. Diseases of the heart and thoracic aorta. on. Further, we know, as a matter of practicalexperience, that this murmur is almost invariably regurgitation generally results from organic changesin the aortic segments (contractions, puckerings, adhesions,ruptures, ulcerations), though it is occasionally due to dilata-tion of the base of the aorta, the valve segments being In one or two cases a diastolic murmur has been produced in an aneurismindependently of any regurgitation through the aortic valves. Such a conditionis, however, so extremely rare, that for practical purposes the
. Diseases of the heart and thoracic aorta. on. Further, we know, as a matter of practicalexperience, that this murmur is almost invariably regurgitation generally results from organic changesin the aortic segments (contractions, puckerings, adhesions,ruptures, ulcerations), though it is occasionally due to dilata-tion of the base of the aorta, the valve segments being In one or two cases a diastolic murmur has been produced in an aneurismindependently of any regurgitation through the aortic valves. Such a conditionis, however, so extremely rare, that for practical purposes the statement in thetext—that a diastolic basic murmur indicates aortic regurgitation—may be safelyrelied upon. 176 Diseases of the Heart. perfectly healthy, it is occasionally due to a conditionof relative incompetence of the aortic orifice.^ 2. The murmurs which occur during the latter part of thelong silence or pause, immediately before the systole ofthe ventricles, and to which the term presystolic is usuallygiven. (Fig. 44.). Fig. 44.—Diagrammatic representation of a presystolic murmur. The presystolic murmur stops abruptly with the systoleof the ventricle, with the occurrence of the first sound ofthe heart—a fact which is at once explained when it isunderstood that the murmur is produced by the formation ofa fluid vein as the blood is forcibly driven by the contractionof the auricle through a stenosed mitral orifice.^ Almost all authorities are agreed in thinking that thepresystolic or auriculo-systolic murmur (as Professor Gairdner,who was one of the first to direct attention to its true signifi-cance, prefers to term it), is always due to organic changes, to stenosis of the mitral or tricuspid orifices. And sincetricuspid stenosis is very rare, a presystolic or auriculo-systolic murmur, in the great majority of cases, indicatesmitral stenosis. The stenosed condition is usually due to adhesion of thecusps, the chordae tendincae are often thickened,
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectheart, bookyear1884
