IX. Diseases of the Valves
Synonyms:—Aortic incompetency; aortic regurgitation.
Definition:—A condition in which the valve of the aorta fails to completely retain the blood which has been forced into it from the ventricle—fails to prevent the return of the blood into the ventricle. There may be an eroded condition of the valve; it may be torn or perforated by ulceration or the segments may be hard from calcification, or they may be shrunken. There is a consequent regurgitation of the blood into the ventricle during diastole, when that chamber is receiving the blood from the left auricle. As a result the ventricle is greatly overdistended, and in time dilatation results.
Etiology:—There are a number of factors which will induce this condition; one of the causes is muscular strain, resulting from excessive muscular action. This condition is found among athletes, and is sometimes called the athletic heart. During the bicycle craze a few years ago it was found in a number of cases. Another cause is dilatation of the aortic orifice from which the valves are too small to close. There is a failure of approximation. The presence of uric acid in inducing chronic changes through irritation of the lining of the heart and of the aorta, is undoubtedly a cause more common than is generally recognized. Other irritants are alcohol within the blood and foreign irritating substances, as lead in chronic lead poisoning. The condition occurs more commonly perhaps in males than in females, because of their occupation.
Symptomatology:—There is a visible pulsation of the vessels of the head, neck and upper extremities, which increases as the condition advances, until a general throbbing throughout the entire body is induced. This occurs when the compensatory hypertrophy of the left ventricle is no longer sufficient to overcome the injurious consequences of the defect in the valves. Prior to this time there are but few evidences of the disease. These symptoms are especially aggravated or exaggerated by the least excess of muscular activity or by some mental excitement, anger or extreme sorrow. With the general pulsation there is a throbbing headache, tinnitus aurium and vertigo, with flashes of light before the eyes, or distorted vision; or dizziness is especially conspicuous upon sudden rising from a recumbent position. There is difficulty in breathing, or shortness of breath, a general sense of uncertainty and lack of assurance, with usually much apprehension.
As the condition progresses, changes take place in the character and distribution of the blood; one of the first results of which is cerebral anemia, and ultimately arteriosclerosis. The face exhibits a peculiar pallor, although there are times when it is flushed with heat. There are hot flashes, general in character, and there is a sensation of oppression in the region of the heart, with sometimes a cord-like or band-like sensation around the chest. There may be an entire absence of pain, although it is not uncommon that there is some distress constantly present, and occasionally there is a genuine attack of angina. Pains radiating from the heart to the left shoulder and extending down the upper arm frequently occur and it is not uncommon to treat these pains as if they were rheumatic in character.
In the later stages of the disease, when compensatory hypertrophy has ceased, the distress of the patient becomes exaggerated. He is obliged to sleep in a sitting posture, and must avoid all physical exercise. He becomes extremely pale, almost pallid, and in an occasional case the face becomes cyanotic. The effort the patient makes at breathing in advanced stages is most distressing to the observer. As these symptoms develop, the mind is apt to give way. There are hallucinations, delusional insanity and strong suicidal tendencies. This is probably due to the improper supply of blood to the brain, as well as to the influence of the toxines, which result from inadequacy of the renal and other excretory organs.
The influence of the condition upon arterial tension induces perverted action of the large glandular organs. Positive congestion of the liver induces chronic hypertrophy. Structural changes in the kidneys occur, and from either or both of these conditions dropsy is induced. General anasarca is uncommon, edema only of the feet and hands being usually observed. Among the physical signs is the general pulsation we have referred to, and the possibility of a capillary pulsation in the lower lip, as seen in the changing shades of color in the mucous membrane. This capillary pulsation is designated as Quincke's pulse, and can be also seen under the nails. There is a characteristic lateral pulse beat, which is induced by the elongation or straightening of the blood vessels, which is called the water-hammer pulse, or Corrigan's pulse. This pulse is a characteristic symptoms at all times. There is a short, quick impulse to the finger, which immediately disappears, as if the artery had collapsed, the blood receding abruptly. When this pulse becomes weak, as it does when the disease progresses, it becomes a serious diagnostic symptom, denoting threatened cardiac failure. Upon auscultation at the sternal end of the second intercostal space, there will be heard in its greatest intensity a diastolic murmur which will be transmitted downward toward the apex of the heart. The area of dulness is gradually increased, extending to at least three inches below the nipple, and sometimes being observable at the right edge of the sternum. The aortic regurgitant murmur is distinct in the fourth left intercostal space, or in the so-called aortic area at the second right costal cartilage. When this sound is greatly exaggerated it will be conveyed by the chest structure to any part of the chest. There is at times a sharp systolic sound, which can be heard through the stethoscope in any of the large superficial arteries, which is known as the pistol-shot sound. This is due to abrupt filling of the vessels with blood, and is strictly local in character.
Diagnosis:—The correct diagnosis cannot always be made in this important condition, but when the diastolic murmur is pronounced, and the characteristic Corrigan pulse, as above described, is found present, with pronounced enlargement of the left ventricle, as determined by the physical signs named, a correct diagnosis is unquestionable. The peculiar throbbing sensations named are also of assistance in determining the character of the lesion. The regurgitant murmur above referred to varies with different patients, of course, and it also varies at different times in the same patient. At one examination it will barely be distinguished, while at another time, or upon change of position, or after excitement or active physical exercise, it may be very conspicuous.
Prognosis:—In all forms of valvular diseases of the heart there are none more likely to induce sudden death with no premonitory symptoms than this; however, with many cases, especially those who are conscious of the condition and who consequently exercise great care for their own welfare, life is prolonged a number of years, although it is rare that a patient exceeds ten years. Where dropsy or other serious conditions are induced by the presence of the aortic lesion, death occurs sooner. The patient who suffers from dissipation will yield more readily than any other. Patients who previously have had good health and good habits may, by care, enjoy a number of years in comparative comfort. The early termination of the disease depends largely upon the seriousness of the complications, which are more than likely to occur, especially those of the kidneys and those which induce structural change in the arteries themselves.