A system of practical medicine. By American authors. Vol. 3

by Unknown

When one cannot reach the sides of the tumors in front, one can resort to Stokes's plan. Place the flat of one hand upon the front of the chest, and the other hand upon the back. By this means the expansile character of the pulsation may sometimes be determined.

Many intra-thoracic aneurisms present a double impulse or two distinct blows to the hand during the cardiac systole; and when these blows are too faint to be felt, they may still be registered by the sphygmograph. This double impulse is not characteristic of aneurism of the aorta, because it may also be felt in aneurisms of the large branches of the arch. Bellingham thought that the second blow was due to a reflex wave from the aortic valves, and was therefore diastolic in rhythm. Jaccoud, however, showed that it occurs even with great insufficiency of the aortic valves, thus excluding reflex waves. François Frank also proved that both blows were systolic in rhythm. He thinks they are due to the fact that the blood enters the aneurism en deux temps. The blood, rushing in at the beginning of the systole, gives a sudden distension of the partially relaxed sac-walls, and thus causes the first impulse. Then the bulk of the blood-waves, following more slowly on account of greater resistance, produces a second elevation more or less pronounced.

Balfour states that aneurismal pulsations are usually more forcible than those of the heart, and that this point has not received the attention which it merits. If the sac contains much fibrin the impulse is feebler than that of the heart.

W. S. Oliver describes a new sign of aneurism and the method for detecting it. Place the patient in the erect position and direct him to close his mouth and elevate his chin to the fullest extent. Grasp the cricoid cartilage between the fingers and the thumb, and push it gently upward. If an aneurism of the arch of the aorta be present, its pulsation will be plainly transmitted up the trachea to the hand. The act of examining will also increase the laryngeal distress if such be present.

The frémissement cataire, or thrill imparted to the hand by an aneurism, has been frequently described. It is very characteristic when felt, but Powers says it is not of frequent occurrence. He has felt it in eight cases of aneurism, but four of them were complicated by regurgitant disease of rheumatic origin, and all were probably of the fusiform kind.

Pulse.—Partial or total obliteration of a large vessel, dilatation of the aorta, compression of an artery by a tumor, may produce a radial pulse similar to that of aneurism. Moreover, we may find the radials differing from each other in persons who are perfectly healthy. It follows, therefore, that, taken by itself, the pulse does not contribute very decisive evidence of an aneurism. When the diagnosis of an aneurism is established or confirmed by other signs, then the added evidence of the pulse does possess some value. The finger will often detect the following characteristics of an aneurismal pulse:

1. Delay.—The pulse at the wrist is normally from ¹¹/100 to ¹⁴/100 of a second later than the cardiac impulse. With aneurism this interval may be prolonged in one or both radials, and the additional delay may amount to ⁴/100 of a second. This sign of delay is of most value when the pulse in one wrist loiters behind its mate. The relative delay of the impulse of the aneurism itself and of the carotid artery may give useful information. If the beat of the tumor precedes that of the left carotid, then the tumor is nearer the heart, whereas the aneurism is evidently beyond the left carotid when the beat of the latter precedes.

2. Diminution in Volume.—The pulse in one radial may be much smaller than in the other or altogether absent.

3. Diminution in Force.—The pulse of one side may convey a less sudden and less forcible blow to the finger. This diminished suddenness of the sensation imparted to the finger corresponds to the sloping up-stroke of the sphygmographic tracing.

4. Thrill.—Under certain rare and not very clearly defined circumstances the pulse imparts a sensation of thrill to the finger. Mahomed says this probably occurs when the entrance to the aneurismal sac is very narrow and the aneurism is directly in the course of the vessel. It may also be occasionally produced by the rigidity of the wall of the vessel or by a partially-dilated clot vibrating in the blood-stream.