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Pulmonic Valve Endocarditis as an Underdiagnosed Disease: Role of Transesophageal Echocardiography
Pulmonic Valve Endocarditis as an Underdiagnosed Disease: Role of Transesophageal Echocardiography Shelley M. Shapiro, MD, PhD, Eddy Young MD, Leonard E. Ginzton, MD, and Arnold S. Bayer, MD, Torrance, Santa Monica, and Los Angeles, California
Pulmonic valve endocarditis is a rare clinical entity. In spite of an increase in the frequency of right-sided endocarditis, primarily it is the tricuspid valve that is involved. Two-dimensional transthoracic echocardiography has improved our ability to diagnose infective endocarditis but has not identified many cases of pulmonic valve endocarditis. With the use of transesophageal echocardiography, three recent cases of pulmonic valve endocarditis were diagnosed by our laboratory. Each of these patients had clinical evidence of right-sided endocarditis, yet routine transthoracic echocardiograms failed to identify any pulmonic valve abnormalities. The true incidence of pulmonic valve endocarditis may be higher than previously reported, and the transesophageal echocardiogram is the preferred method for identifying and evaluating pulmonic valve endocarditis in adults. (JAM Soc EcHOCARDIOGR 1992;5:48-Sl.)
Pulmonic valve endocarditis is a rare clinical entity seen primarily in patients with congenital heart disease. 1 The frequency of pulmonic valve involvement in endocarditis has been estimated at 2% to 3% based on autopsy series. 2 Antemortem clinical recognition of pulmonic valve endocarditis remains infrequent despite the overall increase in right-sided endocarditis cases (predominantly tricuspid valve). 3 Damage to the pulmonic valve caused by widespread use of flowdirected pulmonary-artery catheters in intensive care units has undoubtedly expanded the pool of patients at risk for development of pulmonic valve endocarditis. 4 Although the two-dimensional transthoracic echocardiogram has been exceedingly useful in the diagnosis of endocarditis, 5 the pulmonic valve is not easily imaged in adults and few cases of pulmonic valve endocarditis have been diagnosed echocardiographically.1·4·6·7 Transesophageal echocardiography is becoming increasingly useful as a diagnostic technique in a variety of clinical settings, including the evaluation of endocarditis. 8 •9
From the Divisions of Cardiology and Infectious Diseases, Harbor UCLA Medical Center, the St. John's Cardiovascular Research Center, and the UCLA School of Medicine. Supported by Saint John's Heart Institute (grant SJ-6214-03). Reprint requests: Shelley Shapiro, MD, Department of Medicine, Division of Cardiology, Harbor-UCLA Medical Center, Building F9, 1000 W Carson St., Torrance, CA 90509. 27/l/32656
48
In a 12-month period three patients with pulmonic valve endocarditis have been identified, primarily by transesophageal echocardiography. In contrast, despite performing 2000 to 3000 transthoracic echocardiograms per year in the previous 10 years (many in suspected endocarditis cases), we had not identified a single case of pulmonic valve endocarditis using this technique. Our observations suggest that the true incidence of pulmonic valve endocarditis may be much higher than previously reported, and that transesophageal echocardiography may be the preferred method for identifying and evaluating pulmonic valve endocarditis in adults.
easel A 54-year-old man with extensive history of drug abuse was given a 2-week course of oral antibiotics for a productive cough before coming to our facility complaining of chest pain, mild hemoptysis, and shortness of breath. Four out of four blood cultures on admission yielded Staphylococcus aureus. The patient had a stormy course, with evidence of multiple pulmonary emboli and respiratory failure with hypoventilation. No central venous monitoring was performed during hospitalization. Transthoracic echocardiograms failed to reveal valvular abnormalities. After the patient's respiratory status was stabilized, a transesophageal echocardiogram was performed (Figure 1), demonstrating a 2.5 em pulmonic valve vegetation and pulmonic regurgitation. A re-
Volume 5 Number l january-February 1992
Pulmonic echocarditis and transesophageal echocardiography 49
Figure 1 Still-frame image oftransesophageal echocardiogram (from Case 1). The image is at the level of pulmonic and aortic valves, demonstrating a large pulmonic valve vegetation (at arrow).
peat transthoracic echocardiogram obtained through the subcostal window was now able to identify the vegetation not seen on the previous transthoracic study using routine parasternal views (Figure 2). Case2
A 34-year-old man, previously an intravenous drug abuser, had a documented episode of successfully treated tricuspid valve endocarditis at another hospital several months before coming to HarborUCLA Medical Center in November 1990 with fever, chest pain, and shortness of breath. Admission blood cultures were all negative. Transthoracic echocardiogram demonstrated the previously seen tricuspid valve vegetation, severe tricuspid regurgitation, a moderate-sized pericardia! effusion, and suggestive evidence of tamponade. Diagnostic pericardiocentesis as well as a transesophageal echocardiogram was performed, demonstrating a pulmonic valve vegetation in addition to the prior tricupsid valve abnormalities (Figure 3). In the face of negative blood cultures, both the pulmonic and tricuspid valve vegetations were considered to be sequelae of the previous episode of endocarditis rather than the recurrent infection. The pericarditis was believed to be viral or inflammatory, and the patient was discharged without antibiotics. He subsequently developed constrictive pericarditis and intractable right-sided failure.
Case3
A 35-year-old woman who was an intravenous drug abuser was admitted to Harbor-UCLA Medical Center with a 2-week history of fevers, hemoptysis, and a sore throat. Group A 13-hemolytic streptococci grew out of multiple blood cultures. Chest roentgenogram was consistent with multiple septic pulmonary emboli. Transthoracic echocardiogram demonstrated a mildly thickened mitral valve and no other abnormalities. Transesophageal echocardiogram demonstrated a pulmonic valve vegetation (1.5 em) and confirmed the presence of a mildly thickened mitral valve without vegetations. Treatment with antibiotics resulted in gradual clinical improvement. DISCUSSION
Our study is the first detailed report of the utility of transesophageal echocardiography in the diagnosis of pulmonic valve endocarditis. Our patients initially presented with classical clinical manifestations (fever, hemoptysis, and pleurisy) of right-sided endocarditis in the setting of intravenous drug abuse. Transesophageal echocardiography documented large pulmonic valve vegetations in each, lesions that were undetected by routine transthoracic echocardiography. Moreover, repeat transthoracic studies performed immediately after the transesophageal studies and di-
50
Shapiro et a!.
Figure 2 Short-axis, subcostal transthoracic image at the level of pulmonic valve (from Case l). Arrow identifies pulmonic valve vegetation.
Figure 3 Still-frame image of the transesophageal echocardiogram from Case 2. Pulmonic vegetation is identified by arrow.
Journal of the American Society of Echocardiography
Volume 5 Number l january-February 1992
Pulmonic echocarditis and transesophageal echocardiography 51
rected toward evaluations of the pulmonic valve still failed to demonstrate the pulmonic valve vegetations in two of the three patients. The suboptimal performance of transthoracic echocardiography in detecting pulmonic valve endocarditis is probably multifactorial, related in part to the difficulties of imaging adults with underlying pulmonary disease or respiratory distress. Visualization of the pulmonic valve, even in normal adults, is not entirely satisfactory because of intervening lung tissue and the inability to obtain a cross-sectional view of the valve. 10 The true incidence of pulmonic valve endocarditis has undoubtedly been underestimated. Few patients with right-sided endocarditis die quickly from their infection, so postmortem analyses may underestimate the incidence of pulmonic valve endocarditis. 11 Also, in the absence of severe pulmonary hypertension, the development of even moderately severe pulmonic insufficiency may be of little or no hemodynamic consequence; therefore, surgical confirmation may be difficult to obtain. Our studies were performed using a single-plane transesophageal probe. Improved imaging of the pulmonic valve may be possible with biplane and multiplane systems now becoming available for clinical use. These probes will allow us to routinely image the pulmonic valve both in short and long axis, perhaps further increasing the number of cases of pulmonic valve endocarditis identified. Our findings raise interesting questions about the incidence and significance of pulmonic valve endocarditis and the role of transesophageal echocardiography in evaluation of patients with suspected right-sided endocarditis. They suggest that transesophageal echocardiography 1s the preferred
method for identifying pulmonic valve endocarditis in patients at risk for this entity. REFERENCES l. DePace N, Iskandrian A, Morganroth J, et aL Infective endocarditis involving a presumably normal pulmonic valve. Am J Cardiol 1984;53:385-7. 2. Dressler FA, Roberts WC. Infective endocarditis in opiate addicts: analysis of 80 cases studied at necropsy. Am J Cardiol 1989;63:1240-57. 3. Panidis IP, Kotler MN, Mintz GS, eta!. Right heart endocarditis:clinical and echocardiographic features. Am Heart J 1984;107:759-64. 4. Rowley KM, Clubb KS, Walker Smith GJ, eta!. Right-sided infective endocarditis as a consequence of flow-directed pulmonary-artery catheterization. N Eng! J Med 1984; 311:1152-6. 5. Berger M, Delfin L, Jelveh M, eta!. Two-dimensional echocardiographic findings in right-sided infective endocarditis. Circulation 1980;61:855-61. 6. Lewin RF, Sidi Y, Hermoni Y, eta!. Serial two-dimensional echocardiography in infective endocarditis of the pulmonic valve. Isr J Med Sci 1983;19:53-7. 7. Suwa M, Shimizu G, Yoshinori D, et a!. Two-dimensional echocardiography of ruptured pulmonic valve with infective endocarditis. Am Heart J 1984;107:1027-9. 8. Pavlides GS, Hauser AM, Stewart JR, eta!. Contribution of transesophageal echocardiography to parient diagnosis and treatment: a prospective analysis. Am Heart J 1990;120: 910-4. 9. Shapiro SM, Young E, DeGuzman S, Sanchez-Anaya C, Bayer AS, Ginzton L. Comparison of transesophageal and transthoracic echocardiography in evaluating patients with suspected infectious endocarditis. Clin Res 1991;39:49A. 10. Bitar J, Alam M. Echo-Doppler features of pulmonary valve endocarditis. Henry Ford Hosp Med J 1989;37:41-2. 11. Robbins MJ, Frater RWM, Soeir R, eta!. Influence of vegetation size on clinical outcome of right-sided infective endocarditis. Am J Med 1986;80:165-71.
Pulmonic valve endocarditis is a rare clinical entity. In spite of an increase in the frequency of right-sided endocarditis, primarily it is the tricuspid valve that is involved. Two-dimensional transthoracic echocardiography has improved our ability to diagnose infective endocarditis but has not identified many cases of pulmonic valve endocarditis. With the use of transesophageal echocardiography, three recent cases of pulmonic valve endocarditis were diagnosed by our laboratory. Each of these patients had clinical evidence of right-sided endocarditis, yet routine transthoracic echocardiograms failed to identify any pulmonic valve abnormalities. The true incidence of pulmonic valve endocarditis may be higher than previously reported, and the transesophageal echocardiogram is the preferred method for identifying and evaluating pulmonic valve endocarditis in adults. (JAM Soc EcHOCARDIOGR 1992;5:48-Sl.)
Pulmonic valve endocarditis is a rare clinical entity seen primarily in patients with congenital heart disease. 1 The frequency of pulmonic valve involvement in endocarditis has been estimated at 2% to 3% based on autopsy series. 2 Antemortem clinical recognition of pulmonic valve endocarditis remains infrequent despite the overall increase in right-sided endocarditis cases (predominantly tricuspid valve). 3 Damage to the pulmonic valve caused by widespread use of flowdirected pulmonary-artery catheters in intensive care units has undoubtedly expanded the pool of patients at risk for development of pulmonic valve endocarditis. 4 Although the two-dimensional transthoracic echocardiogram has been exceedingly useful in the diagnosis of endocarditis, 5 the pulmonic valve is not easily imaged in adults and few cases of pulmonic valve endocarditis have been diagnosed echocardiographically.1·4·6·7 Transesophageal echocardiography is becoming increasingly useful as a diagnostic technique in a variety of clinical settings, including the evaluation of endocarditis. 8 •9
From the Divisions of Cardiology and Infectious Diseases, Harbor UCLA Medical Center, the St. John's Cardiovascular Research Center, and the UCLA School of Medicine. Supported by Saint John's Heart Institute (grant SJ-6214-03). Reprint requests: Shelley Shapiro, MD, Department of Medicine, Division of Cardiology, Harbor-UCLA Medical Center, Building F9, 1000 W Carson St., Torrance, CA 90509. 27/l/32656
48
In a 12-month period three patients with pulmonic valve endocarditis have been identified, primarily by transesophageal echocardiography. In contrast, despite performing 2000 to 3000 transthoracic echocardiograms per year in the previous 10 years (many in suspected endocarditis cases), we had not identified a single case of pulmonic valve endocarditis using this technique. Our observations suggest that the true incidence of pulmonic valve endocarditis may be much higher than previously reported, and that transesophageal echocardiography may be the preferred method for identifying and evaluating pulmonic valve endocarditis in adults.
easel A 54-year-old man with extensive history of drug abuse was given a 2-week course of oral antibiotics for a productive cough before coming to our facility complaining of chest pain, mild hemoptysis, and shortness of breath. Four out of four blood cultures on admission yielded Staphylococcus aureus. The patient had a stormy course, with evidence of multiple pulmonary emboli and respiratory failure with hypoventilation. No central venous monitoring was performed during hospitalization. Transthoracic echocardiograms failed to reveal valvular abnormalities. After the patient's respiratory status was stabilized, a transesophageal echocardiogram was performed (Figure 1), demonstrating a 2.5 em pulmonic valve vegetation and pulmonic regurgitation. A re-
Volume 5 Number l january-February 1992
Pulmonic echocarditis and transesophageal echocardiography 49
Figure 1 Still-frame image oftransesophageal echocardiogram (from Case 1). The image is at the level of pulmonic and aortic valves, demonstrating a large pulmonic valve vegetation (at arrow).
peat transthoracic echocardiogram obtained through the subcostal window was now able to identify the vegetation not seen on the previous transthoracic study using routine parasternal views (Figure 2). Case2
A 34-year-old man, previously an intravenous drug abuser, had a documented episode of successfully treated tricuspid valve endocarditis at another hospital several months before coming to HarborUCLA Medical Center in November 1990 with fever, chest pain, and shortness of breath. Admission blood cultures were all negative. Transthoracic echocardiogram demonstrated the previously seen tricuspid valve vegetation, severe tricuspid regurgitation, a moderate-sized pericardia! effusion, and suggestive evidence of tamponade. Diagnostic pericardiocentesis as well as a transesophageal echocardiogram was performed, demonstrating a pulmonic valve vegetation in addition to the prior tricupsid valve abnormalities (Figure 3). In the face of negative blood cultures, both the pulmonic and tricuspid valve vegetations were considered to be sequelae of the previous episode of endocarditis rather than the recurrent infection. The pericarditis was believed to be viral or inflammatory, and the patient was discharged without antibiotics. He subsequently developed constrictive pericarditis and intractable right-sided failure.
Case3
A 35-year-old woman who was an intravenous drug abuser was admitted to Harbor-UCLA Medical Center with a 2-week history of fevers, hemoptysis, and a sore throat. Group A 13-hemolytic streptococci grew out of multiple blood cultures. Chest roentgenogram was consistent with multiple septic pulmonary emboli. Transthoracic echocardiogram demonstrated a mildly thickened mitral valve and no other abnormalities. Transesophageal echocardiogram demonstrated a pulmonic valve vegetation (1.5 em) and confirmed the presence of a mildly thickened mitral valve without vegetations. Treatment with antibiotics resulted in gradual clinical improvement. DISCUSSION
Our study is the first detailed report of the utility of transesophageal echocardiography in the diagnosis of pulmonic valve endocarditis. Our patients initially presented with classical clinical manifestations (fever, hemoptysis, and pleurisy) of right-sided endocarditis in the setting of intravenous drug abuse. Transesophageal echocardiography documented large pulmonic valve vegetations in each, lesions that were undetected by routine transthoracic echocardiography. Moreover, repeat transthoracic studies performed immediately after the transesophageal studies and di-
50
Shapiro et a!.
Figure 2 Short-axis, subcostal transthoracic image at the level of pulmonic valve (from Case l). Arrow identifies pulmonic valve vegetation.
Figure 3 Still-frame image of the transesophageal echocardiogram from Case 2. Pulmonic vegetation is identified by arrow.
Journal of the American Society of Echocardiography
Volume 5 Number l january-February 1992
Pulmonic echocarditis and transesophageal echocardiography 51
rected toward evaluations of the pulmonic valve still failed to demonstrate the pulmonic valve vegetations in two of the three patients. The suboptimal performance of transthoracic echocardiography in detecting pulmonic valve endocarditis is probably multifactorial, related in part to the difficulties of imaging adults with underlying pulmonary disease or respiratory distress. Visualization of the pulmonic valve, even in normal adults, is not entirely satisfactory because of intervening lung tissue and the inability to obtain a cross-sectional view of the valve. 10 The true incidence of pulmonic valve endocarditis has undoubtedly been underestimated. Few patients with right-sided endocarditis die quickly from their infection, so postmortem analyses may underestimate the incidence of pulmonic valve endocarditis. 11 Also, in the absence of severe pulmonary hypertension, the development of even moderately severe pulmonic insufficiency may be of little or no hemodynamic consequence; therefore, surgical confirmation may be difficult to obtain. Our studies were performed using a single-plane transesophageal probe. Improved imaging of the pulmonic valve may be possible with biplane and multiplane systems now becoming available for clinical use. These probes will allow us to routinely image the pulmonic valve both in short and long axis, perhaps further increasing the number of cases of pulmonic valve endocarditis identified. Our findings raise interesting questions about the incidence and significance of pulmonic valve endocarditis and the role of transesophageal echocardiography in evaluation of patients with suspected right-sided endocarditis. They suggest that transesophageal echocardiography 1s the preferred
method for identifying pulmonic valve endocarditis in patients at risk for this entity. REFERENCES l. DePace N, Iskandrian A, Morganroth J, et aL Infective endocarditis involving a presumably normal pulmonic valve. Am J Cardiol 1984;53:385-7. 2. Dressler FA, Roberts WC. Infective endocarditis in opiate addicts: analysis of 80 cases studied at necropsy. Am J Cardiol 1989;63:1240-57. 3. Panidis IP, Kotler MN, Mintz GS, eta!. Right heart endocarditis:clinical and echocardiographic features. Am Heart J 1984;107:759-64. 4. Rowley KM, Clubb KS, Walker Smith GJ, eta!. Right-sided infective endocarditis as a consequence of flow-directed pulmonary-artery catheterization. N Eng! J Med 1984; 311:1152-6. 5. Berger M, Delfin L, Jelveh M, eta!. Two-dimensional echocardiographic findings in right-sided infective endocarditis. Circulation 1980;61:855-61. 6. Lewin RF, Sidi Y, Hermoni Y, eta!. Serial two-dimensional echocardiography in infective endocarditis of the pulmonic valve. Isr J Med Sci 1983;19:53-7. 7. Suwa M, Shimizu G, Yoshinori D, et a!. Two-dimensional echocardiography of ruptured pulmonic valve with infective endocarditis. Am Heart J 1984;107:1027-9. 8. Pavlides GS, Hauser AM, Stewart JR, eta!. Contribution of transesophageal echocardiography to parient diagnosis and treatment: a prospective analysis. Am Heart J 1990;120: 910-4. 9. Shapiro SM, Young E, DeGuzman S, Sanchez-Anaya C, Bayer AS, Ginzton L. Comparison of transesophageal and transthoracic echocardiography in evaluating patients with suspected infectious endocarditis. Clin Res 1991;39:49A. 10. Bitar J, Alam M. Echo-Doppler features of pulmonary valve endocarditis. Henry Ford Hosp Med J 1989;37:41-2. 11. Robbins MJ, Frater RWM, Soeir R, eta!. Influence of vegetation size on clinical outcome of right-sided infective endocarditis. Am J Med 1986;80:165-71.