Criteria for surgery in persistent common atrioventricular canal∗

Criteria Persistent

for Surgery

Common

in

Atrioventricular

Canal*

DENNISON YOUNG, M.D. New York,

New York

ERSISTENT COmmOn atrioventricular canal, however mild, is incompatible with continuing good health and normal life expectancy. Surgical correction must be considered even though collective experience’ -5 (Table I) shows an unacceptable surgical mortality rate in the severe forms of this disease and a high frequency of residual mitral insufficiency in the milder cases.5 Criteria for surgery based on careful anatomic and physiologic evaluation, however, allow for reasonable predictability of a successful outcome, increased life span and improvement in cardiac function.

serves as a reminder of the embryologic origin of the anomalous development, but it is of no value as a diagnostic refinement nor for anticipation of corrective requirements at time of surgery. The nomenclature based on anatomical subdivision into partial, intermediate and complete forms of atrioventricular canal, proposed by Wakai and Edwards,‘O correlates well with the clinical and physiologic assessment. LYhile it is true that clinical distinction between the three groups is not always clear-cut and occasional overlap in specific subgrouping may occur, with this as a working classification reasonable criteria for surgical intervention can be established. Common to all three forms is the persistence of the ostium primum, resulting from failure of upward growth of the endocardial cushions. The severity of the associated defect is determined by the degree of fusion of these two cushions with each other and with the atria1 and ventricular septal complexes. Partial Form: Failure of fusion of the left dorsal and ventral atrioventricular cushions results in a cleft in the anterior leaflet of the mitral valve, but the tricuspid valve leaflets are normal. The intact septal leaflet of the tricuspid valve forms the lower edge of the atria1 septal (primum) defect. Rarely there is some unusual shortening of the septal leaflet. Edwards” has emphasized the importance of recognizing and eliminating the abnormal accessory chordae tendineae. These insert into the valvular tissue bordering on the cleft in the anterior mitral leaflet and attach to varying While they sites on the ventricular septum. may serve a useful function prior to repair of the mitral cleft, their retention following repair may contribute to persistent mitral insufficiency or even intensify the degree of regurgitation (Fig. 1).

P

INCIDENCE Although significantly of lesser incidence than other congenital lesions requiring open heart surgical correction, defects of the atrioIn Keith and ventricular canal are not rare. co-workers’6 experience this lesion represents approximately 2 per cent of all congenital cardiac anomalies in patients up to 14 years of age. Paul7 indicates an incidence of one endocardial cushion defect for each seven or eight ventricular septal defects in a pediatric population. Persistent common atrioventricular canal was the eighth most frequently encountered malformation (4.2%) in Fontana and Edwards8 pathologic study of congenital cardiac disease. In our institution there have been 43 patients (5%) with defects of the atrioventricular canal (exclusive of 8 with levocardia and situs inversus) of 800 patients with congenital heart disease physiologically studied. Their ages have ranged from 2 days to 54 years. Ten of this group have been over 17 years of age, thus comprising 4.4 per cent of a series of adults with congenital heart disease9 (Table II). CLASSIFICATION The

term

“endocardial

* From the Cardiology

Service

cushion (Medical

defect” and Pediatric 80

Divisions),

Mont&xc THE

Hospital,

AMERICAN

New York, N. Y.

JOURNAL

OF

CARDIOLOGY

Common

Atrioventricular ~'ABLE

Operative

Canal

81

I

Mortality-Combined

Series

_Partial No. of Patients

Operative Deaths _ . _________..

No. of Patients

Complete Operative Deaths

Ellis et al.’

66

5 (7.5%)

20

13 (65y0,)

Cooley2

35

4 (llY*)

24

16 (64Yo,!

9

2 (22%)

9

41

9 (22%)

15

4 (27%)

4

Dubost & Blandeau 3 Crafoord & Senning& Scott et al.b Young

(this

series)

Here there is lack of fusion Complete Form: of the two atrioventricular endocardial cushions with each other and with the atria1 and ventricular septal complexes. Thus, in addition to the low-lying primum defect of the atria1 septum, a continuous cleft through both the anterior mitral leaflet and the septal tricuspid leaflet results in a single valve common to both sides of the heart. 4 significant ventricular septal defect is almost invariably present beneath this common atrioventricular valve (Fig. 2). Intermediate Form: This represents a transitional situation somewhat less in severity than the complete form because of a greater degree of fusion of the dorsal and ventral atrioventricular cushions in the midline. Although there are clefts in both the anterior mitral and in the septal tricuspid leaflets, a narrow bridge of valvular tissue is present interrupting what would otherwise be a common cleft and thus a The severity common atrioventricular valve. of the interventricular communication in this type is often much less, and a defect may not even be present. The upper part of the membranous septum, if deficient, may be sealed off almost completely by fused chordae crossing the defect, or only minute communications may exist (Fig. 3). Associated Cardiac .tialformationr: Other congenital cardiac defects may occur in association with those of the endocardial cushions. Except for the presence of a double mitral valve and of pulmonic stenosis, the significance and frequency of most is slight. Wakai and Edwards have called attention to the relatively high incidence of the associated double mitral valve. This anomaly was found in five of their 28 JULY

1363

Intcrmediatc No. of Operati\zc Patients Deaths Of 6 survivors classified as complete 5 were transitional type No brrakdown

5 (55%)

7

1 (14%,

4

3 (75%)

12

14

9 (64%)

3 (35%) No breakdown

3

2 (67%)

4 (100%)

cases, 3 being of the intermediate and 2 of the complete type. Pulmonic stenosis, valvular, infundibular or both, is encountered in association with the complete form and has been unusually common in our experience (Table II). CLINICAL

CONSIDERATIONS

AND

SIJRGIUI.

INDICATIONS The clinical profile of common atrioventricular canal has been adequately described by others5f7’r2-i4and little need be added. It has been stated that no absolute differentiation of the complete from the incomplete forms is possible on clinical grounds,5 but the greater the evidence for pulmonary hypertension, the larger the heart, the sicker the child in infancy, the more likely is a complete defect present. As a corollary of this, the older the patient, the greater is the likelihood that the defect is the partial form (Table II). irhe roentgenographic features in genera1 also correlate with the severity of the illness. Larger hearts and greater degrees of pulmonary engorgement as a rule are associated with more severe anatomic derangements and pulmonary hypertension (Figs. 4A and B). The major exception to this occurs when there is pulmonic stenosis in conjunction with the complete form of the defect (Fig. 4C). l%e electrocardiogram and vectorcardiogram in common atrioventricular canal have been considered nearly diagnostic.15 These demonstrate left axis deviation in the standard extremity leads with a mean electrical axis beyond - 30°, superior orientation of the vector loop with counterclockwise inscription in the frontal plane, and an rSR or right ventricular hypertrophy pattern in the right precordial leads

82

Young TABLE Data

from

43

Cases

of

Persistent

II

Common

Catheterization

iitrioventricular

Canal

Pressures

(mm.W (:‘I%

I 2

Symptoms

1. F 4, F

CHF at 10 mo.; Delayed growth

3 4 5 6 7 8 9 10

0, F 12, F 12, hf 6ii2, &I 17. F F 6. M 14. F

Delayed Limited Limited CHF 1st Fatigue CHF at

11 12

li, M i ,110

Limited activity CHF at 2 mo.

13 14 15 16 17 IX 19 20 21 22 23 24

7. F 9, t 10, F 20. M 14, bf 1’). F 13: F 54, 1: 4, F 4. M 45, I: 32, 1.

2.5 26 27

8, F 29, M 14, F

39:

/ 51

RV

delayed

growth

at 8 yr.

growth

34 yr. 0

CHF

at 12 yr.

Delayed Delayed

growth growth

Limited

activity

0 n 0 hlild

dyspnea

for 8 yr. 0 0

CHF at 41 yr. Dyspnea, cyanosis I.imited

30/10

35/o 63/S 39/o 49 /6 40/3 70/‘7 40/o 56/5

4613 26il5 58113 38/14 60/l 8 47/24 48/12

36/2

36/10

l25/73

46/5 30/l 66/l 50/o 26/3 46/9 4517 50/o 46/10 18/O 64/10 120/o

2817 26/12 34/12 25/12 22/a 30/15 41/12

99/56 120/78

65/3 52/O

activity n 0

Results

Systemic

52/4

.

growth; CHF activity activity year; delayed

PA

82/2

(LV)

.

9613 124/& R0/45 107,‘58 106/65

110/b; 100/75 110/14 130/90 128/66 110/8 (LV) 87/49 123/62 118/65

45/15 1915 151,‘42 52132

.._ 131/77

and

Comments

Died of heart block po~top. Severe CHF due to increased MI; preop. cathetertiation and operation elsewhere 2 yr. p0st0p.---exce11ent 3 yr. postop.-very good; slight MI 3 yr. postop.-very good; slight MI Lifesaving operation; severe MI 41/z yr. postop. 3 y’. postop.-good; moderate MI 2 yr. postop.-very good; moderate MI; no CHF Died of heart block-postop. (Toad operative result-died of acute bacterial endocarditis 8 wk. portop. 1 yr. postop.-very good: slight MI J.igation of patent ductu arteriosus at 3 mo.-dicrl 3 days postop. L yr. postop.--excellent; no CHF 4 yr. posto~.-excellent; no CHF Died of heart block 3 davs Doyto”. 3 yr. postop.--exrellent ’ . No urgency for surgery Awaiting surgrry AwaitinK surgery Refused surgery No urgency for surgery No urgency for surgery Ref”s;d s”;gery Eisenmengcr syndrome; Art. 0% snt 88”;,; no surgery Awaiting surgery Refused surgery To be restudied

Inlermedintc

28 2’) 30

5: b

Limited Cyanosis; I.imited

2, F 18, F

45;o 65/15 28115

activiry CHF activity

86/4 (LV) 60/12 (LV) 95/55

;5/10 26j10

Recent operation-good Died during surgery Died of heart block

5 days

postop.;

retarded

___

31 32 31

15 da., M 2, F 19 mo.. F

34 35

71/t, M 3 mo., M

36

2’/2,

F

CHF at CHF at CHF at Dyspnea, CHF at CHF at

2 dabs 7 weeks 6 mo. cyanosis, clubbing 2 mo 1; cyanosis; clubbing

.., 84/4 7515 85;O

85/39 69/25 92/64

::: 107/O (LV) 96/70 80/10..’ (LV)

59/25

Died during catheterization Sudden death Sudden death: Mongol Mongol Died of infection: CHF: Retarded

retarded

(pul. vein wedgr) 37 38

R, x4 5, F

Ddayedgrowth; Delayed growth;

CHF; CHF

arrhythmias at 3

66’12 45/o

Cqbletc

0

47123

with Pulmonic

39

3, F

40 41 42

3, F 6, M 19, F

Mild cyanosis and clubbing Delayed growth; mod. cyanosis Cyanosis, dyspnca, syncope

87/l’) 88/15 114/9

.,. 38/12 lb/7

43

8, F

Cyanosis,

100/20

g/5

squatting,

RV = right ventricle; PA = sat. = arterial oxygen saturation;

Died Died

107/ 70 96/48

pulmonary angio =

artery; LV = angiocardiography.

left ventricle;

Angio-pulmonic stenosis, ventricular septal died during catheterization; peripheral 89%; Mongol Angie-pulmonic stenosis; no operation No operation Died of shock postop. Died in operating room

98/65 96148 112,67

CHF

MI

postop.

Stenorir

90/o

dyspnea

of heart block postop.; retarded of pulmonary edema and residual

=

congestive

heart

THE

failure;

AMERICAN

MI

=

mitral

JOURNAL

insufficiency;

OF

defect; 02 sat.

Art.

CARDIOLOGY

0%

Common

Atrioventricular

FIG. 1. A, completefornz of persistent cmnmonatrioventricular cannl vicwcd from the left, illustrating chordac tendineae. The anterolatrral (A) and posteromedial (P) papillary muscles rvrei\-e chordae attached to the adjacent portions of the posterior leaflet and cleft anterior leaflet (A.M.) of thr mitral valve. The accessory chorclae (arrows) extend from the edges of the cleft in the leaflet to the ventricular septum. B: similar view subsequent to repair of cleft of anterior mitral lraflet (A.M.) .\ccessory rhordae tendincar I arrows) have not been divided, resulting in restraint dllring systolr and residual or increased mitral insufficiencv. (From Ref. 11, reproduced with permission of the Srction of Publications of Tlw Mayo Clinic, Rochvstvr-, Minn.)

(Fig. 5.4). In our series of such patients with endocardial cushion defects, however, frequent pattern were noted’6 variants of the “typical” (Fig. 5B). In general, the patients in the “atypical” group had more severe heart disease ; 4 showed the complete form of the lesion, 3 of them with associated pulmonic stenosis. I'.-\RTIALFORM

Symptoms in general are significantly fewer in those patients with the partial form of common atrioventricular canal (Table II). Some have JULY

1963

(Zanal

83

no complaints and normal to mildly elevated pressures in the pulmonary artery. More have evidence ofdiminished cardiac function, but the incidence of congestive failure is considerably less than in the complete form. Cardiac enlargement is present to some degree in all and increases proportionately with the clinical and physiologic severity of the disease. In this regard, as has been stated by others, clinical differentiation of the advanced cases of the partial form from the complete variety- may be impossible. Cardiac catheterization, hovvever, usually shows less elevation of pulmonary arterial pressure in the former because of the absence of a ventricular septal defect. M’hen the pressure is inordinatelv high, mitral insufficiency is a ma,jor dynamic factor. Operativr Procedures: Thus, because development of the heart has progressed closer toward the normal condition in the partial than in the other forms, longer survival can be anticipated, at least until early adult life and occasionally beyond. It is in this group that the surgical mortality is acceptably low (Table I) and anatomic correction acceptably- high. Surgery is considered desirable for patients of this group who are symptomatic, have significant cardiac enlargement or show a moderate increase in pulmonary arterial pressures, e\‘en though asymptomatic. It is not imperative, however, that all be operated upon at an early age unless a relatively advanced condition is present. On continued observation of many over a period of several y-ears, it has been found that the tempo of the disease is not necessarily rapid, and no significant ad\.ance in their cardiovascular dynamics need be anticipated. It is possible, therefore, in many to await selection of the most propitious time in regard to weight and age before undertaking surgical correction. Ofierativr Results: Despite a surgical mortality. rate that has now achieved respectability, it must he recognized that this will not be as low as that for surgery of atria1 defects of the secundum type. Even with the best of surgical skills and the most careful electrocardiographic monitoring during surgery, heart block and death will occur in a certain percentage of patients. In addition, despite scrupulous attention to the anatomic details of the cleft in the mitral valve and attached anomalous chordae tendineae, correction will probably still leave some patients with residual mitral insufficiency (Fig. 6).

84

Young

B

A

canal. A, view from the right side of FIG. 2. CLv?l‘bl& form of persutrlzt CoIllmonatriouentricu1nr the heart demonstrating large communicating atria1 and ventricular septal defects and the cleft septal leaflet of the tricuspid valve. B, view from the left side of the heart showing the marked deficiency of the outflow portion of the ventricular septum. (From Ref. 11, reproduccd with permission of the Section of Publications of The Mayo Clinic, Rochester, Minn.) INTERMEDIATE

FORM

Some1~2~5 do not consider this transitional form a separate entity. Because of a functionally insignificant ventricular septal defect, howelTer, the severity of the clinical situation may be somewhat less than in the complete form, and natural survival may therefore be somewhat longer. The less severe anatomic

derangement may allow for a more complete repair. The lesser degree of pulmonary hypertension and the avoidance of right ventriculotomy (because the minor interventricular communication may be closed through the right atrium) serve as additional factors toward recovery from surgery (Table I). Patients in this group are often quite ill and have considerable cardiac enlargement so that surgical correction usually is indicated at a TABLE III Ten

Factors

Responsible

for Operative

Partial

‘4 FIG. 3. Intermedinfc (transitional) form of persistentcommon atrioventricular canal. .4, view from the right side of the heart showing the typical arch-shaped ostium primum atria1 defect and the narrow bridge of valvular tissue (arrow) joining the anterior and posterior components of the cleft septal tricuspid leaflet. B, view from the left side of the heart showing the cleft mitral leaflet. The inferior margin of the atria1 defect is bordered by valvular tissue (arrow) which is at the superior margin of the ventricular septum. (From Ref. 10, reproduced with permission of The .+nerican HeartJournd.)

Heart block Complex irreparable lesions Extensive pump time Extensive manipulation Right ventriculotomy Persistent pulmonary hypcrtension Creation of subaortic stenosis Inadequate common valve repair Inadequate mitral valve repair Congestive heart failure Postoperative shock Bacterial endocarditis

x

Mortality

Intermediate

x

Complete

x

x

s

x

x x

x

x x

x

x

x

x

x

x

x

x

x x

x

x

x

THE AMERICAN JOURNAL OF CARDIOLOGY

C~ornmon

fitrio\-entricular

85

(‘anal

FIG. 4. ,\, Case 18. Pnrtinijorm of pelsi~/ent cnmm0t2 atrrooenlriczrlar canal in a 19 yrar old girl with no symptoms. Roentgenograms show right ventricular and left atrial enlargement and widcnce of substantial increase in pulmonary flow. B, Case 33. Completeform ofprrsister~t atrioomtricular cad in a 15 month old Mongol girl in se\err congestive heart failure. Rocntgenograms show massive cardiac enlargement. C, Case 40. Complrte form of persist& atriwentrmlar canal with pulmonic stenosir in a relatively well 3 year old Mongol girl. Roentgenograms show fairly marked right ventricular mlargcment, concavitv of the pulmonary artery segment and decreased pulmonary \-ascularity.

relatively early age. The mortality (Table I) is not prohibitive, especially when compared with the usually short life span of such patients treated medically. No conclusive information is yet available as to the ultimate degree of improvement in cardiac function obtained for the survivors. It is quite probable that in JULY

1963

most, residual deformity will be present. COMPLETE

of the I‘ep aired v alves

FORM

Life E~xjxtancy: It is in this g;rolup that surviva1 beyond infancy is rare. T ‘he ventric xlar septal defect, resulting in seve re pulmo Inary

Young

frontal

FIG. 5. A, Case 11. Typical e!ectrocnrdiogram and uectorcardiogrnm. There is left axis deviation of - 85 ‘, prolongation of the P-R interval to 0.30 second, and incomplete right bundle branch block. The vector loop sllows superior orientation to the left with counterclockwise inscription in the frontal plane. B, CASE 42. “Atypical ” el~~ctrocardio,~mmand There is marked right axis deviation of +120” and right ventricular hyr )ertrophy only. The uectomrdiogram. vector loop shows inferior orientation to the right with clockwise inscription in the frontal plane.

hypertension and congestive failure, is most likely the major factor in the poor prognosis Due to the complexity of the (Table III). anatomic abnormalities, attempts at surgical correction have added little to decrease the anticipated mortality (Table I). The need for right ventriculotomy in repair of the ventricular septal defect, the persistence of pulmonary hypertension, the potential creation of suhaortic stenosis on placement of the septal prosthesis, and the residual valvular defects are factors responsible for failure. Unmajor doubtedly the added presence of a double mitral valve or pulmonic stenosis, valvular, infundibular or both, is a further obstacle to an already formidable procedure. Although Fontana and Edwards state that life expectancy of patients with the common form of atrioventricular canal and pulmonic stenosis is unaltered, our own experiences have been quite different. Three of 5 such patients survived 18, 8 and 6 years, respectively, the

other 2 having died as a result of surgery. One, now aged 3, is relatively well, and 1 who was asymptomatic died as a result of cardiac catheterization at the age of 3 years. In none of these patients did congestive heart failure develop. Of 5 such patients described by Scott et al.,r’ 4 lived 8, 9, 5 and 26 years, respectively, death resulting from surgery in 2 out of 3. The presence of pulmonic stenosis seems to have a similar beneficial effect, as it does in patients with complete transposition of the great vessels and a ventricular septal defect’s Such children are considerably less disabled, have the longest life expectancy- and are less likely to become disabled by congestive heart failure in comparison with those with transposition and an intact ventricular septum, or with ventricular septal defect and increased pulmonary blood flow. The similarity might be carried further, for in patients with transposition and pulmonarv vascular obstructive disease rela-

Common

Atrioventricular

87

Canal

F’w. 6. Case 6. Roentgenograms illustratinp the rITect of an inadquately corrected mitral ~alvc resulting in an intensification of mitral insuflicicncy. A, preoperative ro?ntgenograms \vhcn pulmonary artery pressure was 58/13 mm. Fig. B, roentgrnograms taken four and one-half years postoperatiwly demonstratr a marked increase in size of the left ventricle and Cardiac catheterization and cineangiocardio;raphy at this time showed no left atrium. rrsidual shunt. marked mitral regurgitation and a plllmonary artery pressure of 60/30 mm.

longer survival is not uncommon. One of our patients with the partial form (Case 24) is now 32 bears of age with pulmonary artery pressure much o\‘er the systemic level, and one with the complete form (Case 34) has equal pulmonic and systemic pressure levels at age 7’:~ years. Operatzr,e Indications and Results: The current operative mortality obtained by all surgeons (Table I) appears to be almost prohibitive; little is kno\vn about the ultimate degree of n’evercardiac repair obtained in survivors. theless, \vhen it is recognized how early in life such children become severely ill and die, any It would, attempt at salvage seems reasonable. of course. be preferable to be certain that the end-result of such a high risk taken would be significantlv improved cardiac function and greater lonievity. that the additional Because it appears presence of pulmonic stenosis has a beneficial effect on the complete form of atrioventricular it seems reasonable to propose that canal,

tively

,rrr.v 1963

banding the pulmonaryartery to create a moderate pulmonic stenosis might be an effective, at least temporizing, surgical procedure in such ill patients. The mortality rate for this procedure is considerably less,‘” and postoperative survival to as much as 5 years in desperately ill patients has been obtained .r9*20 The marked regression of pulmonary vascular disease that occurs sufficiently long after the creation of pulmonary stenosis has allowed for subsequent attempts at definitive corrective procedures. Although to date such second operations for common atrioventricular canal have not been successful, the potential for having a live patient and one in better condition for such surgery subsequent to earlier pulmonar>artery banding should Ix considered. SU\IMARY

AND

~ONCLUSIOKS

Limitation of cardiac function and shortening of normal life expectancy can be anticipated in patients with persistent common atrioventricular

Young canal. Because of this, surgical correction must be considered in all. Subdivision of the anomaly into partial, intermediate and complete forms allows for suflicient clinical and physiologic correlation to determine both the urgency of surgical intervention and the predictability of the result. Patients with the partial form of common atrioventricular canal are the least ill, and man) do not require immediate surgery. The anticipated mortality is, and probably will remain, higher than that for correction of atria1 defects of the secundum type. Chances for complete repair are good, but further surgical attention must be directed to the problem of residual mitral insufliciency. Patients with the intermediate type of defects have more advanced cardiac disease and greater need for earlier surgery, but less chance for recovery from surgery and adequately corrected defects. Patients with the complete form of persistent common atrioventricular canal ha\-c minimal life expectancy if treated medicall>, and relatively Iittle more from surgical intervention because of the complexity of the lesion and the resulting physiologic severity. For this group it is suggested, based on clinical observation, that pulmonar)- artery banding may offer as reasonable a chance for immediate salvage and possibly a lesser risk for corrective surgery at a later date. ADDENDUhl

Since

submission of this

paper t\qo additional patients in this series lvith the partial form of persistent common atrioventricular canal have been operated upon successfully. In Case 25. Table II, repair of a 2.5 cm. ostium primum lesion and a complete cleft of the mitral valve xvas accomplished. In Case 20, that of the oldest patient in this series who x#as unique because of having lived 54 years with this lesion. severe intractable congestive heart failure developed, and therefore she accepted surgery. At operation the huge right atrium had practically no septum, an ostium primum defect measuring 3 cm. in diameter being separated by a small band of tissue from a large secundum defect 3 by 2 cm. in size; the mitral leaflet was totally cleft. Complete repair was obtained with resulting distinct improvement in the patient subsequent to recovery from surgery. Adding the two cases to the group of the partial typeoperated upon would change the figures to 17 patients operated upon with 4 operative deaths, giving a mortality of 23 instead of 27 per cent. In addition, a successful banding of the pulmonary artery has been obtained in a 2’;‘~ month old, 2.4 kg.,

Mongoloid infant with the complete form of persistent common atrioventricular canal. Congestive heart failure \\,hich became progressively severe despite adequate medical therapy, developed in this premature infant at 2 weeks of age. The clinical diagnosis was substantiated by cardiac catheterization and selectivy cineangiocardiography. Pressures at systemic level werr present in the right ventricle and pulmonary artery. At operation a large patent ductus arteriosus was also found and ligated, but there x2;as no subxquent change in the pulmonary artery pressure. Banding the pulmonary artery was accomplished iv-ith a maximally tolerated reduction of the right vcntricuiar pressure from 100 to 60 mm. Hg. A markedly benign postoperative course ensued; the congestive heart failure disappeared tvithin 48 hours postoperatively. She has remained well and has shown progressive gain in weight and vigor now for three months. .kXNOM.LEDGMENT Grateful acknowledgment is extended to Dr. Doris Escher, Physician-in-Charge, Cardiac Catheterization Unit, for making her data available, to Dr. George Robinson, for his description of his findings at surgery, and to Dr. Harry Zimmerman and his staff of the Departmcnt of Pathology for their findings at autopsies. Particular gratitude is expressed to Dr. Jesse E. Edwards, St. Paul. Minn., for his interest and kindness in supplying photographs of pathologic material. REFERENCES 1. lkr.rs, F. H., JK., McGom, II. C. and KIRKLIN, J. W. Surgical management of persistent comInon atriowntricular canal. .-lrn. J. Cardiol., 6: 598, 1960. Results of surgical treatment of 2. COOE’r., 1). A. atria1 scptal defects. Particular consideration of low drftxts includin? ostium primum and atrio4m. .J. Cardiol., 6: 605, 1960. ventricular canal. 3. I~HJST. C. and BL.ANDEAU~ P. Th? surgical repair of persistent atrioventricular canal ; results in twrnty-six oprrative cases. .4m. J. Cardiol., 6: 611. 1960. 4. CRAFOORI), C. and SENNING, A. Persistent atrioventricular canal. Am. J. Cardiol., 6: 618, 1960. 5. SCOTT, L. P., HAUCK, A. J., NADAS, 4. S. and GROSS, R. E. Endocardial cushion defect; preoperative and postoperative survey. Circulation, 26: 218. 1762. 6. KEITH, .I. D., ROWE, R. R. and VLAD, P. Heart Disease in Infancy and Childhood, p. 3. New York, 1958. Macmillan Co. 7. PAUL, M. H. Endocardial cushion defects; persistcnt common atrioventricular canal and persistent ostium primum. Pedint. Clin. rVorth rlmerica. 5: 1029,1358. 8. FON~ANA, R. S. and EDWARDS, J. E. Congenital Cardiac 1Xsrasr: A Rcvirw of 357 Cases Studied Pathologically, p. 55. Philadelphia and London. 1962. \V. B. Saunders Co. 9. MARK, H., ~%CHER, D. and YOUNG, D. Congenital heart dircasc in the adult. To be published. THE AMERICANJOURNAL OF CARDIOLOGY

Common

Atrio\-entricular

10. ,&;AKAI. C. s. and l:DWARDS, .r. t. Pathologic study of persistent common atrioventricular canal. Am. Il~~nrtJ.: 56: 779, 1958. 11, EDWARDS. J. E. The problem of mitral insuffkiwq caused by accessory chordae tcndineae in peratrioventricular sistent common canal. Proc. Stczf Ifcct. Ilfayo Clin., 35: 299, 1960. 12. WAKAI. C. S., SWXN? H. J. C. and \VOOD. E. H. Hemodynamic data and findings of diagnostic valu? in 9 pro\?d cases of persistent common atriowntl.icular canal. P7oc. Stof .1fPet..Ilnw C’lin.. 31: 500. 1956. 13. BLOUNI, S. G., JR..BALC.HUM, 0. J. and GENSINI,G. The persistent ortium primum atria1 scptal dcfeet. Circulntion. 13: 499, 1956. 14. CAMPRELL. M. and MISSEN, G. 4. K. Endocardial cushion defects. common atrioventricular canal and ostium primllm. &it. Heart J.? 19: 403. 1957. 15. BURCHELL. H. B.. LIUSHANE, J. \V. and BRANDENBURG, R. 0. The electrocardiogram of patients with atrio\-entrivular cushion defects (defects of the atrioventricular canal). ilnr.
J"LY

1963

Canal

89

16. MARK, H. and YOUNG, II. .\typical tlectrocardiosrams and vectorcardiograms in endocardial cushion defects. Abstracts of the 35th Scientific Sessions, -American Hpart Association. Circulat/on, 26: 756. 1962. 17. Scw~r: I,. P., HAUCK, A. J. and NADAS. A. S. I