maximal audibility of the murmur in question.

Precordial pain was one of the most consistent symptoms observed. The character of the pain is important. Its distribution was usually around the left nipple, yet in 2 cases it extended down the left arm. It was usually sharp but not in a single instance was it associated with substernal constriction or pain. This observation I believe to be of great clinical value, for it is rare to observe true angina without an associated sense of substernal constriction. Precordial pain is always a symptom which causes anxiety not only in the patient, but in the physician as well. Much care at times is necessary to distinguish the true from the false, yet this distinction must be made. While Mackenzie (24) believes that cardiac pain is but an evidence of myocardial exhaustion, it is difficult to apply this hypothesis to "effort syndrome," for the factors precipitating the symptoms are too varied. One frequently sees all symptoms, including precordial pain, immediately disappear in private patients after they are assured that organic disease does not exist, and are reinstated in their usual habits of exercise.

That hyperthyroidism is not a factor in "effort syndrome" is established. Of the 41 cases which had existed since 1918 or 1919 not a single case developed either exophthalmic goiter or toxic adenomata. This fact has an important bearing on clinical work among private patients. Many of the symptoms and signs presented by these individuals are observed in hyperthyroidism. If perchance a goiter exist the diagnosis of thyroxin intoxi

cation would seem reasonable. Yet one must bear in mind that these same symptoms do exist in individuals who do not have and have never had an elevated basal metabolic rate, hence destructive methods of therapy should not be instituted in the absence of that most reliable single phenomenon of hyperthyroidism-an elevated basal metabolic rate.

SUMMARY AND CONCLUSIONS

The evidence is irrefutable that there exists a group of patients who have symptoms and signs commonly observed in true cardio-vascular disease, tuberculosis, hyperthyroidism and various intoxications, yet in whom is lacking the cardinal evidence necessary to place them in any of these categories. Certain types are prone to develop this symptom-complex, and the erroneous diagnosis of heart disease during convalescence from acute infections, or after any unusual occurrence such as a fainting attack, or palpitation incident to transient ectopic cardiac beats, may induce such acute perception of heart action that an individual becomes invalided by the development of distressing symptoms referable to the cardio-vascular apparatus.

"Effort syndrome" as it occurs in civil practice is divisible into several general types, yet at times the line of division is by no means clear, each type tending to merge into the general class of the neuroses. There are certain individuals having a constitutional inferiority dating from birth, who have always been physically incapable of living a robust life. Their cardio-vascular symptoms incident to exercise are simply a part of a general

physical asthenia. In others "effort syndrome" is a psycho-neurosis with predominating cardio-vascular phenomena but there is operating in its victims an "unknown factor" which breaks through the threshold of unconscious appreciation of somatic function so that such acute perception of these functions is experienced that invaliding subjective symptoms are associated with effort. There exists a large class which does not belong to either of the above groups. This class has its inception as a result of the psychic trauma incident to a misconceived diagnosis of heart disease and in this class cardio-vascular symp

toms tend to persist as long as this impression is allowed to remain uncorrected. This type is best classified as an anxiety neurosis.

A correlation of the information gained from an exhaustive study. of the aforesaid cases, together with impressions gathered from private practice, has impressed me with the very great importance of recognition of this syndrome in patients presenting these elusive symptoms. They constitute a considerable percentage of the referred patients with supposed cardiovascular defects; and on their proper classification depends their future as useful and healthy citizens.

(1) DaCosta, J. M.: Observations upon heart disease in soldiers, E. L. C., etc. Med. Mem., U. S. Sanitary Commission, Washington, 1867, Chap. X, p. 36. (2) MCLEAN, W. C.: On the diseases of the heart in the British army and the remedy. British Med. Jour., London, 1867, i, 161.

(3) MYERS, A. B. R.: On the etiology and prevalence of diseases of the heart among soldiers. London, 1870, 92 pages.

(4) MCCARTY, J. McD.: Functional disease of the heart in soldiers. Thesis for Degree. Cambridge, 1898. (5) TYSON, W. J.: Notes from practice. Clin. Jour., London, 1906, xxviii, 205. (6) LEWIS, THOMAS: Report on soldiers returned as cases of "disordered action of the heart" (D. A. H.) or "Valvular disease of the heart" (V. D. H.). Med. Research Committee, Special Reports, Series, No. 8, 1917.

(7) MEAKINS, J. C., AND GUNSON, E. B.: Orthodiagraphic observations on the size of the heart in cases of so-called "irritable heart." Heart, 1918,

vii, 1.

(8) COTTON, T. F., RAPPORT, D. L., and LEWIS, J.: After effects of exercise on the pulse rate and systolic bloodpressure in cases of "irritable heart." Heart, 1916-1917, vi, 269. (9) PARKINSON, J., AND DRURY, A. N.: The P-R interval before and after exercise in cases of soldiers' hearts. Heart, 1916-1917, vi, 337.

(10) CLOUGH, H. D.: Electrocardiograms in irritable heart. Arch. Int. Med., 1919, xxiv, 284.

(11) PEABODY, F. W., AND WENTWORTH, M. D.: The vital capacity of the lungs, and its relation of dyspnea in heart disease. Trans. Association of American Physicians, 1916. (12) LEVINE, S. A., AND WILSON, F. N.: Observations on the vital capacity of the lungs in cases of "irritable heart." Heart, 1919, vii, 53.

(13) LEWIS, THOMAS, RYFFEL, C. G. L., WOLF, T. COTTON, AND BANCROFT, JOSEPH: Observations relating to dyspnea in cardiac and renal patients. Heart, 1913-1914, v, 45.

(14) WILSON, FRANK N., LEVINE, SAMUEL A., AND EDGAR, A. B.: The bicarbonate concentration of the blood

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plasma in cases of irritable heart. Heart, 1919, vii, 62.

(15) KING, T. JOHN: A study of the incidence of pulmonary tuberculosis in soldiers with irritable hearts. Arch. Int. Med., 1919, xxiv, 238.

(16) TOMPKINS, Edna H., STURGIS, CYRUS C., and WEARN, Jos. T.: Studies on epinephrin. II. The effects of epinephrin on the basal metabolism in soldiers with "irritable heart," in hyperthyroidism and in normal men. Arch. Int. Med., 1919, xxiv, 269.

(17) BARGER AND DALE: Jour. Physiol., 1910, xli, 19.

(18) HAMBURGER, Walter W., and PRIEST, WALTER S.: Structural and functional involvement of the heart following acute respiratory and other acute infections. Amer. Jour. Med. Sci., 1923, clxvi, 629. (19) WOLBACH, S. BURT, AND FROTHINGHAM, CHANNING: The influenza epidemic at Camp Devens in 1918: A

(20) THAYER, W. S.: The medical aspects of reconstruction. Amer. Jour. Med. Sci., 1919, clviii, 765. (21) WIGGERS, CARL J.: Modern aspects of the circulation in health and disease. Lea & Febiger, Philadelphia, 1923.

(22) KESSEL, LEO, AND HYMAN, H. F.: Studies of Graves syndrome and the involuntary nervous system (ii). The clinical manifestations of disturbances of the involuntary nervous system (autonomic imbalance.) Amer. Jour. Med. Sci., 1923, clxv, 513.

(23) LEWIS, THOMAS: Report on soldiers returned as cases of "disordered action of the heart" (D. A. H.), or "valvular diseases of the heart" (V. D. H.). Med. Research Committee, Special Report, Series No. 8, 1917.

(24) MACKENZIE: Diseases of the Heart and Aorta, 1918, 3d ed., London.

T

HROUGH such agencies, as the United States Public Health Service, State and Municipal Boards of Health, Schools of Hygiene, and organized social and industrial welfare, the profession has come to recognize the importance of the social, environmental and occupational factors in the pathogenesis of many forms of acute and chronic affections.

Owing to the trend of modern civilization, an increasing number of individuals are constantly engaged in hazardous occupations by being subjected to a variety of chemical and gaseous poisons in manufacturing and industrial pursuits. Likewise conditions have changed in the home. With the more general use of bituminous coal for fuel, natural and illuminating gas for lighting, cooking and heating, and the introduction of the gasoline engine for motor vehicles and stationary engines, a larger population is exposed to the dangers of gas poisoning. Modern warfare has demonstrated that poisonous chemicals and gases are more deadly than bullets. In chemical warfare the effect must necessarily be acutely fatal, or at least disabling, whereas in civil life the individual is often exposed to slightly noxious quantities over

a

considerable period of

time. As a result, instead of the acute manifestations, the condition is insidious in its onset and the symptoms are often so mild and bizarre that unfortunately the true nature of the malady is frequently not recognized or even suspected.

Unquestionably there are many individuals who suffer from various sorts of pyschoses, neuroses and anemias, as well as cardiorespiratory, gastrointestinal and urogenital disorders, due to the insidious and prolonged effect of exposure to carbon monoxide. Industrial experts, public health administrators, and life insurance actuaries are keenly alert to the situation, but the average physician, who comes in contact with the masses, and has the greatest opportunity of studying these cases, is perhaps not as familiar with the frequency and nature of the condition. Indeed McGurn found but one physician out of more than sixty interviewed, who possessed more than a fragmentary knowledge of chronic carbon monoxide poisoning. It is for this reason we wish to stress the subject and sound a note of warning. The presentation of several illustrative cases may help to serve this purpose.

REPORT OF CASES

On May 10, 1922, Mr. and Mrs. C. (husband and wife) from West Virginia, were admitted to our service at the Mercy Hospital, complaining of weakness and numbness, and exhibiting all the essential signs and symptoms of true Addisonian anemia. The striking feature was the remarkable similarity of the condition in the two individuals.

Mrs. C. was sixty-two years old and had been engaged in housework. Her family history was negative. As a child she had scarlet fever; at the age of thirty-nine, pneumonia, and, until seven years ago, was subject to frequent attacks of quinsy, otherwise her health was good.

The symptoms of her present illness date to the latter part of 1919, when she began to complain of numbness and tingling in the hands and fingers. This gradually became more general and towards spring involved both arms and legs. At the same time there developed a slowly progressive weakness, which was one of her most pronounced symptoms throughout her illness. She was stuporous and subject to vertigo; intellection was retarded, and her speech was slow and drawling, but not incoherent. There was no history of delirium. The appetite was usually good, but owing to periodical soreness of the tongue she had to avoid certain foods, such as acids and sweets. Belching was an annoying symptom, and the bowels were constipated. There were no genitourinary and no cardiorespiratory symptoms, except some dyspnea and palpitation, which occurred on slight exertion. She had lost about 25 pounds in weight.

On examination the patient was found to be almost helpless in bed on account of a general muscular weakness, and the skin and mucous membrane showed marked pallor. The hair was gray and falling out; the skin atrophic, and the muscles soft and flabby. The pupils were normal. There was no evidence of sinus infection. Both upper and lower teeth were artificial. The tongue was smooth and glossy, due to atrophy of the mucous membrane. The tonsils were not enlarged. Both heart and lungs were entirely negative. There was no evidence of enlargement of the spleen or lymphatic glands. Tendon reflexes were

There were no morphological changes in the blood except slight poikilocytosis. Within a week after her second transfusion she returned to her home in West Virginia, and continued to improve steadily, gaining in weight and strength. A blood count made in October 1922 five months after her transfusions, was reported normal; and her condition has remained good since.

The husband, Mr. C., was a farmer, aged sixty-two years. On admission to Mercy Hospital he complained of weakness and pain in abdomen. His father died at fiftynine years of age-cause unknown. His mother died at fifty-nine from pneumonia. One brother died at four from paralysis; one at forty-nine from locomotor ataxia, and one at sixty-four from tuberculosis. As a child the patient was subject to quinsy; as an adult suffered periodically with lumbago; and for the past twenty years com