluid when the experiment has been made with a healthy heart; and I have several times repeated the expe- riment with no better success, unless I pinched in the base of the right ven- tricle surrounding the foramen with my hand. This therefore would be an unfair test, as it would go to prove that almost all tricuspid valves were incomplete. Bouillaud has com- pared the measure of the circumference of the foramen with the height of the valves from their apex to the middle of their base. This latter plan gives a very insufficient idea of the area the valves can cover; because unless the circumference of the foramen be re- tained in its proper position, which is