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Diverticulum arising from mitral valve
Diverticulum Arising From Mitral Valve Radhika Jaladi, MD, William K. Levy, MD, and Paul V. Addonizio, MD, Abington and Philadelphia, Pennsylvania
Diverticula arising from the mitral valve are very rare. They are usually detected by echocardiography as masses arising from the cardiac valves. We present a case of an incidental finding of a diverticulum arising from the mitral valve. This was initially detected by transesophageal echocardiography, and
later confirmed by pathologic appearance. The case illustrates the unique findings on echocardiography that would help to differentiate diverticula from other valvular masses. (J Am Soc Echocardiogr 2004; 17:288-9.)
CASE REPORT A 51-year-old white woman with known coronary artery disease, aortic stenosis, and congestive heart failure presented to a local facility with worsening dyspnea. Her history also included hypertension, hypercholesterolemia, diabetes mellitus, and renal failure. Cardiac catheterization demonstrated severe 3-vessel coronary artery disease, aortic stenosis, and moderate mitral regurgitation. She was transferred for coronary artery bypass operation and aortic valve repair. There was no history of infective endocarditis. On examination the patient was in no distress, with a blood pressure of 90/50 mm Hg and heart rate of 100 bpm. Physical examination was remarkable for crepitations at both lung bases. Heart auscultation revealed a grade 3/6 systolic ejection murmur at left sternal border radiating to the carotids and grade 2/6 apical mitral regurgitation murmur and no gallops. Peripheral edema and jugular venous distention were not appreciated. Electrocardiogram showed in sinus rhythm and a left bundle branch block pattern. Preoperative transesophageal echocardiogram showed severe aortic stenosis (valve area of 0.9 cm2) with mild aortic regurgitation and a calcified mitral valve annulus with mild to moderate mitral regurgitation. The echocardiogram also revealed an echolucent and cystic mass in the left ventricular outflow tract (LVOT) and attached to the anterior leaflet of the mitral valve. The mass was echogenic and tubular. It measured 1 cm in length and 1.2 cm in width in peak systole (Figure 1) and was not From the Department of Internal Medicine (R.J.), Department of Cardiology (W.K.L.), and Cardiac Surgery Division (P.V.A.), Abington Memorial Hospital; and Department of Surgery, Temple University Hospital (P.V.A.). Reprint requests: William K. Levy, MD, Department of Cardiology, Abington Memorial Hospital, 1200 Old York Rd, Abington, PA 19044. 0894-7317/$30.00 Copyright 2004 by the American Society of Echocardiography. doi:10.1067/j.echo.2003.11.003
288
Figure 1 Mass in systole on transesophageal echocardiography. Arrow, Diverticulum; A, left atrium; B, anterior leaflet of mitral valve; C, aortic valve; D, left ventricular outflow tract.
visualized in diastole (Figure 2). This was thought to represent a possible vegetation versus diverticulum. Operation involved triple-vessel bypass operation and replacement of aortic valve with St Jude prosthetic valve. During operation a 1.5-cm hollow mass was resected from the anterior leaflet of mitral valve. Grossly it consisted of a pouchlike structure of white fibrous tissue consistent with diverticulum (Figure 3). Microscopic sections revealed endothelium-lined fibrous tissue with myxoid change also consistent with diverticulum (Figure 4). There was no pathologic evidence for infective endocarditis.
DISCUSSION In this case of aortic stenosis and coronary artery disease, preoperative transesophageal echocardiography revealed the unexpected finding of a mobile mass in the LVOT attached to the base of the anterior leaflet of the mitral valve. The mass did not significantly block the LVOT and the mass was not
Journal of the American Society of Echocardiography Volume 17 Number 3
Figure 2 Disappearance of valvular mass during diastole. A, Left atrium; B, anterior leaflet of mitral valve; C, aortic valve; D, left ventricular outflow tract.
Figure 3 Gross specimen after resection showing diverticulum with trabeculations.
visible on transthoracic echocardiogram. The distinctive features of the mass were its central clearing, expansion during systole, and collapse during diastole. The differential diagnosis of this echocardiographic finding included mitral valve vegetation, papillary fibroelastoma, atypical myxoma, and mitral valve diverticulum. The mass during operation and at pathology was found to be a mitral valve diverticulum without evidence of active endocarditis. Diverticula of the mitral valve have been reported in the literature as a complication of bacterial endocarditis.1-3 In these cases, infection of the mitral valve produced localized destruction and thinning of valve tissue producing an out-pouching and aneurysm formation. In the case here reported there were no clinical history or pathologic findings of active or healed endocarditis. Agathos et al4 described a noninfectious mitral valve diverticulum in the LVOT that produced subvalvular stenosis. That
Jaladi, Levy, Addonizio 289
Figure 4 Microscopic view of diverticulum, which is primarily valvular tissue lined by endothelium on inner and outer surfaces.
diverticulum was attached to the ventricular septum with a fibrous chord and may have been a variant of a subvalvular membrane. In this case the diverticulum may have been caused by a congenital abnormality in the anterior leaflet of the mitral valve or by localized myxomatous degeneration. The expansion of the diverticulum only during systole presumably was related to a suction effect of flow in the LVOT during systole. In summary, we report a case of mitral valve diverticulum present in the LVOT detected incidentally by transesophageal echocardiography. This entity should be included in the differential diagnosis of masses found in this location by echocardiography. There are distinctive features on echocardiography that should lead to correct recognition of this entity. Special thanks to Susan Maleski, CCPT, echocardiography technician at Abington Memorial Hospital.
REFERENCES 1. Saphir O, Leroy EP. True aneurysms of mitral valve in subacute bacterial endocarditis. Am J Pathol 1947;24:83-95. 2. English TAH, Honey M, Cleland WP. Ruptured true aneurysm of mitral valve: a complication of aortic valve endocarditis. Br Heart J 1972;34:434-6. 3. Akinjide-Obonyo AP, Bray CL, Moussali H, Beton DC. Aneurysm of the mitral valve complicating streptococcus milleri endocarditis. Postgrad Med J 1983;59:250-3. 4. Agathos EA, Moran M, Mangion J, Lovell A, Engelman RM, Rousou JA. “Diverticula” of anterior mitral valve leaflet as a cause of subvalvular aortic stenosis. J Heart Valve Dis 1996;5: 309-11.
Diverticula arising from the mitral valve are very rare. They are usually detected by echocardiography as masses arising from the cardiac valves. We present a case of an incidental finding of a diverticulum arising from the mitral valve. This was initially detected by transesophageal echocardiography, and
later confirmed by pathologic appearance. The case illustrates the unique findings on echocardiography that would help to differentiate diverticula from other valvular masses. (J Am Soc Echocardiogr 2004; 17:288-9.)
CASE REPORT A 51-year-old white woman with known coronary artery disease, aortic stenosis, and congestive heart failure presented to a local facility with worsening dyspnea. Her history also included hypertension, hypercholesterolemia, diabetes mellitus, and renal failure. Cardiac catheterization demonstrated severe 3-vessel coronary artery disease, aortic stenosis, and moderate mitral regurgitation. She was transferred for coronary artery bypass operation and aortic valve repair. There was no history of infective endocarditis. On examination the patient was in no distress, with a blood pressure of 90/50 mm Hg and heart rate of 100 bpm. Physical examination was remarkable for crepitations at both lung bases. Heart auscultation revealed a grade 3/6 systolic ejection murmur at left sternal border radiating to the carotids and grade 2/6 apical mitral regurgitation murmur and no gallops. Peripheral edema and jugular venous distention were not appreciated. Electrocardiogram showed in sinus rhythm and a left bundle branch block pattern. Preoperative transesophageal echocardiogram showed severe aortic stenosis (valve area of 0.9 cm2) with mild aortic regurgitation and a calcified mitral valve annulus with mild to moderate mitral regurgitation. The echocardiogram also revealed an echolucent and cystic mass in the left ventricular outflow tract (LVOT) and attached to the anterior leaflet of the mitral valve. The mass was echogenic and tubular. It measured 1 cm in length and 1.2 cm in width in peak systole (Figure 1) and was not From the Department of Internal Medicine (R.J.), Department of Cardiology (W.K.L.), and Cardiac Surgery Division (P.V.A.), Abington Memorial Hospital; and Department of Surgery, Temple University Hospital (P.V.A.). Reprint requests: William K. Levy, MD, Department of Cardiology, Abington Memorial Hospital, 1200 Old York Rd, Abington, PA 19044. 0894-7317/$30.00 Copyright 2004 by the American Society of Echocardiography. doi:10.1067/j.echo.2003.11.003
288
Figure 1 Mass in systole on transesophageal echocardiography. Arrow, Diverticulum; A, left atrium; B, anterior leaflet of mitral valve; C, aortic valve; D, left ventricular outflow tract.
visualized in diastole (Figure 2). This was thought to represent a possible vegetation versus diverticulum. Operation involved triple-vessel bypass operation and replacement of aortic valve with St Jude prosthetic valve. During operation a 1.5-cm hollow mass was resected from the anterior leaflet of mitral valve. Grossly it consisted of a pouchlike structure of white fibrous tissue consistent with diverticulum (Figure 3). Microscopic sections revealed endothelium-lined fibrous tissue with myxoid change also consistent with diverticulum (Figure 4). There was no pathologic evidence for infective endocarditis.
DISCUSSION In this case of aortic stenosis and coronary artery disease, preoperative transesophageal echocardiography revealed the unexpected finding of a mobile mass in the LVOT attached to the base of the anterior leaflet of the mitral valve. The mass did not significantly block the LVOT and the mass was not
Journal of the American Society of Echocardiography Volume 17 Number 3
Figure 2 Disappearance of valvular mass during diastole. A, Left atrium; B, anterior leaflet of mitral valve; C, aortic valve; D, left ventricular outflow tract.
Figure 3 Gross specimen after resection showing diverticulum with trabeculations.
visible on transthoracic echocardiogram. The distinctive features of the mass were its central clearing, expansion during systole, and collapse during diastole. The differential diagnosis of this echocardiographic finding included mitral valve vegetation, papillary fibroelastoma, atypical myxoma, and mitral valve diverticulum. The mass during operation and at pathology was found to be a mitral valve diverticulum without evidence of active endocarditis. Diverticula of the mitral valve have been reported in the literature as a complication of bacterial endocarditis.1-3 In these cases, infection of the mitral valve produced localized destruction and thinning of valve tissue producing an out-pouching and aneurysm formation. In the case here reported there were no clinical history or pathologic findings of active or healed endocarditis. Agathos et al4 described a noninfectious mitral valve diverticulum in the LVOT that produced subvalvular stenosis. That
Jaladi, Levy, Addonizio 289
Figure 4 Microscopic view of diverticulum, which is primarily valvular tissue lined by endothelium on inner and outer surfaces.
diverticulum was attached to the ventricular septum with a fibrous chord and may have been a variant of a subvalvular membrane. In this case the diverticulum may have been caused by a congenital abnormality in the anterior leaflet of the mitral valve or by localized myxomatous degeneration. The expansion of the diverticulum only during systole presumably was related to a suction effect of flow in the LVOT during systole. In summary, we report a case of mitral valve diverticulum present in the LVOT detected incidentally by transesophageal echocardiography. This entity should be included in the differential diagnosis of masses found in this location by echocardiography. There are distinctive features on echocardiography that should lead to correct recognition of this entity. Special thanks to Susan Maleski, CCPT, echocardiography technician at Abington Memorial Hospital.
REFERENCES 1. Saphir O, Leroy EP. True aneurysms of mitral valve in subacute bacterial endocarditis. Am J Pathol 1947;24:83-95. 2. English TAH, Honey M, Cleland WP. Ruptured true aneurysm of mitral valve: a complication of aortic valve endocarditis. Br Heart J 1972;34:434-6. 3. Akinjide-Obonyo AP, Bray CL, Moussali H, Beton DC. Aneurysm of the mitral valve complicating streptococcus milleri endocarditis. Postgrad Med J 1983;59:250-3. 4. Agathos EA, Moran M, Mangion J, Lovell A, Engelman RM, Rousou JA. “Diverticula” of anterior mitral valve leaflet as a cause of subvalvular aortic stenosis. J Heart Valve Dis 1996;5: 309-11.