Left ventricle

“ It sometimes (though rarely) happens, that, with an increase of strength and bulk in its muscular structure, the left ventricle suffers a diminution of capacity in its cavity. In a case reported by Laënnec, the left ventricle was an inch and a half thick at its broadest, and an inch thick at its thinnest part ”

“ Though the left ventricle—dispensing its blood under a high pressure into the aorta—is the master hand in maintaining the arterial blood pressure, the height to which that pressure rises depends primarily on the resistance encountered in the peripheral arterial system, and in the capillaries, and, secondly, on the response of the ventricle to overcome that resistance. Given a normal ventricle the arterial tonus largely determines the ventricular response and the level of the arterial blood pressure ”

“ The disturbed circulation is evidenced by imperfect peripheral circulation and capillary sluggishly, with at times pendent edema of the feet and ankles, but, perhaps, little congestion of the lungs. The left ventricle being sufficient, there is no damming back through the left auricle to the lungs. The left ventricle may, however, become weakened, either by some sudden strain or by a chronic myocarditis, and relative insufficiency of the mitral valve may occur. The subsequent symptoms are typically those of loss of compensation. ”

“ Pericardial adhesions, particularly when in addition to union of the layers the parietal membrane is firmly united to the pleura or to the sternum, may cause hypertrophy of the left ventricle alone, but more commonly of the whole heart. ”

“ He improves, and continues to do so; is able to walk miles without discomfort; and in the course of two months not only do I find his heart reduced in size on physical examination, but I fail to hear the apical murmur, which must have been produced by dilatation of the left ventricle. The bearing of such a case as this on the pathology, prevention and treatment of certain cases of heart disease in old subjects will be obvious to all. ”

“ If, for instance, the orifice of the heart into the aorta is narrowed, then the left ventricle can only accomplish its work of projecting into the aorta a given amount of blood in a given time by contracting with greater force and giving a greater rapidity to the stream passing through the narrow orifice. This the heart can do because, like all other organs of the body, it has a large reserve force which enables it, even suddenly, to meet demands double the usual, and like all other muscles of the body it becomes larger and stronger by increased work. ”

“ Upon the whole, perhaps, the fact may be truly stated thus—that the left ventricle commonly gains an increase of bulk and strength, with an increase of capacity; and that all the other cavities, at the time that they expand, are rather apt to become attenuated. ”