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Idiopathic enlargement of the right atrium
Idiopathic Enlargement of the Right Atrium
JUN ASAYAMA, MD TOHRU MATSUURA, MD NAOTO ENDO, MD HARUO MATSUKUBO, MD KEIZO FURUKAWA, MD Kyoto, Japan
A huge saccular idiopathic dilatation of the right atrium was detected with angiography and echocardiography in a 75 year old man . Cardiac catheterization data were compared with data obtained 4 years earlier . Idiopathic right atria) enlargement Is not usually accompanied by tricuspid valve disease, but in this case tricuspid insufficiency did occur over a period of 4 years, possibly as a complication in the late stage of idiopathic right atria) enlargement .
In 1961 Pastor and Forte' described three cases of isolated right atrial enlargement that they termed idiopathic enlargement of the right atrium . This rare condition is generally considered a congenital anomaly . In some cases, 2 '3 pericardial tap has been performed because of a mistaken diagnosis of cardiac tamponade and thoracotomy for a mistakenly diagnosed mediastinal tumor . In this report we show that echocardiographic studies performed before invasive examination may be useful in determining whether an abnormal cardiac silhouette indicates a dilated chamber and, additionally, whether the right atrium is dilated . We also present the results of 4 year follow-up angiographic studies .
Case Report
From the Second Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan . Manuscript received January 27, 1977 ; revised manuscript received April 5, 1977, accepted April 6, 1977 . Address for reprints: Jun Asayama, MD, Second Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602, Japan .
620
October 1977
The American Journal
A 75 year old man was referred on October 10, because of nasal bleeding due to carcinoma of the larynx. About 10 years previously an abnormal cardiac silhouette had been discovered by the patient's personal physician and 4 years previously he was admitted to another hospital because of exertional and nocturnal dyspnea and dependent edema . A pericardial tap was performed because of pericardial effusion suspected because of an enlarged cardiac silhouette (Fig . 1), distant heart sounds and low voltage electrocardiogram ; pericardial fluid was not obtained . An isolated enlarged right atrium was shown in the angiocardiograms (see Fig . 4A) . Cardiac symptoms were relieved with digitalization . On examination, the blood pressure was 136/86 mm Hg, and the pulse was 90 beats/min and irregular . A grade 5/6 regurgitant systolic murmur was audible at the lower left sternal border (Fig . 2) . The jugular veins were moderately distended . The liver was palpable approximately 3 cm below the right costal margin. There was no pitting edema or ascites . The electrocardiogram revealed atria) fibrillation, incomplete right bundle branch block and low voltage . The chest X-ray film showed prominent cardiac enlargement to the right with a cardiothoracic ratio of 0 .86 (Fig . 1) . The jugular vein and liver pulsations showed prominent V waves (Fig . 2) .
of CARDIOLOGY
Volume 40
IDIOPATHIC ENLARGEMENT OF THE RIGHT ATRIUM-ASAYAMA ET AL .
75 yo.
71 yo.
FIGURE 1 (left) . Chest roentgenograms . Left, at age in cardiothoracic ratio from 0 .81 to 0 .86.
71
years, showing an enlarged cardiac silhouette . Right, at age
75
years, showing increase
FIGURE 2 (right). Simultaneous recordings of phonocardiogram, jugular (Jug .) venous pulse and liver pulsation . Predominant V waves, typical of tricuspid insufficiency, are seen in both pulse tracings . A systolic murmur is recorded at the sixth interspace at the left sternal border . L, M and H indicate low, medium and high frequency phonocardiogram, respectively . ECG = eiectrocardlogram .
Echocardiographic findings : All echocardiograms were recorded with an Aloka SSD-90 echograph using a 2 .25 megahertz transducer 10 mm in diameter . The tracings were recorded on a strip chart recorder at a speed of 50 mm/sec . Echocardiograms, obtained with the beam set in a medial and slightly superior direction through the right fifth intercostal space at the mid clavicular line, demonstrated an enlarged right atrium, aortic root and left atrium . As the transducer was angled slightly laterally, a larger right atrium as well as the interatrial septum and left atrium could be observed . When the transducer was tilted farther laterally, an enlarged right atrium, 116 mm in width, was demonstrated (Fig . 3A) . The echocardiogram, obtained with the beam set straight through the left sixth intercostal space at the mid clavicular line, showed the right ventricle, interventricular septum and the anterior mitral valve leaflet. As the transducer was angled medially, the tricuspid valve with fine diastolic fluttering became evident (Fig. 3B) . When the transducer was placed on the left fifth intercostal space at the sternal border, the diameter of the right ventricular outflow tract was found to be more than 30 mm, and the left atrium was also enlarged . The interventricular septum showed paradoxical movement (Fig . 3C) . Cardiac catheterization : Four years before this admission, the pressure data obtained in the right heart chambers were almost within normal limits. Now, a prominent V wave in the right atrial pressure curve and a moderately elevated pressure in the right side of the heart were observed . Blood oxygen saturation levels indicated no intracardiac shunts (Table I) . Right atrial angiograms made 4 years earlier showed a huge right atrium that enlarged further in the ensuing years (Fig . 4) . Discussion
Abnormal enlargement of the right atrium occurs in many diseases such as atrial septal defect, anomalous pulmonary venous return, Ebstein's anomaly and other lesions of the tricuspid valve, pulmonary stenosis and pulmonary hypertension . In 1961 Pastor and Forte' described three cases of enlarged right atrium without significant enlargement of other cardiac chambers or evidence of heart disease and termed this condition idiopathic enlargement of the right atrium . The condition is generally considered of congenital origin .
October
Summer et al .4 proposed the following criteria for its clinical diagnosis : (1) a right atrium disproportionately large when compared with the other cardiac chambers ; and (2) absence, after systematic exclusion, of all cardiovascular lesions known to produce right atrial enlargement . In most of the reported cases4' 5 the patients were asymptomatic, but a few 3 . 6 had symptoms such as fatigue, palpitation, exertional dyspnea and syncope . The enlarged atrium interposed between the heart and anterior chest wall may result in distant heart sounds and a low voltage electrocardiogram . 2 Moderate right ventricular compression by the weight of the large volume of intraatrial blood may induce paradoxical pulse and low cardiac output 2 In some cases, as in ours, pericaridal tap has been carried out on the basis of a mistaken diagnosis of cardiac tamponade . In our case, Ebstein's anomaly 7 was excluded because a tricuspid valve of normal size was located in the median position from the mitral valve in the M mode echocardiogram . Cardiac tamponade was ruled out by the absence of a significant echo-free space . As mentioned, tricuspid valve disease must be excluded in the diagnosis of idiopathic enlargement of the right atrium . However, in our case the recent appearance of tricuspid insufficiency was assessed from the existence of a
TABLE I Cardiac Catheterization Data 1976 1972
Site Pulmonary artery Right ventricle Right atrium Mean pressure V wave Superior vena cava Interior vans cava Femoral artery
1977
Pressure (mm Hq)
Pressure (mm Hg)
24/10 28/4
38/14 38/6
66.6 66.6
2 4
12 17
66 .3
The American Journal
02
Saturation (%)
65 .2 73.0 87.6
of
CARDIOLOGY Volume
40
621
IDIOPATHIC ENLARGEMENT OF THE RIGHT ATRIUM--ASAYAMA ET AL .
A
rriY
+sr A A 0Mfie fAr,.
RA I AS
06
3cm
FIGURE 3 . M mode echocardiograms . A, scan from the aortic valve to the right atrium (RA) . The aortic wall echoes disappear and the enlarged right atrium gradually increases to a width of 11 .6 cm as the transducer is angled laterally . B, scan from the mitral to the tricuspid valve (TV) with the transducer tilted medially demonstrates the normal pattern of the mitral valve and the fine fluttering of the tricuspid valve in diastole . C, left ventricular echocardiogram showing paradoxical movement of the interventricular septum (IVS) . AAO = anterior aortic wall ; AMV = anterior mitral valve ; IAS = Interatrial septum; LA = left atrium ; PAO = posterior aortic wall ; PW = posterior wall ; RV = right ventricle; TV = tricuspid valve .
holosystolic murmur at the left sternal border, a prominent V wave in the jugular venous pulse and right atrial pressure curve, as well as from the enlargement of the right ventricle and the paradoxical movement of the interventricular septum in the echocardiograms . Echocardiographic identification of right atrium : It is well known that echocardiography is very effective in differentiating an enlarged cardiac silhouette in the chest X-ray film from a pericardial effusion . In cases showing an enlarged cardiac chamber in the echocardiogram, it is desirable to confirm the anatomic relation between the enlarged chamber and the aortic
822
October 1977
The American Journal of CARDIOLOGY
or pulmonary valve by tilting the transducer in various directions on the chest wall corresponding to the enlarged cardiac silhouette . In our case, when the transducer was positioned at the right side of the chest wall, evidence of a large chamber, thought to be the aortic root, was elicited . The interventricular septal motion appeared to be paradoxical, and the diameter of the right ventricle was large . M mode echocardiograms clarified the anatomic relation between the greatly enlarged chamber, the aortic root and the position of the tricuspid valve . We concluded, therefore, that this large chamber was the right atrium .
Volume 40
IDIOPATHIC ENLARGEMENT OF THE RIGHT ATRIUM-ASAYAMA ET AL .
FIGURE 4 . Right atriograms . A and B, at age 71 and 75 years, respectively, in anteroposterior view, and C, at age 75, in lateral view, showing a severely enlarged right atrium (RA) becoming further enlarged after a 4 year interval . Ao = ascending aorta ; C = position of catheter tip ; IVC = inferior vena cava ; RV = right ventricle ; SVC = superior vena cava .
Tricuspid insufficiency : In the postmortem findings reported by Tenckhoff et al ., 2 the floor of the right atrium was abnormally flattened, particularly anterior to the tricuspid anulus, and formed a shelf . The tricuspid ring was normally placed and of normal size but was compressed anteroposteriorly to an elongated slit . The enlarged left portion of the right atrium may result from a heavier blood weight on this shelf, causing insufficiency of the tricuspid valve . The fine diastolic fluttering of the tricuspid valve in the echocardiograms may also be produced by the blood flowing through the
deformed tricuspid valve . Tricuspid insufficiency may occur in the late stage of idiopathic enlargement of the right atrium and may induce further atrial enlargement.
Acknowledgment We acknowledge with much appreciation the support and encouragement of Dr. Hamao Ijichi . We also thank Drs . Takaaki Mizutani, Masaru Tohara, Toshimitsu Watanabe and Tsuguo Isoda for the assistance and many comments on the preparation of the manuscript.
References 1 . Pastor BH, Forte, AL : Idiopathic enlargement of the right atrium . Am J Cardiol 8:513-518, 1961 2 . Tenckhoff L, Stamm SJ, Beckwith JB : Sudden death in idiopathic right atrial enlargement . Circulation 40 :227-235, 1969 3 . Salgusa M, Morlmoto K, Kolke T, et al : Idiopathic enlargement of the right atrium . Jpn Heart J 3 :373-379, 1962 4 . Sumner FIG, Phillips JH, Jacoby WJ, et al : Idiopathic enlargement of the right atrium . Circulation 32 :985-991, 1965
5 . Eshaghpour E, Olley PM, Collins GFN : Idiopathic right atrial enlargement in childhood . Am Heart J 78 :373-378, 1969 6 . Sheldon WC, Johnson CD, Favaloro, RG : Idiopathic enlargement of the right atrium. Report of four cases . Am J Cardiol 23:278-284, 1969 7 . Farooki, ZO, Henry JO, Green EW : Echocardiographic spectrum of Ebstein's anomaly of the tricuspid valve . Circulation 53 :63-68, 1976
October 1977 The American Journal of CARDIOLOGY Volume 40
823
JUN ASAYAMA, MD TOHRU MATSUURA, MD NAOTO ENDO, MD HARUO MATSUKUBO, MD KEIZO FURUKAWA, MD Kyoto, Japan
A huge saccular idiopathic dilatation of the right atrium was detected with angiography and echocardiography in a 75 year old man . Cardiac catheterization data were compared with data obtained 4 years earlier . Idiopathic right atria) enlargement Is not usually accompanied by tricuspid valve disease, but in this case tricuspid insufficiency did occur over a period of 4 years, possibly as a complication in the late stage of idiopathic right atria) enlargement .
In 1961 Pastor and Forte' described three cases of isolated right atrial enlargement that they termed idiopathic enlargement of the right atrium . This rare condition is generally considered a congenital anomaly . In some cases, 2 '3 pericardial tap has been performed because of a mistaken diagnosis of cardiac tamponade and thoracotomy for a mistakenly diagnosed mediastinal tumor . In this report we show that echocardiographic studies performed before invasive examination may be useful in determining whether an abnormal cardiac silhouette indicates a dilated chamber and, additionally, whether the right atrium is dilated . We also present the results of 4 year follow-up angiographic studies .
Case Report
From the Second Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan . Manuscript received January 27, 1977 ; revised manuscript received April 5, 1977, accepted April 6, 1977 . Address for reprints: Jun Asayama, MD, Second Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602, Japan .
620
October 1977
The American Journal
A 75 year old man was referred on October 10, because of nasal bleeding due to carcinoma of the larynx. About 10 years previously an abnormal cardiac silhouette had been discovered by the patient's personal physician and 4 years previously he was admitted to another hospital because of exertional and nocturnal dyspnea and dependent edema . A pericardial tap was performed because of pericardial effusion suspected because of an enlarged cardiac silhouette (Fig . 1), distant heart sounds and low voltage electrocardiogram ; pericardial fluid was not obtained . An isolated enlarged right atrium was shown in the angiocardiograms (see Fig . 4A) . Cardiac symptoms were relieved with digitalization . On examination, the blood pressure was 136/86 mm Hg, and the pulse was 90 beats/min and irregular . A grade 5/6 regurgitant systolic murmur was audible at the lower left sternal border (Fig . 2) . The jugular veins were moderately distended . The liver was palpable approximately 3 cm below the right costal margin. There was no pitting edema or ascites . The electrocardiogram revealed atria) fibrillation, incomplete right bundle branch block and low voltage . The chest X-ray film showed prominent cardiac enlargement to the right with a cardiothoracic ratio of 0 .86 (Fig . 1) . The jugular vein and liver pulsations showed prominent V waves (Fig . 2) .
of CARDIOLOGY
Volume 40
IDIOPATHIC ENLARGEMENT OF THE RIGHT ATRIUM-ASAYAMA ET AL .
75 yo.
71 yo.
FIGURE 1 (left) . Chest roentgenograms . Left, at age in cardiothoracic ratio from 0 .81 to 0 .86.
71
years, showing an enlarged cardiac silhouette . Right, at age
75
years, showing increase
FIGURE 2 (right). Simultaneous recordings of phonocardiogram, jugular (Jug .) venous pulse and liver pulsation . Predominant V waves, typical of tricuspid insufficiency, are seen in both pulse tracings . A systolic murmur is recorded at the sixth interspace at the left sternal border . L, M and H indicate low, medium and high frequency phonocardiogram, respectively . ECG = eiectrocardlogram .
Echocardiographic findings : All echocardiograms were recorded with an Aloka SSD-90 echograph using a 2 .25 megahertz transducer 10 mm in diameter . The tracings were recorded on a strip chart recorder at a speed of 50 mm/sec . Echocardiograms, obtained with the beam set in a medial and slightly superior direction through the right fifth intercostal space at the mid clavicular line, demonstrated an enlarged right atrium, aortic root and left atrium . As the transducer was angled slightly laterally, a larger right atrium as well as the interatrial septum and left atrium could be observed . When the transducer was tilted farther laterally, an enlarged right atrium, 116 mm in width, was demonstrated (Fig . 3A) . The echocardiogram, obtained with the beam set straight through the left sixth intercostal space at the mid clavicular line, showed the right ventricle, interventricular septum and the anterior mitral valve leaflet. As the transducer was angled medially, the tricuspid valve with fine diastolic fluttering became evident (Fig. 3B) . When the transducer was placed on the left fifth intercostal space at the sternal border, the diameter of the right ventricular outflow tract was found to be more than 30 mm, and the left atrium was also enlarged . The interventricular septum showed paradoxical movement (Fig . 3C) . Cardiac catheterization : Four years before this admission, the pressure data obtained in the right heart chambers were almost within normal limits. Now, a prominent V wave in the right atrial pressure curve and a moderately elevated pressure in the right side of the heart were observed . Blood oxygen saturation levels indicated no intracardiac shunts (Table I) . Right atrial angiograms made 4 years earlier showed a huge right atrium that enlarged further in the ensuing years (Fig . 4) . Discussion
Abnormal enlargement of the right atrium occurs in many diseases such as atrial septal defect, anomalous pulmonary venous return, Ebstein's anomaly and other lesions of the tricuspid valve, pulmonary stenosis and pulmonary hypertension . In 1961 Pastor and Forte' described three cases of enlarged right atrium without significant enlargement of other cardiac chambers or evidence of heart disease and termed this condition idiopathic enlargement of the right atrium . The condition is generally considered of congenital origin .
October
Summer et al .4 proposed the following criteria for its clinical diagnosis : (1) a right atrium disproportionately large when compared with the other cardiac chambers ; and (2) absence, after systematic exclusion, of all cardiovascular lesions known to produce right atrial enlargement . In most of the reported cases4' 5 the patients were asymptomatic, but a few 3 . 6 had symptoms such as fatigue, palpitation, exertional dyspnea and syncope . The enlarged atrium interposed between the heart and anterior chest wall may result in distant heart sounds and a low voltage electrocardiogram . 2 Moderate right ventricular compression by the weight of the large volume of intraatrial blood may induce paradoxical pulse and low cardiac output 2 In some cases, as in ours, pericaridal tap has been carried out on the basis of a mistaken diagnosis of cardiac tamponade . In our case, Ebstein's anomaly 7 was excluded because a tricuspid valve of normal size was located in the median position from the mitral valve in the M mode echocardiogram . Cardiac tamponade was ruled out by the absence of a significant echo-free space . As mentioned, tricuspid valve disease must be excluded in the diagnosis of idiopathic enlargement of the right atrium . However, in our case the recent appearance of tricuspid insufficiency was assessed from the existence of a
TABLE I Cardiac Catheterization Data 1976 1972
Site Pulmonary artery Right ventricle Right atrium Mean pressure V wave Superior vena cava Interior vans cava Femoral artery
1977
Pressure (mm Hq)
Pressure (mm Hg)
24/10 28/4
38/14 38/6
66.6 66.6
2 4
12 17
66 .3
The American Journal
02
Saturation (%)
65 .2 73.0 87.6
of
CARDIOLOGY Volume
40
621
IDIOPATHIC ENLARGEMENT OF THE RIGHT ATRIUM--ASAYAMA ET AL .
A
rriY
+sr A A 0Mfie fAr,.
RA I AS
06
3cm
FIGURE 3 . M mode echocardiograms . A, scan from the aortic valve to the right atrium (RA) . The aortic wall echoes disappear and the enlarged right atrium gradually increases to a width of 11 .6 cm as the transducer is angled laterally . B, scan from the mitral to the tricuspid valve (TV) with the transducer tilted medially demonstrates the normal pattern of the mitral valve and the fine fluttering of the tricuspid valve in diastole . C, left ventricular echocardiogram showing paradoxical movement of the interventricular septum (IVS) . AAO = anterior aortic wall ; AMV = anterior mitral valve ; IAS = Interatrial septum; LA = left atrium ; PAO = posterior aortic wall ; PW = posterior wall ; RV = right ventricle; TV = tricuspid valve .
holosystolic murmur at the left sternal border, a prominent V wave in the jugular venous pulse and right atrial pressure curve, as well as from the enlargement of the right ventricle and the paradoxical movement of the interventricular septum in the echocardiograms . Echocardiographic identification of right atrium : It is well known that echocardiography is very effective in differentiating an enlarged cardiac silhouette in the chest X-ray film from a pericardial effusion . In cases showing an enlarged cardiac chamber in the echocardiogram, it is desirable to confirm the anatomic relation between the enlarged chamber and the aortic
822
October 1977
The American Journal of CARDIOLOGY
or pulmonary valve by tilting the transducer in various directions on the chest wall corresponding to the enlarged cardiac silhouette . In our case, when the transducer was positioned at the right side of the chest wall, evidence of a large chamber, thought to be the aortic root, was elicited . The interventricular septal motion appeared to be paradoxical, and the diameter of the right ventricle was large . M mode echocardiograms clarified the anatomic relation between the greatly enlarged chamber, the aortic root and the position of the tricuspid valve . We concluded, therefore, that this large chamber was the right atrium .
Volume 40
IDIOPATHIC ENLARGEMENT OF THE RIGHT ATRIUM-ASAYAMA ET AL .
FIGURE 4 . Right atriograms . A and B, at age 71 and 75 years, respectively, in anteroposterior view, and C, at age 75, in lateral view, showing a severely enlarged right atrium (RA) becoming further enlarged after a 4 year interval . Ao = ascending aorta ; C = position of catheter tip ; IVC = inferior vena cava ; RV = right ventricle ; SVC = superior vena cava .
Tricuspid insufficiency : In the postmortem findings reported by Tenckhoff et al ., 2 the floor of the right atrium was abnormally flattened, particularly anterior to the tricuspid anulus, and formed a shelf . The tricuspid ring was normally placed and of normal size but was compressed anteroposteriorly to an elongated slit . The enlarged left portion of the right atrium may result from a heavier blood weight on this shelf, causing insufficiency of the tricuspid valve . The fine diastolic fluttering of the tricuspid valve in the echocardiograms may also be produced by the blood flowing through the
deformed tricuspid valve . Tricuspid insufficiency may occur in the late stage of idiopathic enlargement of the right atrium and may induce further atrial enlargement.
Acknowledgment We acknowledge with much appreciation the support and encouragement of Dr. Hamao Ijichi . We also thank Drs . Takaaki Mizutani, Masaru Tohara, Toshimitsu Watanabe and Tsuguo Isoda for the assistance and many comments on the preparation of the manuscript.
References 1 . Pastor BH, Forte, AL : Idiopathic enlargement of the right atrium . Am J Cardiol 8:513-518, 1961 2 . Tenckhoff L, Stamm SJ, Beckwith JB : Sudden death in idiopathic right atrial enlargement . Circulation 40 :227-235, 1969 3 . Salgusa M, Morlmoto K, Kolke T, et al : Idiopathic enlargement of the right atrium . Jpn Heart J 3 :373-379, 1962 4 . Sumner FIG, Phillips JH, Jacoby WJ, et al : Idiopathic enlargement of the right atrium . Circulation 32 :985-991, 1965
5 . Eshaghpour E, Olley PM, Collins GFN : Idiopathic right atrial enlargement in childhood . Am Heart J 78 :373-378, 1969 6 . Sheldon WC, Johnson CD, Favaloro, RG : Idiopathic enlargement of the right atrium. Report of four cases . Am J Cardiol 23:278-284, 1969 7 . Farooki, ZO, Henry JO, Green EW : Echocardiographic spectrum of Ebstein's anomaly of the tricuspid valve . Circulation 53 :63-68, 1976
October 1977 The American Journal of CARDIOLOGY Volume 40
823