MONGOLISM 495- Nov.No.13]WRER1935] WARNER: OGLS 9

A SITRVEY OF MONGOLISM, WITH A REVIEW OF ONE HUNDRED CASES* BY ELIZABETH N. WARNER, M.D., C.M., Toronto rela- was as tends to be straight, the normal curves developing THE mongolian syndrome recognized tively late. Muscular weakness may result in the develop- a clinical entity by Langdon Down in 1866. ment of dorso-lumbar kyphosis in the older child. There in The condition is not uncommon, as the Presby- is a generally relaxed state of the ligaments, which, association with the marked hypotonicity of the muscula- terian Hospital in Chicago has given the figures ture, gives rise to an extreme degree of hyperflexibility, of 6 mongols in a series of 3,818 births over a enabling the child to assnme and rest for long periods of time in extraordinary positions. Muscular development six-year period, and the records of the Hospital is delayed and deficient, and such defects as umbilical for Sick Children in Toronto over a period of hernia, cryptorchidism, patent foramen ovale, syndac- tylism, and Darwinian tubercles are common. sixteen years include 125 mongols out of 98,510 total admissions. Extraordinarily little is known Apart from the skeletal peculiarities, to be about mongolism, its etiology, and its pathology. discussed later, the hands frequently show two There are certain features that are suggestive variations from the normal for which no ade- of either thyroid or pituitary dyscrasia, particu- quate explanation has been offered. Penrose, larly the former, although the evidence is in a study of 60 cases of mongolism under his contradictory, and the typical mongol presents care, observed that in 16 of hi's series there was some features characteristic of cretinism to- a departure from the normal arrangement of gether with other features ordinarily associated the creases on the flexor surface of the little with the hyperthyroid individual. The failure finger; instead of the normal three transverse of the mongol to respond to glandular therapy, creases on this finger these mongol hands however, lends weight to the view that the con- showed onlv two, although the correct number of dition is a general failure in development rather phalanges was present. In the anomaly de- than a specific endocrine dyserasia. Many of 'scribed a new crease, usually double in character, the usual characteristics of the mongol are takes the place of the distal and medial creases common in other type's of mental defectives, and, and lies between the distal and proximal inter- as Tredgold has said, "It is necessary to re- phalangeal joints. In half of the cases re- member that mongolism consists in a peculiar ported the anomaly was unilateral. Several combination of anomalies rather than in ano- authors have reported a somewhat similar ano- malies which are distinctive in themselves." maly of the palmar lines, the usual two main a The typical mongolian imbecile is a short, stout, transvetse creases being replaced by single brachycephalic child. The occipito-frontal circumference line. This was found in approximately half of is usually less than the normal, probably due to the and flattened occipital region; the brow is of normal shape, the reported cases in which it was sought, in contrast to the frontal and supra-orbital recession seen is said to be common also in the mixed and in other small-headed types of aments. The eyes are mongolian races and low caste people slanting and widely spaced; epicanthus, nystagmus and higher strabismus are common. The nose is of the saddle-back of Annam and Indo-China. It is also found type, although it is not identical with the flattened bridge occasionally in quite normal persons, and there of the congenital luetic. The ears are frequently lobe- less. The mouth is commonly held open, and the thick is no correlation with the degree of mental grooved tongue protrudes. The hard palate is narrow development. and arched, and the naso-pharynx small, frequently being encroached upon by the projection forwards of one of The osseous system shows both generally the cervical vertebrae. The neck is short and thick. The tardy development and certain specifically skin is very elastic, soft and velvety in the infant, in the older mongol it becomes dry and rough. The hair tends -mongoloid features. The most constant of the to be straight, dry, and sparse. The extremities are short latter is the peculiar deformity of the fiftlh and stubby. The characteristic short skeleton of the mongol is due to this shortness of the long bones, rather finger, the mid-phalanx being shortened and than to alteration in the length of the vertebral column, the terminal phalanx bent towards the fourth and the irregularities of growth characterizing cretinism and achondroplasia are absent in the mongol. The spine finger, so that the fifth finger forms a kind of arch. This deformity may also be found as a * A paper read before the Section of Pathology, Academy of Medicine, Toronto, March 26, 1935. dominant hereditary character apart from mon- 496 THE CANADIAI.Z AUDICAL ASSOCIATION JOURNAL [Nov. 1935

golism. Orel reports a family in which the mongol tends to resemble the hyper- rather curved and shortened fingers were found in than the hypo-thyroid type, being excitable and four generations, affecting a woman, her son, restless, and thyroid treatment does not im- six of his eleven children, and two offspring of prove the condition of the pure mongol, the one of the affected members of the third genera- chief effects of such therapy being the disap- tion; one member of the family was a mongol. pearance of fatty deposits and the increase of Typically, the mongol 's thumb is also shortened, any malnutrition that may be present. One and the hand as a whole is stubby. series of six cases is reported in which all of On account of the wide variation within the patients had basal metabolic rates above normal limits of the time of appearance of the the normal, but some have low basal rates, different centres of ossification it is unsafe to while the great majority reported are within be dogmatic about the question of delayed normal limits. A few cases have been reported skeletal development. However, there seems to of mongolism coincident with definite endocrine be general agreement among the writers upon disease. Gordon, in an article on childhood this topic that there is some definite retarda- myxoedemas, stated that "Infantile myxcedema tion. Closure of the fontanelles and sutures of may be associated with mongolian idiocy, pre- the skull, particularly the frontal suture, is senting a composite picture of both diseases. usually delayed. Occasional evidence of slow The mongolian element is present at birth, osseous growth is seen in the appearance of while the thyroid dyscrasia symptoms appear extra-epiphyseal nuclei at the proximal ends of within a few weeks or months", and he con- one or more of the metacarpals. The failure of cludes that "there is probably no relationship these nuclei to appear in normal persons is ex- between the two diseases, but a coexistence of plained osteogenetically on the ground that a both may be present. Whatever mongolian proximal epiphyseal nucleus is always present idiocy is due to, it is not primarily nor funda- in the primitive formation but that the epi- mentally a form of myxcedema." Collier has physeal line is normally reached by the ossify- reported a case of mongolism and cretinism in ing diaphysis before it has time to attain to an one family. The first child was a mongolian independent formation. Occasionally there may imbecile, the next was a dead fetus with greatly be two isolated osseous nuclei close together in enlarged head; the third and fourth children, the distal ulnar epiphysis. This usually occurs of the same mother but a different father, were between the sixth and the middle of the eighth a normal infant and then a cretin. A two year year but has been observed radiographically in old child at St. Mary's Hospital for Children a mongolian imbecile, thirteen years of age. showed most of the usual features of mon- Pennacchietti and Fuhry both refer also to the golism, and also some definitely cretinoid presence of a hyperealcified border at the end characteristics, and was markedly improved by of the joint cartilages, a sign which likewise thyroid therapy. One case has been reported exists in athyrosis. Dentition is also prone to of a typical mongolian imbecile female who, at occur after the normal time. This is particu- the age of 33, began to gain weight in spite of larly the case with respect to the permanent thyroid treatment, and subsequently showed teeth, and is regarded as evidence of tardy ab- the other signs characteristic of Fr6hlich 's sorption of the roots of the deciduous teeth, so syndrome. that the first and second dentures coexist. Mentally, the majority of mongols belong to Enamelization of the teeth is generally poor, the imbecile class, Tredgold states that many with consequent early decay. are feeble-minded, a few are idiots, but of the General retardation of skeletal growth and 206 cases whose intelligence quotients are re- fusion is likewise seen in cretinism, as are the ported by Brousseau and Brainerd only 1 per short thick neck, widely separated eyes, pro- cent fall into the moron class, while 61 per cent truding tongue, deposits of fat about the neck are imbeciles and 38 per cent idiots. The and back, umbilical hernia, dry skin, and highest intelligence quotient in their series was mental deficiency. The mongol tends to be 66, the lowest was 7. Barnes reported the case normal in size during the first year of life and of a mongol boy who was able to complete a relatively short thereafter. Psychically, the high school course. This case appears to be Nov. WARIITER: MO.NGOLISM 497 Nov 19351195 ANR OGLS 9

unique, the highest mental age reported else- and suggests that the thymus is an organ of where is seven years. One of our series was antitoxic defense, and that here may lie an tested psychometrically; his intelligence quotient explanation for the abnormal susceptibility of was found to be 21. There are no character- the mongolian imbecile to respiratory and in- istic sensory disturbances. Attempts to de- fectious diseases. He refers also to hypotrophy termine the sensory acuity of the mongol are of the adrenal cortex as a frequent finding, severely hampered by the typical failure to fix and to a case in which the thyroid showed the attention and the difficulty of making the alterations similar to those found in Basedow's child understand what is desired of him. disease. Several cases are reported in which Evidence of mental retardation is present from the thyroid showed increase of the interlobular birth. The grasping reflex present in most connective tissue and shortage of colloid. normal new-born infants is much diminished in Examination of mongol brains does not show mongols, and ability to follow light with the any constant pathological picture, but the brain eyes is late in appearing, as are the power of is usually smaller and less complex than the sitting, creeping, walking, and speech. The normal of equal age. The width of the per- young infant appears somewhat apathetic; manent cortex in mongols under one year is later the child becomes restless and lively, but not abnormal, according to Hirning and Farber, is generally cheerful and affectionate and easily but they report definite lag in growth of the managed. There may be considerable power of permanent cortex in older mongols as com- mimicry, making the child appear more intel- pared with the normal group. The reduction in ligent than he actually is. size is said to be relatively more marked with Autopsy reports on cases of mongolism show respect to the pons, medulla, and cerebellum varied and inconstant endocrine findings. than the cerebrum. The defective growth of Gordon reports two cases. The first, a child of the structures at the base of the brain is suffi- fourteen months, showed cirrhosis and dysfunc- cient to account for the flattening of the pos- tion of the thyroid; physiological involution of terior portion of the skull. Davidoff reports the adrenal cortex, with hypoplasia of the ten cases and states that the cerebellum and chromaffin substance; a normal pineal gland, brain-stem are disproportionately small, the save for a cyst lined by glia cells; a normal antero-posterior diameters are narrow, and the pituitary and ovary. The second was an infant lateral diameters relatively wide, and there is, of six weeks who showed similar cirrhosis and as a rule, embryonic simplicity of the convolu- dysfunction of the thyroid; physiological in- tions with absence of secondary gyri. lIe volution of the adrenal cortex with chromaffin further states that there is evidence of a de- hypoplasia, retrogressive changes in Hassall's generative process affecting the ganglion cells, bodies with increase in number; hypoplasia of particularly those of the third cortical layer, the thymic cortex; incipient atrophy of the occurring very early in life. Marked asym- anterior lobe of the pituitary; and a normal metry has been reported in many cases. Bourne- pineal gland. Fromm reported a patient aged ville believes that there is a fibrous meningitis 11/2 years showing hypoplasia of the thyroid without any evidence of a true inflammatory with advanced sclerosis, and Bernheim-Karrer condition. Babonneix suggests that there is noted a small atrophied and partially sclerosed a chronic meningitis as the primary lesion in thyroid and small gelatinous thymus. Of 19 the nervous system, and that the arrest of de- autopsies from the Hospital for Sick Children velopment is very pronounced because of the records, one showed a very small thymus, early stage of cerebral development in which microscopically normal, one showed fibrosis of the meningitis occurs. Encephalograms have the thymus and a very small thyroid; the shown deep subarachnoid spaces and widely adrenal cortex was unusually thick in one case, separated convolutions with deep sulci, and and in one the adrenals were macroscopically dilated ventricles. Abnormalities of the brain normal, but microscopic examination revealed are described in 5 of our series, in 4 of these vacuoles, probably fat, in many of the cortical it is stated that the convolutions were flattened, cells. Pennacchietti mentions a case in which and in 1 the glial tissue was increased. In the precocious involution of the thymus was found, fifth case there was a congenital malformation 498 THE CANADIAN MEDICAL AssocIATION JOURNAL [NOV. 1935 49 THLAAINMDCLASCAINJUNL[o.13 of the left cerebellar hemisphere. In 3 cases also three cases of mongol first cousins, one of it is definitely stated that the convolutions were second cousins, and one family in which a well formed. mongol child had two maternal aunts and one maternal uncle, also mongols. Herrman reports ETIOLOGY the case of a woman who had one normal child The etiology of mongolism has been the sub- by her first husband, by a second husband she ject of very varied and often highly imaginative had a mongol baby, then a normal child, and theories. The ethnological theory of Down, that another mongol. Glassburg reports a family of the condition is the result of arrest of develop- eleven children in which the last two were ment in a fetal period equivalent to the mon- mongols. In one of our cases the mother was golian state, has been discredited by most writers mentally deficient, but in none of the series was on the subject, as have the theories that alco- a history of other mongols in the family obtained. holism, or what Pennacchietti refers to as There is considerable statistical evidence to "blastotoxic hereditary syphilis", i.e., heredi- indicate that the age of the mother is a factor tary syphilis of the second generation, are de- in the production of a mongol offspring. Ac- termining factors. Mebane ha's reported a case cording to Shuttleworth's figures, the greatest of a mongol with characteristic Hutchinson number of births in any age-group i's to mothers teeth and a negative Wassermann test. Van der of twenty-three years, while the mongol births Bogert presented a case of congenital syphilis are maximum in the forty-three year maternal closely resembling mongolism in one of twins; age group. Jenkins states in his article on the the other twin was apparently normal, and the etiology of mongolism that birth control in all Was'sermann test was negative. Doubtless it females of forty or over would reduce the total was cases such as the above that led to the birth rate by 4 per cent, and the mongol birth attempt to find a connecting link between rate by 36 to 38 per cent. Sewell Wright has mongolism and congenital lues. The blood shown the possibility of maternal age as a factor Wassermann test was done in ten of our cases; in the production of congenital defects by in all of these it was negative. Jan'sen has ex- pounded the theory that the amniotic sac may TABLE be small and tight, causing increased pressure and excessive flexion of the fetal head. He Maternal Ages at Time suggests that this condition may result in anen- of Mongol Birth: Control Series: cephaly, achondroplasia, or mongolism, depend- 1 mother aged 47 years 1 " " 46 " ing on the age of the embryo when the pressure 1 " " 45 " 1 mother aged 45 years occurs. It has been suggested that mongolism 5 mothers " 44 " 3 " " 43 " 1 '' "' 43 "' is due to diminished viability of the ova, that 1 mother " 42 " "in the population of ova there is continually a 2 mothers " 41 1 mother " 40 ' certain mortality rate, and in a period between 7 mothers ' 39 " that of complete viability and that of failure of 3 " " 38 " 1 " " 38 " 4 " " 37 " 1 '" ' 37 ' reproductive function the ova pass through a 3 " " 36 " 3 mothers ' 35 " mongolian-genetic stage." Herrman maintains 1 mother " 35 " 1 " ' 34 " that mongolism exhibit's the behaviour of a 2 mothers ' 33 " 1 mother '' 33 " true recessive unit because of which it may be 3 " " 32 " 1 " " 32 g 2 " " 31 " 1 " " 31 " expected to reappear in the general population 1 mother " 30 " 4 mothers ' 30 " from time to time, and that the mongol presents 1 " " 29 " 3 " 29 " 2 mothers " 28 " 3 " 28 g" both mongolian and anthropoid characteristics, 3 " " 27 " 6 " " 27 '' and represents reversion to a primitive type. 4 " 26 ' Macklin suggests that mongolism is hereditary, 2 " " 25 " 1 mother " 24 " 2 " " 24 ' due to a combination of recessive factors. The 1 "' "' 23 '" 7 " ' 23 g 1 "' '" 22 " 2 " " 22 " occurrence of more than one mongol in a family 1 mother " 21 " is rare; out of 2,526 mongols studied Macklin 4 mothers 20 " found only 30 such cases. One family contained 2 mothers " 19 " 2 " " 19 " 4 mongols, there were 3 cases of 3 in a family, Total 53. Total 50. and 26 of 2 mongols in one family. There were Average age 35.7 Average age 27.3 WARNER: MONGOLISM 499 Nov.Nov.1935]1935] WARNER: MONGOLISM 499~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

a relatioiiship between the age of which the mothers were young women and suffered from demonstrating hypothyroidism. Clark, of Edinburgh, believes that the dam and the incidence of polydactylism in mongolism is caused by fetal hyperthyroidism, ceasing at in-bred guinea pigs. This was apparently not birth. In support of this theory he suggests that the mechanics of exophthalmos, with Moebius' sign, occur- wholly due to genetic factors, and could not be ring during antenatal life and ceasing at birth, would segregated. Von Hofe reported that in his account for the changes in and around the eyes of the mongol. These changes, cataract, epicanthus, strabismus, series of 150 cases 86 per cent of the mothers slanting eyes, high arched eyebrows, large orbital fissures, were thirty or over at the time of the mongol etc., differ from arrests of development, and therefore explanation from that of general re- per cent were or over. In our require a different birth; 55 35 tardation. With regard to the peculiar tongue of the series the maternal ages are known in 53 ca'ses. mongol he states, "In my view the mongol 's tongue the As a control series 50 cases were selected at results from participation of the tongue muscles in general muscular hypotonus, the muscles are lax and random from the records of the Hospital for extensile, and tone being defective, the tongue gradually Sick Children. The average age of the mothers expands, due to oral suction. Such an organ functions defectively, and this in turn gives rise to the constant of mongols in our series was 36 yeails, whereas sucking movements." Pennacchietti accepts this theory, the average mother of the normal children was and adds "If we reduce the conditions of hyper- thyroidism to a degree less than those that have been aged 27 years. In the mongol series, half the realized by physiological experience, and if we associate mothers were 37 or over; in the control series, with these conditions a dependent hypo-evolution of organs concerned wvith dimensional growth, i.e., the half were 27 or over. Twenty-eight per cent of thymus, and adrenal cortex, we can easily reconstruct the the mongols were born to mothers of 40 or over, pathogenesis of mongolian idiocy, which consists in a with signs of precocious as to 4 per cent of the normal chil- congenital somatic infantilism, compared senility (involution of the thymus, dystrophy of the dren. Mothers under 30 years of age produced skin and teeth, hypotrophy and involution of the adrenal 21 per cenit of the mongols and 72 per cent of cortex), as dependent on a too rapid and precocious process of differentiation of the diverse structural stages, the normal children. of thyroid origin." A parallel may be drawn with the who fed tadpoles on birth of a mongol findings reported by Gudernatsch, Stekloven stated that the tlhyroid and observed that metamorphosis was brought is frequently preceded by a period of diminished about prematurely, the tadpoles becoming perfect pigmy fecundity; that 87 per cent of normal children frogs; their life span was invariably brief, but even those that were kept alive for several weeks failed to are born after an interval of not more than four show any further growth or differentiation. With regard years since the last previous child, and only 62 to the suggestions of a polyglandular dyscrasia, Loeb and Friedman found that the feeding of anterior per cent of mongols occur after a like interval; pituitary extract to guinea pigs resulted in hypertrophv only 1.37 per cent of normal children follow after of the thyroid with decrease of colloid, and that Grave's disease was simulated with respect to the changes in the an interval of nine or more years, whereas 12 per thyroid and the basal metabolic rate. They also ob- cent of mongols are born after such an interval. served that the exophthalmos thus caused was functional and tended to disappear before death and in complete Our figures closely approximate the above. Of narcosis; similarly, one might expect a fetal tendency to the cases having older siblings, among the mon- exophthalmos to disappear before birth if the hyper- gols the next member of the family was at least thyroidism had ceased. In addition to Clark's explana- tion of his theory of fetal hyperthyroidism, it may be five years older in 29 per cent of cases; in the said that the increase of thyroid activity in the pregnant control series only 19 per cent showed a five- woman is well known, and that Shunkai Ujiie has shown experimentally that the placenta is permeable to the year gap between the patient and the last pre- thyroid and parathyroid hormones. It is also known that vious child. insulin produced by the fetus in the later stages of pregnancy may be utilized by the mother. It remains to When mongolism occurs in dizygotic twins find some explanation for the apparent correlation be- only one twin is affected, the other being normal; tween the changes in the fetus, if these are due to and the diminished fecundity of the in the case of monozygotic twins both are mon- hyperthyroidism, mothers of mongolian offspring. gols. This is a point against the theory that mongolism is due to the modification of sperm The prognosis, mentally and physically, is cells by toxic secretions of the female generative bad. Approximately half of our series died tract, related to the age of the mother. In ex- while under observation, the average age at planation of the above findings with respect to death being 12.6 months. In 56 per cent of the twins it has been suggested that the immediate cases the cause of death was broncho-pneumonia. cause of mongolism may be a local pathological The next most common cause of death was con- change in the uterine mucosa. genital heart disease, 7 per cent. Cardiac and Stoeltzener has advanced the theory that the cause other congenital defects are extremely common. of mongolism may be maternal hypothyroidism during Von Hofe's series of 150 cases showed congenital pregnancy, empoverishing the embryo of sufficient hormones, and two cases are cited by another author in cardiac defects in 9.3 per cent. Thirty-four per 500 THE CANADIAN MEDICAL ASSOCIATION JOURNAL [Nov. 1935 cent of our series had some type of defect apart incapacity but also by defective muscle tone and from the deformities characteristic of the condi- inability to coordinate in fine manual exercises. tior, and 13 per cent of the cases had congenital My thanks are due to Dr. Alan Brown for permission heart lesions. The next most common defects to use the records of the Hospital for Sick Children in were herniae (exclu'sive of umbilical herniw), 5 gathering my material. BIBLIOGRAPHY per cent, and club foot, 3 per cent. In com- 1. GuiERNATSCH, J. F.: Feeding experiments on tadpoles, Am. parison, 100 infant ward charts, selected at J. Anat., 1913-14, 15: 431. 2. PENNACOHIETTI, M.: Idiotie mongolienne et hyperthyroid- random showed only 2 cases of congenital heart isme, Rev. Neurol., 1932, 2: 276. 3. CLARK, R. M.: The mongol, a new explanation, J. Mental disease and 5 other congenital defects. Thacher Sc., 1929, 75: 261. 4. GORDON, M. B.: Morphological changes in the endocrine reports that there is no characteristic electro- glands in mongolian idiocy with report of two cases, Endocimotolgy, 1930, 14: 1. cardiographic abnormality associated with mon- 5. LOEB, L. AND FRIEDMAN, H.: Exophthalnos produced by injections of acid extract of anterior pituitary gland of golism, as is the case in cretinism. cattle, Proc. Soc. Exper. Biol. Med., 1932, 29: 648. 6. VON HoFE, F. H.: Report of 150 cases of mongolian idiocy, The outlook for the mongol is as a rule worse Arch. Pediat., 1922, 39: 737. 7. MA.CKLIN, M. T.: Mongolian idiocy: the manner of its than for other imbecile's of his mental group, inheritance, Am. J. M. Sc., 1929, 178: 315. 8. BROUSSEAU, K.: Mongolism, Williams & Wilkins, Baltimore, as the mongol is hampered not only by mental 1928.

LEFT VENTRICULAR FAILURE* BY F. CARLYLE HAMILTON, B.A., M.B., Toronto IF one omits the discussion of sudden death, currences by reference to insufficiency of the there remain two distinct types of cardiac valves of the heart, resulting in increasing pres- failure with which the practising physician is sure in the systemic veins. Following the familiar. The fitst of these deals not with discredit cast upon the idea of "back-pressure", myocardial disease, but with sclerosis of the the same type of cardiac failure would for a coronary arteries resulting in deficient blo6d time have been attributed to inefficiency of the supply to the heart muscle. The myocardium left ventricle in promoting a forward flow of may quite well be healthy, and the heart valves blood. This latter idea has also been abandoned, normal. In this type the cardinal symptom is for we now realize that the onset of congestive pain. The pain may be that of angina pectoris; failure is due neither to predominant valvular that is, it may occur on effort and disappear leakage nor to diminished left ventricular pro- with re'st, or it may be the more prolonged and pulsive power (the so-called vis a tergo), but severe pain of coronary thrombosis. The diag- essentially to failure on the part of the right nosis of coronary sclerosis cannot be established ventricle to drive forward into the lung circuit clinically except by the occurrence of angina the blood reaching it from the venous return to or coronary thrombosis, or by the demonstra- the heart. The factors which throw strain upon tion of ample electrocardiographic changes. The and eventually weaken the right ventricle are second familiar type of cardiac failure is the increa'sed pressure in the pulmonary circulation, ko-called "congestive heart failure". This may resulting from mitral stenosis, or from pul- occur when there is weakness of the myo- monary disease such as advanced emphysema, or cardium as a whole, or where the right ventricle from a direct load on the right ventricle in alone is at fault. Lewis, in his recent book cases of pulmonary valve stenosis. More com- "Diseases of the Heart", has described beauti- mon than any of these causes of strain on the fully the symptoms and signs of this condition; right heart, is, however, increased pulmonary namely, increasing breathlessness, engorgement pressure due directly to failure of the left of the neck veins, cyanosis, liver enlargement, ventricle, which latter subject will constitute and dependent aedema. The old "back-pres- the balance of this paper. sure" theory would have explained these oc- Isolated left ventricular failure means a * Read before the Section of Medicine, Academy of weakened state of the left ventricular muscula- Medicine, Toronto, March 12, 1935. ture resulting in increased pulmonary pressure,