DISEASE OF THE AORTIC VALVES. 363 



tricle, namely, prominence of the cardiac region, an impulse often 

 enormously increased, and which shakes a broad tract of the thoracic 

 wall and sometimes actually lifts it ; considerable descent of the apex, 

 even as far as the eighth rib, with displacement outward. Percussion 

 also shows an elongation of the heart, where the lower limit of dulness 

 is not obscured by the position of the left lobe of the liver. Upon 

 auscultation (best at the right edge of the sternum, at the second in- 

 tercostal space), instead of the second sound, we hear a murmur, aris- 

 ing from irregular vibrations caused by imperfect tension of the rough- 

 ened, misshapen valves. In very rare instances, besides the murmur, 

 we hear the normal second sound of the heart, although but feebly, 

 and this occurs, as it would seem, when one or other of the valves con- 

 tinues sound, and is thrown by the blood into its normal state of vibra 

 tion. The murmur is usually conducted both to the apex and along 

 the sternum, and may even be heard at the sides of the chest and along 

 the back-bone. The first sound, as heard at the aorta, is pure in the 

 few cases in which insufficience exists without constriction of the valve 

 or roughness upon its under surface. In the majority of cases, how- 

 ever, it has undergone the modifications peculiar to constriction of the 

 aortic orifice. The first sound of the mitral is inaudible in many cases, 

 a fact accounted for by the following excellent explanation of Traube : 

 As the left ventricle is supplied from two sources during diastole, as it 

 receives blood both from the auricle and from the aorta, the force of its 

 internal pressure soon exceeds that with which the blood enters the 

 ventricle from the auricle. A reversed current is thus established, 

 flowing from ventricle to auricle, and which shuts the mitral valve be- 

 fore the diastolic movement is complete. Sometimes, besides the dias- 

 tolic murmur, another sound is heard, caused by the premature closure 

 of the mitral valve. Unless there be some complication, the sounds of 

 the pulmonary artery are normal. The phenomena observed in the 

 peripheral arteries, although chiefly dependent upon the consecutive 

 hypertrophy of the left ventricle, are very characteristic in insufficience 

 of the aortic valves. The carotids often pulsate in a remarkable man- 

 ner. If we listen, we do not hear two distinct tones, as we should do 

 under normal conditions (one supposed to proceed from the vibrations 

 of the wall of the carotid, expanded by the blood-wave ; the second, 

 attributable to conduction of the second sound of the semilunar 

 valves). The second sound is not heard, as the semilunar valves 

 do not vibrate normally, or, as more rarely happens, we hear a 

 murmur which takes its place. According to JBamberger, the first 

 sound is also deadened in the carotids or turned into a murmur, a- 

 phenomenon which he attributes to immoderate tension of the carotid 

 walls. Even the smaller arteries at a distance from the heart produce 



