HYPERTROPHY OF THE HEART.
Definition.—Increase in the thickness of the walls of the heart. The process may be general, affecting the entire organ. More often it is confined to, or predominant in, one side of the heart. The left ventricle is rather more often affected than the right. The amount of muscular tissue in the auricles is scanty even when under the influence of hyper trophic changes.
Varieties.—Simple hypertrophy is as sociated with a normal size of the cardiac cavities. Eccentric hypertrophy implies enlargement of the cavities as well as thickening of their walls. Concentric hypertrophy—thickened walls encroach ing on the cavities—is seldom, if ever, met with. (It is said to occur as a con genital condition. Its existence in any particular case should not be affirmed until by prolonged soaking in water all rigor mortis has softened.) Symptoms. — It is astonishing how little subjective disturbance may be present, even when the hypertrophy is pronounced. To be sure, the enlarge ment is an attempt on the part of nature, as we shall see under ETIOLOGY, to avert symptoms; yet we wonder how the bulk and strength of the organ can fail, as they often do, to attract its owner's attention. There may be cardiac dis comfort, throbbing or heaviness, espe cially when lying on the left side, but seldom any pain. Sometimes there are signs of cerebral hyperemia: vertigo, tinnitus aurium, flashes of light, head ache, and disturbed sleep. In a general way, it is fair to say that the more promi nent the subjective symptoms are in any patient, the more likely it is that he has something more than pure hyper trophy: either a merging of the hyper trophy into dilatation or else some neu rotic disturbance.
Objectively, we notice the pulse, the chest-wall, the epigastrium, and the heart itself. The pulse is regular and of good strength. It is usually not rapid, except in exophthalmic goitre. Irregu larity and intermittence suggest failing compensation. The wall of the artery may be normal, but in many instances it is rather stiff or presents the uneven ridges of calcification. It is said that in hypertrophy of the right auricle there may be such a regurgitation through the tricuspid valves (even if competent) be fore they completely close as to cause a venous pulsation in the root of the neck. This must be a rare phenomenon. In
spection shows a forcible, extended, and dislocated cardiac impulse. This may be powerful enough to render the thorax of a young subject asymmetrical, so that the lower part of the sternum and the ribs adjoining it on the left bulge for ward. If the left ventricle is mainly affected, the apex is lower than normal and displaced to the left; if the right ventricle, the apex is displaced still more to the left, but it is not lowered. En largement of the right ventricle is evi denced also by pulsation in the epigas trium and in some cases at the right edge of the sternum. Universal hypertrophy, as seen in some cases of aortic regurgita tion, lowers the apex to the seventh or eighth intercostal space and displaces it to the nipple-line, while the whole body jars under its powerful efforts like a small tug-boat with a large engine. Upon palpation the apex seems blunter than normal, and its impulse is slow and powerful, contrasting with the rather spiteful tap of dilatation. Sometimes the action of the auricles can be detected by the lightly-opposed hand. Percussion demonstrates an increased area of dull ness, extending a trifle higher than normal, or even up to the second space, but exceeding the normal limits mainly in a lateral direction, one or two fingers' breadths to the right of the sternum, and as far as the nipple or the anterior axillary line on the left. Inasmuch as aortic regurgitation is sometimes asso ciated with dilatation of the aorta, we may in this disease get dullness in the second right interspace at the right edge of the sternum.
The first sound at the apex is dull and loud. It has a booming quality, contrast ing with the valvular snap of hyper trophy. A reduplication of the first sound at the apex (gallop-rhythm) is ominous of beginning cardiac debility. At the base the first sound is not heard so distinctly as in dilatation, while the second sound is loud and clear, with strong accentuation of that valve (aortic or pulmonary) which corresponds to the obstruction that the hypertrophy is trying to overcome. For instance, in chronic nephritis the aortic second sound is accented, and, in right-sided hyper trophy, the pulmonic. In the presence of valvular lesions it need not be said that the murmurs caused by them more or less modify or replace the physiolog ical sounds.