Palpation.—On placing the hand over the præcordial region a heaving, lifting impulse will be perceived, which is transmitted over a large portion of the thoracic walls. The apex-beat is displaced downward and toward the left, sometimes as far as the eighth rib and two and a half inches to the left of the left nipple. Occasionally a continuous diastolic thrill, equally intense during the whole of the diastole, is felt over the sternum, most distinctly at the site of the aortic valves. In some cases there is a slight pulsation in the scrobiculus cordis.
Percussion.—The area of percussion dulness corresponds to the extent of the cardiac enlargement. Deep dulness is elicited below and to the left of the normal area, and its outline has more of an oval contour than in health. So soon as the cardiac dilatation exceeds the hypertrophy, the area of dulness will extend horizontally rather than vertically, and it may be carried slightly upward, the apex beating in the axillary space. The area of dulness may extend six and a half inches from right to left, and from the upper edge of the third rib to the line of the liver dulness. The superficial area of dulness is likewise increased horizontally and toward the left.
Auscultation.—Aortic regurgitation is characterized by a diastolic murmur, which may take the place of, or immediately follow, the second sound of the heart. It is very distinct at any point over the base of the heart, but usually has its maximum intensity either at the sternal end of the second right costal cartilage, in the second right intercostal space, or at the sternal junction of the third rib on the left side. It is transmitted over the sternum, and sometimes will be loudest at the xiphoid cartilage, and is thence transmitted in the direction of the apex. Its area of diffusion is greater than that of any other cardiac murmur: it is not only conducted down the sternum to the xiphoid cartilage and to the apex, but it may be heard at the sides of the chest along the spinal column, and sometimes faintly in the ascending and transverse portions of the arch, in the carotids, and in rare instances as far as the radial arteries. The murmur of aortic reflux is accompanying rather than substitutive, for the pulmonic second sound is audible at the right base.
Foster13 regards incompetency of the posterior segment of the valve as producing a murmur which is conducted to the apex, whereas inadequacy of either or both of the anterior segments is accompanied by a murmur which is conducted to the ensiform cartilage. This point has a practical bearing on account of the relationship of the anterior segments of the valve to the coronary arteries. If the murmur indicates a lesion of the posterior flap of the valve, the prognosis will be better. When the second sound of the heart is distinct the murmur immediately follows it. Many English writers call the murmur a post-diastolic aortic murmur.
13 Med. Times and Gaz., 1873, vol. ii. p. 658 et seq.
Although having the greatest area of diffusion, aortic reflux has not the loudest murmur; it is soft, blowing, sometimes rough, and frequently musical. It is loudest at the beginning of diastole, gradually decreasing in intensity, although it may preserve its rushing, blowing character during all the diastole.
An aortic regurgitant murmur may temporarily disappear if a plug of fibrin closes the orifice, or if the walls of the left ventricle are the seat of extensive fatty degeneration, the aorta being rigid and inelastic.14 When aortic stenosis coexists there will be a double murmur, audible over a very large space, having its maximum intensity at the right edge of the sternum in the second interspace.
14 Brit. Med. Journ., 30th March, 1882.
Systolic and diastolic murmurs, though sometimes separated by a well-defined pause, may run into each other. If mitral regurgitation occurs with aortic regurgitation, each murmur retains its own location of maximum intensity. In rare instances, when two segments of the valve are healthy, a clear aortic second sound is heard, which is preceded by a faint reflux murmur. Such a murmur is said to be prediastolic in rhythm. Aortic reflux murmurs are often very indistinct, and can only be heard when the patient is in the recumbent posture. There is no necessary connection between the amount of reflux and the loudness of the murmur.
A diastolic murmur heard at or below the level of the aortic valves, chiefly audible in the line of the sternum, indicates considerable aortic incompetence. If a diastolic murmur is inaudible in the carotids, it is usually preceded by a systolic murmur, which has its maximum intensity at the aortic valves or in the so-called aortic area: such a murmur indicates comparatively trifling incompetence with considerable obstruction, probably produced by calcified semi-lunar valves.