ORGANIC DISEASES OF THE HEART Part III LECTURE VII.
GENTLEMEN: You have followed me with excellent attention through the lectures on Functional and Inflammatory Diseases of the Heart. It is now my duty to give you the history and treatment of those diseases of the heart which are termed structural, for the reason that they all present some lesion which changes its normal structure, and I will commence with the various forms of
HYPERTROPHY Definition and Varieties of Hypertrophy – Enlargement by Hypertrophy – concentric Hypertrophy – Symptoms and Pathological Effects – Physical signs and Diagnosis of Enlargement by Hypertrophy – Summary of the Physical Signs of Hypertrophy with Enlargement of the Heart. – Treatment.
Enlargement of the heart is a term which embraces abnormal increase of this organ, as regards either volume or weight, or, as is commonly the case, increase both in weight and volume. Increase of the volume of the heart, and increase of its weight, are different forms of enlargement, either of which, although they are usually associated, may exist independently of the other. The heart may exceed the limit of health as regards weight, from an increased thickness of its walls, the normal volume being retained. This is a condition sometimes found after death, although in the vast majority of the cases in which the weight is augmented the volume exceeds the healthy limit.
On the other hand, the volume of the heart may be abnormally great, the cavities being enlarged, while the thickness of the walls is so far diminished that the normal weight is retained. The latter form of enlargement is also of very rare occurrence, the organ generally increasing in weight when its volume is greater than in health. Abnormal increase of the heart in weight, due to morbid thickness of the muscular walls of the organ, constitutes the morbid condition called Pilatation. These names, hypertrophy and dilatation, thus denote different forms of enlargement of the heart, which exist sometimes separately, but usually together. Hypertrophy and dilatation have been subdivided by writers into several varieties, the subdivisions being based on well-marked distinctions.
First. Hypertrophy exists, in some cases, without any alteration of the cavities, the latter remaining normal. This has been called pure or simple hypertrophy.
Second. The cavities are sometimes found to be diminished in size below the limit of health. This has generally been admitted as a variety of hypertrophy, although its existence, as a morbid condition, is open to doubt. It has been distinguished as concentric hypertrophy, or hypertrophy with contraction.
Third. The variety occurring much more frequently than the others is characterized by the co-existence of dilatation to a greater or less extent.
This variety has been called eccentric hypertrophy, or hypertrophy with dilatation. Dilatation, on the other hand, differs in different cases, according to the thickness of the walls of the heart.
First. It exists in some cases, the walls retaining their normal thickness. This has been called pure, or simple dilatation. It is obvious, however, that in proportion to the dilatation, the heart is hypertrophied, assuming the walls to preserve their normal thickness, inasmuch as the quantity of muscular structure and the weight of the organ, under these circumstances, must be increased.
Second. In other cases, in which the capacity of the cavities is increased, the thickness of the walls is diminished. In this variety, the weight of the heart may not exceed, and may even fall below, that of health. This has been distinguished as dilatation with attenuated walls, or attenuated dilatation.
Third. The variety of dilatation which occurs with far greater frequency than either of the other varieties, is characterized by increased thickness of the walls, or well-marked hypertrophy, the dilatation, however, being predominant. These subdivisions, although based on distinctions which are valid, are embarrassing to the student. They are consistent with the different morbid conditions of the heart, as determined by examinations after death; but they are not accompanied by diagnostic criteria, by means of which they may be discriminated at the bedside during life. A simpler arrangement is clinically more available, and suffices for all practical purposes.
We may distribute all cases of enlargement of the heart into two groups: 1st, Enlargement by hypertrophy; and, 2nd, Enlargement by dilatation. These groups will include, respectively, cases in which the hypertrophy or the dilatation is either simple or predominant.
In cases of enlargement by hypertrophy, the cavities may, or may not, exceed their normal capacity. Cases in which the cavities are diminished will also fall in this class. If the hypertrophy be neither simple nor concentric, it is included in this class whenever it is greater than the co-existing dilatation. The symptoms and signs enable the diagnostician to determine, often with positiveness, the existence of hypertrophy, which may be either simple, or predominant over a co-existing dilatation; but to discriminate between the cases in which the hypertrophy is simple, and those in which it predominates over co-existing dilation, is a problem in diagnosis by no means easily solved.
So, in cases of enlargement by dilatation, the quantity of muscular structure may, or may not, exceed the limit of health. The diagnostic criteria of predominant dilatation are often sufficiently positive; but it is far less easy to decide whether the dilatation be accompanied with hypertrophy or attenuation. Moreover, as regards prognosis and treatment, after the existence and degree of enlargement are ascertained, it is enough to determine which form of enlargement pre-dominates, namely, either hypertrophy or dilatation.
ENLARGEMENT BY HYPERTROPHY.
Under this head, it is to be borne in mind, I include, not only enlargement due exclusively to increased thickness of the muscular walls, but enlargement by hypertrophy with dilatation, provided the former predominate over the latter. In examining the heart, after laying open the cavities and removing their contents, the predominance of either hypertrophy or dilatation is generally obvious to the eye. The two forms of enlargement are combined, in different cases, in every degree of relative proportion.
In determining, then, whether the enlargement be by hypertrophy or by dilatation, the question is, which contributes most to the morbid size, increase of the structure, or increased capacity of the cavities. Instances, however, occur in which these too forms of enlargement are about evenly balanced. On measuring and weighing the heart, the excess of weight is greater than the abnormal dimensions, in proportion as hypertrophy preponderates.
The walls are more solid and resisting. The ventricles retain their rounded form when the heart is placed on its posterior surface, not being flattened by the collapse of the ventricular walls. If the increased thickness of the walls of the ventricles be due purely to hypertrophy, they present externally, and on section, the appearances of healthy muscular structure, and the microscope shows the characters of the normal tissue; the hypertrophy, causing abnormal volume and weight, is due to increase of the muscular substance.
The heart may be more or less enlarged by an accumulation of fat upon the surface and between the muscular fibres, or by the presence of different morbid products in these situations. Under these circumstances, notwithstanding the abnormal volume and weight, the muscular substance may be diminished; that is, instead of hypertrophy, there is atrophy of the heart.
The several portions of the heart may collectively participate in the enlargement, or it may be confined to one or more of the anatomical divisions, without extending to the whole organ. In the majority of cases, all portions are involved, but they are rarely affected equally; the enlargement is more marked in some divisions than in others. The different portions may predominate in one part and dilatation in another. If the enlargement be limited to, or be seated chiefly in, the left ventricle, the vertical is more increased than the transverse diameter; the heart is elongated, and the conoidal form may be more marked than in health. If the enlargement be great, the right appears to be merely an appendix of the left ventricle. The apex is lowered, and is more or less removed to the left of its normal situation.
On the other hand, if the enlargement be limited to, or be seated chiefly in the right ventricle, the width, more than the length, is increased; the conoidal form is less marked than in health; and the apex, formed in part or entirely by the right ventricle, is blunt instead of pointed. The apex extends lower than in health, and more in a direction toward the epigastrium than when the enlargement is seated in the left ventricle. If both ventricles be considerably enlarged, the organ has a globular form. The papillary muscles are not infrequently more or less increased in size when the ventricular walls are thickened. The degree of hypertrophy varies greatly in different cases. The thickness of the left ventricle may be increased to an inch, an inch and a half, and even two inches. The walls of the other compartments may, in like manner, be doubled, tripled, and quadrupled. The vertical and transverse dimensions may be five or six inches, or more. The weight may exceed two, three, four, and even more than five times the normal average.
Hale wrote Lectures On Diseases Of The Heart, Materia medica and special therapeutics of the new remedies Volume 1, Materia Medica And Special Therapeutics Of The New Remedies Volume 2, Saw Palmetto: (Sabal Serrulata. Serenoa Serrulata), The Medical, Surgical, and Hygienic Treatment of Diseases of Women, New Remedies: Their Pathogenetic Effects and Therapeutic Application, Ilex Cassine : the aboriginal North American tea, Repertory to the New Remedies with Charles Porter Hart, The Characteristics of the New Remedies, Materia Medica and Special Therapeutics of the New Remedies, The Practice of Medicine, Homoeopathic Materia Medica of the New Remedies: Their Botanical Description etc.