Unusual causes of obstruction at the mitral valve

Unusual

Causes

of Obstruction

Mitral EARL F. BEARD,

Valve*

F.A.c.c., DAN G. MCNAMARA, M.D., DENTON A. COOLEY, HARVEY S. ROSENBERG, M.D. and JERRY D. JORDAN, M.D.

M.D.,

Houston,

T

HE usual cause of obstruction to pulmonary venous return at the level of the mitral valve is rheumatic mitral valve stenosis. Less common causes include (1) tumors of the left atrium, especially left atria1 myxoma, (2) congenital mitral stenosis and (3) car triatriatum. Although primary tumors of the heart are rare, myxoma is the most common of these,ls2 and the majority occur in the left atrium.3 Congenital mitral stenosis is also uncommon2~4,6 and is exceptional as an isolated lesion, most frequently occurring in combination with other cardiac anomalies. Cor triatriatum is a congenital malformation in which a transverse septum separates the left atrium into an upper chamber, which receives the pulmonary veins, and a lower one, which overlies the mitral valve.6-8 Since perforations of this septum are usually small, a situation physiologically similar to mitral stenosis is produced. The purpose of the present report is to compare clinical, physiologic and anatomic features of these lesions. Included are 3 cases of left atria1 myxoma, 9 of congenital mitral stenosis, and 6 of car triatriatum seen in a nine year period, 1953 through 1961. All were confirmed at autopsy or surgery, except 2 cases of congenital mitral stenosis, which were confirmed at cardiac catheterization. CLINICAL OBSERVATIONS LEFT ATRIAL MYXOMA

.

Three

cases of this condition were encounOne of them was a child who presented manifestations of cerebral vascular thrombosis.g Two were adult women with clinical data suggestive of mitral stenosis plus systemic manifestations of recurrent fever or elevated erythrocyte sedimentation rate. In the latter 2 pa-

tered

at the

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169

F.A.c.c.,

Texas

tients, successful removal of the myxoma was accomplished by using total cardiopulmonary bypass with a pump oxygenator.iO The clinical picture of left atria1 myxoma sufficiently large to impede blood flow was usually very similar to that of rheumatic mitral stenosis. Previous authors have emphasized this similarity.3 Systemic manifestations of recurrent fever or continued elevation of erythrocyte sedimentation rate should arouse suspicion of myxoma, as should the presence of changing murmurs. Goodwin and co-workers” also found a high incidence of hypergammaglobulinemia in patients with myxoma. CONGENITAL MITRAL STENOSIS This lesion was usually associated with other congenital cardiac anomalies. In only 2 cases, one a girl of 16 years and the other a 9 month old infant, did it occur as the only cardiac anomaly present. In these cases the clinical picture was similar to rheumatic mitral stenosis with some differences. Murmurs were diastolic, as in the acquired form. However, roentgenograms and electrocardiograms did not show clear-cut evidence of left atria1 enlargement but rather signs of right ventricular hypertrophy and right atria1 enlargement. Most patients with congenital mitral stenosis were infants and young children with associated anomalies, including ventricular septal defect, patent ductus arteriosus, congenital aortic stenosis, coarctation of the aorta, pulmonary atresia and corrected transposition of the great vessels. Several cases showed endocardial sclerosis of the left atrium, but this was considered to be secondary to the obstruction.” While the clinical findings in these complicated cases of congenital mitral stenosis varied with the associated defects, certain features, especially

* From St. Luke’s Episcopal and Texas Children’s Hospitals, Houston, Texas. VOLUME

M.D.,

Heard

170 ‘I’ARLX Clinical

Findings

L

in Nine Casts Strnosis

of Congenital

Mitral

7 7 7 4 6 3

Age under 2 years Associated cardiac anomalic~ Dyspnea Cyanosis Parasternal systolic murmur Diastolic murmur Electrocardiographic evidence of Right ventricular hypertrophy Right atria1 enlargement Left ventricular hypertrophy Left atria1 enlargement

TABLE

et 21

9 6 2 0

II

Pressures (mm. Hg) in Congenital Mitral Stenosis-Averages and Ranges in Five Patients Diastolic

Systolic

Mean

_ Systemic artery Pulmonary artery

(7Os:OO)

(3050,

(SCZO)

(&IO)

(2ZO)

(2Z44)

Left atrium

(1z25)

TABLE

Clinical

Findings

III

in Six Cases of Cor Triatriatum

Age under 2 years Associated cardiac anomalies Dyspnea Parasternal systolic murmur Diastolic or continuous murmur No murmur Pulmonary venous congestion Electrocardiographic evidence of Right atria1 enlargement Right ventricular hypertrophy (No ECG in 2 cases) Sudden death

1,‘1c:.1. Ca.w 1. My:wma wmovcd from lrft atrium at op(,r.ltion. Ttw tumor was 6 cm. in xrc’atrst diametcl anal was atractwd to thr atria1 septum by a narrow ‘I’hc mitral \-al~c was normal. stall,

4 4 s

These constant. infants usually had a sudden onset of dyspnea or congestive failure and frequently became Usually a cyanotic on feeding or crying. systolic murmur was heard in the left parasternal area. The diastolic and presystolic murmurs heard in acquired mitral stenosis were usual11 not heard when congenital mitral stenosis was In spite of complicated by other anomalies. the wide variety of associated anomalies, the electrocardiogram showed changes suggestive of right ventricular hypertrophy in all cases and

in small infants, were relatively

FK;. 2. C&r 2. Congenital mitral stenosis. Phonocardiogram recorded over cardiac apex showing diastolic and presystolic murmurs heard on physical examination. atria1 dilatation in some. The frequency of these findings is shown in Table I. Pressures encountered at cardiac catheterization are shown in Table II. The frequency of associated right

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Unusual

Mitral

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171

Obstruction

FIG. 3. Case 3. Congenital mitral stenosis, congenital aortic stenosis and patent ductus arteriosus. The heart at autopsy. The left ventricle and atrium have been opened to show the hypertrophied walls and small cavity of the left ventricle and the stenotic mitral valve with fusion of its cusps and short, thick chordae tendineae.

anomalies, greatly distorted anatomy of the valve and chordae tendineae precluded surgical correction, although successful operation has been reported by 0thers.n COR TRIATRIATUM

Six cases of car triatriatum were seen. One of these was diagnosed ante mortem and surgiFive patients died during incally corrected. fancy, 2 without suspected cardiac disease because of meager physical findings. In contrast to congenital mitral stenosis, only 2 of the 6 patients had other associated cardiac anomalies. Although there were no diagnostic clinical features, all patients experienced dyspnea, and sudden death was frequent. Pulmonary venous VOLUME

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congestion was a constant radiologic finding. Electrocardiograms suggested right ventricular hypertrophy. Table III shows the relative frequency of these findings. Cardiac catheterization, when done, invariably showed elevated pulmonary artery and pulmonary wedge pressures. It is generally felt that this anomaly results from failure of the common pulmonary vein to be incorporated into the body of the left atrium.* CASE REPORTS Left atria1 myxoma. A 49 year old woman was admitted with symptoms suggestive of mitral stenosis, apical mid-diastolic and presystolic murmurs, and an opening snap of the mitral valve. There had been recurrent low grade fever with negaCASE

1.

172

Beard et al.

1:~;. 4. Case 4. C:or triatriatum. Heart at tiny openings. divides thr lrft atrium tram\ pulmonary veins and a lower one which is mitral valve itsrlf is normal, but inflow to lrft tive blood cultures; the erythrocytc sedimentation rate had been continuously elevated; and at times a systolic murmur had been heard, Roentgenogram\ showed equivocal evidence of left atria1 enlargement as did the electrocardiogram. At right heart cathrterization, the mean pulmonary wedge pressure, approximately 20 mm. Hg at rest, rose to 35 after two minutes of light exercise, and the pulmonary arter! pressure rose from resting levels of 40/20 to 70/50 with exercise. At surgical exploration of the left atrium. a myxoma seemed to obstruct forward flow through the mitral valve. A tumor 6 cm. in diameter (Fig. 1) attached to the atria1 septum was removed, and the patient made an uneventful recovery. CASE 2. Congenital mitral stenosis (isolated). A 13 year old girl had noted exertional dyspnea ever since On physical examination there she was able to walk. was a grade 3 rumbling apical diastolic murmur, as illustrated by the phonocardiogram in Figure 2, and the pulmonic component of the second sound was Roentaccentuated. There was no opening snap. genograms showed diffuse cardiac enlargement without localized chamber enlargement, and the electrocardiogram suggested right ventricular hypertrophy At cardiac catheterizawith right atria1 enlargement. tion, the pulmonary artery pressure was 50/28 mm. Hg (mean 35), and no intracardiac shunts were demonstrated. The mean left atria1 pressure was 20

au:~~l>~y. .\ tlcnsr librous srpturn. pcrlbratrd by t~wly into an upprr chamber which receives the in c:on!lnunication with the mitral valor. The \cwtrirlc is obstructed by the anomalous septum. mm. tlg and that in the left ventricle 100/O. There \vas a 14 mm. diastolic pressure gradient across the mitral valve. At operation, the mitral valve was a firm, fibrous structure without easily palpable commissures and contained a very small central opening. Attempts to split it at the usual location of the commissures were unsuccessful, and the patient was discharged from the hospital essentially unchanged. This case illustrates the clinical findings of a patient in whom congenital mitral stenosis was the only anomaly present, CASE 3. Congenital mitral stenosis (associated with other anomalies). A 9 day old male infant experienced dyspnea and cyanosis on feeding and had a loud pansystolic murmur over the entire precordium. Roentgenograms showed pulmonary venous congestion and a markedly enlarged heart with globular configuration. An electrocardiogram showed evidence of combined right and left ventricular hypertrophy. The child died 24 hours after admission, in spite of intensive medical therapy, and the heart at autopsy showed congenital mitral stenosis associated with congenital aortic stenosis and a patent ductus arteriosus (Fig. 3). CASE 4. Cor triatriatum. A 1 year old boy had progressive dyspnea, fatigability and cardiac enlargement for six months. There was a right ventricular heave and a soft continuous murmur along the left

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AMERICAN

JOURNAL

OF CARDIOLOGY

Unusual

Mitral

Roentgenograms sternal border and at the apex. showed diffuse cardiac enlargement, and electrocardiograms suggested right ventricular hypertrophy with right atria1 enlargement. At right heart catheterization the right ventricular pressure was 100/O mm. Hg, but the pulmonary artery could not be The patient died suddenly four hours after entered. catheterization, and at autopsy a dense fibrous diaphragm perforated by several 1 to 2 mm. openings extended horizontally across the left atrium above the mitral valve (car triatriatum) (Fig. 4). SUMMARY

AND

CONCLUSIONS

The usual cause of obstruction at the mitral valve is rheumatic valvular stenosis. Less common causes include tumors of the left congenital mitral stenosis, and car atrium, triatriatum. 1. Myxoma of th left atrium, when of sufficient size to impede blood flow, usually produced a clinical picture similar to rheumatic mitral stenosis. Systemic manifestations such as recurrent fever and continued elevation of erythrocyte sedimentation rate should arouse suspicion Physiologic data at cardiac catheof myxoma. terization usually resembled those produced by Occasionally perheumatic mitral stenosis. ripheral tumor emboli have led to diagnosis. Angiocardiography may demonstrate the tumor. Left atria1 myxomata may be satisfactorily removed by open heart surgery with cardiopulmonary bypass. 2. Congenital mitral sfenosis was usually associated with other congenital defects of the heart and great vessels, which caused variability in However, patients were usuclinical findings. ally infants who experienced a sudden onset of dyspnea and congestive failure. They often showed cyanosis on feeding or crying and usually had a left parasternal systolic murmur. Electrocardiograms and roentgenograms almost always suggested right ventricular hypertrophy and right, rather than left, atria1 dilatation. Congenital mitral stenosis was seldom isolated, but when it was, clinical features were more similar to those of acquired mitral stenosis. Attempts at commissurotomy were unsuccessful because of profoundly distorted configuration of the valve. 3. In COTtriatriatum, a congenital, transverse,

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fibromuscular septum with small perforations divided the left atrium into an upper chamber, which received the pulmonary veins, and a lower one which communicated with the mitral valve. In conThe mitral valve was usually normal. trast to congenital mitral stenosis, there were usually no other associated cardiac anomalies. Murmurs and other physical findings were at times so inconspicuous that cardiac disease was not suspected. There was no characteristic x-ray appearance of the heart itself, but pulElectromonary venous congestion was usual. cardiograms showed evidence of right ventricular hypertrophy. Cardiac catheterization showed elevation of pltlmonary artery and pulmonary wedge pressures. Sudden death was Cor triatriatum is surgically correctcommon. able if the diagnosis can be made. REFERENCES 1. PRIGHARD, R. W.

Tumors of the heart: Review of the subject and report of 150 cases. Arch. Path., 51: 98, 1951. 2. WOOD, P. Diseases of the Heart and Circulation, p. 630. Philadelphia, 1958. J. B. Lippincott. 3. ALDRIDGE,K. E. and GREENWOOD, W. T. Myxoma of the left atrium. &it. Heart J., 22: 189, 1960. 4. ABBOTT, M. E. Atlas of Congenital Heart Disease, p. 61. New York, 1936. American Heart Association. 5. FERENCZ, C., JOHNSON, A. L. and WIGLESWORTH, F. W. Congenital mitral stenosis. Circulation, 9: 161, 1954. 6. GRIFFITH, T. W. Note on a second example of division of the cavity of the left auricle into two compartments by a fibrous band. J. Anot. G3 Physiol., 37: 255, 1903. 7. PEDERSEN,A. and THERKELSEN,T. Cor triatriatum: A rare malformation of the heart, probably amenable to surgery. Report of a case, with review of literature. Am. Heart J., 47: 676, 1954. 8. EDWARDS, J. E., DUSHANE, J. W., ALCOTT, D. L. and BURCHELL, H. B. Thoracic Venous anomalies. A.M.A. Arch. Path., 51: 446, 1961. 9. CHAO, D. H., HENRY, M. 0. and ROSENBERG,H. S. Myxoma of the heart with internal carotid artery occlusion in a child. Neurology, 10: 418, 1960. 10. COOLEY, D. A., MORRIS, E. C., JR. and ATTAR, S. Cardiac myxoma. Arch. Surg., 78: 410, 1959. 11. GOODWIN, J. F. et al. Clinical features of left atria1 myxoma. Thorax, 17: 91, 1962. 12. ELLIOTT, L. P., ANDERSON, R. C., AMPLATZ, K., LILLEHEI, C. W. and EDWARDS,J. E. Congenital mitral stenosis. Pediatrics, 30: 552, 1962.