ENDOCARDITIS. 



351 



of the intense fever arising from such infection. Physical examination 

 alone can give us the required information, and it should never be neg- 

 lected, though no special signs demand such investigation. "With 

 regard to the origin and course of endocarditis complicating chronic 

 Bright's disease, as this form too usually presents no subjective symp- 

 toms, it is overlooked in most cases if physical exploration be neg- 

 lected. 4 



Physical Signs. The impulse of the heart in the commencement 

 of the attack is almost always stronger and more extended than 

 natural. The smallness and softness of the pulse, when the muscles 

 of the heart are infiltrated with serum and contract feebly, in spite of 

 their furious action, bear striking contrast to the above. The cardiac 

 duluess is normal at first; but, after a few days (Skoda) , the outflow 

 from the pulmonary veins may be so much embarrassed that the 

 blood accumulates in the lef auricle, and the obstruction extends 

 through the vessels of the lungs into the right heart. The right 

 heart is imperfectly emptied, and soon becomes dilated by the blood 

 entering from the vena cava. Hence, as we have already seen, the 

 lulness is rendered abnormally broad. If the tissue of the valves be- 

 come softened, and the valves themselves thickened by the inflamma- 

 tion, it is easy, to see that the heart-sounds must also undergo modifi- 

 cation. It is impossible for the softened and thickened valve to 

 vibrate, like the hard and delicate valve. As the first sound of the 

 heart in the left ventricle proceeds from vibration of the mitral, the 

 substitution of an abnormal murmur at the apex for the first cardiac 

 sound is the most frequent and important sign of endocarditis, which 

 usually has its seat in the left heart. Besides, the thickening of the 

 delicate web on the outer edge of the mitral prevents it from unfold- 

 ing freely, and keeps the softened chordae tendineaa from completely 

 fixing the valve, which, if the chordae tendineae be broken, may even 

 be folded backward toward the auricle during the systole of the ven- 

 tricle. All these forces combine to render it impossible for the valve 

 to perform its function during systole of the ventricle, and to prevent 

 regurgitation of blood into the auricle. That condition, where the 

 valve loses the power of acting as a valve, is called "insitffi* 

 cience" If, however, the valve be but partially fixed, if part of it 

 be free to flap in either direction, if some of the blood pressing against 

 it be opposed by a portion only of its lower surface, while the rest, 

 flowing back into the auricle, bathes its upper face, the vibrations of 

 the mitral become entirely abnormal and irregular, and give rise to 

 another murmur, which takes the place of the first sound of the left 

 ventricle. We have seen that the second sound that we hear at the 

 apex is, under normal conditions, produced by vibration of the semi 



