- Email: [email protected]
An Acquired Interatrial Fistula Secondary to Para-aortic Abscess Documented by Transesophageal Echocardiography
An Acquired Interatrial Fistula Secondary to Para-aortic Abscess Documented by Transesophageal Echocardiography Robert C. Sheppard, MD, Krishnaswamy Chandrasekaran, MD, John Ross, RCPT, and Gary S. Mintz, MD, FACC, Philadelphia) Pennsylvania
Para-aortic ring abscess and resulting fistulous communication between adjacent structures frequently occur in prosthetic aortic valve endocarditis but are rarely diagnosed preoperatively. We report a patient who had an abscess involving the aortic-mitral intervalvular fibrosa that eroded into the interatrial septum, causing an interatrial communication with a left-to-right shunt. The abscess was detected by transthoracic echocardiography, but the fistula was only seen by the subsequent transesophageal echocardiogram. To our knowledge, this is the first report of an interatrial fistula secondary to a para-aortic valve abscess and its diagnosis preoperatively. Transesophageal echocardiography should be performed in any patient suspected to have complicated aortic endocarditis. (JAM Soc EcHo 1991;4:271-6.)
Para-aortic abscess and mycotic aneurysm formation are serious complications of infective aortic valve endocarditis. Operative and postmortem studies suggest that 18% to 57% of patients with prosthetic aortic valve endocarditis are found to have perivalvular abscesses. 1' 4 The infective process may extend into perivalvular structures, causing aorta-left ventricular discontinuity or fistulous communication between cardiac structures. 2 •5 •6 Conventional transthoracic echocardiography has provided inconsistent results in diagnosing aortic root abscesses and their complications. 7-9 The recent use of transesophageal echocardiography is an improvement in assessing infective endocarditis and detecting a perivalvular abscess. 8 Color flow Doppler imaging can provide reliable documentation of fistulous communication. 6 We recently encountered a patient found to have a complication of para-aortic abscess not previously reported: an interatrial communication. The abscess was detected by transthoracic and the interatrial communication by transesophageal echocardiography; both were later confirmed by cardiac catheterization.
From the Department of Cardiology, Likoff Cardiovascular Institute, Hahnemann University Hospital. Reprint requests: Krishnaswamy Chandrasekaran, MD, Mail Stop 313, Hahnemann University Hospital, Broad and Vine Streets, Philadelphia, PA 19102. 27/l/26401
CASE RE,PORT
A 28-year-old black man who was a homosexual and an abuser of intravenous drugs came to the hospital after 1 week of pleuritic chest pain, chills, night sweats, dyspnea, and a cough productive of scant, bloody sputum. Eleven years earlier he had received emergency aortic valve replacement with a No. 19 mm Bjork-Shiley valve prosthesis (Shiley Inc., Irvine, California) for acute aortic insufficiency secondary to gonnococcal infective endocarditis. At that time there were no abnormal communications between the cardiac structures detected by cineangiography, transthoracic echocardiography, or surgery. Although the patient was discharged and given maintenance warfarin therapy, he had not taken any medications for several years. He was thin and toxic with a temperature of 101.4° F, a blood pressure of 102164 mm Hg, a pulse of 100 beats I min, and a respiratory rate of 26 per minute. Chest examination revealed splinting of the left hemithorax with a well-healed median sternotomy wound. His cardiac examination showed a normal first heart sound; a crisp metallic second heart sound, and a grade 3 I 6 harsh, systolic ejection murmur along the left sternal border. There was no hepatosplenomegaly. Extremities showed only old intravenous needle marks on both arms without clubbing or nailfold abnormalities. Chest x-ray film revealed mild left ventricular prominence with clear lung fields. The electrocardiogram showed normal sinus 271
272
Sheppard eta!.
Journal of the American Society of Echocardiography
Figure 1 A, Transthoracic parasternal long-axis view demonstrating the abscess cavity (ABSCESS) pointed out by the arrow located posterior to the aortic valve prosthesis within the left atrium. R VOT, Right ventricular outflow tract; A VR, aortic valve prosthesis; LV, left ventricle; MVL, mitral valve leaflet; LA, left atrium. B, Transthoracic parasternal short-axis view demonstrating the abscess cavity (ABSCESS) in cross-section below the aortic root within the left atrium. R VOT, right ventricular outflow tract; A VR, aortic valve prosthesis; RA, right atrium; LA, left atrium.
Volume4 Number 3 May-June 1991
Acquired interatrial fistula
273
'"' j'li~re 2 Transesophageal cross-sectional view of the abscess cavity with color flow Doppler signal showing its entry site.
rhythm with biatrial abnormality. The white blood cell count was 6,400 mm 3 with 49 segmented polymorphonuclear leukocytes, 9 band forms, 32 lymphocytes, and 10 monocytes. Venereal Disease Research Laboratories serology was positive at 1 : 16 dilution, human immunodeficiency virus serology (by ELISA) was negative. Multiple initial blood cultures grew Enterococcus (nonspeciated) sensitive to ampicillin. Intravenous ampicillin and gentamicin therapy was begun. The patient was afebrile by the second day of treatment, and serial blood cultures beyond 48 hours of presentation were negative. The admission transthoracic two-dimensional echocardiogram (Figure 1) revealed a pulsating, thick-walled mass with an echolucent center located between the posterior aortic root and the anterior left atrial wall extending posteromedially into the aortic trigone area. The mass expanded during systole and shrank during diastole, suggesting a communication with the left ventricular outflow tract.
Eight days later a transesophageal echocardiogram with color flow Doppler imaging obtained by usc of a Hewlett-Packard 5 MHz echoscope (HewlettPackard Company, Palo Alto, California) was performed. The abscess was located in the aortic-mitral intervalvular fibrosa region. The abscess had a thick wall and was communicating with the left ventricular outflow tract by a narrow neck at the base of the anterior mitral leaflet (Figure 2) _The abscess cavity was found to have eroded posteriorly into the interatrial septum, creating an interatrial fistula with a leftto-right shunt documented by color flow Doppler imaging (Figure 3), which had not been recognized on the previous transthoracic echocardiogram. A subsequent cardiac catheterization confirmed the presence of an abnormal interatrial communication by oxygen saturation measurements and hydrogen inhalation testing 10 ; in addition, the left atrium was entered by way of the fistula in the interatrial septum. The patient had repeat aortic valve replacement with a 21 mm St. Jude prosthesis (St. Jude Medical,
Journal of the American Society of Echocardiography
274 Sheppard et al.
Figure 3 Transesophageallong-axis view of the left atrium (LA), right atrium (R.A), and the interatrial septum adjoining the .abscess (ABSCESS), demonstrating the fistulous communication between the left atrium and right atrium (arriJW) . The orange pattern depicted by the color flow Doppler signal in the right atrium represents left-to-right shunting as indicated by the color bar code in the upper right corner.
Inc., St. Paul, Minnesota). An abscess cavity was found without evidence of active infection. The left and right atria were not explored. Immediately after surgery the patient's right atrial and mixed-venous oxygen saturations were high (Po 2 , 62 mm Hg; 0 2 saturation, 92% ), consistent with a persistent left-to-right shunt. Eighteen hours later, however, the values decreased to 79%, indicating closure or reduction in the size of the interatrial communication. Postoperative transesophageal echocardiography showed the abscess cavity to be much smaller, nonpulsatile, and filled with soft tissue echoes consistent with clotted blood. There was no communication between the abscess cavity and the left ventricular outflow tract. A small, much reduced interatrial communication persisted.
DISCUSSION
Para-aortic abscess is a well-known complication of prosthetic and native valve endocarditis. Arnett and Roberts 1 reviewed necropsy specimens from 22 patients with prosthetic aortic valve endocarditis and found that all had developed valve ring abscesses. Surgical and necropsy studies of native aortic valve endocarditis report the incidence of abscess formation to be 18% and 57%, respectively, with the highest incidence found among intravenous drug abusers. 1•4 •11 Necropsy 1 and surgical 12 •13 studies of abscesses in this region describe extension of the infective process through the posterior aortic wall and through the left ventricular outflow tract, into the left atrium and through the ventricular septum into the right ven-
Volume4 Number 3 May-June 1991
tricle and anterobasal left ventricular wall. Holt et al. 5 found at necropsy a patient with aortic valve endocarditis in whom an interatrial abscess with fistula formation developed. To our knowledge, the finding of an interatrial communication secondary to a para-aortic abscess eroding through the interatrial septum in our patient, documented by transesophageal echocardiography, is the first report of such an entity before necropsy or surgery. Transesophageal echocardiography allows adequate visualization of the aortic anulus and its adnexa, the left ventricular outflow tract, and the structures forming the aortic trigone: the aortic root and left and right atria, including the interatrial septum. 14 Ellis et al. 7 found that only one of 22 patients documented to have perivalvular abscesses at surgery or autopsy had a "typical" echo-free abscess cavity on conventional transthoracic echocardiography. Furthermore, except for recent case reports by Fischer et al. 6 and Schwartz et al. 15 no transthoracic echocardiographic study has clearly documented fistulous communication caused by an aortic root abscess. Cineangiography, although often used to show fistulous communications, is limited by the number of views that can be obtained and has inherent risks in patients who are often already unstable. 16 Thus it is difficult to provide the necessary information for planning the appropriate surgical procedure in these patients. However, the recent widespread clinical application of transesophageal echocardiography has demonstrated that para-aortic abscesses and abnormal fistulous communications can be recognized easily. 8,17,18 Of interest was the gradual decrease of right atrial oxygen saturations during the early postoperative period. We speculate two possible mechanisms: closure of the mouth of the abscess altered the hemodynamic forces that maintained the interatrial fistula or stopped the pulsatile trauma of the abscess to the interatrial septum. It is too early to determine whether direct surgical closure of such lesions is necessary because long-term follow-up of this patient is not yet available. We have described a case of an interatrial fistula caused by a pulsatile para-aortic abscess eroding into the interatrial septum. The fistulous communication was documented in vivo by transesophageal echocardiography by use of color flow Doppler imaging. Although conventional transthoracic echocardiography did reveal an abscess cavity, this case illustrates the limitations of the transthoracic approach in eval-
Acquired interatrial fistula
275
uating the complications of abscess as a result of its inability to adequately image all pertinent cardiac structures. Transesophageal echocardiography provides a safe and reliable assessment of the aortic root and its adjoining structures. Thus it helps in planning the appropriate intervention in these patients. Therefore, transesophageal echocardiography should be performed in any patient who is suspected to have an abscess involving the aortic root and trigone. The authors thank Sarah Lohwater for editorial assistance.
REFERENCES
1. Arnett EN, Roberts WC. Valve ring abscess in active infective encocarditis. Circulation 1976;54: 140-5. 2. Saner HE, Asinger RW, Homons DC, Helseth HK, Elsperger KJ. Two-dimensional echocardiographic identification of complicated aortic root endocarditis: implications for surgery. JAm Coli Cardiol1987;l0:859-68. 3. Mammana RB, Levitsky S, Semaque D, Beckman CB, Silverman NA. Valve replacement for left-sided endocarditis in drug addicts. Ann Thorac Surg 1983;35:436-41. 4. Hiratzka LF, Nelson RJ, Oliver CB, Jengo JA. Operative experience with infective endocarditis. J Thorac Cardiovasc Surg 1979;77:355-61. 5. HoltS, Martinez AAG, Coulshed N. Interatrial abscess. Postgrad Med J 1979;55:207-9. 6. Fischer EA, Estioko MR, Stem EH, Goldman ME. Left ventricular to left atrial communication secondary to a paraortic abscess: color flow Doppler documentation. J Am Coli Cardiol 1987;10:222-4. 7. Ellis SG, Goldstein ], Popp RL. Detection of endocarditisassociated perivalvular abscess by two-dimensional echocardiography. JAm Coli Cardiol 1985;5:647-53. 8. Daniel WG, Schroder E, Mugge A, Lichtlen PR. Transesophageal echocardiography in infective endocarditis. Am J Cardiac Imaging 1988;2:78-85. 9. Daniel WG, Nellesen U, Schroder E, Nikutta P, NonnastDaniel B, Mugge A. Transesophageal echocardiography as the method of choice for the detection of endocarditisassociated abscesses [Abstract]. Circulation 1986;74: II55. 10. Hugenholtz PG, Schwark T, Monroe RG, et al. The clinical use of hydrogen gas as an indicator of left-to-right shunts. Circulation 1963;28:542-51. 11. Sheldon WH, Golden A. Abscesses of the valve rings of the heart, a frequent but not well recognized complication of acute bacterial endocarditis. Circulation 1951 ;4: 1-12. 12. Mayer E, Ruffman K, Saggan W, et a!. Ruptured aneurysms of the sinus of valsalva. Ann Thorac Surg 1986;42: 81-5. 13. Stinson EB. Surgical treattnent of infective endocarditis. Prog Cardiovasc Dis 1979;22:145-68.
276 Sheppard eta!.
14. Seward JB, Khandheria BK, Oh JK, et al. Transesophageal echocardiography: technique, anatomic correlations, implementation, and clinical applications. Mayo Clin Proc 1988; 63:649-80. 15. Schwartz DR, Belkin RN, Pucillo AL, et al. Aneurysm of the mitral-aortic intervalvular fibrosa complicating infective endocarditis: preoperative characterization by two-dimensional and color flow Doppler echocardiography, magnetic resonance imaging, and cineangiography. Am Heart J 1990; 119:196-9. 16. Mills J, Abbott J, Utley JR, Ryan C. Role of cardiac cathe-
Journal of the American Society of Echocardiography
terization in infective endocarditis. Chest 1977;5:576-82. 17. Bansal RC, Graham BM, Jutzy KR, et al. 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. JAm Coil Cardiol 1990;15:499504. 18. Chandrasekaran K, Bansal RC, Mintz GS, Ross JR, Shah PM. Impact of transesophageal color flow Doppler echocardiography in current cardiology practice. Echocardiography 1990;7: 125-45.
Bound volumes available to subscribers Bound volumes of the JOURNAL OF THE AMERICAN SOCIETY OF ECHOCARDIOGRAPHY are available to subscribers (only) for the 1991 issues from the Publisher at a cost of $28.00 for domestic, $35.96 for Canadian, and $34.00 for international subscribers for Vol. 4 Oanuary-December ). Shipping charges are included. Each bound volume contains a subject and author index, and all advertising is removed. The binding is durable buckram with the JouRNAL name, volume number, and year stamped in gold on the spine. Payment must accompany all orders. Contact Mosby-Year Book, Inc., Subscription Services, 11830 Westline Industrial Drive, St. Louis, MO 63146-3318, USA; telephone (800)325-4177, ext. 4351. Subscriptions must be in force to qualify. Bound volumes are not available in place of a regular JOURNAL subscription.
Para-aortic ring abscess and resulting fistulous communication between adjacent structures frequently occur in prosthetic aortic valve endocarditis but are rarely diagnosed preoperatively. We report a patient who had an abscess involving the aortic-mitral intervalvular fibrosa that eroded into the interatrial septum, causing an interatrial communication with a left-to-right shunt. The abscess was detected by transthoracic echocardiography, but the fistula was only seen by the subsequent transesophageal echocardiogram. To our knowledge, this is the first report of an interatrial fistula secondary to a para-aortic valve abscess and its diagnosis preoperatively. Transesophageal echocardiography should be performed in any patient suspected to have complicated aortic endocarditis. (JAM Soc EcHo 1991;4:271-6.)
Para-aortic abscess and mycotic aneurysm formation are serious complications of infective aortic valve endocarditis. Operative and postmortem studies suggest that 18% to 57% of patients with prosthetic aortic valve endocarditis are found to have perivalvular abscesses. 1' 4 The infective process may extend into perivalvular structures, causing aorta-left ventricular discontinuity or fistulous communication between cardiac structures. 2 •5 •6 Conventional transthoracic echocardiography has provided inconsistent results in diagnosing aortic root abscesses and their complications. 7-9 The recent use of transesophageal echocardiography is an improvement in assessing infective endocarditis and detecting a perivalvular abscess. 8 Color flow Doppler imaging can provide reliable documentation of fistulous communication. 6 We recently encountered a patient found to have a complication of para-aortic abscess not previously reported: an interatrial communication. The abscess was detected by transthoracic and the interatrial communication by transesophageal echocardiography; both were later confirmed by cardiac catheterization.
From the Department of Cardiology, Likoff Cardiovascular Institute, Hahnemann University Hospital. Reprint requests: Krishnaswamy Chandrasekaran, MD, Mail Stop 313, Hahnemann University Hospital, Broad and Vine Streets, Philadelphia, PA 19102. 27/l/26401
CASE RE,PORT
A 28-year-old black man who was a homosexual and an abuser of intravenous drugs came to the hospital after 1 week of pleuritic chest pain, chills, night sweats, dyspnea, and a cough productive of scant, bloody sputum. Eleven years earlier he had received emergency aortic valve replacement with a No. 19 mm Bjork-Shiley valve prosthesis (Shiley Inc., Irvine, California) for acute aortic insufficiency secondary to gonnococcal infective endocarditis. At that time there were no abnormal communications between the cardiac structures detected by cineangiography, transthoracic echocardiography, or surgery. Although the patient was discharged and given maintenance warfarin therapy, he had not taken any medications for several years. He was thin and toxic with a temperature of 101.4° F, a blood pressure of 102164 mm Hg, a pulse of 100 beats I min, and a respiratory rate of 26 per minute. Chest examination revealed splinting of the left hemithorax with a well-healed median sternotomy wound. His cardiac examination showed a normal first heart sound; a crisp metallic second heart sound, and a grade 3 I 6 harsh, systolic ejection murmur along the left sternal border. There was no hepatosplenomegaly. Extremities showed only old intravenous needle marks on both arms without clubbing or nailfold abnormalities. Chest x-ray film revealed mild left ventricular prominence with clear lung fields. The electrocardiogram showed normal sinus 271
272
Sheppard eta!.
Journal of the American Society of Echocardiography
Figure 1 A, Transthoracic parasternal long-axis view demonstrating the abscess cavity (ABSCESS) pointed out by the arrow located posterior to the aortic valve prosthesis within the left atrium. R VOT, Right ventricular outflow tract; A VR, aortic valve prosthesis; LV, left ventricle; MVL, mitral valve leaflet; LA, left atrium. B, Transthoracic parasternal short-axis view demonstrating the abscess cavity (ABSCESS) in cross-section below the aortic root within the left atrium. R VOT, right ventricular outflow tract; A VR, aortic valve prosthesis; RA, right atrium; LA, left atrium.
Volume4 Number 3 May-June 1991
Acquired interatrial fistula
273
'"' j'li~re 2 Transesophageal cross-sectional view of the abscess cavity with color flow Doppler signal showing its entry site.
rhythm with biatrial abnormality. The white blood cell count was 6,400 mm 3 with 49 segmented polymorphonuclear leukocytes, 9 band forms, 32 lymphocytes, and 10 monocytes. Venereal Disease Research Laboratories serology was positive at 1 : 16 dilution, human immunodeficiency virus serology (by ELISA) was negative. Multiple initial blood cultures grew Enterococcus (nonspeciated) sensitive to ampicillin. Intravenous ampicillin and gentamicin therapy was begun. The patient was afebrile by the second day of treatment, and serial blood cultures beyond 48 hours of presentation were negative. The admission transthoracic two-dimensional echocardiogram (Figure 1) revealed a pulsating, thick-walled mass with an echolucent center located between the posterior aortic root and the anterior left atrial wall extending posteromedially into the aortic trigone area. The mass expanded during systole and shrank during diastole, suggesting a communication with the left ventricular outflow tract.
Eight days later a transesophageal echocardiogram with color flow Doppler imaging obtained by usc of a Hewlett-Packard 5 MHz echoscope (HewlettPackard Company, Palo Alto, California) was performed. The abscess was located in the aortic-mitral intervalvular fibrosa region. The abscess had a thick wall and was communicating with the left ventricular outflow tract by a narrow neck at the base of the anterior mitral leaflet (Figure 2) _The abscess cavity was found to have eroded posteriorly into the interatrial septum, creating an interatrial fistula with a leftto-right shunt documented by color flow Doppler imaging (Figure 3), which had not been recognized on the previous transthoracic echocardiogram. A subsequent cardiac catheterization confirmed the presence of an abnormal interatrial communication by oxygen saturation measurements and hydrogen inhalation testing 10 ; in addition, the left atrium was entered by way of the fistula in the interatrial septum. The patient had repeat aortic valve replacement with a 21 mm St. Jude prosthesis (St. Jude Medical,
Journal of the American Society of Echocardiography
274 Sheppard et al.
Figure 3 Transesophageallong-axis view of the left atrium (LA), right atrium (R.A), and the interatrial septum adjoining the .abscess (ABSCESS), demonstrating the fistulous communication between the left atrium and right atrium (arriJW) . The orange pattern depicted by the color flow Doppler signal in the right atrium represents left-to-right shunting as indicated by the color bar code in the upper right corner.
Inc., St. Paul, Minnesota). An abscess cavity was found without evidence of active infection. The left and right atria were not explored. Immediately after surgery the patient's right atrial and mixed-venous oxygen saturations were high (Po 2 , 62 mm Hg; 0 2 saturation, 92% ), consistent with a persistent left-to-right shunt. Eighteen hours later, however, the values decreased to 79%, indicating closure or reduction in the size of the interatrial communication. Postoperative transesophageal echocardiography showed the abscess cavity to be much smaller, nonpulsatile, and filled with soft tissue echoes consistent with clotted blood. There was no communication between the abscess cavity and the left ventricular outflow tract. A small, much reduced interatrial communication persisted.
DISCUSSION
Para-aortic abscess is a well-known complication of prosthetic and native valve endocarditis. Arnett and Roberts 1 reviewed necropsy specimens from 22 patients with prosthetic aortic valve endocarditis and found that all had developed valve ring abscesses. Surgical and necropsy studies of native aortic valve endocarditis report the incidence of abscess formation to be 18% and 57%, respectively, with the highest incidence found among intravenous drug abusers. 1•4 •11 Necropsy 1 and surgical 12 •13 studies of abscesses in this region describe extension of the infective process through the posterior aortic wall and through the left ventricular outflow tract, into the left atrium and through the ventricular septum into the right ven-
Volume4 Number 3 May-June 1991
tricle and anterobasal left ventricular wall. Holt et al. 5 found at necropsy a patient with aortic valve endocarditis in whom an interatrial abscess with fistula formation developed. To our knowledge, the finding of an interatrial communication secondary to a para-aortic abscess eroding through the interatrial septum in our patient, documented by transesophageal echocardiography, is the first report of such an entity before necropsy or surgery. Transesophageal echocardiography allows adequate visualization of the aortic anulus and its adnexa, the left ventricular outflow tract, and the structures forming the aortic trigone: the aortic root and left and right atria, including the interatrial septum. 14 Ellis et al. 7 found that only one of 22 patients documented to have perivalvular abscesses at surgery or autopsy had a "typical" echo-free abscess cavity on conventional transthoracic echocardiography. Furthermore, except for recent case reports by Fischer et al. 6 and Schwartz et al. 15 no transthoracic echocardiographic study has clearly documented fistulous communication caused by an aortic root abscess. Cineangiography, although often used to show fistulous communications, is limited by the number of views that can be obtained and has inherent risks in patients who are often already unstable. 16 Thus it is difficult to provide the necessary information for planning the appropriate surgical procedure in these patients. However, the recent widespread clinical application of transesophageal echocardiography has demonstrated that para-aortic abscesses and abnormal fistulous communications can be recognized easily. 8,17,18 Of interest was the gradual decrease of right atrial oxygen saturations during the early postoperative period. We speculate two possible mechanisms: closure of the mouth of the abscess altered the hemodynamic forces that maintained the interatrial fistula or stopped the pulsatile trauma of the abscess to the interatrial septum. It is too early to determine whether direct surgical closure of such lesions is necessary because long-term follow-up of this patient is not yet available. We have described a case of an interatrial fistula caused by a pulsatile para-aortic abscess eroding into the interatrial septum. The fistulous communication was documented in vivo by transesophageal echocardiography by use of color flow Doppler imaging. Although conventional transthoracic echocardiography did reveal an abscess cavity, this case illustrates the limitations of the transthoracic approach in eval-
Acquired interatrial fistula
275
uating the complications of abscess as a result of its inability to adequately image all pertinent cardiac structures. Transesophageal echocardiography provides a safe and reliable assessment of the aortic root and its adjoining structures. Thus it helps in planning the appropriate intervention in these patients. Therefore, transesophageal echocardiography should be performed in any patient who is suspected to have an abscess involving the aortic root and trigone. The authors thank Sarah Lohwater for editorial assistance.
REFERENCES
1. Arnett EN, Roberts WC. Valve ring abscess in active infective encocarditis. Circulation 1976;54: 140-5. 2. Saner HE, Asinger RW, Homons DC, Helseth HK, Elsperger KJ. Two-dimensional echocardiographic identification of complicated aortic root endocarditis: implications for surgery. JAm Coli Cardiol1987;l0:859-68. 3. Mammana RB, Levitsky S, Semaque D, Beckman CB, Silverman NA. Valve replacement for left-sided endocarditis in drug addicts. Ann Thorac Surg 1983;35:436-41. 4. Hiratzka LF, Nelson RJ, Oliver CB, Jengo JA. Operative experience with infective endocarditis. J Thorac Cardiovasc Surg 1979;77:355-61. 5. HoltS, Martinez AAG, Coulshed N. Interatrial abscess. Postgrad Med J 1979;55:207-9. 6. Fischer EA, Estioko MR, Stem EH, Goldman ME. Left ventricular to left atrial communication secondary to a paraortic abscess: color flow Doppler documentation. J Am Coli Cardiol 1987;10:222-4. 7. Ellis SG, Goldstein ], Popp RL. Detection of endocarditisassociated perivalvular abscess by two-dimensional echocardiography. JAm Coli Cardiol 1985;5:647-53. 8. Daniel WG, Schroder E, Mugge A, Lichtlen PR. Transesophageal echocardiography in infective endocarditis. Am J Cardiac Imaging 1988;2:78-85. 9. Daniel WG, Nellesen U, Schroder E, Nikutta P, NonnastDaniel B, Mugge A. Transesophageal echocardiography as the method of choice for the detection of endocarditisassociated abscesses [Abstract]. Circulation 1986;74: II55. 10. Hugenholtz PG, Schwark T, Monroe RG, et al. The clinical use of hydrogen gas as an indicator of left-to-right shunts. Circulation 1963;28:542-51. 11. Sheldon WH, Golden A. Abscesses of the valve rings of the heart, a frequent but not well recognized complication of acute bacterial endocarditis. Circulation 1951 ;4: 1-12. 12. Mayer E, Ruffman K, Saggan W, et a!. Ruptured aneurysms of the sinus of valsalva. Ann Thorac Surg 1986;42: 81-5. 13. Stinson EB. Surgical treattnent of infective endocarditis. Prog Cardiovasc Dis 1979;22:145-68.
276 Sheppard eta!.
14. Seward JB, Khandheria BK, Oh JK, et al. Transesophageal echocardiography: technique, anatomic correlations, implementation, and clinical applications. Mayo Clin Proc 1988; 63:649-80. 15. Schwartz DR, Belkin RN, Pucillo AL, et al. Aneurysm of the mitral-aortic intervalvular fibrosa complicating infective endocarditis: preoperative characterization by two-dimensional and color flow Doppler echocardiography, magnetic resonance imaging, and cineangiography. Am Heart J 1990; 119:196-9. 16. Mills J, Abbott J, Utley JR, Ryan C. Role of cardiac cathe-
Journal of the American Society of Echocardiography
terization in infective endocarditis. Chest 1977;5:576-82. 17. Bansal RC, Graham BM, Jutzy KR, et al. 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. JAm Coil Cardiol 1990;15:499504. 18. Chandrasekaran K, Bansal RC, Mintz GS, Ross JR, Shah PM. Impact of transesophageal color flow Doppler echocardiography in current cardiology practice. Echocardiography 1990;7: 125-45.
Bound volumes available to subscribers Bound volumes of the JOURNAL OF THE AMERICAN SOCIETY OF ECHOCARDIOGRAPHY are available to subscribers (only) for the 1991 issues from the Publisher at a cost of $28.00 for domestic, $35.96 for Canadian, and $34.00 for international subscribers for Vol. 4 Oanuary-December ). Shipping charges are included. Each bound volume contains a subject and author index, and all advertising is removed. The binding is durable buckram with the JouRNAL name, volume number, and year stamped in gold on the spine. Payment must accompany all orders. Contact Mosby-Year Book, Inc., Subscription Services, 11830 Westline Industrial Drive, St. Louis, MO 63146-3318, USA; telephone (800)325-4177, ext. 4351. Subscriptions must be in force to qualify. Bound volumes are not available in place of a regular JOURNAL subscription.