BY AUSTIN FLINT, M.D.
The neuroses of the heart are those affections relating to this organ which do not necessarily involve either inflammation or structural lesion of any of its component parts. The larger proportion of these affections may be grouped under the name functional disorders of the heart's action. The affection called angina pectoris is characterized by pain more or less intense. It is generally associated with disordered action of the heart, and also with cardiac lesions. It may, however, exist without either disordered action or lesion, and hence it is with propriety included among the neuroses of the heart. Exophthalmic goitre is invariably associated with disordered action of the heart, but it has other very marked symptomatic traits which give to it a distinctive character. The name of the affection refers to these. The cardiac disorder is, however, the most constant, and, pathologically, the most important, and therefore the affection may be considered as one of the neuroses of the heart. In this article the functional disorders of the heart's action, irrespective of angina pectoris and exophthalmic goitre, will be first considered, and afterward these two affections will receive separate consideration.
Functional Disorders of the Heart's Action.
The disorders of the heart's action which agree in respect of their functional character present marked variations as regards the manner in which the action is disordered. An account of these will be given under the name Varieties, together with the symptomatology.
VARIETIES AND SYMPTOMATOLOGY.—The term palpitation denotes a violent or tumultuous action of the heart. A type of this variety of disorder is afforded when the heart is much excited by fear or some other intense mental emotion. The fact that emotional excitement will produce in some persons notable palpitation, and in others little or no disturbance of the heart's action, illustrates differences inherent in the organ itself as regards susceptibility to disorder. These innate differences are exemplified in cases of disease. In certain persons the heart readily takes on a morbid functional disorder from causes which in other persons do not produce this effect. A peculiar susceptibility to disorder is expressed by the term irritable heart, a term introduced by DaCosta. Instead of the violence which characterizes palpitation, there may be irregularity, with notable feebleness of the heart's action. The patient often describes this variety of disorder as a fluttering of the heart. The consciousness of the disorder is less distinct than when the disordered action is violent. With irregularity are generally associated increased frequency of the heart's action and præcordial distress. The degree of disorder as respects either violence or feebleness and irregularity of action differs in different cases within wide limits. Intermittence is another variety of disorder. The intermission may extend over a period of one, two, three, or more beats. It is sometimes preceded or followed by increased frequency of action, and it sometimes occurs without any other rhythmical disturbance. The patient is usually conscious of the intermittence, and it is apt to occasion great alarm, especially before the mind has become accustomed to it. The intermissions occur more or less frequently in different cases and at different periods in the same case. In the cases of palpitation in which the heart acts with violence it is not probable that the power of the heart's action is increased. The systolic ventricular movements are quick and have a spasmodic violence, without actual increase of force. The first sound of the heart over the apex under these circumstances is short and its quality valvular. The valvular element of this sound is predominant and intensified in consequence of the quickness of the systolic movements and the small quantity of blood in the ventricles when the ventricular systole takes place. Owing to the latter physical condition the range of movement of the auriculo-ventricular valves is greater and the valvular sound proportionately increased. The systolic movements of the apex against the chest-wall sometimes give rise to a ringing or metallic sound (cliquetis métallique).
A rare variety of functional disorder which has received but little attention is notable infrequency of the heart's action. The revolutions of the organ were reduced to sixteen per minute in a case reported by Thornton.1 In 1876, I reported 5 cases, the reduction in frequency varying from 26 to 40 per minute.2 In one of these cases there was marked intermittency, and in another case the action of the heart was irregular. With these exceptions the rhythm was regular. I have met with a few additional instances since these cases were reported. In this variety the disorder continues for several successive days, and it may be for a much longer period. A persistent infrequency sometimes remains as a sequel, recovery in other respects being complete. In one of my reported cases the revolutions were 36 for several weeks after recovery. In these instances the infrequency of the heart's action, which is sometimes a congenital peculiarity, is acquired. Hewan has reported his own case as an illustration of this fact. His normal frequency had been 72, but after a period of intense study the frequency gradually decreased, and finally remained at from 28 to 32 per minute.3 This variety of disorder will claim distinct consideration with reference to diagnosis and etiology. It may or may not be accompanied by præcordial distress.
1 Trans. Clinical Society of London, vol. viii., 1875.
2 American Practitioner, January, 1876.
3 London Med. Times and Gazette, March, 1875.