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Aortoatrial Fistulae Diagnosed by Transthoracic and Transesophageal Echocardiography: Advantages of the Transesophageal Approach
Aortoatrial Fistulae Diagnosed by Transthoracic and Transesophageal Echocardiography: Advantages of the Transesophageal Approach Martyn R. Thomas, MRCP, Mark J. Monaghan, MSc, Lampros K. Michalis, MD, and David E. Jewitt, FRCP, London, United Kingdom
Aortoatrial fistulae are uncommon, providing a difficult diagnostic challenge both in the clinical diagnosis and in the choice of an imaging modality that fully deliniates the abnormal anatomy and flow patterns. This report describes four cases of aortoatrial fistula resulting from three different underlying causes. The fistula communicated with the right atrium in three cases and the left atrium in one. We also describe the diagnostic information obtained during both transthoracic and transesophageal echocardiography and stress that full detail of the abnormal anatomy and shunting could be obtained only with the transesophageal approach, with its improved image quality of the aortic root. No extra information, other than the coronary anatomy, was obtained during aortography in the two patients who underwent cardiac catheterization. Transesophageal echocardiography should, therefore, be the investigation of choice in patients in whom there is a suspicion of aortoatrial shunting after clinical examination and routine transthoracic studies, and it may avoid the need for invasive investigation in these potentially hemodynamically unstable patients. ( J AM Soc EcHOCARDIOGR 1993;6:21-9.)
Fistulous communication between the ascending aorta and atria is rare. Among the limited number of reported causes are ruptured sinus ofValsalva aneurysm, 1' 3 bacterial endocarditis,4 coronary artery to atrial fistula, 5 •6 and dissection of the aorta. 7 Imaging modalities that may be used to diagnose this abnormality include transthoracic echocardiography, magnetic resonance imaging, and cardiac catheterization, but it is difficult for a single study to provide a complete picture of the anatomy. Transesophageal echocardiography now provides an alternative semi-invasive technique that provides excellent visualization of the ascending aorta and both right and left atria. This technique has recently been successfully used to diagnose left ventricular outflow tract-to-left atrial
From the Department of Cardiology, King's College Hospital. Reprint requests: Dr. D.E. Jewitt, Director of Cardiology, Depattment of Cardiology, King's College Hospital, Denmark Hill, London SES 9RS, United Kingdom. Copyright© 1993 by the American Society ofEchocardiography. 0894-7317/93 $1.00 + .10 27 /l/40391
communications complicating infective endocarditis.8 We report the use of transesophageal echocardiography, with color flow Doppler, in diagnosing four cases of aortoatrial fistula resulting from three dif· ferent causes. CASE REPORTS
Over the period of one year, from November 1990, four patients were seen whose eventual diagnosis was one of an aortoatrial fistula. All patients underwent two-dimensional transthoracic echocardiography and transesophageal echocardiography. Two patients had cardiac catheterization including an aortogram. All lesions were subsequently comfirmed at surgery. Two-dimensional echocardiography was performed with a Hewlett-Packard 77020 (HewlettPackard, Andover, Mass.) and used both continuous and color-flow Doppler examination with a 2.5 M-Hz transducer. Transesophageal echocardiography was performed with a similar system and a 5 MHz transesophageal transducer.
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Figure 1 Transthoracic echocardiography, with color flow Doppler in the parasternal shortaxis view (from case 1) demonstrating flow between the aortic root and right atrium (arrow). ao, Aortic root; la, left atrium; ra, right atrium.
CASE 1
A 41-year-old women had a 1-month history of palpitations and shortness of breath. There was no history of chest pain. No past history of rheumatic fever or valvular heart disease was obtained. On examination she was apyrexial, in sinus rhythm with a blood pressure of 110/50, mm Hg. There were both systolic and diastolic murmurs that were interpreted as indicating mixed aortic valve disease. There were no signs of subacute bacterial endocarditis, and serial blood cultures were negative. The chest x-ray film showed a normal cardiac size with clear lung fields. Echocardiography Transthoracic. Transthoracic echocardiography showed normal left ventricular function with no evidence of aortic valve disease. Imaging in the parasternal short-axis view with color flow Doppler indicated continuous flow with multiple aliasing between the aorta and right atrium (Figure 1).
However, no definite structural lesion to explain this phenomenon could be identified. Transesophageal. The abnormal anatomy and flow were clearly demonstrated in the transesophageal four-chamber view. In this view an abnormal, small, tube-like structure indicating a sinus of Valsalva aneurysm was seen originating in the right coronary sinus (Figure 2,A). With the addition of color flow Doppler, continuous turbulent flow was seen passing between the aorta and the right atrium indicating rupture of the aneurysm (Figure 2,B). There were no associated anatomic lesions identified and there was no evidence of compression of any local structures by the aneurysm. Subsequent catheterization (including oximetry and aortography) of the right and left sides of the heart confirmed the transesophageal echocardiographic findings and indicated a left-to-right shunt of 1.8: l. The patient proceeded to cardiac surgery, at which time the echocardiographic findings were confirmed and the patient underwent an uneventful repair of the ruptured aneurysm.
Journal of the American Society of Echocardiography Volume 6, Number l
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Figure 2 A, shows the sinus of Valsalva aneurysm (small arrow) from case l in the transesophageal four-chamber view. The addition of color flow Doppler (B), shows rupture of the aneurysm, with flow between the aortic root and right atrium (lat;ge arrow).
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Figure 3 Transesophageal echocardiography with color flow Doppler in case 2 shows flow (la'lfe arruw) from the aorta into a ruptured sinus.ofValsalva aneurysm (small arrow). (Open arruw indicates ventricular outflow tract.)
CASE 2
A 70-year-old women had a history of apparent cardiac-related chest pain. However, serial electrocardiograms and cardiac enzyme studies failed to confirm the diagnosis of myocardial infarction. She subsequently had symptoms of increasing breathlessness. On examination she was noted to be in atrial fibrillation and had a blood pressure of 120/80 mm Hg. There were signs of marked failure of the right side of the heart consisting of a raised jugular venous pressure and moderate peripheral edema. Auscultation revealed a pansystolic murmur (no diastolic murmur was heard at this time). Despite the lack of confirmation of previous myocardial infarction, the clinical signs appeared consistent with a postinfarct ventricular septal defect.
ure 3). There was clearly a sinus ofValsalva aneurysm of the right coronary sinus, and color flow Doppler studies indicated rupture of the aneurysm into the right atrium. Again in this case there was no evidence of any compression of local structures caused by the aneurysm, and there was no associated cardiac lesions. On the basis of the patient's age, lack of symptoms suggesting significant coronary artery disease, and normal wall motion during echocardiographic studies, the patient proceeded directly to cardiac surgery without undergoing cardiac catheterization. Once again, at operation the transesophageal images were confirmed and the patient underwent an uncomplicated repair of the ruptured aneurysm with a polytetrafluroethylene (Teflon) patch.
Echocardiography
CASE 3
Transthoracic. Transthoracic echocardiographic imaging showed no wall motion abnormality to confirm a previous transmural myocardial infarct. Color flow Doppler studies appeared to indicate flow between the left ventricular outflow tract and the right atrium. Continuous wave Doppler studies indicated this flow to be continuous in nature. Transesophageal. The transesophageal study provided similar images to those seen in case l (Fig-
A 53-year-old man with a known bicuspid aortic valve had a short history of flu-like symptoms (including night sweats) and increasing shortness of breath. On examination the patient was pyrexial, but there were no peripheral stigmata of subacute bacterial endocarditis. Auscultation revealed both systolic and diastolic murmurs suggesting mixed aortic valve disease. Blood cultures grew Streptococcus san-
Journal of the American Society of Echocardiography Volume 6, Number l
Thomas et al.
Figure 4 Transesophageal echocardiographic images in the four-chamber view from case 3. A, clearly demonstrates the aortic root abscess (solid arrow) . The open arrow indicates the left ventricular outflow tract. B, with the addition of color flow Doppler, shows flow from the aortic root abscess into the right atrium (solid arrow). Ia, Left atrium; lv, left ventricle; rv, right ventricle.
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guis confirming the diagnosis of bacterial endocarditis.
erythrocyte sedimentation rate was raised at 50 mm in the first hour.
Echocardiography
Echocardiography
Transthoracic. Transthoracic echocardiography demonstrated markedly thickened aortic valve leaflets but no definite leaflet vegetations. There was moderate aortic stenosis (peak Doppler gradient 60 mm Hg) and mild aortic regurgitation. Left ventricular function was moderately impaired. In the parasternal short-axis view, a thick-walled abscess cavity was seen in the aortic root adjacent to the right coronary sinus. Color flow Doppler studies indicated flow within the structure consistent with an aortic root abscess. A large mass was also seen in association with one of the tricuspid valve leaflets, which suggested extension of the endocarditic process to the tricuspid valve. Color flow Doppler studies indicated turbulent flow within the right atrial cavity, but no definite communication with the abscess cavity could be identified. Transesophageal. In the transesophageal fourchamber view the aortic root abscess was clearly visualized (Figure 4, A). With the addition of color flow Doppler, turbulent flow was easily identified entering the abscess cavity and exiting into the right atrium (Figure 4, B). In this view it was also possible to identify a definite separation between the right atrial mass and the tricuspid leaflet indicating the mass to be an extension of the abscess cavity into the right atrium (a "windsock" type lesion) and not a tricuspid vegetation. The echocardiographic appearances were confirmed at surgery when a root abscess was seen extending from between the right and noncoronary aortic cusp into the right atrium. The windsock extension to the abscess was excised and the fistula closed with a Teflon patch. The aortic valve was replaced with a size 23 mm homograft. The patient underwent a complicated postoperative period with episodes of both renal and liver failure but made a gradual and complete recovery.
Transthoracic. Transthoracic studies proved difficult because of the acoustic shadows caused by the aortic and mitral prostheses. The left atrium was enlarged and left ventricular function was good. There was no evidence of an aortic paraprosthetic leak, and the peak Doppler gradient across the valve was 36 mm Hg. Imaging in the apical four-chamber view with color flow Doppler appeared to indicate an eccentric jet of mitral regurgitation (Figure 5), but continuous turbulent flow was noted on the atrial side of the mitral prosthesis. Transesophageal. In the basal short-axis transesophageal view, a fistula was clearly identified joining the aortic root and the left atrium. With the addition of color flow Doppler (Figure 6), continuous turbulent flow was seen between the aorta and left atrium with the jet passing across the atrial side of the mitral prosthesis to the lateral atrial wall, thereby mimicking mitral regurgitation. No vegetations of the mitral or aortic protheses were identified. Subsequent aortography in the right anterior oblique view confirmed the fistulous communication that was seen during the transesophageal studies. Because of the hemodynamically unstable nature of the patient, urgent surgery was performed. At surgery no definite evidence of infection of the aortic valve was identified. There was partial dehiscence of the aortic valve from the aortic root with communication to the left atrium. The tract was oversewn, initially without complication. However there was difficulty weaning the patient from cardiopulmonary bypass; the patient required large doses of inotropic support. The patient remained hemodynamically unstable in the intensive care unit and subsequently died within 48 hours of surgery.
CASE4
A 70-year-old woman had a l-month history of increasing shortness of breath. She had undergone xenograft mitral and aortic valve replacement 9 years prior to this presentation because of rheumatic valvular heart disease. The patient was noted to be in atrial fibrillation and there were systolic and diastolic murmurs that were interpreted as mixed aortic valve disease. The
DISCUSSION
Aortoatrial fistulae are rare and provide difficulties both in the clinical diagnosis and in the choice of an investigation that will fully identify the anatomic abnormalities. This report describes four cases with differing diagnoses (and varying exit sites of the aortic fistulae) in which a full anatomic picture was provided by the combination of transthoracic and transesophageal echocardiography. Transesophageal echocardiography, however, demonstrated marked advantages over the transthoracic approach in fully defining the anatomic abnormalities.
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Figure 5 Transthoracic echocardiography with color flow Doppler from case 4, in the apical four-chamber view, appears to indicate eccentric mitral regurgitation (arrow).
Figure 6 Transesophageal echocardiography with color flow Doppler from case 4, in the four-chamber view, shows flow from the aorta to the left atrium with the jet passing across the atrial side of the mitral prosthesis (arrow). la, Left atrium; ao, aorta.
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The most commonly reported cause of fistulous communication between the ascending aorta and the atria is rupture of a sinus ofValsalva aneurysm, 1-3 the eventual diagnosis in two of our four patients. The majority of these aneurysms are congenital, although associations with syphilis, Marfan's syndrome, and advanced age have been described. 9 Seventy-five percent arise from the right coronary sinus, as in our case, while 21% occur in association with the noncoronary sinus, and 4% with the left coronary sinus.10-12 The most common sites of rupture are into the right ventricle (63%) and right atrium (32% ). The consequences of rupture may vary from minimal symptoms to sudden death, but most commonly the patients have symptoms of cardiac failure caused by large intracardiac shunts. Full anatomic assessment of these aneurysms is important because many sequelae resulting from local compression of associated structures have been reported. These include right and left ventricular outflow tract obstruction, compression of the atrioventricular node leading to complete heart block, aortic regurgitation, and compression of left main, left anterior descending, and circumflex coronary arteries. 13 To our knowledge our first two cases are only the second and third cases of ruptured sinus of V alsalva aneurysms in which the detailed anatomic and flow abnormalities have been demonstrated by transesophageal echocardiography, the first case having been reported only recently. 3 In both of our patients transthoracic echocardiography with color flow Doppler showed high velocities with continuous flow, indicating shunting from the aorta to the right atrium. The underlying anatomic cause for this abnormality could not, however, be identified, probably because of the small size of the aneurysms. In our second case, limitations of the elevational resolution of the color flow Doppler image during transthoracic echocardiography resulted in the incorrect diagnosis of the fistula originating in the left ventricular outflow tract. A previous review of 12 cases of sinus of V alsalva aneurysms reported a correct anatomic diagnosis in only 58% (7 I 12) with two-dimensional echocardiography. 2 Transesophageal echocardiography was necessary to identifY the tube-like structure of a small sinus of V alsalva aneurysm in both of our cases. These studies clearly indicated the small nature of the aneurysms and excluded any local compression of adjacent structures. Cardiac catheterization provided no additional information (other than delin-
Journal of the American Society of Echocardiography January-February 1993
eating the coronary anatomy) in the case in which it was performed. Our third case demonstrates a fistula between the aortic root and right atrium as a complication of aortic valve endocarditis with associated aortic root abcess. Aortic root abcesses have been found in 56% of patients undergoing surgery for aortic prosthetic endocarditis, 14 in 30% of patients with native aortic endocarditis (diagnosed by transthoracic echocardiography), 4 and in up to 100% of postmortems in patients who had active prosthetic aortic endocarditis.15 Because of the improved image quality of the aortic root during transesophageal echocardiography, it is likely that this complication will be reported with increasing frequency during life in patients with aortic endocarditis if this imaging modality is carried out routinely in these patients. Indeed, it has recently been reported that subaortic complications during aortic endocarditis can be diagnosed with transesophageal echocardiography in 44% of cases. 16 In the case reported here, transesophageal echocardiography identified the aortic root abscess and, with the aid of color flow Doppler studies, flow was identified both into the abcess and also exiting the lesion into the right atrium. The improved image quality also enabled the separation of the apparent tricuspid vegetation from the tricuspid valve leaflet, indicating the mass was an extension of the abscess, causing a windsock type lesion between the aortic root and right atrium. The transesophageal study allowed for emergency surgery with no planned intervention to the tricuspid valve and cardiac catheterization was specifically avoided because of the hemodynamically unstable nature of the patient and the friable appearances of the tissues in the aortic root. Two-dimensional echocardiography alone, again, was unable to provide the correct diagnosis in Case 4. Even with the addition of color flow Doppler it was easy to incorrectly diagnose the patient as having mitral regurgitation. The continuous flow noted on the atrial side of the mitral prosthesis gave an indication of the eventual diagnosis, but acoustic shadowing caused by the prosthetic valves prevented a full appreciation of the abnormal anatomy. The improved image quality of the aortic root and intervalvular fibrosa provided by transesophageal echocardiography was necessary before the correct anatomic diagnosis could be reached. Again, no further anatomic information regarding the fistula was obtained at the time of cardiac catheterization.
Journal of the American Society of Echocardiography Volume 6, Number l
CONCLUSION
In all four cases transthoracic echocardiography was able to suggest the final diagnosis by the demonstration of continuous flow with color flow Doppler in the right or left atrium, suggesting flow from a high-pressure to low-pressure chamber. However, image quality of the aortic root was of insufficient quality to provide the anatomic diagnosis. The improved image quality provided by transesophageal echocardiography gave comprehensive information on the anatomic diagnosis, and the addition of color flow Doppler confirmed the abnormal flow between aorta and atria. Cardiac catheterization did not provide any additional information on the abnormal anatomy of flow in the two patients in which it was performed. In the other two cases, transesophageal echocardiography gave sufficient diagnostic information to allow no invasive studies to be performed. Transesophageal echocardiography should therefore be the investigation of choice in the diagnosis of aortoatrial fistula. These four cases also suggest that transesophageal echocardiography should become a routine part of the investigation of suspected aortic endocarditis so that potential complications may be diagnosed promptly, allowing early referral for surgical intervention. REFERENCES l. Terdjman M, Bourdarias JP, Farcot JC, eta!. Aneurysms of
sinus of Valsalva: two-dimensional echocardiographic diagnosis and recognition of rupture into the right heart cavities. JAm Coli Cardiol1984;3:122 7-35. 2. Chiang CW, Lin FC, Fang BR, Kuo CT, Lee YS, Chang CH. Doppler and two-dimensional echocardiographic features of sinus of V alsalva aneurysm. Am Heart J 1988;116:1283-8. 3. Katz ES, Cziner DG, Rosenzweig BP, Attubato M, Feir F, Kronwn I. Multifaceted echocardiographic approach to the diagnosis of a ruptured sinus ofV alsalva aneurysm. J AM Soc EcHOCARDIOGR 1991;4:494-8.
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4. Arnett EN, Roberts WC. Valve ring abscess in active infective endocarditis. Circulation 1976;54: 140-5. 5. Ludomirsky A, O'Laughlin MP, Reul GJ, Mullins CE. Congenital aneurysm of the right coronary artery with fistulous connection to the right atrium. Am Heart J 1990;119: 672-5. 6. Goldberg N, Zisbrod Z, Kipperman R, et a!. Congenital aneurysm of the left coronary sinus and left main coronary artery with fistulous communication to the right atrium in pregnancy. JAM Soc ECHOCARDIOGR 1990;3:125-30. 7. Oliveira JSM, Bestetti RB, Marin-Neto JA, Costa RS, Cardeiro JJ. Ruptured aortic dissection into the left atrium: a rare cause of congestive heart failure. Am Heart J 1991;121:936-8. 8. Bansal RC, Graham BM, Jutzy KR, Shakudo M, Shah PM. Left ventricular outflow tract to left atrial communication secondary to rupture of mitral-aortic intervalvular fibrosa in infective endocarditis: diagnosis by transesophageal echocardiography and color flow imaging. J Am Coli Cardiol 1990;15:499-504. 9. Boutefeu J-M, Moret PR, Hahn C, HaufE. Aneurysms of the sinus of V alsalva: report of seven cases and review of the literature. Am J Med 1978;65: 18-24. 10. Taguchi K, Sasaki N, Matshura Y, eta!. Surgical correction of aneurysm of the sinus of Valsalva: a report of forty-five consecutive patients including eight with total replacement of the aortic valve. Am J Cardiol 1969;23: 180-91. 11. Meyer J, Wukasch DC, Hallman GL, eta!. Aneurysm and fistula of the sinus of Valsalva: clinical considerations and surgical treatment in 45 patients. Ann Thorac Surg 1975;19:170-9. 12. AbeT, Komatsu S. Surgical repair and long-term results in ruptured sinus of Valsalva aneurysm. Ann Thorac Surg 1988;46: 520-5. 13. Blackshear JL, Safford RE, Lane GE, Freeman WK, Schaff HV. Unruptured noncoronary sinus of Valsalva aneurysm: preoperative characterization by transesophageal echocardiography. JAM Soc ECHOCARDIOGR 1991;4:485-90. 14. Stinson EB. Surgical treatment of infective endocarditis. Prog Cardiovasc Dis 1979;22: 145-68. 15. Arnett EN, Roberts WC. Clinicopathologic analysis of 22 necropsy patients with comparison of observations in 74 necropsy patients with active infective endocarditis involving natural left-sided cardiac valves. Am J Cardiol1976;38:28 192. 16. Bansal RC, Chandrasekaran K, Karalis DG, Applegate PM, Jutzy KR, Ross JJ. Transesophageal echocardiographic recognition of subaortic complications of aortic valve endocarditis [Abstract]. Circulation 1991;84:II-128.
Aortoatrial fistulae are uncommon, providing a difficult diagnostic challenge both in the clinical diagnosis and in the choice of an imaging modality that fully deliniates the abnormal anatomy and flow patterns. This report describes four cases of aortoatrial fistula resulting from three different underlying causes. The fistula communicated with the right atrium in three cases and the left atrium in one. We also describe the diagnostic information obtained during both transthoracic and transesophageal echocardiography and stress that full detail of the abnormal anatomy and shunting could be obtained only with the transesophageal approach, with its improved image quality of the aortic root. No extra information, other than the coronary anatomy, was obtained during aortography in the two patients who underwent cardiac catheterization. Transesophageal echocardiography should, therefore, be the investigation of choice in patients in whom there is a suspicion of aortoatrial shunting after clinical examination and routine transthoracic studies, and it may avoid the need for invasive investigation in these potentially hemodynamically unstable patients. ( J AM Soc EcHOCARDIOGR 1993;6:21-9.)
Fistulous communication between the ascending aorta and atria is rare. Among the limited number of reported causes are ruptured sinus ofValsalva aneurysm, 1' 3 bacterial endocarditis,4 coronary artery to atrial fistula, 5 •6 and dissection of the aorta. 7 Imaging modalities that may be used to diagnose this abnormality include transthoracic echocardiography, magnetic resonance imaging, and cardiac catheterization, but it is difficult for a single study to provide a complete picture of the anatomy. Transesophageal echocardiography now provides an alternative semi-invasive technique that provides excellent visualization of the ascending aorta and both right and left atria. This technique has recently been successfully used to diagnose left ventricular outflow tract-to-left atrial
From the Department of Cardiology, King's College Hospital. Reprint requests: Dr. D.E. Jewitt, Director of Cardiology, Depattment of Cardiology, King's College Hospital, Denmark Hill, London SES 9RS, United Kingdom. Copyright© 1993 by the American Society ofEchocardiography. 0894-7317/93 $1.00 + .10 27 /l/40391
communications complicating infective endocarditis.8 We report the use of transesophageal echocardiography, with color flow Doppler, in diagnosing four cases of aortoatrial fistula resulting from three dif· ferent causes. CASE REPORTS
Over the period of one year, from November 1990, four patients were seen whose eventual diagnosis was one of an aortoatrial fistula. All patients underwent two-dimensional transthoracic echocardiography and transesophageal echocardiography. Two patients had cardiac catheterization including an aortogram. All lesions were subsequently comfirmed at surgery. Two-dimensional echocardiography was performed with a Hewlett-Packard 77020 (HewlettPackard, Andover, Mass.) and used both continuous and color-flow Doppler examination with a 2.5 M-Hz transducer. Transesophageal echocardiography was performed with a similar system and a 5 MHz transesophageal transducer.
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journal of the American Society of Echocardiography january-February 1993
Figure 1 Transthoracic echocardiography, with color flow Doppler in the parasternal shortaxis view (from case 1) demonstrating flow between the aortic root and right atrium (arrow). ao, Aortic root; la, left atrium; ra, right atrium.
CASE 1
A 41-year-old women had a 1-month history of palpitations and shortness of breath. There was no history of chest pain. No past history of rheumatic fever or valvular heart disease was obtained. On examination she was apyrexial, in sinus rhythm with a blood pressure of 110/50, mm Hg. There were both systolic and diastolic murmurs that were interpreted as indicating mixed aortic valve disease. There were no signs of subacute bacterial endocarditis, and serial blood cultures were negative. The chest x-ray film showed a normal cardiac size with clear lung fields. Echocardiography Transthoracic. Transthoracic echocardiography showed normal left ventricular function with no evidence of aortic valve disease. Imaging in the parasternal short-axis view with color flow Doppler indicated continuous flow with multiple aliasing between the aorta and right atrium (Figure 1).
However, no definite structural lesion to explain this phenomenon could be identified. Transesophageal. The abnormal anatomy and flow were clearly demonstrated in the transesophageal four-chamber view. In this view an abnormal, small, tube-like structure indicating a sinus of Valsalva aneurysm was seen originating in the right coronary sinus (Figure 2,A). With the addition of color flow Doppler, continuous turbulent flow was seen passing between the aorta and the right atrium indicating rupture of the aneurysm (Figure 2,B). There were no associated anatomic lesions identified and there was no evidence of compression of any local structures by the aneurysm. Subsequent catheterization (including oximetry and aortography) of the right and left sides of the heart confirmed the transesophageal echocardiographic findings and indicated a left-to-right shunt of 1.8: l. The patient proceeded to cardiac surgery, at which time the echocardiographic findings were confirmed and the patient underwent an uneventful repair of the ruptured aneurysm.
Journal of the American Society of Echocardiography Volume 6, Number l
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Figure 2 A, shows the sinus of Valsalva aneurysm (small arrow) from case l in the transesophageal four-chamber view. The addition of color flow Doppler (B), shows rupture of the aneurysm, with flow between the aortic root and right atrium (lat;ge arrow).
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Figure 3 Transesophageal echocardiography with color flow Doppler in case 2 shows flow (la'lfe arruw) from the aorta into a ruptured sinus.ofValsalva aneurysm (small arrow). (Open arruw indicates ventricular outflow tract.)
CASE 2
A 70-year-old women had a history of apparent cardiac-related chest pain. However, serial electrocardiograms and cardiac enzyme studies failed to confirm the diagnosis of myocardial infarction. She subsequently had symptoms of increasing breathlessness. On examination she was noted to be in atrial fibrillation and had a blood pressure of 120/80 mm Hg. There were signs of marked failure of the right side of the heart consisting of a raised jugular venous pressure and moderate peripheral edema. Auscultation revealed a pansystolic murmur (no diastolic murmur was heard at this time). Despite the lack of confirmation of previous myocardial infarction, the clinical signs appeared consistent with a postinfarct ventricular septal defect.
ure 3). There was clearly a sinus ofValsalva aneurysm of the right coronary sinus, and color flow Doppler studies indicated rupture of the aneurysm into the right atrium. Again in this case there was no evidence of any compression of local structures caused by the aneurysm, and there was no associated cardiac lesions. On the basis of the patient's age, lack of symptoms suggesting significant coronary artery disease, and normal wall motion during echocardiographic studies, the patient proceeded directly to cardiac surgery without undergoing cardiac catheterization. Once again, at operation the transesophageal images were confirmed and the patient underwent an uncomplicated repair of the ruptured aneurysm with a polytetrafluroethylene (Teflon) patch.
Echocardiography
CASE 3
Transthoracic. Transthoracic echocardiographic imaging showed no wall motion abnormality to confirm a previous transmural myocardial infarct. Color flow Doppler studies appeared to indicate flow between the left ventricular outflow tract and the right atrium. Continuous wave Doppler studies indicated this flow to be continuous in nature. Transesophageal. The transesophageal study provided similar images to those seen in case l (Fig-
A 53-year-old man with a known bicuspid aortic valve had a short history of flu-like symptoms (including night sweats) and increasing shortness of breath. On examination the patient was pyrexial, but there were no peripheral stigmata of subacute bacterial endocarditis. Auscultation revealed both systolic and diastolic murmurs suggesting mixed aortic valve disease. Blood cultures grew Streptococcus san-
Journal of the American Society of Echocardiography Volume 6, Number l
Thomas et al.
Figure 4 Transesophageal echocardiographic images in the four-chamber view from case 3. A, clearly demonstrates the aortic root abscess (solid arrow) . The open arrow indicates the left ventricular outflow tract. B, with the addition of color flow Doppler, shows flow from the aortic root abscess into the right atrium (solid arrow). Ia, Left atrium; lv, left ventricle; rv, right ventricle.
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guis confirming the diagnosis of bacterial endocarditis.
erythrocyte sedimentation rate was raised at 50 mm in the first hour.
Echocardiography
Echocardiography
Transthoracic. Transthoracic echocardiography demonstrated markedly thickened aortic valve leaflets but no definite leaflet vegetations. There was moderate aortic stenosis (peak Doppler gradient 60 mm Hg) and mild aortic regurgitation. Left ventricular function was moderately impaired. In the parasternal short-axis view, a thick-walled abscess cavity was seen in the aortic root adjacent to the right coronary sinus. Color flow Doppler studies indicated flow within the structure consistent with an aortic root abscess. A large mass was also seen in association with one of the tricuspid valve leaflets, which suggested extension of the endocarditic process to the tricuspid valve. Color flow Doppler studies indicated turbulent flow within the right atrial cavity, but no definite communication with the abscess cavity could be identified. Transesophageal. In the transesophageal fourchamber view the aortic root abscess was clearly visualized (Figure 4, A). With the addition of color flow Doppler, turbulent flow was easily identified entering the abscess cavity and exiting into the right atrium (Figure 4, B). In this view it was also possible to identify a definite separation between the right atrial mass and the tricuspid leaflet indicating the mass to be an extension of the abscess cavity into the right atrium (a "windsock" type lesion) and not a tricuspid vegetation. The echocardiographic appearances were confirmed at surgery when a root abscess was seen extending from between the right and noncoronary aortic cusp into the right atrium. The windsock extension to the abscess was excised and the fistula closed with a Teflon patch. The aortic valve was replaced with a size 23 mm homograft. The patient underwent a complicated postoperative period with episodes of both renal and liver failure but made a gradual and complete recovery.
Transthoracic. Transthoracic studies proved difficult because of the acoustic shadows caused by the aortic and mitral prostheses. The left atrium was enlarged and left ventricular function was good. There was no evidence of an aortic paraprosthetic leak, and the peak Doppler gradient across the valve was 36 mm Hg. Imaging in the apical four-chamber view with color flow Doppler appeared to indicate an eccentric jet of mitral regurgitation (Figure 5), but continuous turbulent flow was noted on the atrial side of the mitral prosthesis. Transesophageal. In the basal short-axis transesophageal view, a fistula was clearly identified joining the aortic root and the left atrium. With the addition of color flow Doppler (Figure 6), continuous turbulent flow was seen between the aorta and left atrium with the jet passing across the atrial side of the mitral prosthesis to the lateral atrial wall, thereby mimicking mitral regurgitation. No vegetations of the mitral or aortic protheses were identified. Subsequent aortography in the right anterior oblique view confirmed the fistulous communication that was seen during the transesophageal studies. Because of the hemodynamically unstable nature of the patient, urgent surgery was performed. At surgery no definite evidence of infection of the aortic valve was identified. There was partial dehiscence of the aortic valve from the aortic root with communication to the left atrium. The tract was oversewn, initially without complication. However there was difficulty weaning the patient from cardiopulmonary bypass; the patient required large doses of inotropic support. The patient remained hemodynamically unstable in the intensive care unit and subsequently died within 48 hours of surgery.
CASE4
A 70-year-old woman had a l-month history of increasing shortness of breath. She had undergone xenograft mitral and aortic valve replacement 9 years prior to this presentation because of rheumatic valvular heart disease. The patient was noted to be in atrial fibrillation and there were systolic and diastolic murmurs that were interpreted as mixed aortic valve disease. The
DISCUSSION
Aortoatrial fistulae are rare and provide difficulties both in the clinical diagnosis and in the choice of an investigation that will fully identify the anatomic abnormalities. This report describes four cases with differing diagnoses (and varying exit sites of the aortic fistulae) in which a full anatomic picture was provided by the combination of transthoracic and transesophageal echocardiography. Transesophageal echocardiography, however, demonstrated marked advantages over the transthoracic approach in fully defining the anatomic abnormalities.
Journal of the American Society of Echocardiography Volume 6, Number l
Thomas et a!.
Figure 5 Transthoracic echocardiography with color flow Doppler from case 4, in the apical four-chamber view, appears to indicate eccentric mitral regurgitation (arrow).
Figure 6 Transesophageal echocardiography with color flow Doppler from case 4, in the four-chamber view, shows flow from the aorta to the left atrium with the jet passing across the atrial side of the mitral prosthesis (arrow). la, Left atrium; ao, aorta.
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28 Thomas et a!.
The most commonly reported cause of fistulous communication between the ascending aorta and the atria is rupture of a sinus ofValsalva aneurysm, 1-3 the eventual diagnosis in two of our four patients. The majority of these aneurysms are congenital, although associations with syphilis, Marfan's syndrome, and advanced age have been described. 9 Seventy-five percent arise from the right coronary sinus, as in our case, while 21% occur in association with the noncoronary sinus, and 4% with the left coronary sinus.10-12 The most common sites of rupture are into the right ventricle (63%) and right atrium (32% ). The consequences of rupture may vary from minimal symptoms to sudden death, but most commonly the patients have symptoms of cardiac failure caused by large intracardiac shunts. Full anatomic assessment of these aneurysms is important because many sequelae resulting from local compression of associated structures have been reported. These include right and left ventricular outflow tract obstruction, compression of the atrioventricular node leading to complete heart block, aortic regurgitation, and compression of left main, left anterior descending, and circumflex coronary arteries. 13 To our knowledge our first two cases are only the second and third cases of ruptured sinus of V alsalva aneurysms in which the detailed anatomic and flow abnormalities have been demonstrated by transesophageal echocardiography, the first case having been reported only recently. 3 In both of our patients transthoracic echocardiography with color flow Doppler showed high velocities with continuous flow, indicating shunting from the aorta to the right atrium. The underlying anatomic cause for this abnormality could not, however, be identified, probably because of the small size of the aneurysms. In our second case, limitations of the elevational resolution of the color flow Doppler image during transthoracic echocardiography resulted in the incorrect diagnosis of the fistula originating in the left ventricular outflow tract. A previous review of 12 cases of sinus of V alsalva aneurysms reported a correct anatomic diagnosis in only 58% (7 I 12) with two-dimensional echocardiography. 2 Transesophageal echocardiography was necessary to identifY the tube-like structure of a small sinus of V alsalva aneurysm in both of our cases. These studies clearly indicated the small nature of the aneurysms and excluded any local compression of adjacent structures. Cardiac catheterization provided no additional information (other than delin-
Journal of the American Society of Echocardiography January-February 1993
eating the coronary anatomy) in the case in which it was performed. Our third case demonstrates a fistula between the aortic root and right atrium as a complication of aortic valve endocarditis with associated aortic root abcess. Aortic root abcesses have been found in 56% of patients undergoing surgery for aortic prosthetic endocarditis, 14 in 30% of patients with native aortic endocarditis (diagnosed by transthoracic echocardiography), 4 and in up to 100% of postmortems in patients who had active prosthetic aortic endocarditis.15 Because of the improved image quality of the aortic root during transesophageal echocardiography, it is likely that this complication will be reported with increasing frequency during life in patients with aortic endocarditis if this imaging modality is carried out routinely in these patients. Indeed, it has recently been reported that subaortic complications during aortic endocarditis can be diagnosed with transesophageal echocardiography in 44% of cases. 16 In the case reported here, transesophageal echocardiography identified the aortic root abscess and, with the aid of color flow Doppler studies, flow was identified both into the abcess and also exiting the lesion into the right atrium. The improved image quality also enabled the separation of the apparent tricuspid vegetation from the tricuspid valve leaflet, indicating the mass was an extension of the abscess, causing a windsock type lesion between the aortic root and right atrium. The transesophageal study allowed for emergency surgery with no planned intervention to the tricuspid valve and cardiac catheterization was specifically avoided because of the hemodynamically unstable nature of the patient and the friable appearances of the tissues in the aortic root. Two-dimensional echocardiography alone, again, was unable to provide the correct diagnosis in Case 4. Even with the addition of color flow Doppler it was easy to incorrectly diagnose the patient as having mitral regurgitation. The continuous flow noted on the atrial side of the mitral prosthesis gave an indication of the eventual diagnosis, but acoustic shadowing caused by the prosthetic valves prevented a full appreciation of the abnormal anatomy. The improved image quality of the aortic root and intervalvular fibrosa provided by transesophageal echocardiography was necessary before the correct anatomic diagnosis could be reached. Again, no further anatomic information regarding the fistula was obtained at the time of cardiac catheterization.
Journal of the American Society of Echocardiography Volume 6, Number l
CONCLUSION
In all four cases transthoracic echocardiography was able to suggest the final diagnosis by the demonstration of continuous flow with color flow Doppler in the right or left atrium, suggesting flow from a high-pressure to low-pressure chamber. However, image quality of the aortic root was of insufficient quality to provide the anatomic diagnosis. The improved image quality provided by transesophageal echocardiography gave comprehensive information on the anatomic diagnosis, and the addition of color flow Doppler confirmed the abnormal flow between aorta and atria. Cardiac catheterization did not provide any additional information on the abnormal anatomy of flow in the two patients in which it was performed. In the other two cases, transesophageal echocardiography gave sufficient diagnostic information to allow no invasive studies to be performed. Transesophageal echocardiography should therefore be the investigation of choice in the diagnosis of aortoatrial fistula. These four cases also suggest that transesophageal echocardiography should become a routine part of the investigation of suspected aortic endocarditis so that potential complications may be diagnosed promptly, allowing early referral for surgical intervention. REFERENCES l. Terdjman M, Bourdarias JP, Farcot JC, eta!. Aneurysms of
sinus of Valsalva: two-dimensional echocardiographic diagnosis and recognition of rupture into the right heart cavities. JAm Coli Cardiol1984;3:122 7-35. 2. Chiang CW, Lin FC, Fang BR, Kuo CT, Lee YS, Chang CH. Doppler and two-dimensional echocardiographic features of sinus of V alsalva aneurysm. Am Heart J 1988;116:1283-8. 3. Katz ES, Cziner DG, Rosenzweig BP, Attubato M, Feir F, Kronwn I. Multifaceted echocardiographic approach to the diagnosis of a ruptured sinus ofV alsalva aneurysm. J AM Soc EcHOCARDIOGR 1991;4:494-8.
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4. Arnett EN, Roberts WC. Valve ring abscess in active infective endocarditis. Circulation 1976;54: 140-5. 5. Ludomirsky A, O'Laughlin MP, Reul GJ, Mullins CE. Congenital aneurysm of the right coronary artery with fistulous connection to the right atrium. Am Heart J 1990;119: 672-5. 6. Goldberg N, Zisbrod Z, Kipperman R, et a!. Congenital aneurysm of the left coronary sinus and left main coronary artery with fistulous communication to the right atrium in pregnancy. JAM Soc ECHOCARDIOGR 1990;3:125-30. 7. Oliveira JSM, Bestetti RB, Marin-Neto JA, Costa RS, Cardeiro JJ. Ruptured aortic dissection into the left atrium: a rare cause of congestive heart failure. Am Heart J 1991;121:936-8. 8. Bansal RC, Graham BM, Jutzy KR, Shakudo M, Shah PM. Left ventricular outflow tract to left atrial communication secondary to rupture of mitral-aortic intervalvular fibrosa in infective endocarditis: diagnosis by transesophageal echocardiography and color flow imaging. J Am Coli Cardiol 1990;15:499-504. 9. Boutefeu J-M, Moret PR, Hahn C, HaufE. Aneurysms of the sinus of V alsalva: report of seven cases and review of the literature. Am J Med 1978;65: 18-24. 10. Taguchi K, Sasaki N, Matshura Y, eta!. Surgical correction of aneurysm of the sinus of Valsalva: a report of forty-five consecutive patients including eight with total replacement of the aortic valve. Am J Cardiol 1969;23: 180-91. 11. Meyer J, Wukasch DC, Hallman GL, eta!. Aneurysm and fistula of the sinus of Valsalva: clinical considerations and surgical treatment in 45 patients. Ann Thorac Surg 1975;19:170-9. 12. AbeT, Komatsu S. Surgical repair and long-term results in ruptured sinus of Valsalva aneurysm. Ann Thorac Surg 1988;46: 520-5. 13. Blackshear JL, Safford RE, Lane GE, Freeman WK, Schaff HV. Unruptured noncoronary sinus of Valsalva aneurysm: preoperative characterization by transesophageal echocardiography. JAM Soc ECHOCARDIOGR 1991;4:485-90. 14. Stinson EB. Surgical treatment of infective endocarditis. Prog Cardiovasc Dis 1979;22: 145-68. 15. Arnett EN, Roberts WC. Clinicopathologic analysis of 22 necropsy patients with comparison of observations in 74 necropsy patients with active infective endocarditis involving natural left-sided cardiac valves. Am J Cardiol1976;38:28 192. 16. Bansal RC, Chandrasekaran K, Karalis DG, Applegate PM, Jutzy KR, Ross JJ. Transesophageal echocardiographic recognition of subaortic complications of aortic valve endocarditis [Abstract]. Circulation 1991;84:II-128.