Echocardiographic Features of Cor Triatriatum
MARIO I . CANEDO, MD MILTIADIS A . STEFADOUROS, MD, FACC MARTIN J . FRANK, MD, FACC H . VICTOR MOORE, MD DAVID W . CUNDEY, MD, FACC
Augusta, Georgia
A patient is presented who had cor triatriatum documented with angiography and surgery . On echocardiographic study, an abnormal, dense linear echo on "sector scan" was consistently seen to traverse the left atrial cavity obliquely ; the ends of the echo were attached to the posterior aortic and lateral walls of the left atrium . In addition, high frequency oscillatory movements were evident In the echo of the posterior mitral cusp . Both echocardiographic features disappeared promptly after successful resection of the intraatrial fibrinous membrane . This experience indicates that in the presence of strong evidence of mitral stenosis, an unexpectedly normal mitral valve echogram should initiate a thorough echographic search for cor triatriatum, a treatable cardiac malformation whose diagnosis can easily be missed on "routine" echocardiographic studies .
Cor triatriatum is a rare congenital cardiac abnormality .' In its classic form it consists of a perforated fibromuscular septum or membrane that divides the left atrial cavity into a superior chamber connected with the pulmonary veins and an inferior chamber connected with the left atrial appendage and communicating with the left ventricle through a normal mitral valve . The hemodynamic consequences and symptoms resemble those of mitral stenosis . Most of the reported cases of cor triatriatum have been diagnosed at autopsy2 or at operation .' Preoperative diagnosis has been made with invasive methods in a few cases 3 and with echocardiography in only seven ." This is a report on the echocardiographic features of cor triatriatum initially diagnosed with angiocardiography and subsequently documented at operation .
Case Report
From the Section of Cardiology, Department of Medicine, and the Division of Thoracic and Cardiac Surgery, Medical College of Georgia, Augusta, Georgia. Manuscript received January 24, 1977 ; revised manuscript received March 3, 1977, accepted March 16, 1977 . Address for reprints : Miltiadis A . Stefadouros, MD, Department of Medicine, Medical College of Georgia, Augusta, Georgia 30902 .
A 19 year old white youth was admitted to the Eugene Talmadge Memorial Hospital on August 13, 1976 with a 1 year history of exertional fatigue and dyspnea . He had been asymptomatic with normal exercise tolerance until the previous year when he experienced fatigue, dyspnea and cough that increased progressively with exercise. In July 1976 he had frequent palpitations associated with rapid and marked increase in exertional fatigue and dyspnea . He was admitted to another hospital where the electrocardiogram revealed atrial fibrillation and right ventricular enlargement, the chest X-ray film revealed prominent Kerley B lines and pulmonary venous congestion and the echocardiographic study yielded normal findings . Cardiac catheterization on August 2, 1976 disclosed normal left ventricular and aortic pressures, elevated right ventricular, pulmonary arterial and capillary "wedge" pressures and a consistent diastolic pressure gradient between the left ventricular and pulmonary "wedge" pressures with an end-diastolic value of 14 mm Hg (Table I) . A cineangiogram revealed normal left ventricular volume and performance ; there was no mitral regurgitation. To visualize the left atrium, contrast medium was injected into the main pulmonary artery and the levophase angiogram was filmed in the right anterior oblique projection (Fig. 1) . A moving radiolucent membrane within the opacified left atrium divided it into a larger superior chamber connected with the pulmonary veins and a smaller inferior chamber connected with the appendage . The movement of the intraatrial membrane was of small amplitude and was directed toward the mitral valve in diastole and away from it in systole . The
October 1977
The American Journal of CARDIOLOGY
Volume 40
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=
ECHOCARDIOCiiAPHIC FEATURES OF COR TRIATRIATUM-CANEDO ET AL .
TABLE I Cardiac Catheterization Data
Site Main pulmonary artery Right ventricle Pulmonary capillary wedge Left ventricle Aorta Figures in parentheses indicate
Pressure (mm Hg) 55/32 (41) 55/6 (20) 105/6 105/75(90) mean pressure .
Hemoglobin Oxygen Saturation (% ) 75 74 99 96 96
emptying of the left atrium was delayed . On the basis of these findings the diagnosis of the cor triatriatum was made and the patient was referred to our hospital for surgical correction of this malformation. On admission, the patient was not breathless at rest . His pulse rate was 6S/min and regular, blood pressure 100/70 mm Hg and respirations 20/min . The only abnormal physical finding was a soft (1/6) systolic ejection murmur . The electrocardiogram revealed normal sinus rhythm with frequent atrial premature beats and right ventricular enlargement . The chest X-ray film revealed Kerley B lines, prominent pulmonary veins and no cardiomegaly . Echocardlographic Study Echocardiographic study was carried out with the patient in the supine position and the transducer on the fourth or fifth left interspace parasternally (Fig . 2) . During slow continuous scanning from the area of the aortic valve toward the mid portion of the left ventricle, the echocardiographic appearance of the aortic valve, mitral valve and heart chambers was normal except for the presence of a thin but distinct abnormal
echo traversing the left atrial cavity obliquely ; this echo (labeled S) was consistently and reproducibly seen during several attempts to establish its nature and was thought to originate from the intraatrial septum of a cur triatriatum . At the level of the aortic valve (position 1, Fig . 2) echo S was in close proximity to, or fused with, the posterior aortic wall echo . The distance between these two echoes progressively increased during slow transition from position 1 to position 2 and became maximal at the level of the anterior mitral cusp where echo S joined the posterior left atrial wall above the atrioventricular junction at a point labeled A (Fig . 2, top) . Thus the left atrial cavity was separated by echo S into a posterior or upper chamber between echo S and the posterior left atrial wall, and an anterior or lower chamber between echo S and the echo of the anterior mitral cusp . Echo S exhibited a small amplitude motion with a total anteroposterior excursion varying from 4 to 15 mm according to the level at which the measurement was made . To study the pattern of movement of echo S, an echocardiographic strip was obtained with the transducer temporarily held stationary for a few beats before the onset of a "sector scan" at a point marked X (Fig . 2, lower right) . Thus, with the transducer pointed at a plane just beneath the aortic valve, echo S was seen to follow the anterior movement of the posterior aortic wall for the first two thirds of systole ; but during the last third this anterior movement of echo S ceased or even reversed to a posterior direction while the posterior aortic wall was still moving anteriorly. In early diastole, echo S exhibited an abrupt anterior movement at about the same time that the mitral valve opened (solid arrow, bottom strip, Fig . 2) . At that moment, echo S started a slow posterior movement lasting for the remainder of a normal diastole . However, when an exceptionally long diastole followed a premature beat, this slow posterior movement of echo S ended well before the occurrence of the next systole at the point shown by the broken arrow, so that for the last part of this long diastole echo S was
FIGURE 1 . Preoperative levophase angiocardiogram after injection of contrast medium into the pulmonary artery, right anterior oblique view . The intraatrial septum appears as a linear filling defect (arrows) within the opacified left atrium . AO aorta ; LA = left atrium; LAA = left atrial appendage; LV = left ventricle ; UC = upper chamber . 61 6
October 1977 The American Journal of CARDIOLOGY Volume 40
ECHOCARDIOGRAPHIC FEATURES OF COB TRIATRIATUM-CANEDO ET AL.
FIGURE 2 . Preoperative echocardiograms . Upper, Echocardiographic "sector scan" from the area of the aortic valve (left) to the body of the left ventricle (right) recorded simultaneously with electrocardiogram (ECG), phonocardiogram (P) and respiration tracing (R) . Note the abnormal linear echo (S) originating from the intraatrial septum that divides the left atrial cavity into a posterior or upper chamber (UC) and an anterior or lower chamber (LC) . This echo joins the posterior left atrial wall at point A . AAW and PAW = anterior and posterior aortic wall, respectively . Lower left, artist's visualization of the right lateral view of the heart bisected longitudinally on a plane corresponding to the sector scan shown above . The scan started from position 1, passed through position 2 and continued further down into the body of the left ventricle (LV) . Ao = aortic root; IVS = interventricular septum ; 0 = orifice of the intraatrial septum ; PV = pulmonary vein ; RV = right ventricle ; S = intraatrial septum . Lower right, echogram obtained from the fourth left interspace with the transducer pointed toward the aortic root and held stationary for the duration of the first three beats . At point X the transducer Is gradually tilted inferolaterally to record a sector scan . See text. LAW = left atrial wall .
FIGURE 3 . PreoperatIve echogram obtained from position 3 shown in the diagram of Figure 2 . The echo (S) from the intraatrial septum appears between the anterior mitral valve leaflet (AML) and the posterior left atrial wall (LAW), thus separating the left atrial cavity into an upper (UC) and a lower (LC) chamber .
October 1977
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o CARDIOLOGY
Volume 40
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ECHOCARDIOGRAPHIC FEATURES OF COR TRIATRIATJM-CANEDO ET AL.
FIGURE 4 . Mitral valve echogram . Lett, preoperative . Note high frequency fluttering movement of the posterior mitral leaflet in diastole (arrows). Rlght, postoperative . The posterior mitral leaflet in diastole is normal (arrows) .
horizontal and parallel to the posterior aortic and left atrial wall . A different appearance of echo S was obtained when the transducer was placed at the sternal end of the fifth left interspace and pointed in a superior and slightly medial direction (position 3, Fig . 2) ; in the echogram obtained from this position (Fig . 3) echo S was seen as a discrete thin, dense echo located between the anterior mitral cusp and the posterior left atrial wall, thus dividing the left atrial cavity into two chambers . In echograms in which both mitral cusps were represented (Fig. 4), the echo of the posterior cusp exhibited a high frequency fluttering movement throughout diastole, similar to that frequently observed on the anterior mitral cusp in patients with severe aortic regurgitation. This movement was attributed to the effect of the jet of blood flowing through the small orifice of the abnormal intraatrial septum in close proximity to or actually hitting the posterior cusp . The patient underwent surgical excision of the in traatrial membrane on August 16, 1976 . The membrane was about 1 .5 cm above the level of the mitral valve and had an eccentrically located round orifice of 0 .8 to 1 .0 cm 2 that was the sole communication between the superior and inferior chambers . Postoperative recovery was uneventful .
A "sector scan" echogram obtained on the fourth postoperative day was normal in all respects except for the presence of a small pericardial effusion (Fig . 5) . The patient was discharged 6 days later and has remained completely asymptomatic. Discussion Cor triatriatum is a serious congenital cardiac malformation that is amenable to surgical correction by excision of the abnormal intraatrial membrane . However, the majority of reported cases have been diagnosed at autopsy and there are only a few cases in which diagnosis was made either preoperatively 3-i or at operation. ,' Echocardiographic diagnosis : To our knowledge, there are five reports involving seven patients in whom the diagnosis of cor triatriatum was made preoperatively with conventional M-modes-to or cross-sectionals echocardiography or both . In all seven cases the principal abnormality was the presence within the left atrial cavity of a moving dense linear echo located behind the normal anterior mitral leaflet or the posterior wall of the
FIGURES . Postoperative sector scan . The abnormal echo from the intraatrial septum seen preoperatively within the left atrial cavity is no longer present . The terminal third of the scan (right) is electronically dampened.
61 8
October 1977
The American Journal of CARDIOLOGY
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ECHOCARDIOGRAPHIC FEATURES OF COR TRIATRIATUM-CANEDO ET AL .
aortic root, depending on the level at which the ultrasonic beam penetrated the heart . With the cross-sectional echocardiograms the abnormal membrane was seen as a process-like echo structure protruding into the left atrial cavity . 9 The echograms in the few reported cases of cor triatriatum6-10 reveal significant differences among pa-
tients in the pattern of movement of the abnormal intraatrial echo . Because of these differences and the limited number of cases studied, no definitive echocardiographic criteria have been established for the differential diagnosis between cor triatriatum and the abnormal echoes seen in the left atrium in supravalvular ring, 6 total anomalous pulmonary venous connection, 11 left atrial tumor 12 or thrombus 13 or in the absence of any
abnormal echo-producing structure within the left atrium . 13 Special echocardiographic features on sector scans : In addition to the presence within the left atrium of the abnormal septal echo, two echocardiographic features were observed in our case . The first was the attachment of both ends of abnormal echo to the opposite left atrial walls . This feature was not observed in cases of cor triatriatum previously studied with M mode echocardiography 6-10 but was seen in the two cases of Nimura et al. 9 studied with cross-sectional echography .
The second feature was the presence of high frequency
diastolic oscillations exclusively on the posterior mitral leaflet echo and their disappearance postoperatively . Although similar oscillations are common on the anterior mitral cusp and less common on both mitral cusps or the upper part of the left side of the interventricular septum , in patients with severe aortic regurgitation (unpublished observations), we have never observed them exclusively on the posterior mitral cusp in any other patient with or without aortic regurgitation . The specificity of these two echocardiographic features remains to be established by echocardiographic studies of additional cases of cor triatriatum . In conclusion, we suggest that every effort be made to establish or exclude the diagnosis of cor triatriatum in all patients who appear to have mitral valve stenosis on the basis of clinical, electrocardiographic or roentgenologic grounds but who have a normal echogram of the mitral valve . In comparison with the conventional echograms obtained from one or more positions with a stationary transducer, "sector scans" represent a superior technique for the study of the echocardiographic anatomy of the left atrium and should be routinely used in cases of clinically suspected cor triatriatum . Acknowledgment We thank Mrs. Linda Attaway for her secretarial assistance .
References 1 . Wood P: Diseases of the Heart and Circulation, third edition . London, Eyre and Spottiswoode, 1968, p 408 2 . Nlwayama G: Cor triatriatum (review) . Am Heart J 59 :291-317, 1960 3 . Lam CR, Green E, Drake E : Diagnosis and surgical correction of 2 types of triatrial heart. Surgery 51 :127-137, 1962 4 . Abdulla HM, Demany MA, Zimmerman HA : Cor triatriatum : preoperative diagnosis in an adult patient . Am J Cardiol 26 :310-314, 1970 5 . Miller GA, Ongley PA, Anderson MW, et al : Cor triatriatum: hemodynamic and angiocardiographic diagnosis. Am Heart J 68 : 298-304,1964 6 . Lurdstrom NR : Ultrasoundcardiographic studies of the mitral valve
region in young infants with mitral atresia, mitral stenosis, hypoplasia of the left ventricle, and cor triatriatum. Circulation 45 : 324-334,1972 7 . Troy BL, Panepinto M, Harp R, et al : Diagnosis of car triatriatum
by echocardiography (abstr) . J Clin Ultrasound 1 :257, 1973 8. Glbson DG, Honey M, Lennox SC : Cor triatriatum: diagnosis by echocardiography . Br Heart J 36:835-838, 1974 9. Nlmura Y, Matsumoto M, Beppu 5, et al: Noninvasive preoperative diagnosis of cor triatriatum with ultrasonocardiotomogram and conventional echocardiogram . Am Heart J 88 :240-250, 1974 10 . LaCorte M, Hareda K, Williams RG : Echocardiographic features of congenital left ventricular inflow obstruction . Circulation 54: 562-566,1976 11 . Paquet M, Gutgesell H : Echocardiographic features of total anomalous pulmonary venous connection . Circulation 51 :599-605, 1975 12 . Wolfe SB, Popp RL, Feigenbaum H : Diagnosis of atrial tumors by ultrasound . Circulation 39 :615-622, 1969 13 . Feigenbaum H : Echocardiography, first edition . Philadelphia, Lee & Febiger, 1972, p 65, 153
October 1977
The American Journal of CARDIOLOGY Volume 40
619
MARIO I . CANEDO, MD MILTIADIS A . STEFADOUROS, MD, FACC MARTIN J . FRANK, MD, FACC H . VICTOR MOORE, MD DAVID W . CUNDEY, MD, FACC
Augusta, Georgia
A patient is presented who had cor triatriatum documented with angiography and surgery . On echocardiographic study, an abnormal, dense linear echo on "sector scan" was consistently seen to traverse the left atrial cavity obliquely ; the ends of the echo were attached to the posterior aortic and lateral walls of the left atrium . In addition, high frequency oscillatory movements were evident In the echo of the posterior mitral cusp . Both echocardiographic features disappeared promptly after successful resection of the intraatrial fibrinous membrane . This experience indicates that in the presence of strong evidence of mitral stenosis, an unexpectedly normal mitral valve echogram should initiate a thorough echographic search for cor triatriatum, a treatable cardiac malformation whose diagnosis can easily be missed on "routine" echocardiographic studies .
Cor triatriatum is a rare congenital cardiac abnormality .' In its classic form it consists of a perforated fibromuscular septum or membrane that divides the left atrial cavity into a superior chamber connected with the pulmonary veins and an inferior chamber connected with the left atrial appendage and communicating with the left ventricle through a normal mitral valve . The hemodynamic consequences and symptoms resemble those of mitral stenosis . Most of the reported cases of cor triatriatum have been diagnosed at autopsy2 or at operation .' Preoperative diagnosis has been made with invasive methods in a few cases 3 and with echocardiography in only seven ." This is a report on the echocardiographic features of cor triatriatum initially diagnosed with angiocardiography and subsequently documented at operation .
Case Report
From the Section of Cardiology, Department of Medicine, and the Division of Thoracic and Cardiac Surgery, Medical College of Georgia, Augusta, Georgia. Manuscript received January 24, 1977 ; revised manuscript received March 3, 1977, accepted March 16, 1977 . Address for reprints : Miltiadis A . Stefadouros, MD, Department of Medicine, Medical College of Georgia, Augusta, Georgia 30902 .
A 19 year old white youth was admitted to the Eugene Talmadge Memorial Hospital on August 13, 1976 with a 1 year history of exertional fatigue and dyspnea . He had been asymptomatic with normal exercise tolerance until the previous year when he experienced fatigue, dyspnea and cough that increased progressively with exercise. In July 1976 he had frequent palpitations associated with rapid and marked increase in exertional fatigue and dyspnea . He was admitted to another hospital where the electrocardiogram revealed atrial fibrillation and right ventricular enlargement, the chest X-ray film revealed prominent Kerley B lines and pulmonary venous congestion and the echocardiographic study yielded normal findings . Cardiac catheterization on August 2, 1976 disclosed normal left ventricular and aortic pressures, elevated right ventricular, pulmonary arterial and capillary "wedge" pressures and a consistent diastolic pressure gradient between the left ventricular and pulmonary "wedge" pressures with an end-diastolic value of 14 mm Hg (Table I) . A cineangiogram revealed normal left ventricular volume and performance ; there was no mitral regurgitation. To visualize the left atrium, contrast medium was injected into the main pulmonary artery and the levophase angiogram was filmed in the right anterior oblique projection (Fig. 1) . A moving radiolucent membrane within the opacified left atrium divided it into a larger superior chamber connected with the pulmonary veins and a smaller inferior chamber connected with the appendage . The movement of the intraatrial membrane was of small amplitude and was directed toward the mitral valve in diastole and away from it in systole . The
October 1977
The American Journal of CARDIOLOGY
Volume 40
615
=
ECHOCARDIOCiiAPHIC FEATURES OF COR TRIATRIATUM-CANEDO ET AL .
TABLE I Cardiac Catheterization Data
Site Main pulmonary artery Right ventricle Pulmonary capillary wedge Left ventricle Aorta Figures in parentheses indicate
Pressure (mm Hg) 55/32 (41) 55/6 (20) 105/6 105/75(90) mean pressure .
Hemoglobin Oxygen Saturation (% ) 75 74 99 96 96
emptying of the left atrium was delayed . On the basis of these findings the diagnosis of the cor triatriatum was made and the patient was referred to our hospital for surgical correction of this malformation. On admission, the patient was not breathless at rest . His pulse rate was 6S/min and regular, blood pressure 100/70 mm Hg and respirations 20/min . The only abnormal physical finding was a soft (1/6) systolic ejection murmur . The electrocardiogram revealed normal sinus rhythm with frequent atrial premature beats and right ventricular enlargement . The chest X-ray film revealed Kerley B lines, prominent pulmonary veins and no cardiomegaly . Echocardlographic Study Echocardiographic study was carried out with the patient in the supine position and the transducer on the fourth or fifth left interspace parasternally (Fig . 2) . During slow continuous scanning from the area of the aortic valve toward the mid portion of the left ventricle, the echocardiographic appearance of the aortic valve, mitral valve and heart chambers was normal except for the presence of a thin but distinct abnormal
echo traversing the left atrial cavity obliquely ; this echo (labeled S) was consistently and reproducibly seen during several attempts to establish its nature and was thought to originate from the intraatrial septum of a cur triatriatum . At the level of the aortic valve (position 1, Fig . 2) echo S was in close proximity to, or fused with, the posterior aortic wall echo . The distance between these two echoes progressively increased during slow transition from position 1 to position 2 and became maximal at the level of the anterior mitral cusp where echo S joined the posterior left atrial wall above the atrioventricular junction at a point labeled A (Fig . 2, top) . Thus the left atrial cavity was separated by echo S into a posterior or upper chamber between echo S and the posterior left atrial wall, and an anterior or lower chamber between echo S and the echo of the anterior mitral cusp . Echo S exhibited a small amplitude motion with a total anteroposterior excursion varying from 4 to 15 mm according to the level at which the measurement was made . To study the pattern of movement of echo S, an echocardiographic strip was obtained with the transducer temporarily held stationary for a few beats before the onset of a "sector scan" at a point marked X (Fig . 2, lower right) . Thus, with the transducer pointed at a plane just beneath the aortic valve, echo S was seen to follow the anterior movement of the posterior aortic wall for the first two thirds of systole ; but during the last third this anterior movement of echo S ceased or even reversed to a posterior direction while the posterior aortic wall was still moving anteriorly. In early diastole, echo S exhibited an abrupt anterior movement at about the same time that the mitral valve opened (solid arrow, bottom strip, Fig . 2) . At that moment, echo S started a slow posterior movement lasting for the remainder of a normal diastole . However, when an exceptionally long diastole followed a premature beat, this slow posterior movement of echo S ended well before the occurrence of the next systole at the point shown by the broken arrow, so that for the last part of this long diastole echo S was
FIGURE 1 . Preoperative levophase angiocardiogram after injection of contrast medium into the pulmonary artery, right anterior oblique view . The intraatrial septum appears as a linear filling defect (arrows) within the opacified left atrium . AO aorta ; LA = left atrium; LAA = left atrial appendage; LV = left ventricle ; UC = upper chamber . 61 6
October 1977 The American Journal of CARDIOLOGY Volume 40
ECHOCARDIOGRAPHIC FEATURES OF COB TRIATRIATUM-CANEDO ET AL.
FIGURE 2 . Preoperative echocardiograms . Upper, Echocardiographic "sector scan" from the area of the aortic valve (left) to the body of the left ventricle (right) recorded simultaneously with electrocardiogram (ECG), phonocardiogram (P) and respiration tracing (R) . Note the abnormal linear echo (S) originating from the intraatrial septum that divides the left atrial cavity into a posterior or upper chamber (UC) and an anterior or lower chamber (LC) . This echo joins the posterior left atrial wall at point A . AAW and PAW = anterior and posterior aortic wall, respectively . Lower left, artist's visualization of the right lateral view of the heart bisected longitudinally on a plane corresponding to the sector scan shown above . The scan started from position 1, passed through position 2 and continued further down into the body of the left ventricle (LV) . Ao = aortic root; IVS = interventricular septum ; 0 = orifice of the intraatrial septum ; PV = pulmonary vein ; RV = right ventricle ; S = intraatrial septum . Lower right, echogram obtained from the fourth left interspace with the transducer pointed toward the aortic root and held stationary for the duration of the first three beats . At point X the transducer Is gradually tilted inferolaterally to record a sector scan . See text. LAW = left atrial wall .
FIGURE 3 . PreoperatIve echogram obtained from position 3 shown in the diagram of Figure 2 . The echo (S) from the intraatrial septum appears between the anterior mitral valve leaflet (AML) and the posterior left atrial wall (LAW), thus separating the left atrial cavity into an upper (UC) and a lower (LC) chamber .
October 1977
The American Journal
o CARDIOLOGY
Volume 40
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ECHOCARDIOGRAPHIC FEATURES OF COR TRIATRIATJM-CANEDO ET AL.
FIGURE 4 . Mitral valve echogram . Lett, preoperative . Note high frequency fluttering movement of the posterior mitral leaflet in diastole (arrows). Rlght, postoperative . The posterior mitral leaflet in diastole is normal (arrows) .
horizontal and parallel to the posterior aortic and left atrial wall . A different appearance of echo S was obtained when the transducer was placed at the sternal end of the fifth left interspace and pointed in a superior and slightly medial direction (position 3, Fig . 2) ; in the echogram obtained from this position (Fig . 3) echo S was seen as a discrete thin, dense echo located between the anterior mitral cusp and the posterior left atrial wall, thus dividing the left atrial cavity into two chambers . In echograms in which both mitral cusps were represented (Fig. 4), the echo of the posterior cusp exhibited a high frequency fluttering movement throughout diastole, similar to that frequently observed on the anterior mitral cusp in patients with severe aortic regurgitation. This movement was attributed to the effect of the jet of blood flowing through the small orifice of the abnormal intraatrial septum in close proximity to or actually hitting the posterior cusp . The patient underwent surgical excision of the in traatrial membrane on August 16, 1976 . The membrane was about 1 .5 cm above the level of the mitral valve and had an eccentrically located round orifice of 0 .8 to 1 .0 cm 2 that was the sole communication between the superior and inferior chambers . Postoperative recovery was uneventful .
A "sector scan" echogram obtained on the fourth postoperative day was normal in all respects except for the presence of a small pericardial effusion (Fig . 5) . The patient was discharged 6 days later and has remained completely asymptomatic. Discussion Cor triatriatum is a serious congenital cardiac malformation that is amenable to surgical correction by excision of the abnormal intraatrial membrane . However, the majority of reported cases have been diagnosed at autopsy and there are only a few cases in which diagnosis was made either preoperatively 3-i or at operation. ,' Echocardiographic diagnosis : To our knowledge, there are five reports involving seven patients in whom the diagnosis of cor triatriatum was made preoperatively with conventional M-modes-to or cross-sectionals echocardiography or both . In all seven cases the principal abnormality was the presence within the left atrial cavity of a moving dense linear echo located behind the normal anterior mitral leaflet or the posterior wall of the
FIGURES . Postoperative sector scan . The abnormal echo from the intraatrial septum seen preoperatively within the left atrial cavity is no longer present . The terminal third of the scan (right) is electronically dampened.
61 8
October 1977
The American Journal of CARDIOLOGY
Volume 40
ECHOCARDIOGRAPHIC FEATURES OF COR TRIATRIATUM-CANEDO ET AL .
aortic root, depending on the level at which the ultrasonic beam penetrated the heart . With the cross-sectional echocardiograms the abnormal membrane was seen as a process-like echo structure protruding into the left atrial cavity . 9 The echograms in the few reported cases of cor triatriatum6-10 reveal significant differences among pa-
tients in the pattern of movement of the abnormal intraatrial echo . Because of these differences and the limited number of cases studied, no definitive echocardiographic criteria have been established for the differential diagnosis between cor triatriatum and the abnormal echoes seen in the left atrium in supravalvular ring, 6 total anomalous pulmonary venous connection, 11 left atrial tumor 12 or thrombus 13 or in the absence of any
abnormal echo-producing structure within the left atrium . 13 Special echocardiographic features on sector scans : In addition to the presence within the left atrium of the abnormal septal echo, two echocardiographic features were observed in our case . The first was the attachment of both ends of abnormal echo to the opposite left atrial walls . This feature was not observed in cases of cor triatriatum previously studied with M mode echocardiography 6-10 but was seen in the two cases of Nimura et al. 9 studied with cross-sectional echography .
The second feature was the presence of high frequency
diastolic oscillations exclusively on the posterior mitral leaflet echo and their disappearance postoperatively . Although similar oscillations are common on the anterior mitral cusp and less common on both mitral cusps or the upper part of the left side of the interventricular septum , in patients with severe aortic regurgitation (unpublished observations), we have never observed them exclusively on the posterior mitral cusp in any other patient with or without aortic regurgitation . The specificity of these two echocardiographic features remains to be established by echocardiographic studies of additional cases of cor triatriatum . In conclusion, we suggest that every effort be made to establish or exclude the diagnosis of cor triatriatum in all patients who appear to have mitral valve stenosis on the basis of clinical, electrocardiographic or roentgenologic grounds but who have a normal echogram of the mitral valve . In comparison with the conventional echograms obtained from one or more positions with a stationary transducer, "sector scans" represent a superior technique for the study of the echocardiographic anatomy of the left atrium and should be routinely used in cases of clinically suspected cor triatriatum . Acknowledgment We thank Mrs. Linda Attaway for her secretarial assistance .
References 1 . Wood P: Diseases of the Heart and Circulation, third edition . London, Eyre and Spottiswoode, 1968, p 408 2 . Nlwayama G: Cor triatriatum (review) . Am Heart J 59 :291-317, 1960 3 . Lam CR, Green E, Drake E : Diagnosis and surgical correction of 2 types of triatrial heart. Surgery 51 :127-137, 1962 4 . Abdulla HM, Demany MA, Zimmerman HA : Cor triatriatum : preoperative diagnosis in an adult patient . Am J Cardiol 26 :310-314, 1970 5 . Miller GA, Ongley PA, Anderson MW, et al : Cor triatriatum: hemodynamic and angiocardiographic diagnosis. Am Heart J 68 : 298-304,1964 6 . Lurdstrom NR : Ultrasoundcardiographic studies of the mitral valve
region in young infants with mitral atresia, mitral stenosis, hypoplasia of the left ventricle, and cor triatriatum. Circulation 45 : 324-334,1972 7 . Troy BL, Panepinto M, Harp R, et al : Diagnosis of car triatriatum
by echocardiography (abstr) . J Clin Ultrasound 1 :257, 1973 8. Glbson DG, Honey M, Lennox SC : Cor triatriatum: diagnosis by echocardiography . Br Heart J 36:835-838, 1974 9. Nlmura Y, Matsumoto M, Beppu 5, et al: Noninvasive preoperative diagnosis of cor triatriatum with ultrasonocardiotomogram and conventional echocardiogram . Am Heart J 88 :240-250, 1974 10 . LaCorte M, Hareda K, Williams RG : Echocardiographic features of congenital left ventricular inflow obstruction . Circulation 54: 562-566,1976 11 . Paquet M, Gutgesell H : Echocardiographic features of total anomalous pulmonary venous connection . Circulation 51 :599-605, 1975 12 . Wolfe SB, Popp RL, Feigenbaum H : Diagnosis of atrial tumors by ultrasound . Circulation 39 :615-622, 1969 13 . Feigenbaum H : Echocardiography, first edition . Philadelphia, Lee & Febiger, 1972, p 65, 153
October 1977
The American Journal of CARDIOLOGY Volume 40
619
