Lessons in physical diagnosis / by Alfred L. Loomis.

Date:
1872
Catalogue details

Licence: Public Domain Mark

Credit: Lessons in physical diagnosis / by Alfred L. Loomis. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    friction of the blood against the walls of the ventricles, and against the ventricular surface of the valves. Some eminent authorities, however, regard the closure of the above-mentioned valves as tlie one and only cause of this sound. As to the second sound, all are agreed to its proceeding from the sudden closure and tension of the aortic and pulmonary valves, by the reflux of the blood on them during the diastole of the heart. Pathological Modifications of the Nonnal Sounds.-- In disease, the normal sounds of the heart present various definite alterations as regards their intensity, quahty, pitch, seat, and rhythm; and they may also be accompanied, pre- ceded, or followed by adventitious sounds or murmurs. An increase of intensity may be noted in cases of hyper- trophy and dilatation of the ventricles; in cases also of nervous irritability of the heart, or where there is consolida- tion of the adjacent lung tissue. A diminution in intensity may be found depending either upon dilatation of the ventri- cles without hypertrophy of their walls; or upon fatty degen- eration of the muscular tissue of the heart; or on softening of the same, as in typhus and typhoid fevers ; or it may be owing to a muffling of the heart sounds by pericardial effusion, or by emphysematous distension of the anterior border of the lung. Alterations in Quality and Pitch—The heart sounds in disease may become dull and low-]3itched, or sharp and high- pitched. The first sound is dull, muffled, and low-pitched, when hypertrophy is conioined with a thickened condition of the auriculo-ventricular valves. On the other hand, where the ventricular walls are thin, and the valves natural, tlie first sound becomes sharp and clicking in character, and the pitch is raised. The second sound is rendered dull and low-pitched, by diminished elasticity of the arterial walls, and by thicken- ing of the aortic valves, without regiugitation. Sometimes the