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

by Unknown

¹¹ Clinique Médicale.

Since pericarditis is frequently attendant upon certain classes of diseases, as acute articular rheumatism, Bright's disease of the kidneys, the eruptive fevers, it behooves the physician to be on the alert and examine the heart, even though nothing point to its involvement. Reminded of this fact, we must seek for those signs which will enable us to diagnosticate early the cardiac disease. And in any case the first sign of importance detected will be, in all probability, the friction sound, generally, but not invariably, first heard at the base, and prone to mask the natural sounds of the heart. At all events, this is the case when the friction sound is localized at the apex of the heart, as it occasionally is, before there is very marked development of the lymph-deposit; it is then, too, that from its softness the friction may be mistaken for a regurgitant mitral murmur. The friction may at times be felt by applying the hand to the region of the heart. This friction fremitus is, however, far from constant, and can hardly be considered of much diagnostic value, notwithstanding the high authority of Stokes, who looked upon it as distinguishing pericarditis from valvular disease. Prior to the existence of the friction sound we may suspect pericarditis by the sense of general distress and the dropping of pulse-beats or the otherwise altered cardiac rhythm. But the diagnosis is presumptive; the friction phenomena make it positive. Until the quantity of fluid is sufficient to separate the two walls of the sac the rubbing sound will be apparent. The friction sound never disappears suddenly, and this gradual disappearance points to the formation of fluid and may be regarded as a truly diagnostic sign. The fluid, following the laws of gravitation, seeks the most dependent portion of the sac, which it more or less fully distends; in consequence, the disappearance of the friction begins at the bottom of the sac and at the apex of the heart and gradually extends upward to the base. Adhesions of the pericardium will modify and may entirely prevent the formation of the friction sounds. If the adhesions be local, and if no lymph-deposit be present between them, there can be no friction; so also where the adhesion is general the friction sound is destroyed. Where local adhesions and portions of free surface more or less covered by the lymph exist, the heart, being allowed sufficient motion, produces friction sounds which may be found anywhere over its surface except at the points of adhesion. From the character of these sounds the location and the extent of the adhesions and of the cardiac movements may be determined, for "the rhythm of the pericardial friction sound is as the natural movement of the portion of the heart engaged and the mobility of the opposed surfaces," says Hayden¹² very truly.

¹² Diseases of the Heart and Aorta.

In weighing the value of friction sounds in diagnosis, especially in determining whether they are produced in the pericardium and not in the adjacent pleura, we have the simple, though not infallible, method of discrimination of letting the patient cease breathing for a moment and then ausculting the heart: they persist if pericardial. This test will fail, however, in case a portion of the pleura adjacent to the pericardium also be covered with lymph: then the heart's motion, transmitted through the pericardium, may produce pleuritic friction even while the lung is at rest. In such a case if a friction fremitus be felt it will pass beyond the cardiac area, while in pericarditis without associated pleurisy it will not be likely to extend farther than the normal limit of cardiac dulness. The pericardial friction sound may be sometimes noticed more or less extensively over the whole chest in children, and also in adults with hypertrophy of the heart, but this is far from being usual. There may be a friction sound produced by the action of the normal heart in an inflamed roughened pleura. This is very difficult to distinguish except by the attending symptoms. The sound is perceived near the apex of the heart. It is not apt to occur with each beat of the heart, and may be absent in held expiration.

In the diagnosis of pericardial effusion, when at all extensive, we have, in judging of the amount of fluid in the pericardium, to take into account the increasing dyspnoea with a decided suffocative tendency, the dizziness, the pallor or lividity of the countenance, the swollen cervical veins, the bluish nails, the heart flutterings, the weak, rapid, and irregular pulse, the drowsiness or tendency to mental wandering. But the physical signs of the effusion above detailed are of the greatest value, although they give us but little information as to the character of the fluid. Even in large effusions the friction sound may not disappear from the base. Indeed, Balfour¹³ records as the result of his observation that "however large may be the effusion, basic friction, if it have once existed, is never effaced." It is stated that when the amount of fluid does not entirely fill the pericardium there may be a splashing sound, and the location of the sound, as well as that of the percussion dulness, will be changed by changing the position of the patient's body. I have never observed this splashing sound. The extent of percussion dulness is no absolute sign of the extent of effusion. The area of cardiac dulness may be materially influenced by the following circumstances: the anterior margins of the lungs which overlap the front of the heart may, from emphysema, give rise to percussion resonance over the heart, even though considerable effusion have taken place; the anterior margin of the lungs, becoming solidified and having strong pleuritic attachments to the pericardium and anterior chest-wall, may increase the dulness over the heart and prevent the recognition of the effusion in the pericardium; effusion in the pleural cavity of one or both sides may produce similar results. Balfour¹⁴ in fact mentions a case of his own in which the pericardial dulness was merged in the pleuritic dulness, and careful auscultation failed at any time to detect friction sound; the coexistence of pericarditis was surmised, but could not be detected. After death the pericardium was found to be distended with reddish serum, and both its surfaces were coated with shaggy, blood-stained lymph. Such cases are unusual, yet I have met with a similar instance. Lastly, a growth in the anterior mediastinum may be the means of masking or being mistaken for pericardial effusion by changing the dulness in the cardiac region and altering the cardiac sounds, or it may, by obstructing the circulation, cause effusion. When an effusion of fluid takes place into a partially adherent pericardium, the area of cardiac dulness may be irregular or restricted, or both, the shape and size depending on the length and strength of the adhesions.

¹³ Diseases of the Heart.

¹⁴ Ibid.

Some of the results of large effusions show themselves on other organs. The backward pressure of the fluid upon the bronchi, trachea, aorta, and oesophagus interferes with their functions and actions. There may be bronchial or blowing respiration heard over the lung, due to compression of the parenchyma. The fluid around the heart prevents free motion of the organ, although not to so great an extent as in adherent pericardium; complete diastole does not occur; the auricles and ventricles are not completely filled; the systemic and pulmonary circulations become engorged, and pressure is exerted upon the coronary arteries, thus disturbing the nutrition of the heart. The irregular action of the heart occasions at times a vibration which is more or less apparent to the touch. Percussion of the liver shows enlargement of the viscus; this is due to the obstruction of the ascending vena cava, which prevents a free emptying of its blood into the right auricle, and consequently causes a backing up of the blood in the gland. If the pericardial effusion press upon the anterior portion of the chest, it may produce pain and aggravate all the other symptoms, such as the pulmonary oppression, the dizziness, the hurried respiration, the increase of pulse. Water, blood, or pus in the pericardial sac gives rise to the same physical signs as serous effusion, and cannot be distinguished from it with any degree of certainty, although a careful consideration of the general symptoms presented may enable us to make a guess which can only be proved or disproved by an autopsy.

Having endeavored to show the most prominent features characterizing pericarditis in its various stages and bearing in a general way on its diagnosis, we shall examine some of the special maladies which are liable to be confounded with it. The diseases most likely to be mistaken for the acute inflammatory stage of pericarditis are inflammation of the pleura and of the endocardium. They are liable to occur from the same causes, and may be—indeed, often are—concurrent. Pleurisy gives rise to many of the symptoms of pericarditis. The chief difference is in the physical signs, some of which, however, are alike in kind, although different in locality; for in pericarditis they are confined to the region of the heart: in pleurisy they are spread over the whole side of the chest and are most perceptible at the back. This is true of the dulness, and for the most part of the friction sound, which when of pericardial origin is very rarely heard posteriorly. Then stopping the act of breathing if the sound be pleural suspends it. At times, however, as above described, we meet with cases in which a friction sound discovered over the heart may in reality be produced in the adjoining pleura. To confound the dulness on percussion caused by liquid in the pericardium with that due to liquid in the pleura is, from the different site of the liquid, not likely to happen unless the effusion be extremely large; for ordinarily a pericarditis uncomplicated with pleurisy or with pleuro-pneumonia does not change the clear sound at the back of the chest nor enfeeble or abolish there the breath sounds and the vocal fremitus. Besides, effusion into the pleura, if it give rise to a flat sound anteriorly, does not occasion the special præcordial bulging, and shows the sounds of the heart unaltered unless the pericardium contain fluid also.

Acute pericarditis is likely to be confounded with acute endocarditis. The chief difference consists in the physical signs—the friction sounds and signs of effusion in pericarditis, the blowing sounds, the slight alteration of percussion dulness in endocarditis, and the fact that in this disease the abnormal murmurs are often transmitted beyond the cardiac region and heard in the carotids and subclavian, and are far less changeable in character and in pitch.