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Supravalvular stenosing ring of the left atrium associated with corrected transposition of the great vessels
ELLIOT
CHESLER,
MD
(Rand),
FRCP
FACC WALTER BECK, MMed, MRCP, FACC CHRISTIAAN N. BARNARD, MMed, MD, DSc, PhD, FACC VELVA SCHRIRE, MSc, PhD, MD, FRCP (Edin.), FRCP, FACC* (Edin.),
Cape Town, South Africa
A case of supravalvular stenosing ring of the left atrium is described. The severity of the stenosis obscured the features of Ebstein’s malformation of the left atrioventricular valve, which was the only other defect associated with corrected transposition. Analysis of the reported examples of supravalvular stenosing rings reveals that the condition rarely exists as an isolated anomaly but tends to occur in 2 groups of conditions, namely, a developmental complex of obstructive anomalies of the left side of the heart (supravalvular ring, subaortic stenosis, parachute mitral valve and coarctation of the aorta) or a second group associated with a left to right shunt produced by a ventricular septal defect or patent ductus arteriosus. The potential diagnostic value of echocardiography in cases in which there is evidence of pulmonary venous obstruction is discussed.
Among patients with congenital heart disease, anomalies of the left atria1 chamber such as car triatriatum and supravalvular stenosing ring are well recognized causes of pulmonary venous obstruction. A supravalvular ring is an uncommon malformation which is usually associated with other conditions such as ventricular septal defect, patent ductus arteriosus, subaortic stenosis and coarctation of the aorta. Because the degree of obstruction imposed by the ring is frequently moderate, the associated malformations may dominate the clinical findings. The combination of a supravalvular stenosing ring of the left atrium and corrected transposition of the great vessels has been documented in only 2 instances, and in neither case was the obstruction severe. Patients with corrected transposition commonly present with mitral insufficiency but rarely with mitral stenosis. In the case reported here the obstruction produced by a supravalvular stenosing ring was critical so that the signs of “mitral” stenosis dominated the clinical findings, obscuring the features of corrected transposition of the great vessels. Case Report
From the Cardiopulmonary Unit, Groote Schuur Hospital, Departments of Medicine and Cardiothoracic Surgery, University of Cape Town. This study was supported in the Department of Medicine by the South African Medical Research Council, the Cape Town City Council and the Harry Crossley Foundation. Manuscript received February 15. 1972, accepted March 28, 1972. * Deceased. Address for reprints: Elliot Chesler, MD, Cardiopulmonary Unit, Groote Schuur Hospital, Cape Town, South Africa.
84
January
1973
The American
The patient, an 11 year old white girl, had a cardiac murmur noted at age 2 months during an episode of pneumonia. She was the product of a full-term normal pregnancy and delivery and her siblings were healthy. She had recurrent episodes of bronchitis, but there was no history of hemoptysis or paroxysmal nocturnal dyspnea. However, she was permanently incapacitated by dyspnea on the slightest exertion and was receiving maintenance doses of digitalis. There was no history of rheumatic fever. Physical examination disclosed a slenderly built acyanotic patient with a blood pressure of 90/60 mm Hg. All the pulses were present, equal and regular, but of small volume. Inspection of the jugular venous pulse revealed a prominent a wave. Precordial palpation detected an apical diastolic thrill and a parasternal thrust indicating right ventricular hypertrophy. On auscultation, at the apex the first heart sound was of normal intensity and was followed by an ejection click; at times a soft pansystolic murmur was also
Journal of CARDIOLOGY
Volume 31
SUPRAVALVULAR
STENOSIS
OF LEFT ATRIUM-CHESLER
ET AL.
TABLE I Cardiac Catheterization Data Oxygen
Saturations Site Inferior vena cava Right atrium Low Mid High Superior
67.2
a = 11,~ = 8 (4j 6 \
58.2 59.5 61.0 65.5
vena cava
Right ventricle Right atrium At valve Mid Superior vena cava Right pulmonary
Pressures (mm Hg)
(%)
x = 5,y=
58.5
8014-g
60.5 58.5 60.5
capillary
a= %v = 40 (40) x =3O,y=26 i
wedge FIGURE 1. Phonocardiogram. See text. CP = carotid pulse; DM = mid-diastolic murmur; ECG = electrocardiogram; MA = mitral area; X = ejection click; (1) and (2) = first and second heart sounds, respectively.
audible. In diastole, there was a long rumbling middiastolic murmur with presystolic accentuation. In the second left interspace the second sound was narrowly split, and both components were of equal intensity (Fig. 1). The electrocardiogram showed sinus rhythm with a P-R interval of 0.22 second, right axis deviation (+llO”) and right ventricular hypertrophy. On occasional tracings the P wave vector altered in a manner consistent with a low left atria1 rhythm. A small Q wave was present in lead Vs but not in VI. The chest roentgenogram showed moderate cardiomegaly with an enlarged left atrium and evidence of pulmonary venous congestion; the veins of the upper pulmonary lobe were distended, and Kerley-B lines were present in both costophrenic angles (Fig. 2). The clinical diagnosis was tight mitral stenosis with mild mitral insufficiency possibly of congenital origin, because of the history.
Left ventricle
84.0
90/c10
Main pulmonary artery Right brachial artery
59.5 89.0
85/55 (65) 90/60 (70)
Pulmonary ventricle, ventricle, Left ventricle
artery to right high, to right low
85155 8515-g 8515-g
to aorta
90/5-10 90/60
Cardiac output (liters/min) Cardiac index (liters/min per m*) Mitral valve area (cma) Pulmonary vascular resistance (units) Systemic vascular resistance (units) Figures in parentheses
indicate
mean
3.4 2.98 0.89 8.2 20.3
pressures.
The findings at cardiac catheterization are presented in Table I. The presence of corrected transposition was suspected when difficulty was encountered in catheterizing the medially situated pulmonary artery and when a retrograde brachial arterial catheter entered the aorta, which
FIGURE 2. Preoperative chest roentgenogram, frontal view (left) and lateral view (right), showing left atrial enlargement and pulmonary venous congestion with bilateral basal Kerley-B lines.
January
1973
The American Journal of CARDIOLOGY
Volume 31
85
SUPRAVAL\/ULAR
STENOSIS
OF LEFT ATRIUM-CHESCER
ET AL.
FIGURE 3. Biplane angiogram performed in left-sided (systemic) ventricle showing /-transposition of aorta which arises from an anatomic right ventricle; frontal view (left) and lateral view (right). The aortic valve is elevated by the well developed underlying infundibulum (Inf). Mild mitral insufficiency opacifies an enlarged left atrium. The supravalvular ring (between arrows) separating the left ventricle (LV) and the left atrium (LA) was valve. Ao = aorta: INF = infundibulum.
was situated anteriorly and to the left. Pulmonary and systemic arterial pressures were virtually identical, the severe pulmonary hypertension resulting from a greatly increased wedge pressure (mean 32 mm Hg). A mean diastolic gradient of 22 mm Hg was present across the left atrioventricular (A-V) valve. The latter had an orifice calculated to be 0.84 cm2 by the Gorlin formula, assuming no mitral insufficiency. Retrograde biplane angiograms obtained from the leftsided systemic ventricle revealed a chamber with the anatomic characteristics of a right ventricle: a prominently trabeculated inner wall, a well developed infundibulum and obvious separation of the left A-V and aortic valves. The aorta was situated anteriorly and to the left, and the aortic valve was higher than the pulmonary valve; the coronary arteries were inverted (Fig. 3). Cineangiographic studies performed in the right anterior oblique position in this ventricle were interpreted as revealing a rigid A-V valve with mild mitral insufficiency. A pulmonary arterial angiogram filled a large left atrium from which there was
a slow clearing of contrast material. There was no evidence of car triatriatum or myxoma. An echogram was performed after the cardiac catheterization (Fig. 4). The left A-V valve was located 7 cm below the anterior chest wall. The tracing appeared to demonstrate a rapid closing velocity of the valve, but interpretation was difficult because of a heart rate of 92 beats/min and a long P-R interval, factors that tend to obscure the reopening movement of the leaflet produced by atria1 systole. In view of the severity of the patient’s symptoms and the severe hemodynamic disturbance, surgery was recommended. The absence of lesions such as ventricular septal defect and pulmonary stenosis which are commonly associated with corrected transposition lended support to this decision since a ventriculotomy with its attendant potential to produce heart block and damage to the coronary arteries would be avoided. Operation was performed through a median sternotomy. Utilizing cardiopulmonary bypass with moderate hypothermia a left atriotomy was performed. This revealed a fibrous diaphragm with a central aperture of approximately 1 cm2 situated immediately above the annulus of the left A-V valve. The A-V valve itself was completely obscured by the supravalvular stenosing ring. When the ring was excised, the typical anatomic features of an Ebstein’s malformation of the valve were evident. A portion of the anatomic right ventricle was “atrialized” by the downward displacement of the leaflets below the annulus, and the leaflets were plastered to the inner wall of the ventricle (Fig. 5). Because of the severity of the Ebstein’s malformation, the valve was excised and replaced with a 2M Starr-Edwards prosthesis. The patient made an uneventful recovery and has remained well. Comment
F%xT FIGURE 4. Echogram. See text. ANT. = anterior: “mitral.” left sided A-V valve; POST. = posterior.
06
January
1973
“M”V
The American Journal of CARDIOLOGY
=
A supravalvular stenosing ring closely resembles car triatriatum in that the left atrium is divided into 2 chambers. However, it differs in that the circumferential ridge of connective tissue of the ring arises at the base of the atria1 surfaces of the mitral leaflets and protrudes into the orifice of the mitral valve; in addition, the left atria1 appendage and the pulmonary veins communicate with the left atrium in normal fashion.’ The lesion is probably more common
Volume 31
SUPRAVALVULAR
than indicated by the few published reports. We have been able to find documentation of only 1’7 cases. leg Associated anomalies: In none of the reported examples of supravalvular stenosing ring did the lesion exist as an isolated anomaly. The associated malformations may be roughly divided into 2 groups: (1) Those in which the ring exists as a component of the developmental complex of obstructive anomalies of the left side of the heart described by Shone et a1.5 In this syndrome a parachute mitral valve, subaortic stenosis and coarctation of the aorta may coexist. Of the 8 cases described by these authors the ring was obstructive in 3 and nonobstructive in the remainder. (2) Those in which the important associated lesion is a left to right shunt through a ventricular septal defect or a patent ductus arteriosus. In this group of 9 cases, the ring was obstructive in 7 cases and nonobstructive in the remaining 2. The latter 2 cases were examples of corrected transposition in which a patent ductus arteriosus was present in one case and a ventricular septal defect in the other. In both cases the ring measured 2.5 cm in diameter and the associated left atria1 dilatation was thought to result from a combination of the left to right shunt and an incompetent Ebstein’s valve rather than obstruction produced by the ring.4,10 The case reported here thus represents a unique combination of a severely stenotic ring in association with corrected transposition of the great vessels producing the clinical features of mitral stenosis. Among cases of corrected transposition of the great vessels it is well recognized that associated defects such as ventricular septal defect, atria1 septal defect and pulmonary stenosis may be absent. In a recent review of 230 cases of corrected transposition, ShemTov et all1 found 28 cases without associated defects. However, in the majority of these cases, some degree of left sided A-V insufficiency and A-V block was present. Our case would fit into this latter group in that first degree A-V block was present and Ebstein’s malformation of the left A-V valve was found at surgery. However, it differs in that the entire picture was dominated by the severe hemodynamic disturbance resulting from the stenotic supravalvular ring. In contrast to the well recognized frequency of the insufficiency of the left-sided A-V valve in corrected transposition, stenotic lesions are rare. Schiebler et a1.12 pointed out that mild stenosis of the valve may occur in Ebstein’s disease, but severe stenosis of the inverted Ebstein’s valve is rare among cases of corrected transposition, and we have been able to find reports of only 2 such cases with autopsy verification.lsJ4 In an additional case reported by Anderson et al.15 in which the presenting feature was pulmonary venous obstruction, the diagnosis was made at cardiac catheterization and the anatomic lesion could have been a supravalvular stenosing ring or a stenotic Ebstein’s valve. Diagnosis: In the majority of cases of supravalvular stenosing ring, the diagnosis was made at autopsy or at the time of operation for a ventricular
January
STENOSIS
OF LEFT ATWUM-Ci-fESLER
ET AL.
-INF -svR
FIGURE 5. Artist’s impression of malformation described. The stenotic supravalvular ring (SW) is situated above a tricuspid valve (TV) which is displaced downward and plastered to the inner wall of the cavity of left-sided anatomic right ventricle (LV). The infundibulum of this ventricle (INF) elevates the transposed aortic valve. The right-sided ventricle (RV) has anatomic characteristics of a left ventricle with mitral-pulmonary continuity. AM = anterior mitral leaflet; Ao = aorta; LA = left atrium; LCA = left coronary artery: PA = pulmonary artery.
septal defect. The importance of diagnosing this lesion preoperatively is evident. Failure to do so has resulted in fatal outcome in the postoperative period following closure of a ventricular septal defect. Lynch et a1.6 made a correct preoperative diagnosis of supravalvular mitral stenosis in the presence of a ventricular septal defect and successfully repaired both lesions; the supravalvular ring had 2 openings with a total diameter of the orifices of-1 ems. The diagnosis was made by demonstration of an intraatria1 pressure gradient (transbronchial technique) and a gradient between the proximal left atrium and the left ventricle. They suggested that in the presence of a ventricular septal defect with an apical mid-diastolic murmur the diagnosis of supravalvular ring should be entertained when presystolic accentuation of the mid-diastolic murmur is present and when the first heart sound is delayed. Lynch et al.s pointed out that statistically a ventricular septal defect is more likely to be associated with supravalvular rather than mitral valvular stenosis. The presence of a supravalvular ring can presumably be determined with the use of selective left ventricular angiography by distinguishing the mitral valve leaflets separate from the ring above; we are not aware of a case having been diagnosed in this manner. In our patient the leaflets of the Ebstein’s valve were not identified during cineangiography and the ring was thought to be the fused leaflets of a stenotic valve. In retrospect, the fact that the level of
1973
The American
Journal of CARDIOLOGY
Volume 31
87
SUPRAVALVULAR
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OF LEFT ATRIUM-CHESLER
ET AL.
the stenosis was not located below the A-V ring in a case of corrected transposition might have suggested the diagnosis. A more definite way would be by consecutively recording pressure either from the left ventricle to the proximal left atrium (transseptal technique) or conversely from the proximal left atrium to the left ventricle (retrograde left atria1 and left ventricular catheterization from the brachial artery). Diagnostic value of echocardiography: In our case, an attempt was made to evaluate function of the left A-V valve by echocardiography. Full validity of the test was hampered by the presence of a long P-R interval, which commonly occurs in corrected transposition, and a heart rate of 92 beats/min, since these factors tend to obscure the closing velocity of the leaflet before the reopening produced by atria1 systole.r6 The tracing obtained after cardiac catheterization was nevertheless suggestive of a normal closing movement of a nonstenotic valve. Nevertheless, potential value of echocardiography in the diag-
nosis of supravalvular ring, is obvious. Echocardiographic studies of the mitral valve in left to right shunts resulting from ventricular septal defect or patent ductus arteriosus have revealed closing velocities more rapid than normal because of the increased blood flow across the valve.17 Since most reported cases of supravalvular rings associated with a left to right shunt have been obstructive, echocardiographic evidence of rapid closing velocity of the mitral valve would clearly point to a supravalvular ring or car triatriatum as the cause of pulmonary venous obstruction when there is a problem in the interpretation of the significance of a mid-diastolic murmur. The test might be of similar value in the cases described by Shone et al. in which a supravalvular ring is associated with obstructive anomalies of the left side of the heart, provided a parachute mitral valve is not present. The latter obstructive anomaly may be expected to yield an echogram consistent with mitral stenosis.
References 1. Lucas LV, Anderson RC, Amplatr K, et al: Congenital causes of pulmonary venous obstruction. Pediat Clin N Amer 10:781-836.1963 2. Rogers HM, Waldron BR, Murphey DFS, et al: Supravalvular stenosing ring of left atrium in association with endocardial sclerosis (endomyocardial fibroelastosis), and mitral insufficiency. Amer Heart J 50:777-781, 1955 3. Manuleus R, Krovetz W, Adams P: Supravalvular stenosing ring of the left atrium. Amer Heart J 60:286-295, 1960 4. Helmholtz FH, Daugherty GW, Edwards JE: Cardiac clinics insufficiency in association with 145: congenital “mitral” corrected transposition of the great vessels: report of probable clinical case and review of six cases studied pathologically. Proc Staff Meet Mayo Clin 31:82-91, 1956 5. Shone JD, Sellers RD, Anderson RC, et al: The developmental complex of “parachute mitral valve,” supravalvular ring of left atrium, subaortic stenosis and coarctation of aorta. Amer J Cardiol 11:714-725, 1963 6. Lynch HF, Ryan NJ, Williams GR, et al: Preoperative diagnosis and surgical correction of supravalvular mitral stenosis and ventricular septal defect. Circulation 25:854-861, 1962 7. Stretton TB, Fentem PH: Stenosis of left A-V canal. Brit Heart J 241237-240.1962 8. Kipkie CE, Johnson DS: Possible pathogenic mechanisms responsible for human polyarteritis nodosa as suggested by the occurrence of two instances of this disease in association with glomerulonephritis. Arch Path (Chicago) 51:387392,195l
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January
1973
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Journal of CARDIOLOGY
9. Johnson NJ, Dodd, K: Obstruction to the left atrial outflow by a supravalvular stenosing ring. .I Paediat 51:190-193, 1957 10. Edwards JE: Personal communication, 1971 11. Shem-Tov A, Deutsch V, Yahini JH, et al: Corrected transposition of the great arteries. A modified approach to the clinical diagnosis in 30 cases. Amer J Cardiol 27:99-113, 1971 12. Schiebler GL, Edwards JE, Burchell HB, et al: Congenital corrected transposition of the great vessels: a study of 33 cases. Pediatrics 27:suppl:851-888, 1961 13. Kjellberg SR, Mannheimer E, Rudhe U, et al: Diagnosis of Congenital Heart Disease: A Clinical and Technical Study by the Cardiologic Team of the Pediatric Clinic, Karolinska Sjukhuset, Stockholm, second edition. Chicago, Year Book, 1959, p811 14. Thilenius OG, Cassels DE, Toloni F: Retrograde aortography in corrected transposition of the great vessels. J Dis Child 98:221-226, 1959 15. Anderson RC, Lillehei CW, Lester RG: Corrected transposition of the great vessels of the heart. A review of 17 cases. Pediatrics 20:626-646, 1957 16. Zaky A, Nasser WK, Feigenbaum H: A study of mitral valve action recorded by reflected ultrasound and its application in the diagnosis of mitral stenosis. Circulation 37:789-799, 1968 17. Ultan LB, Segal LB, Likofl W: Echocardiography in congenital heart disease. Amer J Cardiol 19:74-83, 1967
Volume 31
CHESLER,
MD
(Rand),
FRCP
FACC WALTER BECK, MMed, MRCP, FACC CHRISTIAAN N. BARNARD, MMed, MD, DSc, PhD, FACC VELVA SCHRIRE, MSc, PhD, MD, FRCP (Edin.), FRCP, FACC* (Edin.),
Cape Town, South Africa
A case of supravalvular stenosing ring of the left atrium is described. The severity of the stenosis obscured the features of Ebstein’s malformation of the left atrioventricular valve, which was the only other defect associated with corrected transposition. Analysis of the reported examples of supravalvular stenosing rings reveals that the condition rarely exists as an isolated anomaly but tends to occur in 2 groups of conditions, namely, a developmental complex of obstructive anomalies of the left side of the heart (supravalvular ring, subaortic stenosis, parachute mitral valve and coarctation of the aorta) or a second group associated with a left to right shunt produced by a ventricular septal defect or patent ductus arteriosus. The potential diagnostic value of echocardiography in cases in which there is evidence of pulmonary venous obstruction is discussed.
Among patients with congenital heart disease, anomalies of the left atria1 chamber such as car triatriatum and supravalvular stenosing ring are well recognized causes of pulmonary venous obstruction. A supravalvular ring is an uncommon malformation which is usually associated with other conditions such as ventricular septal defect, patent ductus arteriosus, subaortic stenosis and coarctation of the aorta. Because the degree of obstruction imposed by the ring is frequently moderate, the associated malformations may dominate the clinical findings. The combination of a supravalvular stenosing ring of the left atrium and corrected transposition of the great vessels has been documented in only 2 instances, and in neither case was the obstruction severe. Patients with corrected transposition commonly present with mitral insufficiency but rarely with mitral stenosis. In the case reported here the obstruction produced by a supravalvular stenosing ring was critical so that the signs of “mitral” stenosis dominated the clinical findings, obscuring the features of corrected transposition of the great vessels. Case Report
From the Cardiopulmonary Unit, Groote Schuur Hospital, Departments of Medicine and Cardiothoracic Surgery, University of Cape Town. This study was supported in the Department of Medicine by the South African Medical Research Council, the Cape Town City Council and the Harry Crossley Foundation. Manuscript received February 15. 1972, accepted March 28, 1972. * Deceased. Address for reprints: Elliot Chesler, MD, Cardiopulmonary Unit, Groote Schuur Hospital, Cape Town, South Africa.
84
January
1973
The American
The patient, an 11 year old white girl, had a cardiac murmur noted at age 2 months during an episode of pneumonia. She was the product of a full-term normal pregnancy and delivery and her siblings were healthy. She had recurrent episodes of bronchitis, but there was no history of hemoptysis or paroxysmal nocturnal dyspnea. However, she was permanently incapacitated by dyspnea on the slightest exertion and was receiving maintenance doses of digitalis. There was no history of rheumatic fever. Physical examination disclosed a slenderly built acyanotic patient with a blood pressure of 90/60 mm Hg. All the pulses were present, equal and regular, but of small volume. Inspection of the jugular venous pulse revealed a prominent a wave. Precordial palpation detected an apical diastolic thrill and a parasternal thrust indicating right ventricular hypertrophy. On auscultation, at the apex the first heart sound was of normal intensity and was followed by an ejection click; at times a soft pansystolic murmur was also
Journal of CARDIOLOGY
Volume 31
SUPRAVALVULAR
STENOSIS
OF LEFT ATRIUM-CHESLER
ET AL.
TABLE I Cardiac Catheterization Data Oxygen
Saturations Site Inferior vena cava Right atrium Low Mid High Superior
67.2
a = 11,~ = 8 (4j 6 \
58.2 59.5 61.0 65.5
vena cava
Right ventricle Right atrium At valve Mid Superior vena cava Right pulmonary
Pressures (mm Hg)
(%)
x = 5,y=
58.5
8014-g
60.5 58.5 60.5
capillary
a= %v = 40 (40) x =3O,y=26 i
wedge FIGURE 1. Phonocardiogram. See text. CP = carotid pulse; DM = mid-diastolic murmur; ECG = electrocardiogram; MA = mitral area; X = ejection click; (1) and (2) = first and second heart sounds, respectively.
audible. In diastole, there was a long rumbling middiastolic murmur with presystolic accentuation. In the second left interspace the second sound was narrowly split, and both components were of equal intensity (Fig. 1). The electrocardiogram showed sinus rhythm with a P-R interval of 0.22 second, right axis deviation (+llO”) and right ventricular hypertrophy. On occasional tracings the P wave vector altered in a manner consistent with a low left atria1 rhythm. A small Q wave was present in lead Vs but not in VI. The chest roentgenogram showed moderate cardiomegaly with an enlarged left atrium and evidence of pulmonary venous congestion; the veins of the upper pulmonary lobe were distended, and Kerley-B lines were present in both costophrenic angles (Fig. 2). The clinical diagnosis was tight mitral stenosis with mild mitral insufficiency possibly of congenital origin, because of the history.
Left ventricle
84.0
90/c10
Main pulmonary artery Right brachial artery
59.5 89.0
85/55 (65) 90/60 (70)
Pulmonary ventricle, ventricle, Left ventricle
artery to right high, to right low
85155 8515-g 8515-g
to aorta
90/5-10 90/60
Cardiac output (liters/min) Cardiac index (liters/min per m*) Mitral valve area (cma) Pulmonary vascular resistance (units) Systemic vascular resistance (units) Figures in parentheses
indicate
mean
3.4 2.98 0.89 8.2 20.3
pressures.
The findings at cardiac catheterization are presented in Table I. The presence of corrected transposition was suspected when difficulty was encountered in catheterizing the medially situated pulmonary artery and when a retrograde brachial arterial catheter entered the aorta, which
FIGURE 2. Preoperative chest roentgenogram, frontal view (left) and lateral view (right), showing left atrial enlargement and pulmonary venous congestion with bilateral basal Kerley-B lines.
January
1973
The American Journal of CARDIOLOGY
Volume 31
85
SUPRAVAL\/ULAR
STENOSIS
OF LEFT ATRIUM-CHESCER
ET AL.
FIGURE 3. Biplane angiogram performed in left-sided (systemic) ventricle showing /-transposition of aorta which arises from an anatomic right ventricle; frontal view (left) and lateral view (right). The aortic valve is elevated by the well developed underlying infundibulum (Inf). Mild mitral insufficiency opacifies an enlarged left atrium. The supravalvular ring (between arrows) separating the left ventricle (LV) and the left atrium (LA) was valve. Ao = aorta: INF = infundibulum.
was situated anteriorly and to the left. Pulmonary and systemic arterial pressures were virtually identical, the severe pulmonary hypertension resulting from a greatly increased wedge pressure (mean 32 mm Hg). A mean diastolic gradient of 22 mm Hg was present across the left atrioventricular (A-V) valve. The latter had an orifice calculated to be 0.84 cm2 by the Gorlin formula, assuming no mitral insufficiency. Retrograde biplane angiograms obtained from the leftsided systemic ventricle revealed a chamber with the anatomic characteristics of a right ventricle: a prominently trabeculated inner wall, a well developed infundibulum and obvious separation of the left A-V and aortic valves. The aorta was situated anteriorly and to the left, and the aortic valve was higher than the pulmonary valve; the coronary arteries were inverted (Fig. 3). Cineangiographic studies performed in the right anterior oblique position in this ventricle were interpreted as revealing a rigid A-V valve with mild mitral insufficiency. A pulmonary arterial angiogram filled a large left atrium from which there was
a slow clearing of contrast material. There was no evidence of car triatriatum or myxoma. An echogram was performed after the cardiac catheterization (Fig. 4). The left A-V valve was located 7 cm below the anterior chest wall. The tracing appeared to demonstrate a rapid closing velocity of the valve, but interpretation was difficult because of a heart rate of 92 beats/min and a long P-R interval, factors that tend to obscure the reopening movement of the leaflet produced by atria1 systole. In view of the severity of the patient’s symptoms and the severe hemodynamic disturbance, surgery was recommended. The absence of lesions such as ventricular septal defect and pulmonary stenosis which are commonly associated with corrected transposition lended support to this decision since a ventriculotomy with its attendant potential to produce heart block and damage to the coronary arteries would be avoided. Operation was performed through a median sternotomy. Utilizing cardiopulmonary bypass with moderate hypothermia a left atriotomy was performed. This revealed a fibrous diaphragm with a central aperture of approximately 1 cm2 situated immediately above the annulus of the left A-V valve. The A-V valve itself was completely obscured by the supravalvular stenosing ring. When the ring was excised, the typical anatomic features of an Ebstein’s malformation of the valve were evident. A portion of the anatomic right ventricle was “atrialized” by the downward displacement of the leaflets below the annulus, and the leaflets were plastered to the inner wall of the ventricle (Fig. 5). Because of the severity of the Ebstein’s malformation, the valve was excised and replaced with a 2M Starr-Edwards prosthesis. The patient made an uneventful recovery and has remained well. Comment
F%xT FIGURE 4. Echogram. See text. ANT. = anterior: “mitral.” left sided A-V valve; POST. = posterior.
06
January
1973
“M”V
The American Journal of CARDIOLOGY
=
A supravalvular stenosing ring closely resembles car triatriatum in that the left atrium is divided into 2 chambers. However, it differs in that the circumferential ridge of connective tissue of the ring arises at the base of the atria1 surfaces of the mitral leaflets and protrudes into the orifice of the mitral valve; in addition, the left atria1 appendage and the pulmonary veins communicate with the left atrium in normal fashion.’ The lesion is probably more common
Volume 31
SUPRAVALVULAR
than indicated by the few published reports. We have been able to find documentation of only 1’7 cases. leg Associated anomalies: In none of the reported examples of supravalvular stenosing ring did the lesion exist as an isolated anomaly. The associated malformations may be roughly divided into 2 groups: (1) Those in which the ring exists as a component of the developmental complex of obstructive anomalies of the left side of the heart described by Shone et a1.5 In this syndrome a parachute mitral valve, subaortic stenosis and coarctation of the aorta may coexist. Of the 8 cases described by these authors the ring was obstructive in 3 and nonobstructive in the remainder. (2) Those in which the important associated lesion is a left to right shunt through a ventricular septal defect or a patent ductus arteriosus. In this group of 9 cases, the ring was obstructive in 7 cases and nonobstructive in the remaining 2. The latter 2 cases were examples of corrected transposition in which a patent ductus arteriosus was present in one case and a ventricular septal defect in the other. In both cases the ring measured 2.5 cm in diameter and the associated left atria1 dilatation was thought to result from a combination of the left to right shunt and an incompetent Ebstein’s valve rather than obstruction produced by the ring.4,10 The case reported here thus represents a unique combination of a severely stenotic ring in association with corrected transposition of the great vessels producing the clinical features of mitral stenosis. Among cases of corrected transposition of the great vessels it is well recognized that associated defects such as ventricular septal defect, atria1 septal defect and pulmonary stenosis may be absent. In a recent review of 230 cases of corrected transposition, ShemTov et all1 found 28 cases without associated defects. However, in the majority of these cases, some degree of left sided A-V insufficiency and A-V block was present. Our case would fit into this latter group in that first degree A-V block was present and Ebstein’s malformation of the left A-V valve was found at surgery. However, it differs in that the entire picture was dominated by the severe hemodynamic disturbance resulting from the stenotic supravalvular ring. In contrast to the well recognized frequency of the insufficiency of the left-sided A-V valve in corrected transposition, stenotic lesions are rare. Schiebler et a1.12 pointed out that mild stenosis of the valve may occur in Ebstein’s disease, but severe stenosis of the inverted Ebstein’s valve is rare among cases of corrected transposition, and we have been able to find reports of only 2 such cases with autopsy verification.lsJ4 In an additional case reported by Anderson et al.15 in which the presenting feature was pulmonary venous obstruction, the diagnosis was made at cardiac catheterization and the anatomic lesion could have been a supravalvular stenosing ring or a stenotic Ebstein’s valve. Diagnosis: In the majority of cases of supravalvular stenosing ring, the diagnosis was made at autopsy or at the time of operation for a ventricular
January
STENOSIS
OF LEFT ATWUM-Ci-fESLER
ET AL.
-INF -svR
FIGURE 5. Artist’s impression of malformation described. The stenotic supravalvular ring (SW) is situated above a tricuspid valve (TV) which is displaced downward and plastered to the inner wall of the cavity of left-sided anatomic right ventricle (LV). The infundibulum of this ventricle (INF) elevates the transposed aortic valve. The right-sided ventricle (RV) has anatomic characteristics of a left ventricle with mitral-pulmonary continuity. AM = anterior mitral leaflet; Ao = aorta; LA = left atrium; LCA = left coronary artery: PA = pulmonary artery.
septal defect. The importance of diagnosing this lesion preoperatively is evident. Failure to do so has resulted in fatal outcome in the postoperative period following closure of a ventricular septal defect. Lynch et a1.6 made a correct preoperative diagnosis of supravalvular mitral stenosis in the presence of a ventricular septal defect and successfully repaired both lesions; the supravalvular ring had 2 openings with a total diameter of the orifices of-1 ems. The diagnosis was made by demonstration of an intraatria1 pressure gradient (transbronchial technique) and a gradient between the proximal left atrium and the left ventricle. They suggested that in the presence of a ventricular septal defect with an apical mid-diastolic murmur the diagnosis of supravalvular ring should be entertained when presystolic accentuation of the mid-diastolic murmur is present and when the first heart sound is delayed. Lynch et al.s pointed out that statistically a ventricular septal defect is more likely to be associated with supravalvular rather than mitral valvular stenosis. The presence of a supravalvular ring can presumably be determined with the use of selective left ventricular angiography by distinguishing the mitral valve leaflets separate from the ring above; we are not aware of a case having been diagnosed in this manner. In our patient the leaflets of the Ebstein’s valve were not identified during cineangiography and the ring was thought to be the fused leaflets of a stenotic valve. In retrospect, the fact that the level of
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the stenosis was not located below the A-V ring in a case of corrected transposition might have suggested the diagnosis. A more definite way would be by consecutively recording pressure either from the left ventricle to the proximal left atrium (transseptal technique) or conversely from the proximal left atrium to the left ventricle (retrograde left atria1 and left ventricular catheterization from the brachial artery). Diagnostic value of echocardiography: In our case, an attempt was made to evaluate function of the left A-V valve by echocardiography. Full validity of the test was hampered by the presence of a long P-R interval, which commonly occurs in corrected transposition, and a heart rate of 92 beats/min, since these factors tend to obscure the closing velocity of the leaflet before the reopening produced by atria1 systole.r6 The tracing obtained after cardiac catheterization was nevertheless suggestive of a normal closing movement of a nonstenotic valve. Nevertheless, potential value of echocardiography in the diag-
nosis of supravalvular ring, is obvious. Echocardiographic studies of the mitral valve in left to right shunts resulting from ventricular septal defect or patent ductus arteriosus have revealed closing velocities more rapid than normal because of the increased blood flow across the valve.17 Since most reported cases of supravalvular rings associated with a left to right shunt have been obstructive, echocardiographic evidence of rapid closing velocity of the mitral valve would clearly point to a supravalvular ring or car triatriatum as the cause of pulmonary venous obstruction when there is a problem in the interpretation of the significance of a mid-diastolic murmur. The test might be of similar value in the cases described by Shone et al. in which a supravalvular ring is associated with obstructive anomalies of the left side of the heart, provided a parachute mitral valve is not present. The latter obstructive anomaly may be expected to yield an echogram consistent with mitral stenosis.
References 1. Lucas LV, Anderson RC, Amplatr K, et al: Congenital causes of pulmonary venous obstruction. Pediat Clin N Amer 10:781-836.1963 2. Rogers HM, Waldron BR, Murphey DFS, et al: Supravalvular stenosing ring of left atrium in association with endocardial sclerosis (endomyocardial fibroelastosis), and mitral insufficiency. Amer Heart J 50:777-781, 1955 3. Manuleus R, Krovetz W, Adams P: Supravalvular stenosing ring of the left atrium. Amer Heart J 60:286-295, 1960 4. Helmholtz FH, Daugherty GW, Edwards JE: Cardiac clinics insufficiency in association with 145: congenital “mitral” corrected transposition of the great vessels: report of probable clinical case and review of six cases studied pathologically. Proc Staff Meet Mayo Clin 31:82-91, 1956 5. Shone JD, Sellers RD, Anderson RC, et al: The developmental complex of “parachute mitral valve,” supravalvular ring of left atrium, subaortic stenosis and coarctation of aorta. Amer J Cardiol 11:714-725, 1963 6. Lynch HF, Ryan NJ, Williams GR, et al: Preoperative diagnosis and surgical correction of supravalvular mitral stenosis and ventricular septal defect. Circulation 25:854-861, 1962 7. Stretton TB, Fentem PH: Stenosis of left A-V canal. Brit Heart J 241237-240.1962 8. Kipkie CE, Johnson DS: Possible pathogenic mechanisms responsible for human polyarteritis nodosa as suggested by the occurrence of two instances of this disease in association with glomerulonephritis. Arch Path (Chicago) 51:387392,195l
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9. Johnson NJ, Dodd, K: Obstruction to the left atrial outflow by a supravalvular stenosing ring. .I Paediat 51:190-193, 1957 10. Edwards JE: Personal communication, 1971 11. Shem-Tov A, Deutsch V, Yahini JH, et al: Corrected transposition of the great arteries. A modified approach to the clinical diagnosis in 30 cases. Amer J Cardiol 27:99-113, 1971 12. Schiebler GL, Edwards JE, Burchell HB, et al: Congenital corrected transposition of the great vessels: a study of 33 cases. Pediatrics 27:suppl:851-888, 1961 13. Kjellberg SR, Mannheimer E, Rudhe U, et al: Diagnosis of Congenital Heart Disease: A Clinical and Technical Study by the Cardiologic Team of the Pediatric Clinic, Karolinska Sjukhuset, Stockholm, second edition. Chicago, Year Book, 1959, p811 14. Thilenius OG, Cassels DE, Toloni F: Retrograde aortography in corrected transposition of the great vessels. J Dis Child 98:221-226, 1959 15. Anderson RC, Lillehei CW, Lester RG: Corrected transposition of the great vessels of the heart. A review of 17 cases. Pediatrics 20:626-646, 1957 16. Zaky A, Nasser WK, Feigenbaum H: A study of mitral valve action recorded by reflected ultrasound and its application in the diagnosis of mitral stenosis. Circulation 37:789-799, 1968 17. Ultan LB, Segal LB, Likofl W: Echocardiography in congenital heart disease. Amer J Cardiol 19:74-83, 1967
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